Falcon 9

**Falcon 9** is a two-stage rocket. It was designed and manufactured by SpaceX in the United States. Parts of the rocket can be used more than one time. The latest version of the first stage can return to Earth and be flown again many times. Both the first and second stages are powered by SpaceX Merlin engines. They use cryogenic liquid oxygen and rocket-grade kerosene (RP-1) as fuel. Its name comes from the fictional Star Wars spacecraft, the *Millennium Falcon*. The 9 is for the nine engines of the rocket's first stage. There have been many versions of the rocket. These include v1.0 (2010–2013), v1.1 (2013–2016) and  v1.2 Full Thrust (2015–present). It also includes the Falcon 9 Block 5 version.

It also includes the Block 5 Full Thrust version. This version has been used since May 2018. Most rockets can only be used one time. SpaceX has landed Falcon 9 boosters over a hundred times.  The first stages have been used as many as eleven times.

Falcon 9 can carry of up to  to low Earth orbit (LEO). If fully used, it can carry  to geostationary transfer orbit (GTO). The rocket can carry  to GTO when the first stage is recovered. It has a cargo size of ]145 cubic meters of volume The heaviest GTO loads carried have been Intelsat 35e () and Telstar 19V ().   

In 2008, SpaceX won a Commercial Resupply Services (CRS) contract in NASA's Commercial Orbital Transportation Services (COTS) program. They would take cargo to the International Space Station (ISS) using the Falcon 9 and Dragon capsule. The first mission under this contract launched on 8 October 2012. Falcon 9 can take NASA astronauts to the ISS. It is also certified for the National Security Space Launch program and NASA Launch Services Program as "Category 3". This means it can be used with the most expensive, important and complex NASA missions. Falcon 9 is said to be the world's most advanced space launch vehicle by many sources. As of January 2021, Falcon 9 has the most launches among all U.S. rockets that are currently being used. It is the only U.S. rocket fully certified for transporting humans to the International Space Station. It is also the only commercial rocket to take humans to orbit. On 24 January 2021, Falcon 9 set a new record for the most satellites launched by a single rocket. It carried 143 satellites into orbit.

Five rockets of the version 1.0 design were launched from June 2010 to March 2013. Version 1.1 had fifteen launches from September 2013 to January 2016. The "Full Thrust" version has been used since December 2015. There are many upgrades to this version. The latest Full Thrust variant, Block 5, was introduced in May 2018. It has more thrust, improved landing legs and other minor improvements to help recovery and reuse. The Falcon Heavy version was first flown in February 2018. It has a stronger Falcon 9 first stage as its center core. It also has two added Falcon 9 first stages used as boosters. SpaceX plans to replace Falcon 9 and Falcon Heavy with the much larger Starship launch system.

## Development history 
, v1.1, Full Thrust, Block 5, and Falcon Heavy.]]

### Conception and funding 
In October 2005, SpaceX said it was going to launch Falcon 9 in the first half of 2007. The first launch took place in 2010.

SpaceX spent its own money to create the Falcon 1. Creating the Falcon 9 was faster because NASA helped with the cost. They also said they would buy several commercial flights. This started with money from the Commercial Orbital Transportation Services (COTS) program in 2006. The contract was a Space Act Agreement (SAA) "to develop and demonstrate commercial orbital transportation service". The contract was US$278 million to provide development funding for Dragon, Falcon 9, and demonstration launches of Falcon 9 with Dragon. In 2011 other milestones were added, This made the total contract value US$396 million.

NASA became the main user for the vehicle in 2008. They agreed to buy 12 Commercial Resupply Services launches to the International Space Station. The money would be paid after the demonstration missions were completed successfully. The space logistics delivery contract was worth US$1.6 billion for a minimum of 12 missions to carry supplies to and from the International Space Station.

Elon Musk has said that it would have taken longer without the NASA money.SpaceX has only come this far by building upon the incredible achievements of NASA, having NASA as an anchor tenant for launch, and receiving expert advice and mentorship throughout the development process. SpaceX would like to extend a special thanks to the NASA COTS office for their continued support and guidance throughout this process. The COTS program has demonstrated the power of a true private/public partnership, and we look forward to the exciting endeavors our team will accomplish in the future.

A 2011 NASA report said that it would have cost them about US$4 billion to develop a rocket like the Falcon 9 booster. "A more commercial development" approach might have let the agency to pay only US$1.7 billion".

Congressionaltestimony by SpaceX in 2017 said that the normal NASA process of setting only a requirement and leaving the details to SpaceX let them make the Falcon 9 rocket at a muchlower cost. 

### Development 
At first, SpaceX wanted to follow the Falcon 1 with a larger capacity vehicle, the Falcon 5. In 2005, SpaceX said it was working on the Falcon 9 instead. They said that they already had a government customer. The Falcon 9 was said to be able of carrying approximately  to low Earth orbit. They said it would cost US$27 million per flight with a  payload. It would cost US$35 million with a  payload. SpaceX also said a heavy version of the Falcon 9 would have a payload capacity of about . SpaceX  scheduled launch date of March 2010. 

In February 2010, SpaceX's first flight stack was set up at Space Launch Complex 40, Cape Canaveral. The factory was making one Falcon 9 vehicle per month as of November 2013. The company wanted to increase that to 18 vehicles per year in mid-2014 and  24 per year by the end of 2014. They wanted to be making 40 rocket cores per year by the end of 2015.

These production rates were not achieved by February 2016. The company said that production rate for Falcon 9 cores had only increased to 18 per year. They also said that the number of first stage cores that can be made at one time had doubled from three to six. The rate was expected to grow to 30 cores per year by the end of 2016. Still, By August 2016, SpaceX was working towards a production capacity of 40 cores per year. 

Since 2018, SpaceX has usually reused first stages. This has reduced the need for new cores. In 2021, SpaceX had 31 F9 launches. Only two of those used new boosters. They recovered the booster on all but one flight.

## Design 
The Falcon 9 is a two-stage rocket. it is powered by LOX and RP-1.   Both stages have Merlin 1D rocket engines. The first stage has nine that are adapted for use at sea-level. The second stage has one that is adapted for use in a vacuum. The engines uses a pyrophoric mixture of triethylaluminum-triethylborane (TEA-TEB) to ignite the engine. Many cores have four landing legs at the base of the Octaweb. To control the core while it falls through the atmosphere, SpaceX uses grid fins. They deploy from the vehicle after separation. The legs deploy moments before landing.

The propellant tank walls and domes are made from aluminum–lithium alloy.  The second stage tank of a Falcon 9 is a shorter version of the first stage tank. This decreases the cost to make them.

The Falcon 9 uses a payload fairing to protect satellites during launch. The fairing is  long,  in diameter, weighs approximately .  It is made of a carbon fiber skin on an aluminum honeycomb core. Testing of the design was done at NASA's Plum Brook Station facility in spring 2013.

SpaceX uses multiple flight computers. This makes the system less affected by faults. Each Merlin rocket engine is controlled by three computers. Each of these computers has two processors that check each other. The software runs on Linux. It is written in C++.

The Falcon 9 rocket can lose up to two of the engines and still complete the mission. Each engine creates  of thrust.

## Launcher versions 
The Falcon 9 v1.0 flew five times in 2010–2013. The Falcon 9 v1.1 made its first flight in September 2013. The mission carried a very small  payload, the CASSIOPE satellite. Both Falcon 9 v1.0 and Falcon 9 v1.1 were expendable launch vehicles (ELVs). The Falcon 9 Full Thrust made its first flight in December 2015. The first stage of the Falcon 9 Full Thrust version can be used many times. The current version, known as Falcon 9 Block 5, made its first flight in May 2018.

## Pricing 
In 2010, the price of a Falcon 9 v1.0 launch was US$49.9 to US$56 million. The DSCOVR mission, for National Oceanic and Atmospheric Administration (NOAA), cost US$97 million.

In 2004, Elon Musk said "long term plans call for development of a heavy lift product and even a super-heavy, if there is customer demand. [...] Ultimately, I believe US$500 per pound (US$1100/kg) [of payload delivered to orbit] or less is very achievable".

CNBC reported in April 2020 that the United States Air Force's launches were costing US$95 million This was because of the extra security used. SpaceX executive Christopher Couluris stated that reusing rockets can bring prices even lower, that it "costs US$28 million to launch it, that's with everything".

## Gallery

File:CRS-8 (26239020092).jpg|A first-stage booster rocket (Falcon 9, serial number B1021) after landing from a flight in 2016. This rocket landed on a drone ship.

## References 
## Other websites 
* Falcon 9 official page
* SAOCOM 1B | Launch and Landing
* Test firing of two Merlin 1C engines connected to Falcon 9 first stage, Movie 1, Movie 2 (18 January 2008)
* Press release announcing design (9 September 2005)
* SpaceX hopes to supply ISS with new Falcon 9 heavy launcher (Flight International, 13 September 2005)
* SpaceX launches Falcon 9, With A Customer  (Defense Industry Daily, 15 September 2005)