Atlas V
Atlas V is an expendable launch system and the fifth major version in the Atlas launch vehicle family. It was originally designed by Lockheed Martin, now being operated by United Launch Alliance (ULA), a joint venture between Lockheed Martin and Boeing. Atlas V is also a major NASA launch vehicle. In August 2021, ULA announced that Atlas V would be retired, and all 29 remaining launches had been sold. , 24 launches remain. As of 2022, it is the oldest active American rocket. Each Atlas V launch vehicle consists of two main stages. The first stage is powered by  a Russian RD-180 engine manufactured by Energomash and burning kerosene and liquid oxygen. The Centaur upper stage is powered by one or two American RL10 engine(s) manufactured by Aerojet Rocketdyne and burning liquid hydrogen and liquid oxygen. The Star 48 upper stage was used on the "New Horizons" mission as a third stage. AJ-60A strap-on solid rocket boosters (SRBs) are used in some configurations. In November 2020, they were replaced by the Graphite-Epoxy Motor (GEM-63) SRBs. The standard payload fairings are in diameter with various lengths. Vehicle description. The Atlas V was developed by Lockheed Martin Commercial Launch  Services (LMCLS) as part of the U.S. Air Force Evolved Expendable Launch Vehicle (EELV) program and made its inaugural flight on 21 August 2002. The vehicle operates from SLC-41 at Cape Canaveral Space Force Station (CCSFS) and SLC-3E at Vandenberg Space Force Base. LMCLS continued to market the Atlas V to commercial customers worldwide until January 2018, when United Launch Alliance (ULA) assumed control of commercial marketing and sales. Atlas V first stage. The Atlas V first stage, the Common Core Booster (CCB), is in diameter and in length. It is powered by one Energomash RD-180 main engine burning of  liquid oxygen and RP-1. The booster operates for about four minutes, providing about of thrust. Thrust can be augmented with up to five Aerojet AJ-60A or Northrop Grumman GEM-63 strap-on solid rocket boosters, each providing an additional of thrust for 94 seconds. The main differences between the Atlas V and earlier Atlas I and II family launch vehicles are: Centaur upper stage. The Centaur upper stage uses a pressure-stabilized propellant-tank design and cryogenic propellants. The Centaur stage for Atlas V is stretched relative to the Atlas IIAS Centaur and is powered by either one or two Aerojet  Rocketdyne RL10A-4-2 engines, each engine developing a thrust of . The inertial navigation unit (INU) located on the Centaur provides guidance and navigation for both the Atlas and Centaur and controls both Atlas and Centaur tank pressures and propellant use. The Centaur engines are capable of multiple in-space starts, making possible insertion into low Earth parking orbit, followed by a coast period and then insertion into GTO. A subsequent third burn following a multi-hour coast can permit direct injection of payloads into geostationary orbit. , the Centaur vehicle had the highest proportion of burnable propellant relative to total mass  of any modern hydrogen upper stage and hence can deliver substantial payloads to a high-energy state. Star 48 third stage. Star 48 is a type of solid rocket motor used by many space propulsion and launch vehicle stages. It was developed primarily by Thiokol Propulsion, and is now, after several mergers, manufactured by Northrop Grumman's Space Systems division. A Star 48B stage is also one of the few man-made items sent on escape trajectories out of the Solar System, although it is derelict since its use. It has been used once on the Atlas V as a  third stage for the "New Horizons" mission. Payload fairing. Atlas V payload fairings are available in two diameters, depending on satellite requirements. The diameter fairing, originally designed for the Atlas II booster, comes in three different lengths: the original version and extended versions, first flown respectively on the AV-008/Astra 1KR and AV-004/Inmarsat-4 F1 missions. Fairings of up to diameter and length have been considered but were never implemented. A diameter fairing, with an internally usable diameter of , was developed and built by RUAG Space in Switzerland. The RUAG fairing uses carbon fiber composite construction and is based on  a similar flight-proven fairing for the Ariane 5. Three configurations are manufactured to support the Atlas V: , , and long. While the classic fairing covers only the payload, the RUAG fairing is much longer and fully encloses both the Centaur upper stage and the payload. Upgrades. Many systems on the Atlas V have been the subject of upgrade and enhancement both prior to the first Atlas V flight and since that time. Work on a new Fault Tolerant Inertial Navigation Unit (FTINU) started in 2001 to enhance mission reliability for Atlas vehicles by replacing the existing non-redundant navigation and  computing equipment with a fault-tolerant unit. The upgraded FTINU first flew in 2006, and in 2010 a follow-on order for more FTINU units was awarded. In 2015, ULA announced that the Aerojet Rocketdyne-produced AJ-60A solid rocket boosters (SRBs) currently in use on Atlas V will be superseded by new GEM 63 boosters produced by Northrop Grumman Innovation Systems. The extended GEM-63XL boosters will also be used on the Vulcan Centaur launch vehicle that will replace the Atlas V. The first Atlas V launch with GEM 63 boosters happened on 13 November 2020. Human-rating certification. Proposals and  design work to human-rate the Atlas V began as early as 2006, with ULA's parent company Lockheed Martin reporting an agreement with Bigelow Aerospace that was intended to lead to commercial private trips to low Earth orbit (LEO). Human-rating design and simulation work began in earnest in 2010, with the award of US$6.7 million in the first phase of the NASA Commercial Crew Program (CCP) to develop an Emergency Detection System (EDS). As of February 2011, ULA had received an extension to April 2011 from NASA and was finishing up work on the EDS. NASA solicited  proposals for CCP phase 2 in October 2010, and ULA proposed to complete design work on the EDS. At the time, NASA's goal was to get astronauts to orbit by 2015. Then-ULA President and CEO Michael Gass stated that a schedule acceleration to 2014 was possible if funded. Other than the addition of the Emergency Detection System, no major changes were expected to the Atlas V rocket, but ground infrastructure modifications were planned. The most likely candidate for the human-rating was the N02 configuration, with no fairing, no solid rocket boosters, and dual RL10 engines on the  Centaur upper stage. On 18 July 2011, NASA and ULA announced an agreement on the possibility of certifying the Atlas V to NASA's standards for human spaceflight. ULA agreed to provide NASA with data on the Atlas V, while NASA would provide ULA with draft human certification requirements. In 2011, the human-rated Atlas V was also still under consideration to carry spaceflight participants to the proposed Bigelow Commercial Space Station. In 2011, Sierra Nevada Corporation (SNC) picked the Atlas V to be the booster for its still-under-development Dream Chaser crewed spaceplane. The Dream Chaser was intended  to launch on an Atlas V, fly a crew to the ISS, and landing horizontally following a lifting-body reentry. However, in late 2014 NASA did not select the Dream Chaser to be one of the two vehicles selected under the Commercial Crew competition. On 4 August 2011, Boeing announced that it would use the Atlas V as the initial launch vehicle for its CST-100 crew capsule. CST-100 will take NASA astronauts to the International Space Station (ISS) and was also intended to service the proposed Bigelow Commercial Space Station. A three-flight test program was projected to be completed  by 2015, certifying the Atlas V/CST-100 combination for human spaceflight operations. The first flight was expected to include an Atlas V rocket integrated with an uncrewed CST-100 capsule, the second flight an in-flight launch abort system demonstration in the middle of that year, and the third flight a crewed mission carrying two Boeing test-pilot astronauts into LEO and returning them safely at the end of 2015. These plans did not materialize. In 2014, NASA selected the Boeing CST-100 space capsule as part of the CCD program after extensive delays. Atlas V is the launch vehicle of the  CST-100. The first launch of an uncrewed CST-100 capsule occurred atop a human-rated Atlas V on the morning of 20 December 2019, however an anomaly with the Mission Elapsed Time clock aboard the CST-100 caused the spacecraft to enter a suboptimal orbit. As a result, the CST-100 could not achieve orbital insertion to reach the International Space Station, and instead deorbited after two days. Project Kuiper. Amazon has selected the Atlas V to launch satellites for Project Kuiper. Project Kuiper will offer a high-speed satellite internet constellation service. The contract signed with Amazon is for nine launches. Project  Kuiper aims to put thousands of satellites into orbit. ULA is Amazon's first launch provider. Versions. Each Atlas V booster configuration has a three-digit designation. The first digit shows the diameter (in meters) of the payload fairing and has a value of "4" or "5" for fairing launches and "N" for crew capsule launches (as no payload fairing is used when a crew capsule is launched). The second digit indicates the number of solid rocket boosters (SRBs) attached to the base of the launch vehicle and can range from "0" through "3" with the fairing, and "0" through  5 with the fairing. As seen in the first image, all SRB layouts are asymmetrical. The third digit represents the number of engines on the Centaur stage, either "1" or "2". For example, an Atlas V 551 has a 5-meter fairing, 5 SRBs, and 1 Centaur engine, whereas an Atlas V 431 has a 4-meter fairing, 3 SRBs, and 1 Centaur engine. The Atlas V N22 with no fairing, two SRBs, and 2 Centaur engines was first launched in 2019. The flight carried the Starliner vehicle for its first orbital test flight. , all versions of the Atlas V , its design and production rights, and intellectual property rights are owned by ULA and Lockheed Martin. Capabilities. List date: 8 August 2019 Mass to LEO numbers are at an inclination of 28.5°. Launch cost. Before 2016, pricing information for Atlas V launches was limited. In 2010, NASA contracted with ULA to launch the MAVEN mission on an Atlas V 401 for approximately US$187 million. The 2013 cost of this configuration for the U.S. Air Force under their block buy of 36 launch vehicles was US$164 million. In 2015, the TDRS-M launch on an Atlas 401 cost  NASA US$132.4 million. Starting in 2016, ULA provided pricing for the Atlas V through its RocketBuilder website, advertising a base price for each launch vehicle configuration, which ranges from US$109 million for the 401 up to US$153 million for the 551. Each additional SRB adds an average of US$6.8 million to the cost of the launch vehicle. Customers can also choose to purchase larger payload fairings or additional launch service options. NASA and Air Force launch costs are often higher than equivalent commercial missions due to additional government accounting, analysis, processing, and mission assurance requirements, which  can add US$30–80 million to the cost of a launch. In 2013, launch costs for commercial satellites to GTO averaged about US$100 million, significantly lower than historic Atlas V pricing. However, in recent years the price of an Atlas V  has dropped from approximately US$180 million to US$109 million, in large part due to competitive pressure that emerged in the launch services marketplace during the early 2010s. ULA CEO Tory Bruno stated in 2016 that ULA needs at least two commercial missions each year in order to stay profitable going forward. ULA is not attempting  to win these missions on purely lowest purchase price, stating that it "would rather be the best "value" provider". In 2016, ULA suggested that customers would have much lower insurance and delay costs because of the high Atlas V reliability and schedule certainty, making overall customer costs close to that of using competitors like the SpaceX Falcon 9. Historically proposed versions. In 2006, ULA offered an Atlas V Heavy option that would use three Common Core Booster (CCB) stages strapped together to lift a payload to low Earth orbit. ULA stated at the time that 95% of the hardware required  for the Atlas V Heavy has already been flown on the Atlas V single-core vehicles. The lifting capability of the proposed launch vehicle was to be roughly equivalent to the Delta IV Heavy, which uses RS-68 engines developed and produced domestically by Aerojet Rocketdyne. A 2006 report, prepared by the RAND Corporation for the Office of the Secretary of Defense, stated that Lockheed Martin had decided not to develop an Atlas V heavy-lift vehicle (HLV). The report recommended for the U.S. Air Force and the National Reconnaissance Office (NRO) to "determine the necessity of an EELV heavy-lift  variant, including development of an Atlas V Heavy", and to "resolve the RD-180 issue, including coproduction, stockpile, or United States development of an RD-180 replacement". In 2010, ULA stated that the Atlas V Heavy variant could be available to customers 30 months from the date of order. In late 2006, the Atlas V program gained access to the tooling and processes for 5 meter diameter stages used on Delta IV when Boeing and Lockheed Martin space operations were merged into the United Launch Alliance. This led to a proposal to combine the 5 meter diameter Delta IV tankage production processes  with dual RD-180 engines, resulting in the Atlas Phase 2. An Atlas V PH2-Heavy consisting of three 5 meter stages in parallel with six RD-180s was considered in the Augustine Report as a possible heavy lifter for use in future space missions, as well as the Shuttle-derived Ares V and Ares V Lite. If built, the Atlas PH2-Heavy was projected to be able to launch a payload mass of approximately into an orbit of 28.5° inclination. The Atlas V Common Core Booster was to have been used as the first stage of the joint US-Japanese  GX rocket, which was scheduled to make its first flight in 2012. GX launches would have been from the Atlas V launch complex at Vandenberg Air Force Base, SLC-3E. However, the Japanese government decided to cancel the GX project in December 2009. In May 2015, a consortium of companies, including Aerojet and Dynetics, sought to license the production or manufacturing rights to the Atlas V using the AR1 engine in place of the RD-180. The proposal was rejected by ULA. Atlas V launches. ULA has stopped selling the Atlas V. It will fly 24 more launches. For planned launches, see  List of Atlas launches (2020–2029). Notable missions. The first payload, the Hot Bird 6 communications satellite, was launched to geostationary transfer orbit (GTO) on 21 August 2002 by an Atlas V 401. On 12 August 2005, the Mars Reconnaissance Orbiter was launched aboard an Atlas V 401 launch vehicle from Space Launch Complex 41 at Cape Canaveral Air Force Station (CCAFS). The Centaur upper stage of the launch vehicle completed its burns over a 56-minute period and placed MRO into an interplanetary transfer orbit towards Mars. On 19 January 2006, New Horizons was launched by a Lockheed Martin Atlas  V 551 rocket. A third stage was added to increase the heliocentric (escape) speed. This was the first launch of the Atlas V 551 configuration with five solid rocket boosters, and the first Atlas V with a third stage. On 6 December 2015, Atlas V lifted its heaviest payload to date into orbit – a Cygnus resupply craft. On 8 September 2016, the OSIRIS-REx Asteroid Sample Return Mission was launched on an Atlas V 411 launch vehicle. It was scheduled to arrive at the asteroid Bennu in 2018 and return with a sample ranging from 60 grams to 2 kilograms  in 2023. The first four Boeing X-37B spaceplane missions were successfully launched with the Atlas V. The X-37B, also known as the Orbital Test Vehicle (OTV), is a reusable robotic spacecraft operated by USAF that can autonomously conduct landings from orbit to a runway. The first four X-37B flights were launched on Atlas V's from Cape Canaveral Air Force Station in Florida with subsequent landings taking place on the Space Shuttle runway located at Vandenberg Air Force Base in California. On 20 December 2019, the first Starliner crew capsule was launched in Boe-OFT un-crewed test flight. The  Atlas V launch vehicle performed flawlessly but an anomaly with the spacecraft left it in a wrong orbit. The orbit was too low to reach the flight's destination of ISS, and the mission was subsequently cut short. Mission success record. In its 85 launches (as of October 2020), starting with its first launch in August 2002, Atlas V has achieved a 100% mission success rate and a 97.65% vehicle success rate. This is in contrast to the industry success rate of 90%–95%. The first anomalous event in the use of the Atlas V launch system occurred on 15 June  2007, when the engine in the Centaur upper stage of an Atlas V shut down early, leaving its payload – a pair of NROL-30 ocean surveillance satellites – in a lower than intended orbit. The cause of the anomaly was traced to a leaky valve, which allowed fuel to leak during the coast between the first and second burns. The resulting lack of fuel caused the second burn to terminate 4 seconds early. Replacing the valve led to a delay in the next Atlas V launch. However, the customer (the National Reconnaissance Office) categorized the mission as a success. A flight on  23 March 2016, suffered an underperformance anomaly on the first-stage burn and shut down 5 seconds early. The Centaur proceeded to boost the Orbital Cygnus payload, the heaviest on an Atlas to date, into the intended orbit by using its fuel reserves to make up for the shortfall from the first stage. This longer burn cut short a later Centaur disposal burn. An investigation of the incident revealed that this anomaly was due to a fault in the main engine mixture-ratio supply valve, which restricted the flow of fuel to the engine. The investigation and subsequent examination of  the valves on upcoming missions led to a delay of the next several launches. Replacement with Vulcan. In 2014, geopolitical and U.S. political considerations led to an effort to replace the Russian-supplied RD-180 engine used on the first-stage booster of the Atlas V. Formal study contracts were issued in June 2014 to a number of U.S. rocket-engine suppliers. The results of those studies led to a decision by ULA to develop the new Vulcan Centaur launch vehicle to replace the existing Atlas V and Delta IV. In September 2014, ULA announced a partnership with Blue Origin to  develop the BE-4 LOX/methane engine to replace the RD-180 on a new first-stage booster. As the Atlas V core is designed around RP-1 fuel and cannot be retrofitted to use a methane-fueled engine, a new first stage is being developed. This booster will have the same first-stage tankage diameter as the Delta IV and will be powered by two thrust BE-4 engines. The engine was already in its third year of development by Blue Origin, and ULA expected the new stage and engine to start flying no earlier than 2019. Vulcan was initially planned to  use the same Centaur upper stage as on Atlas V, and later to later upgrade to ACES, however ACES is no longer being pursued, and Centaur V will be used instead. It will also use a variable number of optional solid rocket boosters, called the GEM 63XL, derived from the new solid boosters planned for Atlas V. As of 2017, the Aerojet AR1 rocket engine was under development as a backup plan for Vulcan. , Vulcan was expected to be available in 2022. Retirement. In August 2021, ULA announced that they are no longer selling launches on the Atlas V. They  will fulfill their 29 existing launch contracts. They made a final purchase of the RD-180 motors they need and the last of those motors were delivered in April 2021. The last launch will occur "some time in the mid-2020s". See also. Comparable rockets: