prompt_front: Answer the question based on the given passages. Only give me the answer and do not output any other words.

Question: Who play's Marty's girlfriend in back to the future?

The following are given passages.
Context 1: Passage 1:
Marty McFly
Martin Seamus "Marty" McFly is a fictional character and the protagonist of the Back to the Future franchise  Canadian actor Michael J  Fox portrays him in all three films  McFly also appears in the animated series, where David Kaufman voices him  In the video game developed and published by Telltale Games, A  J  Locascio does his voice; Fox does the lines for McFly's future counterparts at the end of the game, too  Olly Dobson played him in the original stage musical adaptation (the West End production), and Casey Likes will play in the upcoming Broadway production  In 2019, Empire magazine selected McFly as the 12th Greatest Movie Character of All Time 

Biography
Marty McFly is the Back to the Future protagonist  Born in Hill Valley, California, he is a part of the McFly family of Irish descent  Little is known about the character's life before the first Back to the Future film, except that he set fire to the living room rug when he was 8 years old (in a statement of Marty's to his future parents)  Despite never explicitly being explained in the film, Bob Zemeckis confirmed that Marty met his friend Dr  Emmett "Doc" Brown when he was around 14 after hearing that Brown was a dangerous lunatic  Marty wanted to go and see what it was all about for himself  He snuck into Doc's lab and was fascinated by all his inventions  When Doc caught him, he was glad to have someone interested in his work, and their friendship began In the first film, in 1985, Marty plays guitar with his group The Pinheads and likes listening to Huey Lewis and the News, Tom Petty and the Heartbreakers, Van Halen, and Michael Jackson  In the film, he is also a talented skateboarder and proves to be an excellent pistol shot, a skill he has honed by playing shooting games such as Wild Gunman at his local 7-Eleven In an alternate timeline shown in Back to the Future Part II, a hand injury has left Marty unable to play the guitar  This injury occurs in 1985 after Marty accepts his school nemesis Douglas J  Needles' challenge to a road race after being labeled a "chicken" and crashes into a Rolls-Royce  In 1885, Biff Tannen's great-grandfather, Buford, goads Marty into a showdown, which Marty wins despite refusing to draw a gun against Buford  Once he returns to 1985, he remembers this event and his great-great-grandfather Seamus McFly's advice and drops out of Needles' challenge, avoiding the collision that would have ruined his prospects for success as a guitarist 

Movie events and time travel
In the first film, Back to the Future, Dr  Brown shows Marty the time machine, in the form of a DeLorean, which he had invented after stealing plutonium (used as fuel for the vehicle's time circuits) from Libyan terrorists, who wanted him to build a nuclear weapon  During this exchange, the enraged terrorists shoot the doctor, and Marty escapes from them in the time machine, accidentally traveling back to 1955  There, he encounters his teenage parents and disrupts how they meet  Marty contacts the 1955 Dr  Brown and, with his help, reunites his parents and travels back to an alternate 1985, where his father, George, is a novelist, and Biff, his father's high school bully, becomes their caretaker  He also discovers that Dr  Brown is still alive because he had worn a bulletproof vest after Marty warned him about his fate in 1955 
In the second film, Back to the Future Part II, Dr  Brown brings Marty and Jennifer to 2015  They had married, and their teenage son, Marty Jr, was arrested, costing the whole McFly family  Jennifer is knocked unconscious by Brown, and Marty (from 1985) disguises himself as his son and comes into contact with the elder Biff  His son is supposed to meet Biff's grandson, Griff, who forces him to commit a crime with Griff and his gang  The disguised Marty prevents this from happening and gets into a hoverboard dash, resulting in Griff and his crew getting arrested instead of Marty Jr  Jennifer, who was left behind, is taken back to her 2015 home by the police after tracing her there using her fingerprints  Marty and Dr  Brown rescue her while, unbeknownst to them, Elder Biff steals their time machine and returns to 1955, where he gives his younger self an Almanac from the future to use for gambling  When they all return to 1985, they discover that Hill Valley is now a dystopia, with Biff becoming extraordinarily rich and corrupt  He had forcefully married Marty's mother, Lorraine, and secretly murdered Marty's father  He also legalized gambling in the process of becoming known as the 'Luckiest Man on Earth ' Marty and Dr  Brown return to 1955 again to steal the Almanac from 1955 Biff, in which they succeed  Dr  Brown, however, is sent to 1885 after lightning strikes the DeLorean  Marty receives a letter from Brown, written on September 2, 1885 
In the third film, Back to the Future Part III, Marty re-contacts 1955 Dr  Brown and informs him of everything that has happened  Together they discover that someone killed the doctor six days after he wrote the letter and that he had hidden the DeLorean in a cave  Marty goes back to 1885 and meets his great-great-grandparents, Seamus and Maggie, and their son, his great-grandfather  He searches for Dr  Brown and finds out he has become a blacksmith  Marty crosses paths with "Mad Dog" Tannen, Biff's great-grandfather, and gets into a brawl with him  While they plan their escape, Marty and Dr  Brown meet Clara Clayton, a teacher, and the doctor falls in love with her  During the festival, "Mad Dog" and Marty agree on a one-on-one showdown the next morning; however, that is the day Marty is meant to travel back to 1985  During the showdown, Marty defeats "Mad Dog" and proceeds the plan with the doctor  Finally, Dr  Brown decides to stay in 1885 with Clara while Marty travels back to 1985  The time machine is destroyed by an oncoming train, with Marty barely escaping  He reunites with Jennifer and decides not to race Needles, which would have cost him his music career 

Family
In the Back to the Future film franchise, Marty McFly is the youngest of three children of George McFly and Lorraine Baines-McFly  He has a brother, Dave McFly, and a sister, Linda McFly  In addition, he has uncles Milton, Toby, and Joey, as well as aunts Sally and Ellen (Ellen was born in 1956, so the first movie did not feature her)  Joey served a prison sentence in 1985, and the court denied his parole again  In the first movie, Lorraine is 17 (nearly 18), Milton is 12, Sally is 6, Toby is 4, and Joey is 1  Ellen was born a year later 
Marty's secondary entourage consists of his girlfriend, Jennifer Parker, and best friend, Emmett Brown, a scientist Marty and Jennifer call "Doc " There is an implication that Marty is ashamed of his family and does not spend much time at home, preferring to hang out with Doc, Jennifer, or the guys in Marty's band, The Pinheads  However, Marty's relationships with his family change after he returns from 1955, with him no longer being alienated by his parents and his father working as a local college professor and a successful novelist in the alternate timeline he inadvertently created  Marty meets his great-great paternal grandparents, Seamus and Maggie, too, when stranded in 1885  He also meets their infant son William, Marty's great-grandfather  Through his interaction with Seamus and Maggie, Marty discovers that Seamus had a brother named Martin, thus Marty's great-great-granduncle, who died after being goaded into a fight and killed in Virginia City, Nevada 
By 2015, Marty married his girlfriend Jennifer and had two children, Martin "Marty" Jr  and Marlene 

Aliases
Marty has had many aliases throughout the Back to the Future series, usually because of meeting his relatives in the past, such as Lorraine mistakenly thinking his name is "Calvin Klein" due to that being Marty's brand of underwear  In the first film, Marty uses the alias "Darth Vader, an extraterrestrial from the Planet Vulcan" while wearing a radiation suit to attempt to coerce George into asking Lorraine out to the dance  In Part III, Marty uses the name "Clint Eastwood" when asked by Maggie McFly and later by Buford Tannen  In Back to the Future: The Game, he uses one of three aliases; "Sonny Crockett," "Harry Callahan," or "Michael Corleone "

Other appearances
Stage actor Olly Dobson debuted the role of Marty in Back to the Future: The Musical  In the London production, Will Haswell, Glen Facey, and Ben Joyce have since played the character  Casey Likes will play him in the upcoming Broadway production of the musical 
David Kaufman voices Marty in Back to the Future: The Animated Series 
Marty makes a cameo in the Lego Jurassic World video game 
Fox reprises his role in the crossover toys-to-life Lego video game Lego Dimensions 
Doc Brown and Marty appeared on Jimmy Kimmel Live! on October 21, 2015, the day the characters traveled to in Part II 
A cinema scene in Season 3 of Stranger Things shows a section of Back to the Future with Marty and Doc Brown 

Influence
Morty Smith of the American animated series Rick and Morty (voiced by Justin Roiland) began as a parody of Marty McFly Japanese pro wrestler Kushida dresses as Marty McFly as part of his ring character 
Passage 2:
Giorgi Chantouria
Giorgi Chantouria (Georgian: გიორგი ჭანტურია, romanized: giorgi ch'ant'uria, pronounced [ɡiorɡi tʃʼantʼuria]; born January 23, 1989) is a former tennis player from Georgia, who played on the ITF Futures tournaments and Davis Cup  
In the 2007 Davis Cup he played against future world number one tennis player Novak Djokovic  Djokovic led 6–1, 5–0 when Chantouria retired 
Passage 3:
Back to the Future (franchise)
Back to the Future is an American science fiction comedy franchise created by Robert Zemeckis and Bob Gale  The franchise follows the adventures of a high school student, Marty McFly, and an eccentric scientist, Dr  Emmett "Doc" Brown, as they use a DeLorean time machine to time travel to different periods in the history of the fictional town of Hill Valley, California 
The first Back to the Future film was the highest-grossing film of 1985 and became an international phenomenon, leading to the second and third films, which were back-to-back film productions, released in 1989 and 1990, respectively  Though the sequels did not perform quite as well at the box office as the first film, the trilogy remains immensely popular and has yielded such spin-offs as an animated television series and a motion-simulation ride at the Universal Studios Theme Parks in Universal City, California; Orlando, Florida; and Osaka, Japan (all now closed), as well as a video game and a stage musical  The film's visual effects were done by Industrial Light and Magic  The first film won an Academy Award for Sound Editing 

Films
Back to the Future (1985)
Seventeen-year-old Marty McFly is accidentally sent back in time from October 26, 1985, to November 5, 1955, in a time machine built from a DeLorean by eccentric scientist Emmett "Doc" Brown, when they are attacked and Doc is apparently killed by Libyan terrorists from whom he stole the plutonium that gives the flux capacitor the 1 21 gigawatts it needs to time-travel  Soon after his arrival in 1955, Marty's mother, Lorraine, falls in love with him, rather than with his father George McFly, threatening to cause a paradox that would result in Marty ceasing to exist  Without plutonium to power the time machine, Marty must find the 1955 Doc Brown to help him reunite his parents and return to 1985 
The efforts of Biff Tannen, George's bully and supervisor, further complicate Marty's situation until Marty successfully causes his parents to fall in love and simultaneously convinces George to finally stand up to Biff  Returning to the future via a lightning strike that powers the machine, Marty discovers a vastly improved situation for the McFly family, as a much more confident George has become an accomplished science fiction author, Marty's two older siblings have better lives, he owns the car of his dreams, and an apparently-softened Biff is now an auto detailer, rather than George's supervisor  Despite 1955 Doc's insistence on not knowing details of the future, a note Marty leaves in his pocket on November 12, 1955, prevents him from being killed by the terrorists  In the film's final moments, Doc Brown appears in a modified version of the DeLorean and tells Marty and his girlfriend Jennifer Parker that they must travel to the future to fix a problem caused by Marty and Jennifer's kids 

Back to the Future Part II (1989)
The series continues as Doc Brown travels with Marty and Jennifer to the year 2015, where he has discovered Marty's family is in ruins  Shortly after rectifying the situation, Marty buys a sports almanac containing the outcomes of 50 years (1950–2000) worth of sporting events to make easy money  However, Doc talks him out of it and throws the almanac in the trash bin, where the 2015 Biff Tannen finds it  A sleeping Jennifer has been taken by police to her future home, needing Marty and Doc to retrieve her before returning to 1985  While Marty and Doc are at the 2015 McFly home, 2015 Biff steals the DeLorean time machine and gives the book to his 1955 self just before he goes to the dance at the end of the first film  When Doc and Marty return to 1985, they find that Biff has used the sports almanac's knowledge for financial gain, which allowed him to turn Courthouse Square into a casino with 27 floors, take over Hill Valley, get away with the murder of Marty's father, and later marry Marty's mother  Marty learns that Biff was given the book by 2015 Biff on November 12, 1955, so he and Doc go back to that date in order to steal the almanac from Biff before he can use it to destroy their lives  They accomplish this in a complex fashion, often crossing their own past selves' paths  When the duo is about to travel back to 1985, a lightning bolt strikes the DeLorean and activates the time circuits, sending Doc back to 1885 and leaving Marty stranded once again in 1955 

Back to the Future Part III (1990)
After finding out that Doc Brown was trapped in 1885, Marty and the 1955 Doc find and fix the DeLorean  Learning that Doc gets shot in 1885 by Biff's great-grandfather, the outlaw Buford "Mad Dog" Tannen, Marty travels back in time to save Doc (who has become a blacksmith) and bring him back to the future  Arriving in the middle of a chase between the United States Cavalry and American Indians, Marty is forced to flee to a cave, discovering the DeLorean's fuel line is torn  Marty convinces Doc to come back with him and find a way to get back to his time before it is too late, but Doc is smitten after saving schoolteacher Clara Clayton  After running afoul of and defeating Buford Tannen and several dramatic action scenes involving using a speeding locomotive to push the DeLorean to 88 miles per hour (142 km/h), Marty returns to 1985 without Doc Brown  When the DeLorean appears in 1985, a modern train destroys it, with Marty barely escaping  Reuniting with Jennifer, Marty avoids a street race and the two visit the scene of the wreckage of the DeLorean  Suddenly, Doc, Clara and their children appear in a time-travelling steam locomotive  Doc reminds Marty and Jennifer that "[their] future is whatever [they] make it", so they must "make it a good one"  The locomotive lifts off the tracks and departs from 1985, ending the trilogy 

Future
Co-writer and director Robert Zemeckis, who has final rights to all films in the Back to the Future franchise, has stated that he will block all attempts to remake or reboot the original film  Co-writer Bob Gale commented that he did not wish to see another film in the series without the Marty McFly character nor any other actor than Michael J  Fox playing him, while acknowledging that Fox's current health condition would make this impossible  He illustrated this at a 2008 fan convention in Florida, stating: "The idea of making another Back to the Future movie without Michael J  Fox – you know, that's like saying, 'I'm going to cook you a steak dinner and I'm going to hold the beef '" Gale also said that the Telltale video-game adaptation is the closest thing to what a fourth film could be like  In an interview on October 21, 2015, the day of Marty McFly's purported arrival in the future, Christopher Lloyd stated that he would consider making a fourth film under the condition that the original cast and creative team returned, along with a story "worth telling"  The same day, Lloyd reprised his role as Doc Brown in a brief segment in which the character returns with a special message marking the 2015 date  In 2020, actor Tom Holland claimed in an interview with BBC Radio 1 that he was approached by an unnamed producer over a possible reboot of the franchise with him starring the lead role as Marty McFly (or a similarly new character)  However, Holland stated that he was reluctant to take up this offer as he described the existing films as "perfect films", though he would be interested in re-creating scenes from the films in a deep-fake homage video or short film 

Short film
Doc Brown Saves the World (2015)
Doc Brown Saves the World is a 2015 direct-to-video short film starring Christopher Lloyd as Emmett Brown  The short debuted on the 2015 Blu-ray and DVD release of the Back to the Future trilogy commemorating the franchise's 30th anniversary  The short was released on October 20, 2015 Emmett Brown is in an undisclosed location outside Hill Valley, California  He sets a video camera to track his body in order to videotape a message for Marty McFly  He explains that it is October 21, 2015, one hour before Marty, Doc, and Jennifer Parker arrive from 1985  He explains that when he traveled to the future, he discovered that there was a nuclear holocaust that occurred on October 21, 2045  He tracked it down to four inventions: the food hydrator, self-lacing shoes, the hoverboard, and the Mr  Fusion home energy reactor 
The former three inventions led to the world becoming lazy and obese, leading to widespread waste  The invention of hoverboards led to hovercars, which led to people throwing their trash out of the windows, causing a great trash storm in 2021  All of this trash needed to be disposed of, which led to 100 million Mr  Fusion units being manufactured  All of the Mr  Fusion units had a tiny nuclear reactor inside, and all of them detonated on October 21, 2045  The chain of events that led to this happening began less than twenty-four hours after Marty caused Griff Tannen to crash his hoverboard into the Hill Valley Courthouse when Griff was sentenced  He vowed to get back at the world for laughing at him and planned to do it through a company that he would found, GriffTech 
Doc holds up a tablet computer with a digital version of the Hill Valley Telegraph  On June 13, 2032, GriffTech invented a social media network called ThingMeme, which secured funding from Douglas J  Needles  ThingMeme allowed inanimate objects to post selfies on the internet, but it was a scam, as it allowed Griff to gain access to every object on Earth  On the 30th anniversary of his arrest, on October 21, 2045, he uploaded a virus that was supposed to flash the word "butthead" on everything  However, it short-circuited the Mr  Fusion network, causing nuclear explosions in 100 million homes worldwide 
Doc Brown travels to an unknown date to ensure these inventions are never created, which will prevent the nuclear explosion  He leaves his camera on, which captures the inventions being erased from history  He arrives back in 2015, in a winter jacket and ski goggles, declaring that the mission was more complicated than he calculated, but declaring it a success  He holds up the tablet computer, where the headline on the Hill Valley Telegraph changes from "Griff Tannen Founds Grifftech" to "Griff Tannen Found Guilty" 
Doc's excitement is short-lived, however, as he reaches in his pocket  He pulls out the Quantum Mind Jar, which he thought he disposed of in 2075  He is worried that not doing so will unravel everything they accomplished  The artificial intelligence of the Quantum Mind Jar tells Brown that they need to go back to the future, which he dismisses as he does not want to risk further time travel 
Another Emmett Brown then arrives, also declaring his experiment a success  Both versions of Brown, along with the artificial intelligence of the Quantum Mind Jar, are shocked at discovering that there are two Emmett Browns present 

Television
Back to the Future (1991–1992)
An animated television series, Back to the Future: The Animated Series, lasted two seasons, each featuring 13 episodes, and ran on CBS from September 14, 1991, to December 26, 1992 
The TV series Back to the Future was an animated science-fiction comedy adventure television series for television, based on the live-action film trilogy  Although the series takes place after the films, creator Bob Gale stated that the animated series and the comic books take place in their own 'what if' and alternate timelines The show lasted two seasons, each featuring 13 episodes, and ran on CBS from September 14, 1991 to December 26, 1992 with reruns until August 14, 1993  The network chose not to renew the show for a third season (citing low ratings)  It was later rerun on Fox, as a part of the FoxBox block, from March 22 to August 30, 2003  This show marked the debut television appearance of Bill Nye on a nationally broadcast show 
The central premise of the TV series was that, after the conclusion of Back to the Future Part III, in 1991, Dr  Emmett Brown moved into a farm in Hill Valley with his wife Clara, their sons Jules and Verne, and the family dog, Einstein  As with the films, time travel was achieved through the use of a modified DeLorean, which had apparently been re-built after it was destroyed at the end of the trilogy  The DeLorean now has voice-activated "time circuits" and can also travel instantaneously to different locations in space and time, in addition to folding into a suitcase  The characters also travel through time using the steam engine time machine Doc invented at the end of the third film 
Although Marty McFly is the show's main character and Jennifer Parker makes occasional appearances, the show focused primarily on the Brown family, whereas the films focused on the McFly family  The film's villain, Biff Tannen, also appeared frequently  In addition, relatives of McFly, Brown, and Tannen families were plentiful in the past or future parallel time zones visited  Unlike the films, which took place entirely in Hill Valley and the surrounding area, the series frequently took the characters to exotic locations  At the end of every episode, Doc Brown would appear to do an experiment, often related to the episode's plot  The first season also included post-credits segments with Biff Tannen telling a joke related to the episode, alluding to Thomas F  Wilson's career as a stand-up comedian 

Cast and crew
Cast and characters
S indicates an appearance as a character's singing voice 

Reception
Box office performance
(A) indicates the adjusted totals based on current ticket prices (by Box Office Mojo) As of June 2011, the Back to the Future series is the 14th-highest-grossing trilogy of all time at the domestic market (adjusted for inflation), 17th-highest-grossing trilogy of all time at the domestic market (not adjusted for inflation), and the 13th-highest-grossing trilogy of all time, worldwide (not adjusted for inflation) The trilogy was re-released in certain countries worldwide on October 21, 2015, to commemorate the date traveled to by the protagonists in Back to the Future Part II and generated $4 8 million on its opening day  In the United States and Canada, it earned $1 65 million from ticket sales across 1,815 North American theaters on its opening day  Germany opened with $1 4 million and the United Kingdom with $345,000  Revenues from other territories such as Australia, Austria, France, Italy were moderate The first movie in the trilogy returned to certain countries once again for the 35th anniversary of the first film  In the United Kingdom, this was originally scheduled to begin on May 29, 2020, but due to the COVID-19 pandemic the opening dates of various cinemas were delayed, and on a cinema-by-cinema basis slowly reopened  Many cinemas also showed the rest of the trilogy, partially due to the coinciding 30th anniversary of Part III 

Critical and public response
Marty McFly and Doc Brown were included in Empire's 100 Greatest Movie Characters of All Time, ranking No  39 and No  76 respectively 

Cultural impact
Back to the Future Day
October 21, 2015, the date used for the setting of the future events during the first act of the second film, has been called "Back to the Future Day" by the media  The year 2015 also commemorated the 30th anniversary of the release of the original film 
Many promotions were planned to mark the passing of the date, with many playing to the depiction of the future in the film, including:

Universal Pictures created a trailer for Jaws 19, the fictional 3D film advertised in the future setting 
Universal and Mattel produced an advertisement for the hoverboard seen in the film 
Pepsi produced a limited run of the "Pepsi Perfect" soft drink, including the unique bottles, which sold out before October 21, 2015 
The Ford Motor Company allowed users configuring a Ford Focus on their website to add a Flux Capacitor as a $1 2 million option 
Nintendo released the game Wild Gunman, which Marty is seen playing in the Cafe '80s scene, on the Wii U's Virtual Console service 
The October 22, 2015 edition of USA Today used a mock-front page which was a recreation of the one seen in the film on that date  The back of the mock page contains an advertisement for Jaws 19, as well as ads for the 30th anniversary Back to the Future box set and The Michael J  Fox Foundation  On the real front page, the USA Today blue dot is replaced with a drone camera like the one seen in the film  The print edition of this edition sold out in record time, according to USA Today 
Nike revealed that they had recreated the Nike Mag shoes that Michael J  Fox wears in the film, complete with self-lacing power laces (a 2011 design was based on the same shoes, but lacked the power laces)  Although the laces operated more slowly than those seen in the film, they were nonetheless shown to work as intended in an eight-second video featuring Fox wearing the shoes  Pairs of the shoes were sold via auction in 2016 to benefit The Michael J  Fox Foundation for Parkinson's Research 
Toyota and Universal Pictures celebrated the 30th anniversary of the film series with a Toyota Tacoma Concept that was inspired by the original 1985 pickup that Toyota created for the 1985 film  The 2016 Tacoma 4WD was recreated using the same features and black color paint trim, KC HiLite driving lamps (modified with LED lighting), modified headlights and taillights (matching the 1985 version), the Toyota badging to the truck's tailgate, as well as the same D-4S fuel injection, the 1985-inspired mudflaps, and customized license plates matching the 2015 vehicles in Part II  The only difference between the 1985 original and the 2016 concept is the tires: Goodyear was featured in the 1985 film, while BF Goodrich is used on the concept  Toyota notes that this is a one-off concept as there are no plans to offer it as a package or level trim  Toyota also produced a promotional video starring Michael J  Fox and Christopher Lloyd and featuring many of the locations depicted in the film series, wherein the DeLorean's Mr  Fusion is used as a comparison for Toyota's hydrogen powered Mirai 
Universal re-released all three films on DVD and Blu-ray disc on October 20, 2015 
Telltale Games re-released their licensed Back to the Future the Game in a 30th Anniversary edition for newer consoles a week in advance of October 21  Several video games released downloadable content related to Back to the Future to coincide with October 21, 2015, including Rocket League and LittleBigPlanet 3 
Back to the Future: The Ultimate Visual History is an officially licensed book which includes 224 pages of behind-the-scenes stories, interviews, rare and never-before-seen images, concept art, storyboards, photos, and special removable replicas of paper items from the films, written by Michael Klastorin with Randal Atamaniuk  The book was released on October 16, 2015 Cast members appeared on Today and Jimmy Kimmel Live! on October 21, 2015  Nearly 2,000 theaters worldwide showed back-to-back screenings of the Back to the Future trilogy on October 21 and continuing through that weekend, which earned over $4 8M in single day ticket sales  Universal Studios offered location tours of the various filming locations around the date  The town of Reston, Virginia, temporarily changed its name to "Hill Valley" to commemorate the series during its annual film festival  Esquire Network aired the trilogy all day that day, plus all weekend 

Music
Home media box sets
2002 VHS and DVD release: "The Complete Trilogy"
In July 1997, Universal Studios announced that Back to the Future would be one of their first ten releases on the new DVD format, though it ended up being delayed for five years  The films were released as a box set on VHS and DVD on December 17, 2002 in both widescreen (1 85:1) and full screen (1 33:1) formats  The widescreen DVDs had to be reissued a year later because of framing errors in converting from open matte to widescreen 

2010 DVD and Blu-ray release: "25th Anniversary Trilogy"
In June 2008, a special screening of the trilogy was held in Celebration, Florida  Bob Gale told the crowd they were seeing the digitally remastered version that was going to be used for the Blu-ray version of the movies  The Blu-ray box set was released on October 26, 2010, and includes bonus features, such as a newly-produced six-part retrospective documentary titled Tales from the Future  There have been numerous complaints about the R1 packaging, leading to the release of an instruction sheet on how to safely remove and insert discs 

2015 DVD and Blu-ray release: "30th Anniversary Trilogy"
On October 20, 2015, one day before the date of the fictional events transpiring in the 2015 segment of Part II, the trilogy was once again released on Blu-ray and DVD  A bonus disc was included, which featured new bonus material such as Outatime which is a look into the restoration of the time machine from 2012; Doc Brown Saves the World!, a new short movie starring Christopher Lloyd; two episodes from The Animated Series; two novelty commercials about "Jaws 19" and the "2015 Hoverboard"; and other additional features 

2020 Blu-ray and Ultra HD Blu-ray release: "The Ultimate Trilogy"
A new set was released in October 2020 for The Ultimate Trilogy, to celebrate the franchise's 35th anniversary, and featured a release on Ultra HD Blu-ray for the first time  The set included a new digitally remastered 4K picture, Dolby Atmos sound, and more previously unreleased content 

Other media
Board and card games
The Back to the Future: Back in Time board game was released in 2020  It is a fully cooperative game, in which each player is a character in the film, and must collect items to help Marty McFly and Doc to return from 1955 to their own time, as depicted in the first film in the trilogy In 2010, Looney Labs introduced Back to the Future: The Card Game, a strategy game using the same mechanics as the company's game Chrononauts  In the game, a timeline of cards are laid out in a grid with each era in the movies grouped together  Randomly distributed ID cards outline goals or timeline changes necessary to make sure the future character exists  The license for this game expired in 2012 and is no longer being produced 

Comic books
A comic book series was published by Harvey Comics in 1992 detailing further adventures of the animated series  Only seven issues were produced  IDW published a mini-series which presents the first meeting of both Marty and Doc Brown and is written by co-screenwriter Bob Gale, which was released in stores on October 21, 2015, the same date that Marty travels with Doc Brown to the future depicted in the storyline for Part II  In issue #3, it was revealed that it had become an ongoing monthly comic due to popular demand 
Beginning in issue #6, the original format of one or two untold stories per issue was replaced with a multi-issue ongoing story arc  The original subtitle for the comic, "Untold Tales and Alternate Timelines", was used for the trade paperback which contained the first five comics in the series  The series has now gone on to what IDW calls "chapter 2" of the series with "Tales from the Time Train"  This is a series of stories detailing where Doc and the Brown family went after time traveling at the end of Back to the Future Part III  Other mini-series published by IDW include "Citizen Brown", which adapts the Telltale video game, and "Biff to the Future", which depicts Biff Tannen's rise to power after being given the almanac by his future self  The latter is also co-written by Gale 
Transformers/Back to the Future is a four-issue crossover comic miniseries published by IDW Publishing, to commemorate the 35th anniversaries of Back to the Future and Hasbro's Transformers franchise  It was published from October 7, 2020, to May 12, 2021 
A Japanese light novel adaptation was announced in August 2021 

Books
Each film in the trilogy also received a novelization that expanded on the movies by adding scenes, characters, and dialog, often culled from early-draft scripts In 2012, Hasslein Books released A Matter of Time: The Unauthorized Back to the Future Lexicon, written by Rich Handley  The book was released in cooperation with BTTF com, the official Back to the Future website  A second volume, Back in Time: The Unauthorized Back to the Future Chronology, by Greg Mitchell and Rich Handley, was released in 2013 Back to the Future: The Ultimate Visual History is an officially licensed book which includes 224 pages of behind-the-scenes stories, interviews, rare and never-before-seen images, concept art, storyboards, photos, and special removable replicas of paper items from the films  The book was written by Michael Klastorin, who was the production publicist on Back to the Future Part II and Part III, with Randal Atamaniuk  The book includes a foreword by Michael J  Fox, preface by Christopher Lloyd, introduction by Bob Gale and an afterword by Robert Zemeckis  It was released on October 16, 2015, to coincide with Back to the Future Day, and was published by Titan Books in the UK and Harper Design in the US  It was reissued on November 3, 2020, with added contents, to commemorate the 35th anniversary of the trilogy 

Video games
Various video games based on the Back to the Future movies have been released over the years for home video game systems, including the Atari ST, ZX Spectrum, Commodore 64, Master System, Genesis, Nintendo Entertainment System, Super Famicom, Microsoft Windows, macOS, PlayStation 3, PlayStation 4, Wii, iOS, Xbox 360 and Xbox One platforms 
Lego Dimensions (2015) features two Back to the Future-themed toy packs  The Level Pack adds a bonus level that adapts the events of the first film and includes a Marty McFly Minifigure, along with a constructible DeLorean and Hoverboard  The Fun Pack includes a Doc Brown Minifigure and a constructible Time Train from Part III  Both unlock access to an in-game open world set in Hill Valley  Michael J  Fox and Christopher Lloyd reprise their roles as Marty McFly and Emmett "Doc" Brown respectively  A downloadable content pack for Planet Coaster (2016), titled the Back to the Future Time Machine Construction Kit, includes customizable in-game replicas of the DeLorean time machine 

Episodic video game
Back to the Future: The Game (2010) was released from December 22, 2010, to June 23, 2011, developed and published by Telltale Games  The game is an episodic graphic adventure, and takes place in an alternate timeline based on the original trilogy  It was released as five episodes, with Christopher Lloyd reprising his role as Emmett "Doc" Brown, Claudia Wells reprising her role as Jennifer Parker, and Michael J  Fox making cameo appearances in the final episode  A  J  Locascio provided the voice for Marty McFly, and Bob Gale assisted with the script  Thomas Wilson reprised his role as Biff Tannen in the 2015 re-release 
The plot of the video game depicts Marty traveling back to 1931 to help Doc, who is in trouble again  The video game depicts several trips by Marty and Doc back and forth from 1931 to the present, due to multiple disruptions to the timeline  In several separate differing timelines, various altered outcomes are shown for the McFly family, and then separately for the entire Hill Valley region  At the conclusion of the game, the timeline is largely restored by Marty and Doc, although with some small differences from the "original" timeline 

Pinball
Two pinball adaptations of the film trilogy were released   The first pinball adaptation was a physical one produced by Data East, available in 1990, and titled Back to the Future: The Pinball   Over two decades later, Zen Studios developed and released a new, digital pinball adaptation in 2017, available as add-on content for Pinball FX 3 along with two other tables based on iconic classic films from Universal Pictures, Jaws and E T  The Extra-Terrestrial  The latter table behaves differently than the original Data East version and features 3-D animated figures and visual effects that are impossible to reproduce on a physical table 

Musical
Back to the Future: The Musical is a stage musical with music and lyrics by Alan Silvestri and Glen Ballard, and a book by Robert Zemeckis and Bob Gale, adapted from their original screenplay  The show features original music alongside hits from the film, including "The Power of Love" and "Johnny B  Goode" 
The musical originally was slated to make its world première in London's West End in 2015, the year to which the film trilogy's characters traveled in Part II  However, after director Jamie Lloyd left the production in August 2014, due to "creative differences" with Zemeckis, the production's release date was pushed to a 2016 opening  The show received its premiere at Manchester Opera House in February 2020 ahead of an expected West End transfer  The cast recording was initially set to be released on November 26, 2021, but was ultimately released on March 11, 2022 A Broadway production is set to commence in 2023 

Automotive commercials
In 2015, Fox and Lloyd starred alongside popular YouTube science personality Go Tech Yourself in an extended Toyota commercial for Toyota's new fuel cell vehicle, the Mirai, entitled Fueled by the Future  The commercial doubled as a tribute to the franchise and illustrated how the idea of converting trash into fuel had become reality  The commercial was released on October 21—the same date to which Marty, Doc and Jennifer traveled in Back to the Future Part II 

Theme park ride
Back to the Future the Ride was a simulator ride based on and inspired by the Back to the Future films and is a mini-sequel to the 1990s Back to the Future Part III  The original attraction opened on May 2, 1991, at Universal Studios Florida  It also opened on June 2, 1993, at Universal Studios Hollywood and on March 31, 2001, at Universal Studios Japan  The rides in the United States have since been replaced by The Simpsons Ride  The ride in Japan remained operational until May 31, 2016 

Documentaries
In the fall of 2015, after a successful Kickstarter project, the Back in Time documentary film was released  The film features interviews with the members of the cast and crew along with the cultural impact of the trilogy 30 years later  In 2016, the OUTATIME: Saving the DeLorean Time Machine documentary film was released and presents the efforts of Bob Gale, Universal Studios, and a team of fans as they work to restore one of the original screen-used DeLorean time machines  Like the Back in Time documentary, OUTATIME was also successfully funded by a Kickstarter project  A 2021 documentary, titled Expedition: Back to the Future, featured Josh Gates and Christopher Lloyd searching for and restoring an original DeLorean used in the film, with appearances from several original cast members 

Explanatory notes
Passage 4:
Claudia Wells
Claudia Grace Wells (born July 5, 1966) is an American actress and businesswoman, best known for her role as Jennifer Parker in the 1985 film Back to the Future 

Life and career
Wells was born in Kuala Lumpur, Malaysia to American parents of Ashkenazi Jewish descent (from Germany, Russia and Czechia)  Her family moved to San Francisco when she was seven weeks old  She went to Marin Country Day School and French-American Bilingual School  Her father, a parasitologist, and sister, Jennifer, still live in San Francisco, but Wells moved to Los Angeles at the age of 14, later graduating from Beverly Hills High School  Wells also has a brother She started acting with appearances in TV shows  When she was 15, she became a born-again Christian at the urging of Dean Jones on the set of Herbie, the Love Bug Wells played Jennifer Parker, Marty McFly's girlfriend, in the 1985 film Back to the Future  She almost did not end up in the first film of the successful franchise  According to Wells, she had been cast, but a pilot she had done for ABC had been picked up, and she was contractually forced to drop out of Back to the Future  During that time, Eric Stoltz had been shooting for five weeks in the role of Marty McFly  Melora Hardin was slated for the role of Jennifer though she never actually filmed any scenes  The producers halted filming and replaced Stoltz with Michael J  Fox  By then, Wells's pilot had been finished and she was recast as Jennifer, now shooting alongside Fox, having never filmed a frame with Stoltz That same year (1985), Wells co-starred in Stop the Madness, an anti-drug music video sponsored by the Reagan administration, featuring several famous musicians, actors and athletes  The following year, she appeared in the TV movie Babies Having Babies, and the short-lived series Fast Times, a TV adaptation of the 1982 film Fast Times at Ridgemont High (Wells played Linda Barrett, portrayed by Phoebe Cates in the film)  Following Fast Times, she did not appear again on-screen until the 1996 independent film, Still Waters Burn (released on DVD February 12, 2008) 

Leaving acting
After her mother was diagnosed with cancer, Wells put her career on hold for family reasons, and told the studio she would be unavailable to reprise her Back to the Future role for the two sequels  Actress Elisabeth Shue replaced her 
In the early 1990s, Wells started a clothing store, Armani Wells, which she still manages as of 2023 

Return to acting
After a lengthy absence, Wells returned to acting in 2011 with a small role in the independent science-fiction film, Alien Armageddon The same year, Wells had the opportunity to reprise her role from Back to the Future 26 years after her last appearance in the series  She provided the voice of Jennifer Parker for Back to the Future: The Game  Wells announced that her next project would be a horror film titled Room & Board 

Filmography
Film
Television
Video games
Passage 5:
Paul Koulibaly
Keba Paul Koulibaly (born 24 March 1986) is a Burkinabé footballer who plays as a defender for EFO and the Burkina Faso national team  He plays as a centre-back or a left-back 

Personal life
Paul's twin brother, Pierre Koulibaly is also a professional footballer 

Club
Paul Koulibaly began his career with EFO in Burkina Faso In January 2008, he signed a contract with Al-Ittihad Tripoli  club, but due to the maximum numbers of foreigners players playing in squad, they loaned him out to Al-Nasr Benghazi 
He went for a trial with Leeds United towards the end of July 2010, but was not kept 
In 2010–2011, he played for Asswehly and then left for R O C  de Charleroi-Marchienne 
In 2012, he moved to Dinamo București  Won the 2012 Romanian Supercup with the club  After playing in the club for six months, he went to the Iraqi club Al Shorta  He won the Iraqi Premier League with the club 
In 2014, he moved to the Guinean club Horoya AC  With him he won all the trophies in Guinea (championship, cup and super cup)  In 2017 he returned to the EFO 
Koulibaly made his debut for Burkina Faso in 2006  Together with the Burkina Faso national team, he took part in four African Cups of Nations  In 2013, together with her, he reached the final of the tournament, where his team lost to Nigeria 0–1  On January 10, 2015, Koulibaly played his last international match in a friendly against Swaziland 

Honours
Team
EFOBurkinabé Premier League: 2008
Coupe du Faso: 2006, 2008Dinamo București
Romanian Supercup: 2012Al-Shorta
Iraqi Premier League: 2012–13

Trivia
His twin brother Pan Pierre Koulibaly is also a footballer 
Passage 6:
List of Back to the Future characters
The Back to the Future film trilogy and subsequent animated series feature characters created by Robert Zemeckis and Bob Gale 
The lead character of the series is Marty McFly  During the course of the trilogy, he travels through time using a DeLorean time machine invented by his friend Emmett Brown  He also encounters the central antagonist, Biff Tannen, in several different time periods and visits his ancestors and descendants 

Main characters
Marty McFly
Martin Seamus "Marty" McFly (portrayed by Michael J  Fox in the films and voiced by him in Lego Dimensions, voiced by David Kaufman in the animated series) is the son of George McFly and Lorraine Baines McFly  Marty travels between the past and the future, encountering his ancestors and descendants  Marty and his friend Doc Brown help restore the space-time continuum while encountering Biff Tannen (or members of the Tannen clan) at various points in time 

Emmett "Doc" Brown
Doctor Emmett Lathrop "Doc" Brown (portrayed by Christopher Lloyd and voiced by him in Lego Dimensions, voiced by Dan Castellaneta in the animated series) is the inventor of the DeLorean time machine  At various points in time, Doc helps Marty restore the space-time continuum and reverse the changes that were caused by time travel 
In 2008, the character was selected by film magazine Empire as one of The 100 Greatest Movie Characters of All Time, ranking at No  20 

George McFly
George Douglas McFly (portrayed by Crispin Glover in Back to the Future, Jeffrey Weissman in Back to the Future Part II and Back to the Future Part III, voiced by Michael X  Sommers in Back to the Future: The Game) is married to Lorraine Baines McFly and is the father of Marty, Linda and Dave  Although he is one of the main characters in the first movie, George only makes cameos in Back to the Future Part II and Back to the Future Part III 
In the first film, George is portrayed as weak and the main target of Biff Tannen's bullying  The novelization of the film expounds on George's history of weakness, describing two incidents in which he is unable to stand up for himself  In 1955, in contrast with Marty, George did not have any friends for support and was targeted not only by Biff and his gang but also other kids in school  He has a penchant for science fiction, and writes some of his own but never allows himself to share them with anyone due to his fear of rejection  In 1955, with Marty's help, he gets the courage to stand up to Biff, knocking him unconscious  As a result, he and Lorraine fall in love and George becomes popular in school for defeating Biff in a fight  In the new future, they are both married with George working as a college professor and being a successful writer who orders Biff around  In the dystopian timeline in Part II, George was murdered by Biff in 1973 
George's character was greatly reduced in the sequels, and the role was recast  Weissman wore prosthetics to resemble Glover and imitated Glover's rendering of McFly, and his scenes were spliced with shots of Glover from Back to the Future  The result was so convincing that many people were fooled by it  However, Glover did not appreciate this and sued  The lawsuit resulted in the adoption of stricter rules by the Screen Actors Guild to prevent this situation from occurring again 

Lorraine Baines-McFly
Lorraine Baines-McFly (portrayed by Lea Thompson, voiced by Aimee Miles in Back to the Future: The Game) is married to George McFly and the mother of Marty, Linda and Dave  She is the oldest daughter of Sam (George DiCenzo) and Stella (Frances Lee McCain) Baines, and sister of Milton (Jason Hervey), Sally (Maia Brewton), Toby, and Joey 
In Back to the Future, Lorraine is initially portrayed in 1985 as middle-aged and unhappy  After Marty changes the timeline, she is shown to be fit and happily married to George in 1985  In Part II, Lorraine is still happily married to George in 2015 but they are constantly disappointed in Marty for giving in to peer pressures that make his life difficult  In the alternate 1985 timeline, she is widowed and married to Biff Tannen 

Clara Clayton
Clara Clayton (portrayed by Mary Steenburgen in both Back to the Future Part III and the animated series) is married to Doc Brown and is the mother of Jules and Verne Brown 
Clara moved to Hill Valley and originally died in an accident when her wagon plummeted into Shonash Ravine, which was renamed Clayton Ravine in her memory  This later changed after Doc rescued her, with Mayor Herburt naming it Eastwood Ravine in honor of Marty's alias Clint Eastwood, remembered as a town hero who saved Clara, defeated Buford Tannen, and allegedly died trying to stop two bandits who hijacked a locomotive  The animated series reveals that Clara, along with the rest of the family, moves to the early 1990s and lives in a farmhouse outside of Hill Valley  She then became a teacher at Hill Valley Elementary School 

Jennifer Parker
Jennifer Jane Parker (portrayed by Claudia Wells in the first film and voiced by her in Back to the Future: The Game, Elisabeth Shue in the second and third film, voiced by Cathy Cavadini in the animated series) is dating Marty McFly  In 2015 as seen in Back to the Future Part II, they are married 
In 1985, Jennifer attends Hill Valley High School, along with her boyfriend Marty  In the animated series, Jennifer is enrolled to Hill Valley College with Marty after graduating high school and working part-time as a tutor  She lives with her family on a ranch, the deed to which was owned by Biff Tannen, after one of his ancestors forced Jennifer's great-great-grandfather to sign it over by holding Jennifer's great-great-grandmother hostage  In the episode "A Friend in Deed", Marty travels back in time to 1875 and sabotages the deal with help from Jules and Verne In the future witnessed in Back to the Future Part II, Jennifer and Marty had two children, Marlene and Marty Jr  (both played by Michael J  Fox) 
Melora Hardin was initially cast in the role, to appear alongside Eric Stoltz' Marty McFly  After Stoltz was fired from the production and Michael J  Fox was brought in, Claudia Wells was cast to portray the character, as Hardin was deemed too tall to appear next to the much shorter Fox  However, Wells was not available to film the sequels for personal reasons, and the role was recast to Elisabeth Shue although Wells reprised her role as Jennifer in Back to the Future: The Game as a punk rock version of her character  Consequently, the opening scene of Back to the Future Part II was re-shot with Shue taking Wells' place, rather than using the ending of Back to the Future 

Biff Tannen
Biff Howard Tannen (portrayed by Thomas F  Wilson) is the main antagonist of the first two films, and a local bully who harassed George McFly and managed to alter history in the second film  He comes from a long line of bullies in Hill Valley, most of whom harassed members of the McFly family, including Buford "Mad Dog" Tannen (also portrayed by Wilson, in Part III), who is one of Hill Valley's outlaws during the 1880s 

McFly family
Dave McFly
David "Dave" McFly (portrayed by Marc McClure) is the eldest child of George and Lorraine McFly  In 1985, before Marty went to 1955, Dave works at Burger King, but in the post-time travel 1985, he wears a suit as a nondescript white-collar worker for an accounting firm  In a deleted scene from Part II, the alternate 1985 timeline shows that Dave is an alcoholic and a gambling addict following George's death and Lorraine's second marriage to Biff Tannen 

Linda McFly
Linda McFly (portrayed by Wendie Jo Sperber) is the middle child and only daughter of George and Lorraine McFly  In 1985 before Marty went to 1955, Linda is having boy trouble and it is unknown if she is in college or has a job  In 1985 after Marty went to 1955, Linda works in a boutique and has gained the attention of many boys 

Seamus and Maggie McFly
Seamus and Maggie McFly (portrayed by Michael J  Fox and Lea Thompson) are Irish immigrants and the paternal great-great-grandparents of Marty McFly  In Part III, Marty is befriended by Seamus and Maggie  While Maggie does not trust the "strange young man", Seamus has a familiar feeling about him and believes that helping him is the right thing to do  They have a son named William (Marty's great-grandfather)  Much like his descendants, Seamus is harassed by a member of the Tannen family, Buford Tannen  He also had a brother, Martin, who was fatally stabbed prior to the film's events 
Maggie McFly is played by Lea Thompson, who also plays Marty's mother Lorraine, even though Maggie is not an ancestor of Lorraine; in a DVD commentary track for Part III, Bob Gale states that the creative team considered it important to include Thompson in the film, and he imagines that McFly men are simply "genetically predisposed" to be attracted to women who look like her 

William McFly
William "Willie" McFly (voiced by Michael J  Fox in Back to the Future: The Game) is the son of Seamus and Maggie McFly as well as Marty's great-grandfather  Baby Willie was played by Lindsay Clark  She left acting shortly after this role 

Arthur McFly and Sylvia Miskin
Arthur "Artie" McFly and Sylvia Miskin (stage name "Trixie Trotter") are Marty's paternal grandparents and George's parents introduced in Back to the Future: The Game and voiced by Michael X  Sommers and Melissa Hutchison respectively 

Marty Jr  and Marlene McFly
Marty Jr  and Marlene McFly (both portrayed by Michael J  Fox) are Marty McFly and Jennifer Parker's future son and daughter in 2015 in Part II 
Originally, 17-year-old Marty Jr  was to be arrested and sentenced to fifteen years in prison for joining a robbery initiated by Griff and his gang  Marlene attempted to help Marty Jr  break out of jail but failed and was sentenced to twenty years in a woman's prison  Doc and Marty prevented the event from ever happening 

Baines family
Sam Baines
Sam Baines was the husband of Stella Baines and the father of six children, including Lorraine, Milton, Toby, Joey, Sally, and Ellen Baines  He is the father-in-law of George McFly and the maternal grandfather of Marty, David, and Linda McFly 

Stella Baines
Stella Baines (portrayed by Frances Lee McCain) was the wife of Sam Baines and the mother of six children, including Lorraine, Milton, Toby, Joey, Sally, and Ellen Baines  She is the mother-in-law of George McFly and the maternal grandmother of Marty, David, and Linda McFly 

Milton Baines
Milton Samuel Baines (portrayed by Jason Hervey) is the second child of Sam and Stella Baines, the brother of Lorraine, Sally, Toby, Joey, and Ellen Baines, the brother-in-law of George McFly, and the uncle of David, Linda, and Marty McFly  He was 12 years old in 1955  In 1955, Milton liked to wear a coonskin cap, a fad inspired by the Davy Crockett film and television show, which Stella took off his head twice while Marty was eating dinner with the family, putting it back on both times 

Sally Baines
Sally Flora Baines (portrayed by Maia Brewton) was the third child of Sam and Stella Baines, the sister of Lorraine, Milton, Toby, Joey, and Ellen Baines, the sister-in-law of George McFly, and the aunt of David, Linda, and Marty McFly  Born in 1949, she was present when Marty McFly in 1955 had dinner with her family, but did not speak 

Toby Baines
Toby Baines was the fourth child of Sam and Stella Baines, the brother of Lorraine, Milton, Sally, Joey, and Ellen Baines, the brother-in-law of George McFly, and the uncle of David, Linda, and Marty McFly  He was born in 1951  On November 5, 1955, he sat at the dinner table with his family and Marty McFly, whom his father had hit with the car earlier that day  He remained silent while the guest was present 

Joey Baines
Joey Baines was born on August 28, 1954, to Sam and Stella Baines, and was the fifth child in the Baines family  In the early 1970s, Joey was Marty McFly's favorite uncle  Joey would allow Marty to do dangerous things, but would always be there to make sure he was all right  He spent many years in Folsom Prison  On October 25, 1985, he failed to earn his release on parole for at least the second time 
By the 21st century, USA Today ran an article on Joey Baines in their October 22, 2015 issue, titled Parole denied again, which mentioned that this was Joey's twelfth consecutive parole hearing to end in denial  He was serving a twenty-year term at Folsom for racketeering and had spent two-thirds of his life behind bars 

Ellen Baines
Ellen Baines was the sixth child of Sam and Stella Baines, the sister of Lorraine, Milton, Sally Toby, and Joey Baines, the sister-in-law of George McFly, and the aunt of David, Linda, and Marty McFly  Born in 1956 (a few months after Marty's trip to 1955), she moved to Chicago at some point prior to 1986 

Brown family
Jules and Verne Brown
Jules Eratosthenes Brown and Verne Newton Brown (portrayed by Todd Cameron Brown and Dannel Evans in Back to the Future Part III, voiced by Josh Keaton and Troy Davidson in the animated series) are the two children of Doc Brown and his wife, Clara, who named them after their favorite author Jules Verne 
The characters had minor, non-speaking roles in Back to the Future Part III but were further developed in the animated series  Jules, an introvert, mostly imitates his father's interests and mannerisms while Verne appears to be more outgoing and extroverted  Several plot points of the animated series revolve around either Jules or Verne altering history and the steps necessary to correct the damage 
In the Back to the Future game when asked about his family, Doc reveals that his sons are now teenagers and their parents are discussing what time period they should attend college at 

Copernicus
Copernicus is Doc's dog from 1955  Like his other dogs, Copernicus was used in many of Doc's experiments  When Copernicus died, he was eventually replaced by Einstein 

Einstein
Einstein (portrayed by Tiger and stuntman Dick Butler in the first film and Freddie in the other two, voiced by Danny Mann in the animated series) is Doc Brown's pet Catalan sheepdog  He later becomes one of the main characters in the animated series as the Brown family's dog 
In the first film, Doc successfully tests his time machine by placing Einstein in it and sending him one minute into the future  In the animated series, Einstein becomes anthropomorphic and smarter, helping Doc with his inventions for traveling to the past and the future 

Tannen family
Irving "Kid" Tannen
Kid Tannen (voiced by Owen Thomas) is Biff's father who only appears in the Back to the Future: The Game  Kid is a gangster who runs a local speakeasy in the 1930s Hill Valley  He, like the rest of the Tannen family, bullies the McFly family forcing Marty's grandfather Arthur to do his accounting  Kid is brought down with the help of Marty, a young version of Doc, and Arthur McFly  He later marries Edna Strickland and reforms from his criminal ways with her help 

Buford "Mad Dog" Tannen
Buford Tannen (portrayed by Thomas F  Wilson in Back to the Future Part III, Liam O'Brien in Lego Dimensions) is the main antagonist of the third film  He is the great-grandfather of Biff Tannen and the local town outlaw in 1885 Hill Valley  He was nicknamed "Mad Dog" by a newspaper reporter, due to his violent temper and propensity for drooling, a nickname Tannen greatly despises  Buford is cruel, homicidal, rude, and emotionally unstable  He displays a need for control and is brought down to childlike tantrums when he is humiliated or makes mistakes, whether it be something that happens to him or something he says or does  He is often accompanied by his gang (played by Christopher Wynne, Sean Sullivan and Mike Watson), and developed a feud with Marshal James Strickland and his deputies  Like his descendant Biff, he has a dislike for manure 

Griff Tannen
Griff Tannen (portrayed by Thomas F  Wilson in both Back to the Future Part II and in the animated series) is a grandson of Biff  He is part of a gang that also consists of Rafe "Data" Unger, Leslie "Spike" O'Malley and Chester "Whitey" Noguera  Unlike his grandfather and great-great-great-grandfather whose gangs only consisted of Caucasian males, his accomplices are one Caucasian male (Data), one Caucasian female (Spike), and one Asian-American male (Whitey) 
In the animated series, Griff makes a brief cameo appearance in the episode "Solar Sailors" where his grandson, Ziff (also voiced by Wilson), is detained after he attempts to sabotage Marta McFly's space cruiser due to his hatred towards her family 
Griff's last name is never mentioned in the movie, which means he could either be the son of Biff's son Biff Jr, or the son of Biff's daughter, Tiffaney, but in the animated series, Ziff says that both he and Griff are Tannens 

Biff Tannen Jr 
In the animated series, Biff Jr  (voiced by Benji Gregory) is the son of Biff Tannen  Like his father and paternal relatives, he likes to bully and steal from children around him including Jules and Verne Brown with whom he developed a feud  In addition, Biff Jr  delights in vandalizing other people's properties  Biff Jr  lives with his father with whom he has an abusive relationship 

Strickland family
Gerald Strickland
Gerald Strickland (portrayed by James Tolkan) is the strict principal of Hill Valley High School  He is a descendant of Chief Marshal James Strickland of Hill Valley 1885  He frequently makes a great noisy show of sternly reprimanding his students for faults such as "slacking" or liquor consumption, although he himself is revealed to sneak a drink of alcohol at his desk at school 
There is a reference from Verne Brown that there is another Strickland who works at Hill Valley Elementary School as its vice principal 

James Strickland
James Strickland (portrayed by James Tolkan in Back to the Future Part III) is the chief marshal of Hill Valley in 1885 and an ancestor of Mr  Strickland  He also has an unnamed son (portrayed by Kaleb Henley) 
In a deleted scene not included in the final cut, and in the movie's novelization, Strickland is killed by Buford Tannen  In the theatrical release Strickland simply remains absent for the latter half 
In the Back to the Future game, Edna Strickland in 1986 notes that James was shot and killed by Buford  Marty remarks that's a detail he doesn't remember, possibly a reference to the differences between the film and the movie novelization 

Edna Strickland
Edna Strickland (voiced by Rebcca Sweitzer) is introduced in Back to the Future: The Game where she is the sister of Gerald Strickland  She is somewhat nicer than her brother, but still set in her ways towards upholding strong morals and abolishing crime and laziness  After Marty alters her original timeline, Edna married Kid Tannen and became the stepmother of Biff Tannen 

Other characters
Marvin Berry
Marvin Berry (portrayed by Harry Waters Jr ) is an African-American jazz musician and electric guitar player whose band was hired in Back to the Future Part I to perform at the "Enchantment Under The Sea" dance  He is also the cousin of then-rising musician Chuck Berry  After injuring his hand while helping Marty McFly out of a car's trunk, Marty takes his place as guitarist in the evening's most important dance  When Marty subsequently performs Johnny B  Goode to the audience's excitement, Marvin immediately calls Chuck to introduce him to the new music style, thereby humorously implying that Chuck stole the song to further his musical career  This creates a time paradox, since Marty was playing a song made famous by Chuck Berry, before Berry wrote it, so the song either has no actual creator or Berry was essentially stealing a song from his alternate timeline self  Another theory was that Chuck was going to write it anyway, but after hearing it maybe wrote it faster 

Otis "Old Man" Peabody
Otis Peabody (portrayed by Will Hare) is the patriarch of a 1950s farmer family in Back to the Future Part I  For some obscure reason, he decided to plant pines on his land; while his plan ultimately came to no fruition, the area was decades later converted into a shopping mall named "Twin Pines Mall" as a testimony to his efforts  The town sees Peabody odd including Doc Brown, who himself has a similar reputation  When Marty McFly makes his involuntary time trip back to 1955, he ends up crashing into Peabody's shed with the DeLorean and then flattening one of his two growing pine saplings while escaping  The farmer's family believes that the time-traveling car and its driver in an NBC suit are extraterrestrial  As results, according to a headline of the newspaper Hill Valley Telegraph with Peabody being photographed in a straitjacket, he is committed to a county asylum after claiming "'space zombie' wrecked his barn," and after Marty returns to 1985, the mall is found having been (re)named "Lone Pine Mall" 

Douglas J  Needles
Douglas J  Needles (portrayed by Flea in Back to the Future Part II and Back to the Future Part III) is the rival of Marty McFly in Hill Valley High School  Like his school's alumnus, Biff Tannen, Needles also has his own gang and develops a rivalry with Marty (although he doesn't outright bully him like Biff did to George and has no relation to the Tannens)  He often goads Marty into doing reckless things, leveraging on Marty's fear of being labeled as a "chicken" 

Goldie Wilson
Goldie Wilson (played by Donald Fullilove in the first film) is a young man working at Lou's Cafe in 1955 who goes on to become the first black Mayor of Hill Valley in the 1980s  By 1985, he creates a controversy when he plans to replace the damaged clock from the Hill Valley Courthouse's clock tower, which continues in 2015 after he left the office  A campaign poster shows the name Goldie in quotation marks, suggesting Goldie is a nickname, presumably in reference to his gold tooth 
He would also have a grandson, Goldie Wilson III (also played by Fullilove) who works as a car salesman in Back to the Future: Part II 

Match, Skinhead and 3-D
"Match" O'Malley (portrayed by Billy Zane), Joey "Skinhead" Unger (portrayed by Jeffrey Jay Cohen), and "3-D" Noguera (portrayed by Casey Siemaszko) are the three high school boys who make up Biff Tannen's gang in 1955  Their nicknames are only given in the films' novels, screenplays, and credits  Only one of their real names is mentioned in the movies – Biff refers to Skinhead as Joey in one of the 1955 scenes in Back to the Future Part II, while outside of the "Enchantment Under the Sea" dance 
In the alternate 1985, the three work in Biff's casino as his bodyguards  Each get their nickname from a distinctive character trait  Match often has a match sticking out of his mouth; Skinhead has very short, close-cropped hair; 3-D is always wearing a pair of anaglyphic 3-D glasses (a reference to the 3-D movies that were popular in the 1950s) 

Spike, Data and Whitey
Leslie "Spike" O'Malley (portrayed by Darlene Vogel), Rafe "Data" Unger (portrayed by Ricky Dean Logan) and Chester "Whitey" Noguera (portrayed by Jason Scott Lee) they are high school kids who make up Griff Tannen's gang in 2015  Each one of them is also the grandchild of Biff Tannen's original gang  Spike is Match's granddaughter, Data is Skinhead's grandson, and Whitey is 3-D's grandson 



ground_truth: Claudia Wells

prompt_front: Answer the question based on the given passages. Only give me the answer and do not output any other words.

Question: Who does the performer of Don't Be Cruel play in the wire?

The following are given passages.
Context 2: Passage 1:
Don't Be Cruel (album)
Don't Be Cruel is the second studio album by American singer Bobby Brown  It was released in the United States on June 20, 1988, by MCA Records  MCA changed producers for this album and had Brown work with hit-making songwriting and production duo Babyface and L A  Reid  Brown dedicated the album to his deceased best friend James "Jimbo" Flint who was stabbed to death when Brown was aged 11  Don't Be Cruel incorporates new jack swing, R&B, funk, dance and soul Don't Be Cruel peaked at number one on the US Billboard 200 and included five top 10 Billboard Hot 100 hits, with "My Prerogative" being a US number-one hit  Three of the singles also reached number one on Billboard's Hot R&B Songs chart  "My Prerogative" was also the second-biggest single of 1989, ranking at number two on the Billboard Year-End Hot 100 singles of 1989  The album also spent a total of 11 non-consecutive weeks atop the Billboard R&B Albums chart over the course of 1988 and 1989  Internationally, it reached number one in Ireland and the top five in Australia, New Zealand, and the United Kingdom 
At the 32nd Grammy Awards, Brown won Best Male R&B Vocal Performance for "Every Little Step"  Don't Be Cruel received extremely positive reviews from music critics  It was far more successful than Brown's debut album, spending a total of six weeks on top of the Billboard 200 and being the best-selling album of 1989 in the United States  On April 28, 1995, it was certified 7× Platinum by the Recording Industry Association of America (RIAA)  The album sold over 12 million copies worldwide in total  In 2015, Billboard ranked Don't Be Cruel at number 82 on its list of the Greatest of All Time Billboard 200 Albums The album will receive a 2-disc and vinyl deluxe edition physical release commemorating its 35th anniversary on June 16, 2023 by Iconoclassic Records 

Development
Brown changed producers for this album, and worked extensively with hit-making songwriting and production duo Babyface and L A  Reid  Alex Henderson of AllMusic writes:

Don't Be Cruel was to Bobby Brown what Control was to Janet Jackson – a tougher, more aggressive project that shed his "bubblegum" image altogether and brought him to a new artistic and commercial plateau  With "My Prerogative" and the title song, Brown became a leader of new jack swing – a forceful, high-tech blend of traditional soul singing and rap/hip-hop that's also associated with Guy and Brown's New Edition colleagues, Bell Biv DeVoe 

Singles
All five singles released from the album reached the top 10 of the Billboard Hot 100  "Don't Be Cruel" was released as the lead single  The second single, "My Prerogative", earned Brown his first number one on the Billboard Hot 100  "My Prerogative" was also the second-biggest single of 1989, finishing at number two on the Year-End Billboard Hot 100 Singles of 1989  Three of the singles also reached number one on Billboard's Hot R&B Songs chart 
All singles except "Roni" were certified Gold by the RIAA 

Commercial performance
Don't Be Cruel debuted at number 74 on the Billboard 200 on July 23, 1988  It wasn't until six months later that the album reached number one, starting a six-week non-consecutive run at number one, from January 21, 1989 – February 4, 1989 and February 18, 1989 – March 4, 1989  Its reign at number one was interrupted for one week by Guns N' Roses' Appetite for Destruction 
The album also spent a total of 11 non-consecutive weeks atop the Billboard R&B/Hip-Hop Albums chart over the course of 1988 and 1989  It spent an eight-week non-consecutive run at number one from September–November 1988, and then returned to number one four months later in March 1989 
Don't Be Cruel was the best-selling album of 1989 in the United States, and finished number one on the Billboard Year-End album chart  Eventually the album sold 12 million copies worldwide in less than a decade 

Track listing
Personnel
Credits adapted from AllMusic 

Charts
Certifications
Passage 2:
Up All Night (Matt Willis song)
"Up All Night" is the debut solo single by English musician Matt Willis  It was released as a single on 22 May 2006 and appears on his debut album, Don't Let It Go to Waste  The song is about how Willis keeps thinking of a girl, and as a result cannot sleep at night  It debuted at number 52 on the UK Singles Chart on download sales alone  The following week, it peaked at number seven after the physical release  It stayed in the UK chart for a total of four weeks 
The video for "Up All Night" features Willis in a house late at night and flashes back and forth between scenes of Willis having difficulty sleeping and Willis in the midst of a party  Willis's first televised performance of "Up All Night" took place on 7 May 2006 on Top of the Pops  He then performed the song again on the same show on 28 May 2006, three weeks since his TV debut 

Track listings
CD2 contains a free beer mat, with images of a dragon on the front and Willis on the rear 

Charts
Passage 3:
Police of The Wire
The Baltimore Police Department plays an integral part in The Wire 

Command
The department is led by a Police Commissioner assisted by Deputy Commissioners of Operations (often shortened to Deputy Ops) and Administration  The Police Commissioner answers directly to the city mayor and outlines the departmental goals which are then enforced by the Deputy Commissioners  The Deputy Ops wields a great deal of power and is responsible for the day-to-day activity of the department's district and investigative unit commanders  
The Administrative Deputy oversees the Internal Investigations Division (IID) and other units  The real-life chain of command from the Commissioner downwards is Deputy Commissioner, Chief, Colonel, Lieutenant Colonel, Major, Captain, Lieutenant, Sergeant, and Detective/Officer  However, in the series, any mention of the ranks of Chief, Lieutenant Colonel, and Captain are omitted  Presumably this is to avoid confusion and make the relationships between different members of the hierarchy clearer to the viewer  
Detectives fall into a rank that coincides with their administrative position  The Criminal Investigations Division (CID), commanded usually by a Colonel, is the division responsible for the Homicide unit, Narcotics unit, and Major Crimes Unit (MCU) among others  
The IID, homicide unit, and narcotics unit are each led by a Major  MCU is commanded by a lieutenant  A Major commands each of the nine patrol districts - the Central, Northern, Northeastern, Eastern, Southeastern, Southern, Southwestern, Western and Northwestern districts 

Department commanders
William Rawls
Rawls is Acting Commissioner on a temporary basis  Rawls is Caucasian, and Mayor Tommy Carcetti is unwilling to attempt a permanent promotion fearing that it would not be acceptable to the politically influential and largely black ministers  Rawls is a careerist and is feared by many of his subordinates  He has been known to punish anyone who crosses him with transfers to undesirable posts  Rawls is played by John Doman 

Cedric Daniels
Daniels is the Deputy Commissioner of Operations  He is a direct commanding officer of many of the show's characters in earlier seasons  Daniels previously worked as a lieutenant in the Eastern District Drug Enforcement Unit, CID Narcotics Unit, and was the first commander of the MCU  Daniels is promoted to Major and Western District Commander after his successful case work in the MCU  
He draws Carcetti's attention as a young and capable black commander and is quickly promoted to CID Colonel  He is eventually promoted to Police Commissioner, but resigns to practice law  Daniels is played by Lance Reddick 

Stanislaus Valchek
Valchek is the Deputy Commissioner of Administration  Valchek was previously the Southeastern District commander  His grudge against Frank Sobotka led to the formation of a specialised detail which became the Major Crimes Unit  Valchek is well-connected with the city's politicians, and was promoted because of his political association with Mayor Carcetti  Valchek is played by Al Brown 

Bobby Reed
Played by: Tony D  Head
Appears in:Season one: "The Buys"; "Lessons" (uncredited); "The Hunt" and "Cleaning Up" 
Season three: "Time After Time"; "Dead Soldiers"; "Reformation"; "Middle Ground" and "Mission Accomplished" 
Season four: "Misgivings" (uncredited)Reed is a Major in the Baltimore Police Department and commands the Internal Investigations Division  He is very loyal to Ervin Burrell's command, often more focused on protecting Burrell's status and command than on rigorously investigating individual officers  He often appears with discrediting evidence about officers for Burrell to use as blackmail 
In the first season Reed investigates the brutality charges made against Roland "Prez" Pryzbylewski for blinding a teenager in one eye  Reed dismisses the witnesses based upon their criminal records but suspends Prez from street duty pending a Grand Jury hearing  Reed then intervenes when the Barksdale detail stop State Senator Davis' driver (who received a bag full of cash from a Barksdale soldier) and again when Daniels tries to withhold the location of a Barksdale stash house to protect his investigation 
In the third season, Reed attends the weekly comstat meetings of Ervin Burrell and William Rawls  In the fourth season, Reed briefly appears when Burrell is contemplating the best method to keep his appointed position as commissioner 

Former members
Warren Frazier
Played by: Dick Stilwell
Appears in:Season one: "The Hunt" Frazier is the Commissioner in season one  He gives the order for citywide raids following the shooting of Kima Greggs  As actor Dick Stilwell died in a real-life car accident after appearing in this single episode, his character is retired and replaced by Ervin Burrell as commissioner 

Ervin Burrell
Burrell is a by-the-book careerist officer who reached the level of Commissioner  Initially appointed as an Acting Commissioner, Burrell negotiated for a permanent posting with the Royce administration  When Carcetti replaced Royce he immediately began looking to depose Burrell  He is eventually forced to resign in a scandal over manipulation of crime statistics but receives a highly paid replacement job in order to leave quietly  Burrell is played by Frankie Faison 

Raymond Foerster
Played by: Richard DeAngelis
Appears in:Season one: "The Target"; "The Detail"; "The Buys"; "The Wire"; "The Cost"; "The Hunt" and "Sentencing" 
Season three: "Time After Time "; " All Due Respect "; "Dead Soldiers"; "Straight and True"; "Homecoming"; "Slapstick" and "Mission Accomplished" 
Season four: "Refugees"Raymond Foerster was a Major and unit commander of the Baltimore narcotics division in season one  According to Season 4, he served 39 years on the force, suggesting he joined the BPD in 1967  When Judge Phelan questioned Deputy Commissioner Burrell about the Barksdale operation, Majors Foerster and Rawls faced his subsequent wrath and demands for more information  Foerster's response was to ask his shift lieutenant Cedric Daniels for a report and then to assign Daniels and his team to the Barksdale detail 
When Daniels's investigation became drawn out and relied upon wiretaps and surveillance, Foerster took the side of Deputy Commissioner Burrell against Daniels when he tried to explain the necessity of this technique to reach the heads of the organization  Foerster's and Burrell's insistence on using buy busts led to the operation that resulted in the shooting of Detective Greggs  Foerster visited Greggs in the hospital with many other command officers and appeared anxious when trying to find a tape recorder to replay the last transmissions before she was shot 
Foerster was promoted to colonel and took over as commander of the criminal investigations division when Rawls was promoted to deputy commissioner of operations  He was replaced as the Narcotics Major by George Smith, an associate of Major Colvin  He attended Rawls' weekly comstat meetings and worked with Sergeant Jay Landsman in running the homicide division  He was put under intense pressure to keep the murder rate down Foerster continued to command CID in season four and was involved in the management of the murder of a state's witness that became a politically important case  When Burrell ordered Foerster to replace veteran investigator Ed Norris with rookie homicide detective, Kima Greggs, Foerster realized that Burrell hoped to slow the investigation, assuming Burrell's intent was to prevent the investigation from revealing the victim's witness status as a possible motive for the murder before the upcoming mayoral election  Foerster argued with Burrell and Rawls about the decision and discussed it with Jay Landsman  
Actor Richard DeAngelis suffered from cancer during this time and was often absent from work  Repeated courses of chemotherapy failed to cure the disease  DeAngelis died of cancer after filming scenes for the fourth season  Landsman announced the Colonel's death to the homicide unit, stating that he served 39 years in the department without leaving a trace of bitterness or hatred with any officers, a miraculous career by BPD standards  A police wake was held at an Irish bar in his honor 

Major Crimes Unit
The Major Crimes Unit was established by Cedric Daniels in season three as part of a prior agreement with Commissioner Ervin Burrell  The unit's main responsibility is to build cases against high-profile targets responsible for murder, drug distribution and money laundering in Baltimore  The unit was originally formed by a group of detectives dumped upon Daniels by shift Lieutenants to make a case against Avon Barksdale  It is currently under the command of the Criminal Investigation Division  It is run by Lester Freamon, even though on paper it is commanded by Lieutenant Asher 
In the first season the detail's office is located in the basement of a downtown building where the only redeeming features are working telephones and electricity  In the second season, the detail is moved into an old building located at 1911 South Clinton Street in the southeastern part of town, leased by the Transportation Authority courtesy of Major Valchek  The office remains the permanent location of the unit when it is formed in season three 

Current members
Command
Jimmy Asher
Played by: Gene Terinoni
Appears in:Season four: "Boys of Summer"; "Home Rooms" and "That's Got His Own" 
Season five: "More with Less"Asher is the lenient lieutenant who was picked to command the Major Crimes Unit by Cedric Daniels  He normally lets the detectives do as they wish while working on his beach house in Delaware  Lieutenant Charles Marimow replaced him for purposes of properly "supervising" the Major Crimes Unit under the orders of Deputy Commissioner Rawls  With Daniels' promotion to C I D  colonel, Asher is reinstalled as commander of the unit again as Freamon feels he will effectively let the detectives do what they need to make a case without interference from the commissioner's office 

Lester Freamon
Freamon is a quiet and methodical veteran detective who makes major contributions to the unit's investigations  He is the unit's de facto commander, as he lays out their investigative strategies and specifically chose Lieutenant Asher to be the shift Lieutenant due to his lenient, hands-off attitude 

Detectives/Officers
Kenneth Dozerman
Played by: Rick Otto
Appears in:Season three: "Time After Time", "All Due Respect" and "Back Burners" 
Season four: "Refugees", "Alliances", "Know Your Place", "Misgivings", "That's Got His Own" and "Final Grades" 
Season five: "More with Less", "Clarifications", "Late Editions", and "–30–" Kenneth Dozerman is a plainclothes cop in the Western District  In season 3, he is part of Carver's Drug Enforcement Unit squad  He becomes friends with Herc and Carver while working in the squad accompanying them in various activities off duty  Dozerman gets shot in the face and critically injured in a buy bust operation gone wrong and gets decommissioned from duty for the rest of the season  Major Colvin uses Dozerman's shooting as the impetus for his "Hamsterdam" experiment, a way to reduce crime and not see any more of his men get hurt  The shooter also steals Dozerman's service weapon and Bunk Moreland is ordered to locate it  Dozerman is presented with it at a press conference In season four, Dozerman transfers to the Major Crimes Unit when Herc transfers in, filling the gap left by Greggs and Freamon leaving  Dozerman takes part in Lieutenant Charles Marimow's first series of failed raids as unit commander  Following these raids he helps Herc to set up video surveillance of Marlo Stanfield  Dozerman remains in the unit as an ally to both Herc and Leander Sydnor, who mentor Dozerman on his investigative strategies  All three detectives maintain a dislike for Marimow's caustic command style often fearing the repercussions that he has threatened them with  Dozerman remains in the unit following Marimow's departure and Herc's suspension under the new leadership of Lester Freamon 
In Season five, Dozerman is still with Major Crimes working with the detail on the row house serial murders  He still meets his old Western district DEU buddies for drinks along with Herc  After Major Crimes is disbanded, Dozerman is transferred to the Tactical division 

Jimmy McNulty
McNulty is known as “natural police” and ultimately whom the show centers around  He is dedicated and a highly driven Baltimore police detective but is riddled with many complicated personal problems, such as a ruined marriage, a series of flings with multiple women, and alcoholism  McNulty came up under the guidance of Bunny Colvin, a western district Major, who often  refers to McNulty as “Bushytop” for McNulty’s wavy or curly locks of hair  McNulty is liked by non-commanding officers and is most friendly to Bunk and Kima Greggs  The first three seasons foundation story revolves around McNulty’s obsession with arresting Stringer Bell 

Leander Sydnor
Sydnor is a young, married detective in the Baltimore Major Crimes Unit with a talent for investigative work and the stomach for drawn-out cases   Sydnor has been part of the Major Crimes Unit throughout seasons one, three, and four of the show 

Former members
Command
Cedric Daniels
Daniels left the unit when he was promoted to Major, taking the District Commander post in the Western 

Charles Marimow
Played by: Boris McGiver
Appears in season four: "Home Rooms", "Refugees", "Alliances", "Corner Boys", "Misgivings", "That's Got His Own" Bill Rawls installs Lieutenant Marimow as the commander of the Major Crimes Unit after Lester Freamon issues a series of subpoenas  Marimow attempts to change the unit's focus to the more obviously violent drug dealers and closes down their wiretaps on Marlo Stanfield  His caustic command style drives away Lester and Kima Greggs, leaving him with Leander Sydnor and Caroline Massey  His unit's staffing problems are relieved when Sergeant Herc Hauk transfers back  Dozerman joins him  Marimow and Herc develop an immediate mutual dislike 
Marimow is one of the most disliked commanders, often referred to as a "Trojan Horse", "Virus" and a "Unit Killer"  It is stated by Jay Landsman that "Marimow does not cast off talent lightly  He heaves it away with great force"  Marimow is also unafraid to threaten his subordinates' careers as a means of punishing them for insubordination or similar defiance  He prides himself on being a streetwise commander and having worked his way up through the ranks  While Marimow has worked hard to earn his rank, his hostile command style has established his negative reputation throughout the department 
He believes it would be easy to topple Marlo, but his first series of raids fail, as he underestimates his targets  Marimow orders his men to take Marlo down, leading Herc to break several rules by hiring a lip reader to spy on Marlo, and using a video camera without a court order or Marimow's approval  Marimow accurately suspects Herc of lying to him about the source of his information  
Herc also has Internal Investigations Division (IID) complaints sent to the office for attempted arrests based on misinformation  Marimow vows to Herc that he would be happy to attend his "execution" at an IID trial if he could prove he was lying  Marimow leaves the Unit when Cedric Daniels becomes the Criminal Investigations Division colonel and reinstalls Lester and Asher 
Show creator David Simon left the Baltimore Sun after a bitter feud with editor William K  Marimow   Simon chose to name an unsympathetic character after his old enemy 

Thomas "Herc" Hauk
Herc was a narcotics detective but his tendency towards brutality and acting without thinking held up his career progression as a member of the Barksdale and Sobotka details  To improve his chances of making sergeant he transferred to the Mayor's security detail  He returned to the Major Crimes Unit as a newly promoted sergeant  Herc is fired from the department after an Internal Investigation Division hearing 

Detail members
Ellis Carver
A detective on Daniels narcotics shift who followed him into the Barksdale and Sobotka details  He left the detail in season 2 for a drug enforcement unit sergeant posting in the Western District 

Patrick Mahon
Played by: Tom Quinn
Appears in season one: "The Detail"; "The Buys" and "Old Cases" Mahon was an elderly detective from the property unit who briefly worked with the Barksdale detail  Dubbed as a departmental "hump", he and his partner Polk had not made a single case in property crimes over their last ten years  The two were also regarded as a pair of drunks who were incapable of driving soberly  
He is punched by Bodie Broadus, a young drug dealer, when the detail raid the low rise projects  Mahon takes early retirement following his injury, and is last seen encouraging Polk to do the same 
Along with his counterpart Polk, his name is a reference to the Irish phrase "póg mo thóin" ("pogue mahone"), or "kiss my arse" 

Augustus Polk
Played by: Nat Benchley
Appears inSeason one: "The Detail"; "The Buys"; "Old Cases"; "The Pager" and "The Wire" 
Season two: "Collateral Damage" (uncredited) and "Hot Shots" (uncredited) 
Season five: "Late Editions" Polk was an aging detective from the property unit who worked briefly in the Barksdale and Sobotka details  He is often called "Auggie" by his partner Pat Mahon  He is generally regarded as a "hump", since he has not made a single case in property crimes over their last ten years  He is also an alcoholic 
After his partner Mahon retired due to injury, Polk considers deliberately injuring himself to follow in his partner's footsteps  Unable to follow through on his plan, he becomes despondent and goes on a drinking binge  He misses several days' work and finally shows up drunk at 9am  Lieutenant Daniels tells him to take sick leave for his alcohol problem or work "wet"  Polk opted for sick leave and is off until the case is closed 
In the second season, he is briefly assigned to the first Sobotka detail under Lieutenant Grayson  When Major Valchek complains about the unit being full of humps, Daniels is put in command and Polk is moved back to property 
In the ninth episode of the fifth season, Polk makes a small cameo, as the officer running the evidence control locker in one of the precincts  After helping Commissioner Daniels locate a crucial piece of evidence, Daniels tells Polk that he's "glad he landed okay"  Displaying his usual sarcasm, Polk replies "Yeah   beats working" 

Michael Santangelo
For a full character description see Western District section, below 
Original Barksdale detail member partnered with Jimmy McNulty  He was dumped from homicide by Major Rawls for refusal to act as an insider in on Rawls' behalf  Santangelo took a post driving the narcotics wagon in the Western District 

Unit members
Shakima "Kima" Greggs
Daniels' protege who mentored Herc and Carver while in Narcotics  She transferred to homicide when Lieutenant Marimow came into the unit as he was a caustic commander who was difficult to work for  When Marimow left, she remained in homicide due to the higher pay 

Roland "Prez" Pryzbylewski
Prez was the son-in-law of deputy commissioner Stan Valchek who had a knack for tracing phone patterns and money accounts but was inept on the streets  Prez left the department after accidentally shooting a plainclothes black officer Derrick Waggoner  He becomes a teacher at Tilghman Middle School soon after 

Caroline Massey
Played by: Joilet F  Harris
Appears inSeason three: "Time After Time"; "All Due Respect"; "Dead Soldiers"; "Reformation" and "Middle Ground" 
Season four: "Boys of Summer"; "Soft Eyes"; "Refugees" Officer Massey joined the show in season three as a member of the Major Crimes Unit under Lieutenant Cedric Daniels  Massey is a world-weary officer with a penchant for sarcasm and cutting coupons  She was particularly adept at deciphering the slang used by Barksdale drug dealers on wiretaps of cellular phones  Her diligent work manning wiretaps earned the respect of Lester Freamon when she was part of his successful undercover operation to supply pre-wiretapped phones to the Barksdale organization 
In season four, Massey continued to work with the Major Crimes Unit and settled into her role  When the unit was assigned Lieutenant Marimow as a commander, Freamon transferred out  Massey and Sydnor were left to face Marimow closing down their wiretaps and ordering raids on weeks old targets 

Homicide unit
The Homicide Unit of the Baltimore City Police Department is responsible for the investigation of all unexplained deaths that take place within Baltimore City   They are also responsible for investigating all police-related shootings  Because the homicide unit is generally regarded as containing the best detectives on the police force, they are often given high-profile cases which are not necessarily homicides  
A clearance rate of 50% or more for the year is aimed for and the unit is among the most demanding in the Criminal Investigations Division  Sergeant Landsman's squad is typically the focus of the show, though there is at least one other squad (according to David Simon's book, there are typically three homicide squads in Baltimore, on rotating shifts)  The unit is under the C I D  supervision of Rawls in season 2, then Raymond Foerster from the start of season 3 until Foerster's death from cancer, at which point the role is taken over by Cedric Daniels 
Like the real department described in David Simon's Homicide: A Year on the Killing Streets, the unit uses a red-black system of tracking cases where red is the color for an open/not cleared case and black is the color for a closed/cleared case  Additionally similar slang such as "dunkers" (easy cases), "whodunits" (difficult cases), and "redball" (media attention gaining cases) are used to describe the various cases   Victims who are not associated with the drug trade or other crime are often referred to as "taxpayers" 
A running practical joke within the unit is that if a detective is caught sleeping at his desk, his necktie will be cut off with scissors and pinned to a "necktie mausoleum"  Detectives often fall asleep in the office (or on stakeout) because of the overtime demands and have at times worked double and triple shifts as they have dealt with multiple murders  This is used most prominently in the third season, where Bunk is shown cutting Crutchfield's tie, and later Crutchfield gets to repay the favor 

Current members
Jay Landsman
Landsman is a squad sergeant in the homicide unit who must divide his loyalties between his men and his superiors 

Frank Barlow
Played by: Michael Stone Forrest
Appears in:Season one: "The Target"
Season five: "Not for Attribution", "Took" (uncredited), "Clarifications"Frank Barlow is a Caucasian detective in the homicide unit who first appeared as the primary detective at the trial of D'Angelo Barksdale  Despite having two witnesses, D'Angelo is found not guilty due to witness intimidation in the court room  Barlow appears later in the series with open murders of homeless men that McNulty ties into his fabricated serial killer  
Barlow then sees that McNulty is falsifying paper work on the homeless murders case to provide resources for detectives to investigate unrelated cases  Barlow blackmails McNulty into providing funds for him to take a long weekend to play golf in South Carolina 

Christeson
Played by: Dennis Hill
Appears in:Season five: "More with Less", "Took", "Clarifications", "Late Editions" and "–30–" Christeson is a young black detective who is the homicide unit's newest detective  He first appears assisting Bunk and Norris on a "polygraph-by-copier" where an idiotic suspect confesses to a homicide  Christeson is the first detective whom Jimmy McNulty covers for the "homeless killer" and he is granted overtime to solve a case which the department's upper command interferes with 

Michael Crutchfield
Played by: Gregory L  Williams
Appears in:Season three: "Back Burners", "Moral Midgetry", "Slapstick" and "Mission Accomplished" 
Season four: "Home Rooms", "Soft Eyes", "Refugees", "Alliances", "Margin of Error", "Unto Others", "Corner Boys", "A New Day" and "Final Grades" 
Season five: "More With Less", "Unconfirmed Reports", "Not for Attribution", "Took", "Clarifications", and "–30–" Crutchfield is a detective in the homicide unit whose name is mentioned earlier in the series but who does not appear on screen until season three  He was the primary detective at the murder that took place in Major Colvin's "free zone" and withheld the investigation at Colvin's request  Colvin then helped create a "dunker" case having his suspect turned in after threatening the drug dealers in the "free zone" 
In season four, Crutchfield plays a bigger role, appearing with Vernon Holley getting an identification of Omar Little as a murder suspect from Old Face Andre  When Bunk Moreland wants to re-examine the case, Crutchfield displays his anger over Bunk wanting to reverse one of his clearances  Crutchfield then promises to reverse a clearance of Bunk's as payback for going back on a solved case  
When Carver leaves a message for Bunk, Crutchfield deliberately throws it away, causing a lengthy delay in the discovery of the bodies being left all over the city by the Stanfield Organization, and also indirectly ruining Randy Wagstaff's life in the process  Crutchfield ends season four investigating murders at the hands of the Stanfield Organization 
In season five Crutchfield remains with Sergeant Jay Landsman's homicide squad  Crutchfield helps Bunk to manipulate a confession from DeShawn Williams  Crutchfield buys Monell, another involved party, a McDonald's meal and parades the boy in front of Bunk's interrogation room to lead Bunk's suspect to believe that his friend had turned against him  When departmental cut backs lead to the withholding of overtime, Crutchfield secures part-time work as a security guard to replace his lost pay  Crutchfield is later assigned along with Kima Greggs to Chris Partlow and Snoop's triple murder of Junebug, Junebug's partner, and bodyguard  He is last seen watching as Kenard is being placed in the back of a squad car, presumably having arrested him for the murder of Omar Little 
According to Homicide: A Year on the Killing Streets, there was actually a Caucasian detective in the Baltimore Police Department homicide division named Michael Crutchfield 

Shakima "Kima" Greggs
Greggs is a tenacious investigator and a rookie homicide detective  She was a key member of the Major Crimes Unit and proved herself on both the Barksdale and Sobotka investigations  She struggles to balance her life as a police officer with her role as a potential mother with her partner 

Vernon Holley
Played by: Brian Anthony Wilson
Appears in:Season one: "The Wire" and "The Hunt" 
Season two: "Port in a Storm" (uncredited) 
Season three: "All Due Respect" (uncredited), "Dead Soldiers", "Hamsterdam"; "Slapstick"; "Reformation" and "Mission Accomplished" 
Season four: "Soft Eyes", "Alliances", "Margin of Error", "Unto Others", "Corner Boys", "A New Day" and "Final Grades" 
Season five: "React Quotes", "The Dickensian Aspect", "Took", and "–30–" Holley is a detective in the homicide unit under the command of Bill Rawls, and later Raymond Foerster followed by Cedric Daniels  Holley often works with Norris, Bunk, or Crutchfield and is one of the unit's more short tempered and physically intimidating detectives  He first appears with partner Ed Norris and catches the case of the murder of Omar Little's boyfriend Brandon  They recognize a connection to the recent murder of Omar's crew member Bailey because both corpses are found in Kevlar vests  They call in Jimmy McNulty and the Barksdale detail's work secured a conviction for the murder against soldier Wee-Bey Brice 
Following the shooting of detective Kima Greggs, Holley tracks down Bubbles paging her from a payphone  Holley assumes he is a suspect and has uniformed officers bring him in for an interrogation  Believing Bubbles to be the shooter, Holley tries to interrogate Bubbles in an accusatory and threatening manner  When Bubbles is unable to respond to his questions, Holley quickly loses his temper and tries to beat a confession out of him  Once McNulty intervenes, the situation is cleared up and Holley lies about Bubbles trying to attack him as a means of justifying the beating 
In season two, Holley is briefly seen investigating the murder of Frank Sobotka 
In season three he is assigned to investigate the murder of Tosha Mitchell and Tank and later the shooting of Stringer Bell, both working with Bunk Moreland  During this season, he is also seen called to duty for other investigations as the city's homicide rate rapidly approaches 300 murders for the year 
In season four, Holley initially works as the secondary investigator on Norris' case of a murdered state's witness named Braddock that becomes a "red ball" case  Later in that investigation, he is replaced by Kima Greggs for political reasons  Holley and Crutchfield are then seen catching the case of a delivery woman murdered by Chris Partlow in Old Face Andre's convenience store  They interview Andre, who quickly (as ordered by Chris) identifies Omar Little as the killer in a photo array When Omar is arrested he manages to convince Bunk Moreland he is innocent and Bunk asks Crutchfield and Holley to re-open the case  Crutchfield refuses to entertain the idea but Holley agrees that Andre is a possible drug dealer and goes with Bunk to the crime scene reluctantly  At the scene revisitation, Bunk views evidence confirming Omar's innocence in the shooting He states that Andre's store is a drug stash house, Andre's story makes no sense, and in addition to his fear of Chris, he was likely willing to implicate Omar for ripping off his stash  Holley and Bunk then reappear with a grand jury summons where at the courtroom, Holley manages to intimidate Andre both physically and legally to have him confess his role in lying about the murder  Holley ends Season 4 assisting Crutchfield, Norris, and Bunk in the investigations of murders caused by Marlo Stanfield's crew According to Homicide: A Year on the Killing Streets, there was actually a black detective in the Baltimore Police Department homicide division named Vernon Holley  The real life Holley has worked in security for the Baltimore Ravens 

William "Bunk" Moreland
Bunk is a well liked and proficient member of the homicide unit  Although he is a capable detective, Bunk is a known alcoholic with a penchant for infidelity 

Ed Norris
Played by: Ed Norris
Appears in:Season one: "The Wire", "The Cost", "The Hunt" and "Sentencing" 
Season two: "Stray Rounds"
Season three: "Time After Time", "All Due Respect" and "Dead Soldiers" 
Season four: "Boys of Summer", "Soft Eyes", "Alliances" (uncredited), "Margin of Error", "Unto Others", "A New Day" and "Final Grades" 
Season five: "More With Less", "Transitions", "React Quotes", "The Dickensian Aspect" (uncredited), "Took", and "–30–" Norris is a homicide detective who has been in the unit for 15 years since 1991 according to Season 4  Norris and his squad mate Vernon Holley first appeared assigned to the case of the murder of Omar Little's boyfriend Brandon  They recognized a connection to the recent murder of Omar's crew member Bailey because both corpses were found in Kevlar vests  They called in their colleague Jimmy McNulty and the Barksdale detail's work secured a conviction for the murder against soldier Wee-Bey Brice 
Norris was also lead detective on the shooting of Wendell "Orlando" Blocker and Kima Greggs this time working with Detective Ray Cole  This case was also solved when Wee-Bey confessed to the shooting 
In season two he appeared briefly when investigating the shooting of a child by a stray bullet  In season three he attended the wake of his colleague Ray Cole  Norris remains with the homicide unit in season four when he is the lead investigator in the politically important murder of a state's witness  He is briefly taken off the case and replaced with Greggs, now a rookie in the squad, in order to slow progress because of pressure from the Mayor  Norris is soon reinstated when this story is leaked to the press  
He works alongside Greggs to maintain a coverup story that they were always working together  Norris secures an informant for the witness murder, but his attempt to break the story right before the election leads to him and Greggs being sent off to a security detail at a polling station for the day  Norris continues to pursue this lead after the election, however Greggs solves the case with a careful recanvassing of the crime scene before he is able to make progress  She earns Norris' respect with her work although he responds to the knowledge that the shooting was random with incredulity because of the political ramifications it had Norris is played by ex-police commissioner of Baltimore and convicted felon Ed Norris  His cameo appearances are a source of irony on the show, and he is often given dialogue bemoaning the state of the Baltimore Police Department 

Winona
Appears in:Season two: "Ebb Tide", "Hard Cases"
Season three: "Dead Soldiers", Mission Accomplished (uncredited)
Season four: "Soft Eyes", "Refugees", "Corner Boys"; "Know Your Place", "A New Day", "Final Grades" Winona is a recurring background character who maintains The Board at the offices of the BPD Homicide Division  She is a middle-aged black woman with a distinctive, bouffant hairdo  Detective McNulty greets her by name in episode 14 

Former members
Ray Cole
Played by: Robert F  Colesberry
Appears in:Season one: "The Target" (uncredited); "The Detail" (uncredited); "The Wire" (uncredited); "The Cost" (uncredited); "The Hunt" (uncredited); "Sentencing" (uncredited) 
Season two: "Ebb Tide" (uncredited); "Collateral Damage" (uncredited); "Undertow (uncredited); "Stray Rounds" (uncredited) Ray Cole was a somewhat inept member of Sergeant Landsman's homicide squad under the command of William Rawls 
Cole was the lead investigator of the death of Anton "Stinkum" Artis  His colleague Bunk Moreland told him that there was information about the case as part of a wiretap investigation that Bunk's partner Jimmy McNulty was involved in  The information would jeopardize the wiretap so they promised they would give it to Cole when the case closed  McNulty never intended to give Cole the information because the perpetrator was his informant Omar Little 
Cole was secondary investigator on the shooting of Wendell "Orlando" Blocker and Detective Kima Greggs  Cole achieved a clearance in the case working alongside lead investigator Detective Ed Norris when the case was solved with a confession from Wee-Bey Brice 
Cole was initially assigned the fourteen Jane Doe homicides that Rawls had tried to avoid  Jimmy McNulty was responsible for proving the cases fell under Rawls' jurisdiction  McNulty called Cole collateral damage when discussing Cole's misfortune with Bunk  Landsman reassigned the case to Bunk and Lester Freamon because he felt he needed his most capable detectives on it 
Cole died unexpectedly and the department held a wake for him  Landsman gave a eulogy for Cole at the wake Cole was played by the show's executive producer, Robert F  Colesberry, who died unexpectedly of complications from heart surgery  The character's wake was in part a tribute to Colesberry   In all subsequent seasons, the opening titles showed Cole's photo at the wake 

Lester Freamon
Freamon is a methodical detective who was very skilled at homicide investigations but was once kicked out of the unit for angering the Deputy of Operations  He was let back in by William Rawls on two occasions transferring out on both to be of more assistance in leading the Major Crimes Unit 
Freamon is a methodical and competent homicide detective who was exiled to the Pawn Shop Unit – for thirteen years (and four months) – for angering the then-Deputy of Operations  He was transferred to the Barksdale detail in Season One, later returning twice to the Homicide unit 

Jimmy McNulty
McNulty was one of the homicide unit's better detectives until his insubordination drew the ire of his commander Major Rawls  Rawls had him transferred out of homicide at the end of season one, although he did return in Season Five 

William Rawls
Rawls was a Major in homicide promoted to Criminal Investigations Division Colonel and then Deputy Commissioner of Operations  He was a ruthless and feared commander of the unit who expected nothing less than unwavering loyalty and competence from his detectives 

Western District
The Western District (along with the Eastern District as shown in Season 3) of the Baltimore Police Department is one of the city's most violent districts and is located in the middle of West Baltimore at 1034 North Mount Street  The Western District has been examined in greater depth than any other on The Wire and was the center of the major investigations in seasons one, three and four 

Current staff
Command
Currently, the Western District is administered by Major Dennis Mello, former deputy to Howard Colvin, who was forced into retirement 

Dennis Mello
Played by: Jay Landsman
Appears in:Season 2: "Stray Rounds" (uncredited) 
Season 3: "Time After Time"; "All Due Respect"; "Dead Soldiers"; "Hamsterdam"; "Straight and True"; "Homecoming"; "Back Burners"; "Reformation"; "Middle Ground" and "Mission Accomplished" 
Season 4: "Boys of Summer"; "Margin of Error"; "Misgivings"; "A New Day"; "Final Grades" 
Season 5: "More With Less", "Took"Mello first appeared on the series as Western District administrative lieutenant and Major "Bunny" Colvin's second in command and confidante before Colvin's forced retirement  Mello then ran the district until Major Daniels was named district commander  Mello ran briefings for the Western district at roll call maintaining a sense of humor, typically dismissing the men with "don't get captured" and jokingly referring to them as "humps" and "mopes"  
Mello was once again given command of the Western district after Daniels' promotion to C I D  colonel, at least until a new Major is given district command  The actor who plays Dennis Mello is a retired Baltimore detective named Jay Landsman, and was the real-life basis for the character of the same name in the show 
Mello appeared with Colvin during the accidental shooting of a nine-year-old child after Colonel Rawls' command to shake down the district for all known drug dealers to get a murder suspect  Mello comments that it was too bad a child had to die before locking all the drug dealers up, while Colvin questions what it is they are really doing 
He accompanied Colvin to comstat meetings  Mello was aware of Colvin's "Hamsterdam" free zone where he allowed drug dealing to go unpunished  Mello was worried, but did not report Colvin's actions to his superiors  Colvin protected Mello following the discovery of Hamsterdam by their superiors  After Colvin's departure, Mello was temporarily promoted to Western District Commander  The two remained friends 
In season four Mello returned to his post of administrative lieutenant after Major Daniels was granted the district commander post  Mello worked closely with Daniels  The two tried to convince Officer McNulty to take a position in their operations unit  Both rated his capabilities highly but could not convince him to leave his position in patrol  Daniels, however, remembering McNulty's past insubordination, viewed McNulty's position as a patrolman as a self-redeeming job and was more understanding of McNulty's desire to work as a patrolman Mello was given command of the Western district again when Daniels was promoted to Criminal Investigations Division colonel  Mello continues to give charismatic roll call briefings including readying his men for polling station duty and introducing the murder warrant for Omar Little  When Commissioner Burrell tried to reassert his command of the force by "juking the stats", the district commanders were told to increase the number of arrests in their districts whether they be felonies or minor infractions After seeing his officers at work, he went to Daniels to discuss the orders patrol had been given  Mello was personally opposed to this statistical posturing, claiming that while the troops were increasing the minor infraction arrests, they were locking up the neighborhood people in the process  Claiming that half of his officers felt the same way, he then asked who they were doing this for as the election was over Daniels informed Mayor Carcetti, who then initiated a new order for the department to no longer make arrests based on statistical quotas but rather quality felonies, something Daniels had been lobbying for  Mello then was later seen commanding the Western troops to do the complicated (by Baltimore Police standards which Mello jokingly states is uncomplicated only if officers went to college or were born by women who did not drink alcohol while they were pregnant) task of searching empty homes for bodies at the request of former district major Cedric Daniels and detective Lester Freamon The character is named after a real-life Captain Dennis Mello, who was the Western District commander when Ed Burns was an officer 

Ellis Carver
Sergeant Carver is SIC (Sergeant in Charge) of the Western District under Major Mello  At the end of the series Carver is promoted to Lieutenant 

Uniformed Patrolmen
Brian Baker
Played by: Derek Horton
Appears inSeason three: "Time After Time"; "All Due Respect"
Season four: "Misgivings"; "A New Day" (uncredited) 
Season five: "Took" (uncredited)Baker is a rookie patrolman assigned with Castor to the Western District under the command of Bunny Colvin in Season three  He and Castor are both forced by Colvin to carry a compass until they can correctly identify the north direction  In Season four, Baker teams with officer Jimmy McNulty to arrest two people for a string of felony church burglaries  McNulty allows him credit for the arrest, later concurring with Bunk Moreland that Baker could be "good police" 

Bobby Brown
Played by: Bobby J  Brown
Appears inSeason one: "The Target" (uncredited); "The Wire" (uncredited)  and "The Cost" (uncredited) 
Season three: "Middle Ground" (uncredited) 
Season four: "Refugees"; "Know Your Place"; "Misgivings"; "A New Day"  (uncredited) 
Season five: "More With Less"; "Unconfirmed Reports"; "Clarifications"; "Late Editions"; and "–30–" Bobby Brown is a Western District uniformed officer  He was the first officer on scene at the shooting of William Gant  He was also at the Brandon Wright crime scene  Detective Jimmy McNulty later enlisted Brown to help watch the home of Wallace  In season 3 when Major Colvin institutes the Hamsterdam initiative Brown is one of the officers freed up to be assigned to investigate complaints rather than perform radio car patrols and he solves a church burglary case 
Brown was later present with Sergeant Ellis Carver to both warn and arrest Namond Brice for selling drugs on a pre-indicted corner  In season five Brown is livid about the withholding of his overtime pay and is insubordinate in Carver's first roll-call briefing as Sergeant in charge  Brown is involved in a parking lot brawl with another officer over the poor state of a vehicle he hands over  Later, Brown is the first officer at a suspicious death that is investigated by Detective McNulty—the death is later ruled natural as predicted by Brown and McNulty 
Brown's character is the same Baltimore police officer also called Bob Brown, played by the same featured in David Simon's miniseries, The Corner  Bobby J  Brown is also featured in The Corner as another officer  Brown would later portray real-life, corrupt BPD Sergeant Thomas Allers in another of Simon's series, and the “spiritual successor” to The Wire, We Own This City 

Aaron Castor
Played by: Lee E  Cox
Appears inSeason three: "Time After Time"; "All Due Respect" and "Moral Midgetry" (uncredited)
Season five: "More With Less"; "Unconfirmed Reports"Castor is a rookie patrolmen, assigned with Baker to the Western District under the command of Howard Colvin in season three  He and Baker are both ordered by Colvin to carry a compass until they can correctly identify the north direction  He is apparently the nephew of former Baltimore Police officer Lloyd Castor, whom Major Colvin has dubbed as "good police"  In season five Castor is first seen warning his new Major, Dennis Mello, about a brawl in the district parking lot  Later, Castor is the first officer attending the triple homicide of Junebug and his wife and associate, investigated by Detective Kima Greggs  Castor fails to notice a child hiding in a closet when he secures the scene and Greggs hears the child when she arrives 

Michael Santangelo
Played by: Michael Salconi
Appears inSeason one: "The Target"; "The Detail"; "The Buys"; "Old Cases"; "The Wire"; "One Arrest"; "Game Day"; "The Cost"; "The Hunt"; "Cleaning Up" and "Sentencing" 
Season two: "Port in a Storm" 
Season three: "Dead Soldiers"; "Straight and True"; "Homecoming"; "Slapstick" and "Mission Accomplished" 
Season four: "Boys of Summer"; "Margin of Error"; "Misgivings"; "A New Day" 
Season five: "Transitions", "Took", and "–30–" Mike "Sanny" Santangelo is an Italian American officer responsible for driving the district arrest van in the Western District 
In season one, Santangelo is an eight-year veteran in the Homicide Unit  Santangelo is, along with McNulty, assigned to the Barksdale detail by Rawls, to spy on McNulty  This also allows Rawls to unburden himself of one of his more inept homicide detectives, as Santangelo has a clearance rate of less than 40%, with his excuse for his performance being a lack of easy cases  He tries to resist, saying that it isn't his job to inform on a fellow cop  Rawls orders him either to solve one of his open cases, all of which are difficult cases, inform on McNulty or leave the Homicide Unit altogether  
Landsman eventually recommends a psychic, "Madame LaRue", and Santangelo, in desperation, follows her instructions to bury a doll in the murder victim's grave  That evening, McNulty solves another of the open cases, and Santangelo, though pleased, doesn't understand why a different case was solved  Landsman tells him that the psychic was meant as a joke and that Bunk and McNulty did his work for him  With the clearance, Santangelo is able to refuse Rawls' demands and is grateful enough to tell McNulty that Rawls wants him fired 
Santangelo is demoted to patrol officer at the end of season one for failing to give Rawls any more information  In season two, he is seen briefly as a beat officer, arresting Bubbles and Johnny when they try to steal medical supplies from an ambulance  In season three, he drives the Western district prisoner transport vehicle under the command of Major Colvin  When he encounters former Barksdale detail members McNulty and Kima Greggs, Santangelo mentions that he is happy at being a patrolman as his job is easier: he is no longer a detective, he no longer deals with difficult commanders like Rawls and still takes home the same pay and pension contributions He remains a patrolman in the Western District in season four, when McNulty transfers in alongside him  During a counter-terrorism seminar, he was the first officer to point out the uselessness of Western District officers learning anti-terrorism tactics in a crime-ridden district  Santangelo is also one of several officers present for the arrest of Omar Little on a murder warrant 

Eddie Walker
Played by: Jonnie Louis Brown
Appears in: Season four: "Soft Eyes"; "Refugees"; "Margin of Error"; "Unto Others"; "Misgivings"; "A New Day" Walker is a corrupt black patrolman in the Western District  He is a violent bully, who is feared and loathed by Namond, Michael, and the other young drug dealers in the area, and several times is seen brutalizing them  He is first seen stealing money from Randy  Later he steals bootleg DVDs from Bubbles, after Bubbles attempted to report a robbery  He is the arresting officer for Omar Little, stealing a ring from him in the process  
After Walker breaks Donut's fingers for giving him more paper work to do after a car chase, Michael orchestrates an act of revenge  When Walker exits a club late one night, Dukie runs down the sidewalk keying cars  Walker chases him into an alley, where Michael and Namond are waiting for him  Michael makes Walker drop to his knees at gunpoint and sees the ring that Walker stole from Omar (who stole it from Marlo, who took it from Old Face Andre); he takes it before Namond drenches Walker with paint  Walker tells fellow officers that he was attacked by Bloods  
Walker's attitude earns him the respect of more zealous officers and the disdain of others, such as Jimmy McNulty  McNulty later describes Walker as an "asshole", while talking to Bodie Broadus 

Plainclothes Officers
Anthony Colicchio
Played by: Benjamin BuschSeason three: "Time After Time"; "All Due Respect"; "Dead Soldiers"; "Hamsterdam"; "Straight and True"; "Homecoming"; "Back Burners"; "Moral Midgetry"; "Slapstick" and "Mission Accomplished" 
Season four: "Boys of Summer"; "Alliances" (uncredited); "Margin of Error"; "Misgivings"; "That's Got His Own" and "Final Grades" 
Season five: "More With Less", "Transitions"Anthony "Tony" Colicchio is a narcotics officer in Sergeant Ellis Carver's drug enforcement unit squad in the Western District of Baltimore  He was often partnered with fellow squad members Herc Hauk and Lloyd "Truck" Garrick  Colicchio is part of the operation that resulted in the shooting of Officer Dozerman  Along with the rest of the squad, Colicchio is involved in policing drug tolerant zones set up by his district commander Major Colvin without the knowledge of his superiors  It is Colicchio who inspires the name Hamsterdam, after citing Amsterdam's liberal drug laws as a metaphor for Colvin's new policies  As Colicchio is zealously committed to using brute force to fight the war on drugs, he describes the drug-free zones as "moral midgetry "
Colicchio remains in Carver's squad in season four, and Carver tries to bring him around to his new way of doing things—getting to know the street dealers and cultivating informants  Colicchio takes part in Lieutenant Marimow's failed raids in the Western district  Colicchio is also present for the arrest of Omar Little on a murder warrant, relishing finally bringing in the legendary criminal With his overzealous attitude, Colicchio is delighted to participate in the arrest hike ordered by Commissioner Burrell to appease the city's politicians  He appears outside a bar with other officers, causing a near riot with their "quality of life violation" arrests against people with open alcohol containers  (Major Colvin had compared "Hamsterdam" to the practice of not enforcing violations of open-container laws when the bottles were obscured by paper bags ) Colicchio's method of policing supports the Broken Windows Theory In season five, Colicchio remains in the Western District drug enforcement unit and continues to take a combative approach to his work  He is the subject of an Internal Investigation Division investigation after he attacks a teacher who had asked him to move a vehicle while he was making an arrest  Carver refuses to back Colicchio when he shows no remorse for his action, and charges him with conduct unbecoming an officer and excessive force  Colicchio accuses Carver of being a rat, but Carver is not deterred by the damage to his reputation Colicchio is played by Benjamin Busch, who spent two tours of duty in Iraq with the U S  Marine Corps 

Lloyd "Truck" Garrick
Played by: Ryan Sands
Appears in:Season three: "Time After Time"; "All Due Respect"; "Homecoming"; "Back Burners"; "Moral Midgetry"; "Slapstick"; "Reformation" and "Mission Accomplished" 
Season four: "Boys of Summer"; "Alliances"; "Margin of Error"; "Corner Boys"; "Know Your Place"; "Misgivings"; "A New Day"; "That's Got His Own" and "Final Grades" 
Season five: "More With Less"; "Clarifications"; "Late Editions"Lloyd "Truck" Garrick is a black narcotics officer in Sergeant Ellis Carver's squad in the Western District of the Baltimore Police Department, often partnered with fellow squad members Herc, Lambert and Colicchio  Garrick was part of the operation that resulted in the shooting of Officer Dozerman  Along with the rest of the squad Garrick was involved in policing drug tolerant zones set up by his district commander Howard "Bunny" Colvin without the knowledge of his superiors  He was with Herc when he phoned the paper to report Colvin's actions and again when he met with a reporter In season 4, Truck appeared briefly at a useless lesson for Western police on counter-terrorism, and once while assisting Herc and Carver  In Season 5, Truck appears with the Western District officers who are frustrated by the lack of overtime pay due to city cutbacks  During Detective Jimmy McNulty's homeless killer case, McNulty has Western District Sergeant Ellis Carver detail officers to track Marlo Stanfield's crew including officers Brown, Dozerman, and Truck 

Lambert
Played by: Nakia Dillard
Appears in:Season three: "Time After Time"; "All Due Respect"; "Homecoming"; "Back Burners"; Reformation Lambert is a black narcotics officer in Sergeant Ellis Carver's Drug Enforcement Unit in the Western District of the Baltimore Police Department, often seen with fellow squad members Herc, Anthony Colicchio, and Lloyd "Truck" Garrick  He was part of the operation that resulted in the shooting of Officer Dozerman  After Dozerman's shooting the D E U 's hand-to-hand operations were suspended as Major Colvin did not want to see any more of his men come close to death over a minimal amount of drugs 

Former staff
Major Howard "Bunny" Colvin
Colvin was the veteran Major and District commander who was forced out of the department due to his "Hamsterdam" experiment that de-criminalized drugs, despite this causing a reduction in felonies 

Kenneth Dozerman
Dozerman was a friend of Carver and Herc in the DEU that moved into the Major Crimes Unit in season 4 

Thomas "Herc" Hauk
A former D E U  member who was a partner of Ellis Carver  He left the Western District to work on the Mayor's security detail 

Jimmy McNulty
McNulty was a former beat officer who became a detective  He returned to patrol in season 4 but after the death of an informant, he rejoined the Homicide Unit 

Others
The following are former officers or assistant police not part of a District, Administrative, or Criminal Investigation Division 

Walter Cantrell
Played by: Dave Trovato
Appears inSeason one: "The Detail" and "Sentencing" (uncredited) 
Season four: "Unto Others" (uncredited) Walter Cantrell is a major and the Southern District commander  He is first seen in season one where he is a lieutenant and commands Roland "Prez" Pryzbylewski and Leander Sydnor  Lieutenant Cedric Daniels bargains with Cantrell to have the highly competent Sydnor assigned to the Barksdale detail to compensate for taking the erratic Pryzbylewski  Cantrell and Daniels are both candidates for the next post of major, and because of Daniels' insubordination while conducting the Barksdale investigation, Cantrell receives the promotion at the end of the first season  He is seen again in season four commanding the Southern District and preparing new mayor Tommy Carcetti for a ride-along 

Claude Diggins
Played by: Jeffrey Fugitt
Appears in season two: "Ebb Tide"; "Collateral Damage"; "Undertow"; "All Prologue"; "Duck and Cover"; "Storm Warnings" and "Port in a Storm" Diggins is a Baltimore police department Marine Unit officer who partners with Jimmy McNulty when he is assigned to the unit  He advises McNulty on how to make the best of the situation, but McNulty hates the fumes  Diggins is forgiving of McNulty's time away from the unit and shares his own boat with Bunk Moreland and McNulty to pose as a fishing craft when observing Spiros "Vondas" Vondopoulos  He has a noticeable Baltimore accent 

Randall Frazier
Played by: Erik Todd Dellums
Appears inSeason one: "The Detail"; "The Wire"
Season two: "Collateral Damage"; "Hot Shots" and "All Prologue"
Season three: "All Due Respect"Frazier is a Baltimore police department medical examiner  He is involved in the investigation of the death of William Gant  Later he was responsible for the autopsies of fourteen unidentified women found at the Baltimore docks  He helped Jimmy McNulty to prove that the deaths occurred in the city jurisdiction, by establishing their time of death based upon the air supply in the container the bodies were discovered in  He also linked the bodies to a specific plastic surgery clinic by identifying a breast implant type that several of the women shared and tracing the serial number  This information helped the detectives to establish that the women were sex trade workers 

Beadie Russell
Russell is a port authority police officer and a single mother who develops an interest in case work following a chance discovery  She also develops a relationship with Jimmy McNulty in seasons 4 and 5 

Marvin Taylor
Played by: Barnett Lloyd
Appears inSeason three: "Time After Time"; "All Due Respect"; "Dead Soldiers"Taylor is a black Major who was the acting commander of the Eastern District  Under pressure from the Mayor's office, Ervin Burrell is told to start coming down on the department to reduce the crime rate by any means possible  As Taylor's district had a low number of felony arrests and handgun confiscations in addition to a high number of homicides in a very short period of time, Deputy Rawls angrily tells him that he had eight hours to get a grip on his district or he would be fired  
Cedric Daniels and Jimmy McNulty then arrested an eastside drug dealer named "Cheese" whom they suspect of being responsible for some of the murders in his district  When insufficient evidence against "Cheese" or any other suspected murderers is present, Rawls berates him one last time at a Comstat meeting, after which Commissioner Burrell relieves Taylor of command  This is intended as an example to all the other commanders in the department, that if they did not improve their statistics they will also be replaced 

Torret
Played by: Derren M  Fuentes
Appears inSeason one: "The Hunt", "Cleaning Up"
Season two: "Stray Rounds"
Season three: "Middle Ground", "Mission Accomplished"Lieutenant Torret is a black officer who appears in charge of the Quick Response Team (QRT) when they are required for raids and arresting criminals  He first appeared in Season 1 leading the search for Savino and then commanding the unit to surround Avon Barksdale's strip club during his arrest  In Season 2, he appeared leading the raid on the Franklin Terrace towers when a nine-year-old child was accidentally shot and killed by a stray round in a shootout between drug dealers  In that raid he had the unit arrest everyone in "The Pit" as he assumed them a suspect for being around that area  
In Season 3, he appeared at the rank of Major commanding QRT and Tactical units citywide no longer actively participating in the raids  He helped plan and lead the raid to shut down "Hamsterdam" at the orders of Deputy Rawls  He was present with Rawls when finding the body of drug addict Johnny Weeks, who was then taken to the morgue in a squad car as a means of preventing the media from linking the death to the "Hamsterdam" experiment 

Relatives
Cheryl
Played by: Melanie Nicholls-King
Appears inSeason one: "The Target"; "Old Cases"; "The Cost"; "The Hunt" and "Sentencing" 
Season two: "Ebb Tide"; "Hard Cases"; "All Prologue"; "Storm Warnings" and "Port in a Storm" 
Season three: "All Due Respect" and "Back Burners" 
Season four: "Know Your Place"
Season five: "Transitions",Cheryl is Kima Greggs' live-in partner; she works in the television news industry and often worries about Kima's safety as a police officer  She hopes that Kima will take a less dangerous job and start a family with her  She also appears to do most of the cooking and cleaning in the relationship 
After Kima's shooting, Cheryl insists that Kima take a desk job  Kima acquiesces for a time but eventually returns to investigative work in season 2  Cheryl jealously insists on accompanying Kima when she goes to interview a contact in a strip club  Cheryl finds the assignment hard to understand, until Kima shows her the conditions in which fourteen girls were murdered 
In season 2, Cheryl becomes pregnant by artificial insemination, and in season 3, the couple has a baby boy  Kima begins to spend less time at home, and Cheryl is left to deal with motherhood alone  Kima eventually realizes she does not want to be a parent and moves out of their shared home  Kima is behind on her child support for much of season 4, but gets some overtime in Homicide and visits Cheryl, who is now happy with her new partner 

Elena McNulty
Played by: Callie Thorne
Appears in:Season one: "Old Cases" and "The Cost" 
Season two: "Hot Shots"; "Hard Cases"; "Undertow"; "All Prologue" and "Backwash" 
Season three: "Time After Time"; "Hamsterdam" and "Straight and True" 
Season four: "Misgivings"
Season five: "React Quotes"Elena was Jimmy McNulty's wife  They are divorced and have two sons, Sean and Michael 
Elena is angered by Jimmy due to catching him in bed with another woman  She uses her lawyer to try to destroy Jimmy throughout the first season as much as she can  She is also protective of her sons and worries that Jimmy is a dangerous influence on them because of his drinking  When he exposes them to danger by having them tail the subject of his investigation, Stringer Bell, she files for an emergency order to prevent him from seeing the boys  At the court hearing, the judge convinces them to work out arrangements between themselves 
In season two Elena is seen at work as a realtor showing a house to Nick Sobotka  Jimmy tries to initiate a reconciliation with Elena and considerably cleans up his drinking habits and behaviour  The two sleep together, but in the morning Elena asks Jimmy to leave as she feels it would be unfair on her sons for them to see him in the house 
In season three, Elena is established as seriously dating a man named Dennis who sits front row at Orioles games but wears a suit and spends most of the game talking on a cell phone  Jimmy's partner Bunk Moreland suspects that Dennis is a downtown lawyer due to his appearance and mannerisms 
In season four, Elena sees that Jimmy is becoming more stable as a patrolman and states to him that "If I knew you were going to grow up to be a grown up   " suggesting that she wishes she was the one reaping the benefits of this new Jimmy McNulty 
In season five, Elena confronts Jimmy because she notices he is going back to his old ways  She tells him Beadie knows she is losing him just like she, herself, knew back then  She tells him she was actually happy for him that he found Beadie and that he was really turning his life around  She convinces him to try to work things out with Beadie 

Sean James McNulty
Played by: Eric Gershowitz
Appears in:Season one: "The Wire"; "Lessons" and "Sentencing" 
Season two: "Hot Shots" 
Season three: "Time After Time"; "Straight and True" and "Slapstick" 
Season four: "Misgivings"
Season five: "React Quotes"Sean is Elena and Jimmy McNulty's oldest son  He lives with his mother and his brother Michael following his parents separation but still sees his father  Jimmy teaches his sons the front and follow technique and when he spots Stringer Bell in a market he has them follow him  Michael and Sean manage to record Stringer's number plate, which aids their father's investigation  In a brief appearance in the fourth season, he says he wants to be a rock star 

Michael Barnes McNulty
Played by: Antonio Cordova
Appears in:Season one: "Old Cases"; "The Wire" and "Lessons" 
Season three: "Time After Time"; "Hamsterdam"; "Straight and True" and "Slapstick" 
Season four: "Misgivings"
Season five: "React Quotes"Michael is Elena and Jimmy McNulty's younger son  He lives with his mother and his brother Sean following his parents separation but still sees his father  Michael plays soccer and Jimmy tries to attend his games  Jimmy teaches his sons the front and follow technique and when he spotted Stringer Bell in a market he had them follow him  Michael and Sean managed to record Stringer's number plate, which aided their father's investigation  In a brief appearance in the fourth season, he says he wants to be a video game designer 

Actual BPD Officers who have appeared
The following is a list of actual Baltimore Police Department officers who have appeared on the show at some point  Many of these officers were either commanders of the department or featured officers in the David Simon's books of The Corner and Homicide: A Year on the Killing Streets 

Gary D'Addario
Recurring character
A former Baltimore Police Department Major who was featured homicide unit shift lieutenant in David Simon's Homicide: A Year on the Killing Streets  He appears recurringly as a grand jury prosecutor named Gary DiPasquale 

Leonard Hamm
Season five: "Not for Attribution"A former Baltimore Police Department Commissioner who appears as a midnight shift homicide detective in Season 5 

Jay Landsman
Recurring character
A former Baltimore Police Department Sergeant who was featured homicide unit sergeant in David Simon's Homicide: A Year on the Killing Streets  He appears recurringly as Western District Administrative Lieutenant turned Major Dennis Mello 

Edward Norris
Recurring character
A former Baltimore Police Department Commissioner who appears as a recurring character of the same name working as a homicide detective 

Jimmy Rood
Season four: "Boys of Summer"A Baltimore Police Department C I D  Major who appears as a patrolman in Season 4 who encounters mayoral candidate Tommy Carcetti 

Donald Worden
Worden is a former Baltimore Police Department homicide detective featured in David Simon's Homicide: A Year on the Killing Streets who appears as a midnight shift homicide detective in season five  He is also mentioned in episodes in season one ("The Pager"), season three ("Slapstick"), season four ("Margin of Error") and season five ("Not for Attribution") 

Other officers mentioned
The following is a list of other Baltimore Police Department officers who have been mentioned on the show at some point  Many of these officers were either commanders of the department or featured officers in the David Simon's books of The Corner and Homicide: A Year on the Killing Streets 

Ed Burns
Mentioned in :Season three: "Slapstick"
A former Baltimore Police Department narcotics detective turned school teacher who co-authored The Corner with David Simon 

Michael Crutchfield
Recurring character of the same name
A former Baltimore Police Department homicide detective mentioned in David Simon's Homicide: A Year on the Killing Streets who inspired a character of the same name played by actor Gregory L  Williams throughout the series 

Richard Garvey
Mentioned in :Season one: "Cleaning Up"
A Baltimore Police Department homicide detective featured prominently in David Simon's 'Homicide: A Year on the Killing Streets'  He is mentioned by his last name as the detective investigating the murder of Nakeysha Lyles 

Vernon Holley
Recurring character of the same name
A former Baltimore Police Department homicide detective mentioned in David Simon's Homicide: A Year on the Killing Streets who inspired a character of the same name played by actor Brian Anthony Wilson throughout the series 

Roger Nolan
Mentioned  in :Season one: "The Target"
A former Baltimore Police Department Sergeant who was featured homicide unit sergeant in David Simon's Homicide: A Year on the Killing Streets  Nolan's name is mentioned as the sergeant of another homicide unit in the department 

Rick Requer
Mentioned in :Season five: "Transitions"
A former Baltimore Police Department homicide detective featured in David Simon's Homicide: A Year on the Killing Streets  He inspired a character named Oscar Requer played by actor Roscoe Orman in Season 5  Requer was the basis for the character of Bunk Moreland 



ground_truth: a Western District uniformed officer

prompt_front: Answer the question based on the given passages. Only give me the answer and do not output any other words.

Question: What is the experimental satellite which was the forerunner to the communication satellite of the operator of GSAT-7 called?

The following are given passages.
Context 3: Passage 1:
Polar Satellite Launch Vehicle
The Polar Satellite Launch Vehicle (PSLV) is an expendable medium-lift launch vehicle designed and operated by the Indian Space Research Organisation (ISRO)  It was developed to allow India to launch its Indian Remote Sensing (IRS) satellites into sun-synchronous orbits, a service that was, until the advent of the PSLV in 1993, only commercially available from Russia  PSLV can also launch small size satellites into Geostationary Transfer Orbit (GTO) Some notable payloads launched by PSLV include India's first lunar probe Chandrayaan-1, India's first interplanetary mission, Mars Orbiter Mission (Mangalyaan) and India's first space observatory, Astrosat PSLV has gained credibility as a leading provider of rideshare services for small satellites, owing to its numerous multi-satellite deployment campaigns with auxiliary payloads, usually ride-sharing along with an Indian primary payload  As of June 2022, PSLV has launched 345 foreign satellites from 36 countries  Most notable among these was the launch of PSLV-C37 on 15 February 2017, successfully deploying 104 satellites in sun-synchronous orbit, tripling the previous record held by Russia for the highest number of satellites sent to space on a single launch, until 24 January 2021, when SpaceX launched the Transporter-1 mission on a Falcon 9 rocket carrying 143 satellites into orbit Payloads can be integrated in tandem configuration employing a Dual Launch Adapter  Smaller payloads are also placed on equipment deck and customized payload adapters 

Development
Studies by the PSLV Planning group under S Srinivasan to develop a vehicle capable of delivering a 600 kg payload to a 550 km sun-synchronous orbit from SHAR began in 1978  Among 35 proposed configurations, four were picked; by November 1980, a vehicle configuration with two strap-ons on a core booster (S80) with 80 tonne solid propellant loading each, a liquid stage with 30 tonne propellant load (L30), and an upper stage called the Perigee-Apogee System (PAS) was being considered By 1981, confidence grew in remote sensing spacecraft development with the launch of Bhaskara-1, and the PSLV project objectives were upgraded to have the vehicle deliver a 1000 kg payload into a 900 km SSO  As technology transfer of Viking rocket engine firmed up, a new lighter configuration with the inclusion of a liquid powered stage was selected  Funding was approved in July 1982 for the finalized design, employing a single large S125 solid core as first stage with six 9 tonne strap-ons (S9) derived from the SLV-3 first stage, liquid fueled second stage (L33), and two solid upper stages (S7 and S2 ) This configuration needed further improvement to meet the orbital injection accuracy requirements of IRS satellites, and hence, the solid terminal stage (S2) was replaced with a pressure fed liquid fueled stage (L1 8 or LUS) powered by twin engines derived from roll control engines of the first stage  Apart from increasing precision, liquid upper stage also absorbed any deviation in performance of solid third stage  The final configuration of PSLV-D1 to fly in 1993 was (6 × S9 + S125) + L37 5 + S7 + L2 The inertial navigation systems are developed by ISRO Inertial Systems Unit (IISU) at Thiruvananthapuram  The liquid propulsion for the second and fourth stages of the PSLV as well as the Reaction control systems (RCS) are developed by the Liquid Propulsion Systems Centre (LPSC) at Valiamala near Thiruvananthapuram, kerala  The solid propellant motors are processed at Satish Dhawan Space Centre (SHAR) at Sriharikota, Andhra Pradesh, which also carries out launch operations 
The PSLV was first launched on 20 September 1993  The first and second stages performed as expected, but an attitude control problem led to the collision of the second and third stages at separation, and the payload failed to reach orbit  After this initial setback, the PSLV successfully completed its second mission in 1994  The fourth launch of PSLV suffered a partial failure in 1997, leaving its payload in a lower than planned orbit  In November 2014, the PSLV had launched 34 times with no further failures  (Although launch 41: August 2017 PSLV-C39 was unsuccessful )
PSLV continues to support Indian and foreign satellite launches especially for low Earth orbit (LEO) satellites  It has undergone several improvements with each subsequent version, especially those involving thrust, efficiency as well as weight  In November 2013, it was used to launch the Mars Orbiter Mission, India's first interplanetary probe In June 2018, the Union Cabinet approved ₹6,131 crore (equivalent to ₹72 billion or US$900 million in 2023) for 30 operational flights of the PSLV scheduled to take place between 2019 and 2024 ISRO is working towards handing over the production and operation of PSLV to private industry through a joint venture  On 16 August 2019, NewSpace India Limited issued an invitation to tender for manufacturing PSLV entirely by private industries  On 5 September 2022, NewSpace India Limited signed a contract with Hindustan Aeronautics Limited and Larsen & Toubro led conglomerate for the production of five PSLV-XL launch vehicles after they won competitive bidding  Under this contract, they have to deliver their first PSLV-XL within 24 months and the remaining four vehicles every six months 

Vehicle description
The PSLV has four stages, using solid and liquid propulsion systems alternately 

First stage (PS1)
The first stage, one of the largest solid rocket boosters in the world, carries 138 t (136 long tons; 152 short tons) of hydroxyl-terminated polybutadiene-bound (HTPB) propellant and develops a maximum thrust of about 4,800 kN (1,100,000 lbf)  The 2 8 m (9 ft 2 in) diameter motor case is made of maraging steel and has an empty mass of 30,200 kg (66,600 lb) Pitch and yaw control during first stage flight is provided by the Secondary Injection Thrust Vector Control (SITVC) System, which injects an aqueous solution of strontium perchlorate into the S139 exhaust divergent from a ring of 24 injection ports to produce asymmetric thrust  The solution is stored in two cylindrical aluminium tanks strapped to the core solid rocket motor and pressurised with nitrogen  Underneath these two SITVC tanks, Roll Control Thruster (RCT) modules with small bi-propellant (MMH/MON) liquid engine are also attached On the PSLV-G and PSLV-XL, first stage thrust is augmented by six strap-on solid boosters  Four boosters are ground-lit and the remaining two ignite 25 seconds after launch  The solid boosters carry 9 t (8 9 long tons; 9 9 short tons) or 12 t (12 long tons; 13 short tons) (for PSLV-XL configuration) propellant and produce 510 kN (110,000 lbf) and 719 kN (162,000 lbf) thrust respectively  Two strap-on boosters are equipped with SITVC for additional attitude control  The PSLV-CA uses no strap-on boosters 
First stage separation is aided by four pairs of retro-rockets installed on inter-stage (1/2L)  During staging, these eight rockets help push away the spent stage away from second stage 

Second stage (PS2)
The second stage is powered by a single Vikas engine and carries 41 5 t (40 8 long tons; 45 7 short tons) of Earth store-able liquid propellant – unsymmetrical dimethylhydrazine (UDMH) as fuel and nitrogen tetroxide (N2O4) as oxidiser in two tanks separated by a common bulkhead  It generates a maximum thrust of 800 kN (180,000 lbf)  The engine is gimbaled (±4°) in two planes to provide pitch and yaw control by two actuators, while roll control is provided by a Hot gas Reaction Control Motor (HRCM) that ejects hot gases diverted from gas generator of Vikas engine On inter-stage (1/2U) of PS2  there are two pairs of ullage rockets to maintain positive acceleration during PS1/PS2 staging and also two pairs of retro-rockets to help push away spent stage during PS2/PS3 staging Second stage also carries some quantity of water in a toroidal tank at its bottom  Water spray is used to cool hot gases from Vikas' gas generator to about 600 °C before entering turbopump  Propellant and water tanks of second stage are pressurized by Helium 

Third stage (PS3)
The third stage uses 7 6 t (7 5 long tons; 8 4 short tons) of HTPB solid propellant and produces a maximum thrust of 250 kN (56,000 lbf)  Its burn duration is 113 5 seconds  It has a Kevlar-polyamide fibre case and a submerged nozzle equipped with a flex-bearing-seal gimbaled nozzle with ±2° thrust vector for pitch and yaw control  Roll control is provided by the fourth stage reaction control system (RCS) during thrust phase as well as during combined-coasting phase under which burnt-out PS3 remains attached to PS4 

Fourth stage (PS4)
The fourth stage is powered by regeneratively cooled twin engines, burning monomethylhydrazine (MMH) and mixed oxides of nitrogen (MON)  Each pressure fed engine generates 7 4 kN (1,700 lbf) thrust and is gimbaled (±3°) to provide pitch, yaw and roll control during powered flight  Coast phase attitude control is provided by six 50N RCS thrusters  The stage is pressurized by Helium and carries up to 2,500 kg (5,500 lb) of propellant in the PSLV and PSLV-XL and 2,100 kg (4,600 lb) in the PSLV-CA On PSLV-C29/TeLEOS-1 mission, the fourth stage demonstrated re-ignition capability for the first time which was used in many subsequent flights to deploy payloads in multiple orbits on a single campaign As a space debris mitigation measure, PSLV fourth stage gets passivated by venting pressurant and propellant vapour after achieving main mission objectives  Such passivation prevents any unintentional fragmentation or explosion due to stored internal energy 

PS4 stage as orbital platform
PS4 has carried hosted payloads like AAM on PSLV-C8, Rubin 9 1/Rubin 9 2 on PSLV-C14 and mRESINS on PSLV-C21  But now, PS4 is being augmented to serve as a long duration orbital platform after completion of primary mission  PS4 Orbital Platform (PS4-OP) will have its own power supply, telemetry package, data storage and attitude control for hosted payloads On PSLV-C37 and PSLV-C38 campaigns, as a demonstration PS4 was kept operational and monitored for over ten orbits after delivering spacecraft PSLV-C44 was the first campaign where PS4 functioned as independent orbital platform for short duration as there was no on-board power generation capacity  It carried KalamSAT-V2 as a fixed payload, a 1U cubesat by Space Kidz India based on Interorbital Systems kit On PSLV-C45 campaign, the fourth stage had its own power generation capability as it was augmented with an array of fixed solar cells around PS4 propellant tank  Three payloads hosted on PS4-OP were, Advanced Retarding Potential Analyzer for Ionospheric Studies (ARIS 101F) by IIST, experimental AIS payload by ISRO and AISAT by Satellize  To function as orbital platform, fourth stage was put in spin-stabilized mode using its RCS thrusters On PSLV-C53 campaign the PS4-OP was referred as PSLV Orbital Experimental Module (POEM) and it hosted six payloads  POEM was first PSLV fourth stage based orbital platform to be actively stabilised using Helium based cold gas thrusters after the primary mission and stage passivization 

Payload fairing
Payload fairing of PSLV, also referred as its "Heatshield" consists of a conical upper section with spherical nose-cap, a cylindrical middle section and a lower boat-tail section  Weighing 1,182 kilograms (2,606 lb), it has 3 2 meter diameter and 8 3 meter height  It has Isogrid construction and is made out of 7075 aluminum alloy with a 3 mm thick steel nose-cap  The two halves of fairing are separated using a pyrotechnic device based jettisoning system consisting horizontal and lateral separation mechanisms  To protect spacecraft from damage due to excessive acoustic loads during launch, the heatshield interior is lined with acoustic blankets 

Variants
ISRO has envisaged a number of variants of PSLV to cater to different mission requirements  There are currently two operational versions of the PSLV — the core-alone (PSLV-CA) without strap-on motors, and the (PSLV-XL) version, with six extended length (XL) strap-on motors carrying 12 tonnes of HTPB based propellant each  These configurations provide wide variations in payload capabilities up to 3,800 kg (8,400 lb) in LEO and 1,800 kg (4,000 lb) in sun-synchronous orbit 

PSLV-G
The standard or "Generic" version of the PSLV, PSLV-G had four stages using solid and liquid propulsion systems alternately and six strap-on motors (PSOM or S9) with 9 tonne propellant loading  It had capability to launch 1,678 kg (3,699 lb) to 622 km (386 mi) into sun-synchronous orbit  PSLV-C35 was the last operational launch of PSLV-G before its discontinuation 

PSLV-CA
The PSLV-CA, CA meaning "Core Alone", model premiered on 23 April 2007  The CA model does not include the six strap-on boosters used by the PSLV standard variant but two SITVC tanks with Roll Control Thruster modules are still attached to the side of the first stage with addition of two cylindrical aerodynamic stabilizers  The fourth stage of the CA variant has 400 kg (880 lb) less propellant when compared to its standard version  It currently has capability to launch 1,100 kg (2,400 lb) to 622 km (386 mi) Sun-synchronous orbit 

PSLV-XL
PSLV-XL is the upgraded version of Polar Satellite Launch Vehicle in its standard configuration boosted by more powerful, stretched strap-on boosters with 12 tonne propellant load  Weighing 320 t (310 long tons; 350 short tons) at lift-off, the vehicle uses larger strap-on motors (PSOM-XL or S12) to achieve higher payload capability  On 29 December 2005, ISRO successfully tested the improved version of strap-on booster for the PSLV  The first use of PSLV-XL was the launch of Chandrayaan-1 by PSLV-C11  The payload capability for this variant is 1,800 kg (4,000 lb) to Sun-synchronous orbit 

PSLV-DL
PSLV-DL variant has only two strap-on boosters with 12 tonne propellant load on them  PSLV-C44 on 24 January 2019 was the first flight to use PSLV-DL variant of Polar Satellite Launch Vehicle  It is capable of launching 1,257 kg (2,771 lb) to 600 km (370 mi) Sun-synchronous orbit 

PSLV-QL
PSLV-QL variant has four ground-lit strap-on boosters, each with 12 tonnes of propellant  PSLV-C45 on 1 April 2019 was the first flight of PSLV-QL  It has the capacity to launch 1,523 kg (3,358 lb) to 600 km (370 mi) Sun-synchronous orbit 

PSLV-3S (concept)
PSLV-3S was conceived as a three-staged version of PSLV with its six strap-on boosters and second liquid stage removed  The total lift-off mass of PSLV-3S was expected to be 175 tonnes with capacity to place 500 kg in 550 km low Earth orbit 

Launch Profile
PSLV - XL:

The PS1 ignites at T+0 providing 4846  kN of thrust 
Within T+1, 4 out of the 6 boosters ignite on ground, each producing 703 kN of thrust  7658 kN of total thrust is produced by the combined propulsion of the PSOMs and the PS1 
At around T+23/26, the remaining 2 unlit boosters are air-lit bringing the rocket at its maximum thrust capacity 
At T+1:10, the first 4 ground-lit PSOMs have depleted its propellant and now separates and falls down to the  ocean  The remaining 2 PSOMs and the PS1 continue to burn 
At T+1:35, the remaining 2 PSOMs complete its 70 seconds burn and separate, leaving the rocket in a Core- Alone configuration 
At T+1:50, the PS1 has completed its 110-second burn and it separates and the Vikas Engine inside the PS2 ignites 
The second stage burns for around 130 seconds and around T+4 minutes, the second stages shuts off and separates 
The third stage, which is a solid rocket booster, and burns 80 seconds and then coasts for the remainder of time and around T+8/10 minutes, it separates and the 4th stage ignites to give the rocket a final push into the orbit 
This 4th stage burn is highly variable and depends on the mass and number of payloads and usually is around 500 seconds long  The 4th stage may shut off around T+16/18 minutes followed by the Payload Deployment 

Launch statistics
As of May 22, 2023 the PSLV has made 57 launches, with 54 successfully reaching their planned orbits, two outright failures and one partial failure, yielding a success rate of 94% (or 95% including the partial failure)  All launches have occurred from the Satish Dhawan Space Centre, known before 2002 as the Sriharikota Range (SHAR) 

Launch system status

Decade-wise summary of PSLV launches:

See also
GSLV Mark II
LVM 3
Comparison of orbital launchers families
Medium-lift launch vehicle, 2,000 to 20,000 kg to LEO
Comparison of orbital rocket engines
Comparison of orbital launch systems
Passage 2:
USA-214
USA-214, also known as Advanced Extremely High Frequency-1 or AEHF-1, is a military communications satellite operated by the United States Air Force  It is the first of six satellites to be launched as part of the Advanced Extremely High Frequency program, which will replace the earlier Milstar system 

Satellite description
The USA-214 satellite was constructed by Lockheed Martin Space, and is based on the A2100 satellite bus  The satellite has a mass of 6,168 kg (13,598 lb) and a design life of 14 years  It will be used to provide super high frequency (SHF) and extremely high frequency (EHF) communications for the United States Armed Forces, as well as those of the United Kingdom, the Netherlands, and Canada 

Launch
Though initially scheduled for launch on 30 July 2010, delays with the launch vehicle pushed flight back to 10 August 2010, and finally to 14 August 2010 USA-214 was launched by United Launch Alliance, aboard an Atlas V 531 flying from Space Launch Complex-41 (SLC-41) at the Cape Canaveral Air Force Station (CCAFS)  The launch occurred at 11:07:00 UTC on 14 August 2010, and resulted in the satellite being deployed successfully into a geostationary transfer orbit (GTO) with a perigee of 221 km (137 mi), an apogee of 50,179 km (31,180 mi), and 22 2° Orbital inclination 

Anomaly
The satellite was intended to maneuver from the transfer orbit into which it was launched to its operational geosynchronous orbit by means of a liquid apogee engine (LAE) and several 
Hall-effect thrusters, a process which normally takes 105 days  However, the satellite's Liquid Apogee Engine malfunctioned shortly after ignition on both its first burn on 15 August 2010 and a second attempt on 17 August 2010, and it was declared inoperable To solve the problem, the perigee altitude was raised to 4,700 km (2,900 mi) using twelve firings of the smaller Reaction Engine Assembly thrusters, originally intended for attitude control during LAE maneuvers  From this altitude, the solar arrays were deployed and the orbit was raised toward the operational orbit over the course of nine months using the 0 27 Newton Hall effect thruster, a form of electric propulsion which is highly efficient, but produces very low thrust and is therefore very slow 
The problem with the liquid apogee engine was later blamed on a piece of cloth accidentally left in a fuel line leading up to the engine while the line was taken apart for repair during the manufacture of the satellite  The cloth was likely placed in the line to prevent impurities from entering the fuel line and did not get removed when the line was put back together 

See also
2010 in spaceflight
Passage 3:
Communications satellite
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth  Communications satellites are used for television, telephone, radio, internet, and military applications   Many communications satellites are in geostationary orbit 22,300 miles (35,900 km) above the equator, so that the satellite appears stationary at the same point in the sky; therefore the satellite dish antennas of ground stations can be aimed permanently at that spot and do not have to move to track the satellite  Others form satellite constellations in low Earth orbit, where antennas on the ground have to follow the position of the satellites and switch between satellites frequently 
The high frequency radio waves used for telecommunications links travel by line of sight and so are obstructed by the curve of the Earth   The purpose of communications satellites is to relay the signal around the curve of the Earth allowing communication between widely separated geographical points   Communications satellites use a wide range of radio and microwave frequencies  To avoid signal interference, international organizations have regulations for which frequency ranges or "bands" certain organizations are allowed to use  This allocation of bands minimizes the risk of signal interference 

History
Origins
In October 1945, Arthur C  Clarke published an article titled "Extraterrestrial Relays" in the British magazine Wireless World  The article described the fundamentals behind the deployment of artificial satellites in geostationary orbits to relay radio signals  Because of this, Arthur C  Clarke is often quoted as being the inventor of the concept of the communications satellite, and the term 'Clarke Belt' is employed as a description of the orbit 

The first artificial Earth satellite was Sputnik 1 which was put into orbit by the Soviet Union on 4 October 1957  It was developed by Mikhail Tikhonravov and Sergey Korolev, building on work by Konstantin Tsiolkovsky  Sputnik 1 was equipped with an on-board radio transmitter that worked on two frequencies of 20 005 and 40 002 MHz, or 7 and 15 meters wavelength  The satellite was not placed in orbit to send data from one point on Earth to another; the radio transmitter was meant to study the properties of radio wave distribution throughout the ionosphere   The launch of Sputnik 1 was a major step in the exploration of space and rocket development, and marks the beginning of the Space Age 

Early active and passive satellite experiments
There are two major classes of communications satellites, passive and active  Passive satellites only reflect the signal coming from the source, toward the direction of the receiver  With passive satellites, the reflected signal is not amplified at the satellite, and only a very small amount of the transmitted energy actually reaches the receiver   Since the satellite is so far above Earth, the radio signal is attenuated due to free-space path loss, so the signal received on Earth is very, very weak  Active satellites, on the other hand, amplify the received signal before retransmitting it to the receiver on the ground  Passive satellites were the first communications satellites, but are little used now 
Work that was begun in the field of electrical intelligence gathering at the United States Naval Research Laboratory in 1951 led to a project named Communication Moon Relay  Military planners had long shown considerable interest in secure and reliable communications lines as a tactical necessity, and the ultimate goal of this project was the creation of the longest communications circuit in human history, with the moon, Earth's natural satellite, acting as a passive relay  After achieving the first transoceanic communication between Washington, D C , and Hawaii on 23 January 1956, this system was publicly inaugurated and put into formal production in January 1960 

The first satellite purpose-built to actively relay communications was Project SCORE,  led by Advanced Research Projects Agency (ARPA) and launched on 18 December 1958, which used a tape recorder to carry a stored voice message, as well as to receive, store, and retransmit messages  It was used to send a Christmas greeting to the world from U S  President Dwight D  Eisenhower  The satellite also executed several realtime transmissions before the non-rechargeable batteries failed on 30 December 1958 after eight hours of actual operation The direct successor to SCORE was another ARPA-led project called Courier  Courier 1B was launched on 4 October 1960 to explore whether it would be possible to establish a global military communications network by using "delayed repeater" satellites, which receive and store information until commanded to rebroadcast them  After 17 days, a command system failure ended communications from the satellite NASA's satellite applications program launched the first artificial satellite used for passive relay communications in Echo 1 on 12 August 1960  Echo 1 was an aluminized balloon satellite acting as a passive reflector of microwave signals  Communication signals were bounced off the satellite from one point on Earth to another  This experiment sought to establish the feasibility of worldwide broadcasts of telephone, radio, and television signals 

More firsts and further experiments
Telstar was the first active, direct relay communications commercial satellite and marked the first transatlantic transmission of television signals  Belonging to AT&T as part of a multi-national agreement between AT&T, Bell Telephone Laboratories, NASA, the British General Post Office, and the French National PTT (Post Office) to develop satellite communications, it was launched by NASA from Cape Canaveral on 10 July 1962, in the first privately sponsored space launch Another passive relay experiment primarily intended for military communications purposes was Project West Ford, which was led by Massachusetts Institute of Technology's Lincoln Laboratory  After an initial failure in 1961, a launch on 9 May 1963 dispersed 350 million copper needle dipoles to create a passive reflecting belt  Even though only about half of the dipoles properly separated from each other, the project was able to successfully experiment and communicate using frequencies in the SHF X band spectrum An immediate antecedent of the geostationary satellites was the Hughes Aircraft Company's Syncom 2, launched on 26 July 1963  Syncom 2 was the first communications satellite in a geosynchronous orbit  It revolved around the earth once per day at constant speed, but because it still had north–south motion, special equipment was needed to track it  Its successor, Syncom 3, launched on 19 July 1964, was the first geostationary communications satellite  Syncom 3 obtained a geosynchronous orbit, without a north–south motion, making it appear from the ground as a stationary object in the sky A direct extension of the passive experiments of Project West Ford was the Lincoln Experimental Satellite program, also conducted by the Lincoln Laboratory on behalf of the United States Department of Defense  The LES-1 active communications satellite was launched on 11 February 1965 to explore the feasibility of active solid-state X band long-range military communications  A total of nine satellites were launched between 1965 and 1976 as part of this series 

International commercial satellite projects
In the United States, 1962 saw the creation of the Communications Satellite Corporation (COMSAT) private corporation, which was subject to instruction by the US Government on matters of national policy  Over the next two years, international negotiations led to the Intelsat Agreements, which in turn led to the launch of Intelsat 1, also known as Early Bird, on 6 April 1965, and which was the first commercial communications satellite to be placed in geosynchronous orbit  Subsequent Intelsat launches in the 1960s provided multi-destination service and video, audio, and data service to ships at sea (Intelsat 2 in 1966–67), and the completion of a fully global network with Intelsat 3 in 1969–70  By the 1980s, with significant expansions in commercial satellite capacity, Intelsat was on its way to become part of the competitive private telecommunications industry, and had started to get competition from the likes of PanAmSat in the United States, which, ironically, was then bought by its archrival in 2005 When Intelsat was launched, the United States was the only launch source outside of the Soviet Union, who did not participate in the Intelsat agreements  The Soviet Union launched its first communications satellite on 23 April 1965 as part of the Molniya program  This program was also unique at the time for its use of what then became known as the Molniya orbit, which describes a highly elliptical orbit, with two high apogees daily over the northern hemisphere  This orbit provides a long dwell time over Russian territory as well as over Canada at higher latitudes than geostationary orbits over the equator 

Satellite orbits
Communications satellites usually have one of three primary types of orbit, while other orbital classifications are used to further specify orbital details  MEO and LEO are non-geostationary orbit (NGSO) 

Geostationary satellites have a geostationary orbit (GEO), which is 22,236 miles (35,785 km) from Earth's surface  This orbit has the special characteristic that the apparent position of the satellite in the sky when viewed by a ground observer does not change, the satellite appears to "stand still" in the sky   This is because the satellite's orbital period is the same as the rotation rate of the Earth   The advantage of this orbit is that ground antennas do not have to track the satellite across the sky, they can be fixed to point at the location in the sky the satellite appears 
Medium Earth orbit (MEO) satellites are closer to Earth  Orbital altitudes range from 2,000 to 36,000 kilometres (1,200 to 22,400 mi) above Earth 
The region below medium orbits is referred to as low Earth orbit (LEO), and is about 160 to 2,000 kilometres (99 to 1,243 mi) above Earth As satellites in MEO and LEO orbit the Earth faster, they do not remain visible in the sky to a fixed point on Earth continually like a geostationary satellite, but appear to a ground observer to cross the sky and "set" when they go behind the Earth beyond the visible horizon  Therefore, to provide continuous communications capability with these lower orbits requires a larger number of satellites, so that one of these satellites will always be visible in the sky for transmission of communication signals   However, due to their closer distance to the Earth, LEO or MEO satellites can communicate to ground with reduced latency and at lower power than would be required from a geosynchronous orbit 

Low Earth orbit (LEO)
A low Earth orbit (LEO) typically is a circular orbit about 160 to 2,000 kilometres (99 to 1,243 mi) above the earth's surface and, correspondingly, a period (time to revolve around the earth) of about 90 minutes Because of their low altitude, these satellites are only visible from within a radius of roughly 1,000 kilometres (620 mi) from the sub-satellite point  In addition, satellites in low earth orbit change their position relative to the ground position quickly  So even for local applications, many satellites are needed if the mission requires uninterrupted connectivity 
Low-Earth-orbiting satellites are less expensive to launch into orbit than geostationary satellites and, due to proximity to the ground, do not require as high signal strength (signal strength falls off as the square of the distance from the source, so the effect is considerable)  Thus there is a trade off between the number of satellites and their cost 
In addition, there are important differences in the onboard and ground equipment needed to support the two types of missions 

Satellite constellation
A group of satellites working in concert is known as a satellite constellation  Two such constellations, intended to provide satellite phone and low-speed data services, primarily to remote areas, are the Iridium and Globalstar systems  The Iridium system has 66 satellites, which orbital inclination of 86 4° and inter-satellite links provide service availability over the entire surface of Earth  Starlink is a satellite internet constellation operated by SpaceX, that aims for global satellite Internet access coverage 
It is also possible to offer discontinuous coverage using a low-Earth-orbit satellite capable of storing data received while passing over one part of Earth and transmitting it later while passing over another part   This will be the case with the CASCADE system of Canada's CASSIOPE communications satellite  Another system using this store and forward method is Orbcomm 

Medium Earth orbit (MEO)
A medium Earth orbit is a satellite in orbit somewhere between 2,000 and 35,786 kilometres (1,243 and 22,236 mi) above the earth's surface   MEO satellites are similar to LEO satellites in functionality  MEO satellites are visible for much longer periods of time than LEO satellites, usually between 2 and 8 hours  MEO satellites have a larger coverage area than LEO satellites  A MEO satellite's longer duration of visibility and wider footprint means fewer satellites are needed in a MEO network than a LEO network  One disadvantage is that a MEO satellite's distance gives it a longer time delay and weaker signal than a LEO satellite, although these limitations are not as severe as those of a GEO satellite 
Like LEOs, these satellites do not maintain a stationary distance from the earth   This is in contrast to the geostationary orbit, where satellites are always 35,786 kilometres (22,236 mi) from the earth 
Typically the orbit of a medium earth orbit satellite is about 16,000 kilometres (10,000 mi) above earth  In various patterns, these satellites make the trip around earth in anywhere from 2 to 8 hours 

Examples of MEO
In 1962, the communications satellite, Telstar, was launched  It was a medium earth orbit satellite designed to help facilitate high-speed telephone signals  Although it was the first practical way to transmit signals over the horizon, its major drawback was soon realised  Because its orbital period of about 2 5 hours did not match the Earth's rotational period of 24 hours, continuous coverage was impossible  It was apparent that multiple MEOs needed to be used in order to provide continuous coverage 
In 2013, the first four of a constellation of 20 MEO satellites was launched  The O3b satellites provide broadband internet services, in particular to remote locations and maritime and in-flight use, and orbit at an altitude of 8,063 kilometres (5,010 mi)) 

Geostationary orbit (GEO)
To an observer on Earth, a satellite in a geostationary orbit appears motionless, in a fixed position in the sky   This is because it revolves around the Earth at Earth's own angular velocity (one revolution per sidereal day, in an equatorial orbit) 
A geostationary orbit is useful for communications because ground antennas can be aimed at the satellite without their having to track the satellite's motion  This is relatively inexpensive 
In applications that require many ground antennas, such as DirecTV distribution, the savings in ground equipment can more than outweigh the cost and complexity of placing a satellite into orbit 

Examples of GEO
The first geostationary satellite was Syncom 3, launched on 19 August 1964, and used for communication across the Pacific starting with television coverage of the 1964 Summer Olympics  Shortly after Syncom 3, Intelsat I, aka Early Bird, was launched on 6 April 1965 and placed in orbit at 28° west longitude  It was the first geostationary satellite for telecommunications over the Atlantic Ocean 
On 9 November 1972, Canada's first geostationary satellite serving the continent, Anik A1, was launched by Telesat Canada, with the United States following suit with the launch of Westar 1 by Western Union on 13 April 1974 
On 30 May 1974, the first geostationary communications satellite in the world to be three-axis stabilized was launched: the experimental satellite ATS-6 built for NASA 
After the launches of the Telstar through Westar 1 satellites, RCA Americom (later GE Americom, now SES) launched Satcom 1 in 1975   It was Satcom 1 that was instrumental in helping early cable TV channels such as WTBS (now TBS), HBO, CBN (now Freeform) and The Weather Channel become successful, because these channels distributed their programming to all of the local cable TV headends using the satellite   Additionally, it was the first satellite used by broadcast television networks in the United States, like ABC, NBC, and CBS, to distribute programming to their local affiliate stations   Satcom 1 was widely used because it had twice the communications capacity of the competing Westar 1 in America (24 transponders as opposed to the 12 of Westar 1), resulting in lower transponder-usage costs  Satellites in later decades tended to have even higher transponder numbers By 2000, Hughes Space and Communications (now Boeing Satellite Development Center) had built nearly 40 percent of the more than one hundred satellites in service worldwide  Other major satellite manufacturers include Space Systems/Loral, Orbital Sciences Corporation with the Star Bus series, Indian Space Research Organisation, Lockheed Martin (owns the former RCA Astro Electronics/GE Astro Space business), Northrop Grumman, Alcatel Space, now Thales Alenia Space, with the Spacebus series, and Astrium 

Molniya orbit
Geostationary satellites must operate above the equator and therefore appear lower on the horizon as the receiver gets farther from the equator  This will cause problems for extreme northerly latitudes, affecting connectivity and causing multipath interference (caused by signals reflecting off the ground and into the ground antenna) 
Thus, for areas close to the North (and South) Pole, a geostationary satellite may appear below the horizon  Therefore, Molniya orbit satellites have been launched, mainly in Russia, to alleviate this problem 
Molniya orbits can be an appealing alternative in such cases  The Molniya orbit is highly inclined, guaranteeing good elevation over selected positions during the northern portion of the orbit  (Elevation is the extent of the satellite's position above the horizon  Thus, a satellite at the horizon has zero elevation and a satellite directly overhead has elevation of 90 degrees )
The Molniya orbit is designed so that the satellite spends the great majority of its time over the far northern latitudes, during which its ground footprint moves only slightly  Its period is one half day, so that the satellite is available for operation over the targeted region for six to nine hours every second revolution  In this way a constellation of three Molniya satellites (plus in-orbit spares) can provide uninterrupted coverage 
The first satellite of the Molniya series was launched on 23 April 1965 and was used for experimental transmission of TV signals from a Moscow uplink station to downlink stations located in Siberia and the Russian Far East, in Norilsk, Khabarovsk, Magadan and Vladivostok  In November 1967 Soviet engineers created a unique system of national TV network of satellite television, called Orbita, that was based on Molniya satellites 

Polar orbit
In the United States, the National Polar-orbiting Operational Environmental Satellite System (NPOESS) was established in 1994 to consolidate the polar satellite operations of
NASA (National Aeronautics and Space Administration)
NOAA (National Oceanic and Atmospheric Administration)  NPOESS manages a number of satellites for various purposes; for example, METSAT for meteorological satellite, EUMETSAT for the European branch of the program, and METOP for meteorological operations 
These orbits are sun synchronous, meaning that they cross the equator at the same local time each day  For example, the satellites in the NPOESS (civilian) orbit will cross the equator, going from south to north, at times 1:30 P M , 5:30 P M , and 9:30 P M 

Beyond geostationary orbit
There are plans and initiatives to bring dedicated communications satellite beyond geostationary orbits 
NASA proposed LunaNet as a data network aiming to provide a „Lunar Internet for cis-lunar spacecraft and Installations 
The Moonlight Initiative is an equivalent ESA project that is stated to be compatible and providing navigational services for the lunar surface  Both programmes are satellite constellstions of several satellites in various orbits around the Moon 
Other orbits are also planned to be used  Positions in the Earth-Moon-Libration points are also proposed for communication satellites covering the Moon alike communication satellites in geosynchronous orbit cover the Earth  Also, dedicated communication satellites in orbits around Mars supporting different missions on surface and other orbits are considered, such as the Mars Telecommunications Orbiter 

Structure
Communications Satellites are usually composed of the following subsystems:

Communication Payload, normally composed of transponders, antennas, and switching systems
Engines used to bring the satellite to its desired orbit
A station keeping tracking and stabilization subsystem used to keep the satellite in the right orbit, with its antennas pointed in the right direction, and its power system pointed towards the sun
Power subsystem, used to power the Satellite systems, normally composed of solar cells, and batteries that maintain power during solar eclipse
Command and Control subsystem, which maintains communications with ground control stations  The ground control Earth stations monitor the satellite performance and control its functionality during various phases of its life-cycle The bandwidth available from a satellite depends upon the number of transponders provided by the satellite  Each service (TV, Voice, Internet, radio) requires a different amount of bandwidth for transmission  This is typically known as link budgeting and a network simulator can be used to arrive at the exact value 

Frequency allocation for satellite systems
Allocating frequencies to satellite services is a complicated process which requires international coordination and planning  This is carried out under the auspices of the International Telecommunication Union (ITU) 
To facilitate frequency planning, the world is divided into three regions:

Region 1: Europe, Africa, the Middle East, what was formerly the Soviet Union, and Mongolia
Region 2: North and South America and Greenland
Region 3: Asia (excluding region 1 areas), Australia, and the southwest PacificWithin these regions, frequency bands are allocated to various satellite services, although a given service may be allocated different frequency bands in different regions  Some of the services provided by satellites are:

Fixed satellite service (FSS)
Broadcasting satellite service (BSS)
Mobile-satellite service
Radionavigation-satellite service
Meteorological-satellite service

Applications
Telephony
The first and historically most important application for communication satellites was in intercontinental long distance telephony  The fixed Public Switched Telephone Network relays telephone calls from land line telephones to an earth station, where they are then transmitted to a geostationary satellite   The downlink follows an analogous path   Improvements in submarine communications cables through the use of fiber-optics caused some decline in the use of satellites for fixed telephony in the late 20th century 
Satellite communications are still used in many applications today  Remote islands such as Ascension Island, Saint Helena, Diego Garcia, and Easter Island, where no submarine cables are in service, need satellite telephones  There are also regions of some continents and countries where landline telecommunications are rare to non existent, for example large regions of South America, Africa, Canada, China, Russia, and Australia  Satellite communications also provide connection to the edges of Antarctica and Greenland  Other land use for satellite phones are rigs at sea, a backup for hospitals, military, and recreation  Ships at sea, as well as planes, often use satellite phones Satellite phone systems can be accomplished by a number of means  On a large scale, often there will be a local telephone system in an isolated area with a link to the telephone system in a main land area  There are also services that will patch a radio signal to a telephone system  In this example, almost any type of satellite can be used  Satellite phones connect directly to a constellation of either geostationary or low-Earth-orbit satellites  Calls are then forwarded to a satellite teleport connected to the Public Switched Telephone Network  

Television
As television became the main market, its demand for simultaneous delivery of relatively few signals of large bandwidth to many receivers being a more precise match for the capabilities of geosynchronous comsats   Two satellite types are used for North American television and radio: Direct broadcast satellite (DBS), and Fixed Service Satellite (FSS) 
The definitions of FSS and DBS satellites outside of North America, especially in Europe, are a bit more ambiguous  Most satellites used for direct-to-home television in Europe have the same high power output as DBS-class satellites in North America, but use the same linear polarization as FSS-class satellites  Examples of these are the Astra, Eutelsat, and Hotbird spacecraft in orbit over the European continent  Because of this, the terms FSS and DBS are more so used throughout the North American continent, and are uncommon in Europe 
Fixed Service Satellites use the C band, and the lower portions of the Ku band  They are normally used for broadcast feeds to and from television networks and local affiliate stations (such as program feeds for network and syndicated programming, live shots, and backhauls), as well as being used for distance learning by schools and universities, business television (BTV), Videoconferencing, and general commercial telecommunications  FSS satellites are also used to distribute national cable channels to cable television headends 
Free-to-air satellite TV channels are also usually distributed on FSS satellites in the Ku band  The Intelsat Americas 5, Galaxy 10R and AMC 3 satellites over North America provide a quite large amount of FTA channels on their Ku band transponders 
The American Dish Network DBS service has also recently used FSS technology as well for their programming packages requiring their SuperDish antenna, due to Dish Network needing more capacity to carry local television stations per the FCC's "must-carry" regulations, and for more bandwidth to carry HDTV channels 
A direct broadcast satellite is a communications satellite that transmits to small DBS satellite dishes (usually 18 to 24 inches or 45 to 60 cm in diameter)  Direct broadcast satellites generally operate in the upper portion of the microwave Ku band  DBS technology is used for DTH-oriented (Direct-To-Home) satellite TV services, such as DirecTV, DISH Network and Orby TV in the United States, Bell Satellite TV and Shaw Direct in Canada, Freesat and Sky in the UK, Ireland, and New Zealand and DSTV in South Africa 
Operating at lower frequency and lower power than DBS, FSS satellites require a much larger dish for reception (3 to 8 feet (1 to 2 5 m) in diameter for Ku band, and 12 feet (3 6 m) or larger for C band)   They use linear polarization for each of the transponders' RF input and output (as opposed to circular polarization used by DBS satellites), but this is a minor technical difference that users do not notice  FSS satellite technology was also originally used for DTH satellite TV from the late 1970s to the early 1990s in the United States in the form of TVRO (Television Receive Only) receivers and dishes  It was also used in its Ku band form for the now-defunct Primestar satellite TV service 
Some satellites have been launched that have transponders in the Ka band, such as DirecTV's SPACEWAY-1 satellite, and Anik F2  NASA and ISRO have also launched experimental satellites carrying Ka band beacons recently Some manufacturers have also introduced special antennas for mobile reception of DBS television  Using Global Positioning System (GPS) technology as a reference, these antennas automatically re-aim to the satellite no matter where or how the vehicle (on which the antenna is mounted) is situated   These mobile satellite antennas are popular with some recreational vehicle owners   Such mobile DBS antennas are also used by JetBlue Airways for DirecTV (supplied by LiveTV, a subsidiary of JetBlue), which passengers can view on-board on LCD screens mounted in the seats 

Radio broadcasting
Satellite radio offers audio broadcast services in some countries, notably the United States  Mobile services allow listeners to roam a continent, listening to the same audio programming anywhere 
A satellite radio or subscription radio (SR) is a digital radio signal that is broadcast by a communications satellite, which covers a much wider geographical range than terrestrial radio signals 

Amateur radio
Amateur radio operators have access to amateur satellites, which have been designed specifically to carry amateur radio traffic  Most such satellites operate as spaceborne repeaters, and are generally accessed by amateurs equipped with UHF or VHF radio equipment and highly directional antennas such as Yagis or dish antennas  Due to launch costs, most current amateur satellites are launched into fairly low Earth orbits, and are designed to deal with only a limited number of brief contacts at any given time  Some satellites also provide data-forwarding services using the X 25 or similar protocols 

Internet access
After the 1990s, satellite communication technology has been used as a means to connect to the Internet via broadband data connections  This can be very useful for users who are located in remote areas, and cannot access a broadband connection, or require high availability of services 

Military
Communications satellites are used for military communications applications, such as Global Command and Control Systems  Examples of military systems that use communication satellites are the MILSTAR, the DSCS, and the FLTSATCOM of the United States, NATO satellites, United Kingdom satellites (for instance Skynet), and satellites of the former Soviet Union  India has launched its first Military Communication satellite GSAT-7, its transponders operate in UHF, F, C and Ku band bands  Typically military satellites operate in the UHF, SHF (also known as X-band) or EHF (also known as Ka band) frequency bands 

Data collection
Near-ground in situ environmental monitoring equipment (such as weather stations, weather buoys, and radiosondes), may use satellites for one-way data transmission or two-way telemetry and telecontrol  It may be based on a secondary payload of a weather satellite (as in the case of GOES and METEOSAT and others in the Argos system) or in dedicated satellites (such as SCD)  The data rate is typically much lower than in satellite Internet access 

See also
Passage 4:
ATS-6
ATS-6 (Applications Technology Satellite-6)  was a NASA experimental satellite, built by Fairchild Space and Electronics Division It has been called the world's first educational satellite as well as world's first experimental Direct Broadcast Satellite as part of the Satellite Instructional Television Experiment between NASA and Indian Space Research Organisation (ISRO)  It was launched May 30, 1974, and decommissioned July 1979  At the time of launch, it was the most powerful telecommunication satellite in orbit  ATS-6 carried no fewer than 23 different experiments, and introduced several breakthroughs  It was the first 3-axis stabilized spacecraft in geostationary orbit  It was also the first to use experimentally with some success electric propulsion in geostationary orbit  It also carried several particle physics experiments, including the first heavy ion detector in geostationary orbit 
During its five-year life, ATS-6 transmitted connection programming to various countries, including India, the United States and other regions  The vehicle also conducted air traffic control tests, was used to practice satellite-assisted search and rescue techniques, carried an experimental radiometer subsequently carried as a standard instrument aboard weather satellites, and pioneered direct broadcast TV 
ATS-6 was a precursor to many technologies still in use today on geostationary spacecraft: large deployable antenna, 3-axis attitude control with slewing capabilities, antenna pointing through RF sensing, electric propulsion, meteorological radiometer in geostationary orbit, and direct to home broadcasting  It is also possible that ATS-6 was a forerunner of the large ELINT satellites such as Mentor 

Launch
ATS-6 was launched on May 30, 1974, by a Titan III-C launch vehicle  The spacecraft was inserted directly in the geosynchronous orbit  This reduced the on-board fuel requirements to less than 40 kilograms (88 lb) (for a total mass at launch of nearly 1,400 kilograms (3,100 lb))  The highly accurate orbit insertion further lowered the amount of fuel required for final positioning to 9 kilograms (20 lb)  This enabled a life extension from the original 2 year to 5 years, even accounting for the premature failure of the electric propulsion subsystem (the station-keeping fuel requirement being around 1 6 kilograms per year (3 5 lb/a)) 

Structure, power subsystem and antenna
One of the major innovations of ATS-6 was an in-flight deployable antenna of more than 9 metres (30 ft) in diameter  The antenna reflector was furled during launch under the launch vehicle fairing, and was deployed in orbit much like an umbrella  The antenna reflector was built from 48 aluminum ribs, supporting a metallized Dacron mesh  The antenna feeds (in C, S, L, UHF and VHF bands) were placed on the spacecraft body, facing the antenna reflector, and linked to the antenna and the solar panels masts by a carbon-fiber reinforced plastic (CFRP) truss  The solar panels were rigidly mounted on two deployable masts  They were of hemi-cylinder shape, thus providing a relatively constant power (595 W beginning of life)  Electric power was supplied during eclipses by two Nickel cadmium batteries of 15-A·h capacity, powering a regulated 30 5-V bus  The satellite dimensions in orbit were 15 8-metre (52 ft) width by 8 2-metre (27 ft) height 
This deployable antenna parabola was designed and developed by Lockheed Missiles and Space Company (LMSC), now Lockheed Martin, under subcontract to Fairchild Aerospace, after several years of small study contracts at LMSC   The program manager at LMSC was GKC (Colin) Campbell   The deployment of the reflector was initiated by pyrotechnically operated SQUIB cable cutters   Deployment time was on the order of 2 5 seconds producing 3,400 newton-metres (2,500 lb⋅ft) of torque at the spacecraft interface   The reflector surface was designed for optimal operation at S-Band frequencies  It weighed 83 kilograms (182 lb) at launch and stowed into a toroidal volume (doughnut shaped) approximately 1 8 metres (6 ft) in diameter and 250 millimetres (10 in) thick   Three models were fabricated, the STM or structural test model, the F reflector and the G reflector   The STM was destroyed by Fairchild shortly after the program was finished and the F model was launched with the spacecraft in 1972   The G model sat unprotected in the Farchild parking lot for several years before it was donated to the Smithsonian   Bill Wade, the assistant program manager and test manager on the program supported The Smithsonian in the restoration by providing a complete set of drawings and specifications and visited the Silver Hill facility to provide technical guidance At the time of launch it was the largest parabolic surface launched into orbit 

Three-axis stabilisation
ATS-6 has been the first geostationary satellite with three-axis stabilization and pointing , This subsystem was capable of a highly accurate pointing (better than 0 1° through the inertial measurement units, down to 0 002° by using a radio-frequency interferometer )  Furthermore, the satellite was able to follow low earth orbit satellites through slewing, by tracking the low earth-orbit satellite through an S-band RF sensing  The system was also able to perform orbitography of the tracked satellite, and was a precursor to the operational system TDRSS 
This highly advanced (for the time) pointing subsystem used earth and sun sensors, a star tracker pointed to the pole star, Polaris, and three inertial sensors  The sensor measurements were fed to two digital computers (nominal and redundant), as well to a back-up analog computer  It was also possible to orient the satellite by using radio-frequency sensors   Actuators were three momentum wheels, and hot gas (hydrazine mono-propellant) thrusters  One of the momentum wheels having failed in July 1975, an alternative scheme was developed, allowing station-keeping with the two remaining wheels and thrusters 

Electric propulsion
ATS-6 was equipped with two electric thrusters based on the acceleration of cesium ions, that were to be used for North-South Station Keeping  This subsystem development followed earlier failed attempts on the previous ATS spacecraft  Each of the thrusters had a mass of 16 kilograms (35 lb), used 150 W of electric power, and produced a thrust of 4 newton-metres (3 0 lbf⋅ft), with a specific impulse of 2500s  The on-board supply of cesium would have been sufficient for 4400 hours of thrust  Unfortunately, both thrusters failed prematurely, one after 1 hour of operation, one after 95 hours  However, some of the experiments objectives could be met, such as the measurement of the effective thrust, the absence of any interference with the radio-frequency payloads (from 150 MHz to 6 GHz), no cesium redeposition on the critical parts of the payload (such as the radiometer), and the correct neutralisation of the spacecraft versus its environment 

Payload
Radiometer
A radiometer was on board ATS-6, mounted on the earth-facing panel  This instrument was (for the time) of very high resolution  It operated on two channels: infra-red (10 5 to 12 5 µm) and visible light (0 55 to 0 75 µm)  Images taken with the radiometer covered the whole earth disk, with a resolution of 1,200 lines of 2,400 pixels each (11-kilometre (6 8 mi) square pixel in infra-red, and 5 5-kilometre (3 4 mi) square in visible light)  The IR detector was passively cooled at 115K, and the visible light detector maintained at 300K  A complete image of earth's disk was transmitted to ground every 25 minutes  Several hundreds images were taken and transmitted, until a mechanical component of the radiometer failed, two and a half months after launch 

Telecommunication experiments
The main mission of ATS-6 was to demonstrate the feasibility of direct-to-home (DTH) television broadcasting  To this end, in addition to the high-gain antenna, the spacecraft payload was able to receive in any of the VHF, C, S and L-bands, and to transmit in S-band (2 GHz) through a 20-W solid state transmitter, in L-band (1650 MHz) at 40W, in UHF (860 MHz) at 80W (which was used for the Satellite Instructional Television Experiment (SITE)), and with a TWTA-based transmitter of 20 W in C-band (4 GHz)  The antenna produced two spots on earth of 400,000 square kilometres (150,000 sq mi) each, in which the TV broadcast could be received with 3 metres (9 8 ft) diameter antennas  This payload was first used over the United States for tele-education and tele-medicine experiments, from August 1974 to May 1975 as part of the HET, or Health, Education, Telecommunications experiment developed jointly by NASA and the US Department of Health, Education, & Welfare (now DHHS)  The spacecraft was then moved over the geo-stationary arc from 94 °W to 35 °E, in collaboration with the Indian Space Agency (ISRO), who had deployed in India more than 2500 receive ground stations  The move of the satellite from 94 degrees West to 35 degrees East, a journey of 12,800 kilometres (8,000 mi), was actioned from the ground station at Rosman North Carolina  This relocation involved 2 rocket burns of the onboard rocket motor  The 2nd burn lasting 5 hours 37 minutes and 17 seconds  The longest burn ever done by a chemical rocket in space at that time  A tele-education programme was started – Satellite Instructional Television Experiment or SITE – and run for one year  During the experiment, a receive station was offered by the Indian Government to Arthur C  Clarke, who was living in Sri Lanka  This experiment was highly successful, and encouraged ISRO to start building an operational program, with the Indian spacecraft  INSAT IB (launched 1983)  After the SITE experiment, the satellite was brought back over the United States, and served notably as a data-relay and tracking satellite for low-orbit spacecraft such as Nimbus 6, and for the Apollo-Soyuz flight 

Particle physics experiments
Several particle physics experiments were on board ATS-6  The most significant measured low energy protons (from 25 keV to 3 6 MeV), as well as detected heavy ions (up to 6 MeV)  This latter experiment allowed to detect the first heavy ions (Z > 6) with an energy  E > 4 MeV, in geostationary orbit 

Propagation experiments
Finally, ATS-6 embarked several radio beacons, which allowed to measure electromagnetic propagation properties of the atmosphere at 13, 18, 20 and 30 GHz 

Decommissioning
By June 30, 1979, only one of the four ATS-6 station keeping thrusters was working, and was showing signs of unreliability  This thruster was used to move ATS-6 out of geostationary orbit to an orbit several hundred kilometers higher  This was to vacate the geostationary slot for the next satellite 

See also
1974 in spaceflight
Applications Technology Satellite
Passage 5:
FedSat
FedSat (Australia's 'Federation Satellite'; sometimes FedSat 1; COSPAR 2002-056B, SATCAT 27598) was an Australian scientific research satellite launched from Tanegashima Space Center, Japan by a NASDA H-IIA launch vehicle  on 14 December 2002 (NASDA is now merged with JAXA)  The satellite was developed by the Cooperative Research Centre for Satellite Systems, a cooperative made up of several universities, commercial organisations and government bodies  The ground station was at the Institute for Telecommunications Research, part of the University of South Australia, near Adelaide  Since 2005 it was operated by the Australian Department of Defence 

Payloads
The satellite had six payloads, as given below:

Communications Payload: A collection of three components (UHF transponder, Ka-band transponder and base-band processor) used to perform several experiments in satellite communications 
High Performance Computing Experiment: A reconfigurable computer based on a Xilinx XQR4062 FPGA, the first of its kind to be used in space 
GPS Payload: A Global Positioning System receiver built by NASA  Conceived especially for ionospheric studies between GPS constellation levels and FedSat orbit 
NewMag Payload: A magnetometer built by the University of Newcastle, Australia, used to take measurements of the Earth's magnetic field near its poles 
Star Camera: An experimental star camera built by the University of Stellenbosch, used to determine the position of the satellite in space by analysing images of surrounding stars 
Compact Disk: A nickel "master" disk "cultural time capsule" with tracks including Paul Kelly's performance of the song he co-wrote with Kev Carmody, "From Little Things, Big Things Grow", and recorded statements from several hundred Australian school children about how they imagined a future Australia and its place in the Asia-Pacific The satellite platform, comprising the structural/thermal components, power system, attitude control system, onboard computer and groundlink, was originally developed in the United Kingdom by Space Innovations Limited  It was later completed along with integration of payloads in Canberra, Australia 

Declared Dead
The spacecraft's battery failed in May 2007 and the mission has been terminated, after lasting 18 months longer than expected 
Passage 6:
NOAA-4
NOAA-4, also known as ITOS-G was a weather satellite operated by the National Oceanic and Atmospheric Administration (NOAA)  It was part of a series of satellites called ITOS, or improved TIROS  NOAA-4 was launched on a Delta rocket on November 15, 1974  The launch carried two other satellites: AMSAT-OSCAR 7 and Intasat  It remained operational for 1463 days until it was deactivated by NOAA on November 18, 1978 
Passage 7:
Hans K  Ziegler
Hans K  Ziegler (March 1, 1911, Munich, Germany – December 11, 1999 Colts Neck Township, New Jersey, United States) was a pioneer in the field of communication satellites and the use of photovoltaic solar cells as a power source for satellites 

Life
Hans Ziegler was born in Munich, Germany  There, he studied at the Technische Hochschule, which is today the Technische Universität München (TUM), and began his career as Wissenschaftlicher Assistant (Scientific Assistant)  Following that, he was a researcher in German industry for ten years  During the Second World War, he worked for the company Rosental Selb in Bavaria on high tension porcelain 
In 1947, he came to the US with Wernher von Braun under Operation Paperclip, by means of which the USA gained Nazi engineers and scientists  He went to the US Army Signal Corps' Laboratories in Fort Monmouth, New Jersey, and became a US citizen in 1954 
Ziegler's work in the US was very influential in the development of military electronics, especially in the electronics for the early phases of the US space program  During the thirty years he worked as an engineer in the field of electronics and electrical engineering in the research and development department of the U S  Army in Fort Monmouth, N J  (from 1947 to 1976), he held the top position of Chief Scientist for 12 years  In Fort Monmouth, he worked as a Scientific Consultant, Assistant Director of Research, Director of the Astro-Electronics Division and Chief Scientist (1959)  After the Army was restructured, he became Deputy for Science and Chief Scientist of the US Army Electronics Command in 1963 and Director of the US Army Electronics Technology & Devices Laboratory from 1971 until his retirement 
In May 1954, after examining the solar cells of Daryl Chapin, Calvin Fuller and Gerald Pearson at Bell Laboratories, Ziegler wrote, "Future development [of the silicon solar cell] may well render it into an important source of electrical power [as] the roofs of all our buildings in cities and towns equipped with solar [cells] would be sufficient to produce this country's entire demand for electrical power "Referring to silicon solar cells, he said to the head of the U  S  Signal Corps, General James O'Connell, at a meeting in September 1955, "In fact, in the long run, mankind has no choice but to turn to the sun if it wants to survive "He and his team produced a report on the prospects for application of this technique in the field of communication and they named the supply of energy for artificial satellites as the most important application  He knew that he was not the first to suggest this application  For example, the science fiction author, Arthur C  Clarke had already made this suggestion in 1945, but without having a concrete technology for it at that time 
Ziegler participated in the development of the first planned satellites  The first satellite,
Explorer 1, still went into space without solar cells, since it was a quick, less-than-ideal solution after the start of the Sputnik to show the American public that America's scientists could also start a satellite  The actual scheduled satellite project, Project Vanguard, successfully put a satellite named Vanguard I in orbit around Earth on March 17, 1958 
Over the objections of the Navy, which still thought that solar cells were not a mature technology, this satellite had four solar cells on its outer hull, due to the persistent work of Ziegler, which powered the instruments and performed their duties reliably for more than seven years  After this success, solar cells were established as the energy supply for satellites  He was also involved with the development of the first communication satellite in the world, SCORE, which was started in 1958 
He was awarded the Meritorious Civilian Service Award by the US Department of Defense in 1963 as a " world pioneer in communications satellites and solar energy systems to power satellites"  When he retired in 1977, he was decorated with the highest award of the Army for "exceptional civilian service" 
Ziegler was the author of many technical papers, a member of the IEEE, and represented the US, in military and civilian matters, in many national and international committees  In 1958, he was a member of the US delegation to the International Geophysical Year in Moscow, USSR, and in 1964, he gave advice on the scientific activities in Antarctica and at the South Pole, under the direction of the US National Science Foundation 
Ziegler's wife Friederike died in 1996  He last lived in Colts Neck Township, New Jersey and died at the age of 88 on December 11, 1999  He was survived by his daughters, Christine Griffith and Friederike Meindl, and his son, Hans 

See also
Solar power
Solar panel
Active solar
Photovoltaic components, projects and howtos
Passage 8:
TDRS-6
TDRS-6, known before launch as TDRS-F, is an American communications satellite, of first generation, which is operated by NASA as part of the Tracking and Data Relay Satellite System  It was constructed by TRW, and is based on a custom satellite bus which was used for all seven first generation TDRS satellites 

History
TDRS-F was deployed from Space Shuttle Endeavour during the STS-54 mission in 1993  Endeavour was launched from Launch Complex 39B at the Kennedy Space Center, at 13:59:30 UTC on 13 January 1993  TDRS-F was deployed from Endeavour around six hours after launch, and was raised to geosynchronous orbit by means of an Inertial Upper Stage 

Deployment
The two-stage solid-propellent Inertial Upper Stage made two burns  The first stage burn occurred shortly after deployment from Endeavour, and placed the satellite into a geosynchronous transfer orbit (GTO)  At 02:26 UTC on 14 January 1993, it reached apogee, and the second stage fired, placing TDRS-F into geosynchronous orbit  At this point, it received its operational designation, TDRS-6 

Operation
In 1994, it was placed at a longitude 46 0° West of the Greenwich Meridian, to serve as an on-orbit spare  In 1996, it was moved to 47 0° West, where it remained until 2005, when it was repositioned to 174 0° West, where, as of August 2009, it was used to provide communications with spacecraft in Earth orbit, such as the International Space Station (ISS) and spacecraft bringing astronauts to the ISS 

See also
List of TDRS satellites
Passage 9:
GSAT-7
GSAT-7 or INSAT-4F is a multi-band military communications satellite developed by the Indian Space Research Organisation  The Indian Navy is the user of the multi-band communication spacecraft, which has been operational since September 2013  According to defense experts, the satellite will enable the navy to extend its blue water capabilities and stop relying on foreign satellites like Inmarsat, which provide communication services to its ships 

Satellite
GSAT-7, the multi-band communication satellite named Rukmini carries the payloads in UHF, C band and Ku band  It is the first dedicated military communication satellite (unlike earlier dual use satellites) built by ISRO that will provide services to the Indian Armed Forces with the main user being the Indian Navy  Its procured launch cost has been put at ₹480 crore, with the satellite costing ₹185 crore  Cost of whole project per Memorandum of Understanding with ISRO was ₹950 crores The multiple-band spacecraft will be used exclusively by the Navy to shore up secure, real-time communications among its warships, submarines, aircraft and land systems  GSAT-7/ INSAT-4F is said to significantly improve the country's naval operations around the world  
GSAT 7 satellite carrying payloads operating in UHF, S, C and Ku bands, had a lift-off mass of 2,650 kilograms (5,840 lb) and is based on ISRO's 2,000 kilograms (4,400 lb) class satellite bus I-2K with some new technological elements, including the antennae  After a flight of almost 34 minutes, the satellite was injected into a geosynchronous transfer orbit (GTO) of 249-kilometre (155 mi) perigee, 35,929-kilometre (22,325 mi) apogee and an inclination of 3 5 degree with respect to the equator ISRO launched a second satellite, GSAT-7A for Indian Air Force on 19 December 2018 on its Geosynchronous Satellite Launch Vehicle (GSLV-F11) 

Launch
The satellite was launched early on 30 August 2013 atop an Ariane 5 ECA rocket from Kourou, French Guiana India's first dedicated military satellite was put into a geosynchronous orbit, about 36,000 kilometres (22,000 mi) above Earth, five days after it was launched after three orbit-raising manoeuvres from ISRO's Master Control Facility at Hassan in Karnataka  The 2 5-tonne spacecraft's antennae, including the ultra high frequency Helix antenna were deployed before it was stabilised on its three-axis in the orbit  All of the on-board transponders were switched on successfully on September 18, 2013

Capability
Rukmini will provide networking capabilities to various Indian Naval assets  During Theater-level Readiness and Operational Exercise (Tropex) in the Bay of Bengal in 2014, Rukmini was able to network about 60 ships and 75 aircraft seamlessly  Rukmini has a nearly 2,000 nautical mile 'footprint' over the Indian Ocean Region 

Replacement
The Indian Navy placed an order for GSAT-7R on June 11, 2019  GSAT-7R is expected to eventually replace GSAT-7 

See also
Indian military satellites
GSAT-7A
GSAT
Indian National Satellite System
List of Indian satellites



ground_truth: ATS - 6 (Applications Technology Satellite - 6)

ATS-6