Falcon 9

Falcon 9

A Falcon 9 v1.1 carrying a Dragon cargo spacecraft
Function	Orbital launch vehicle
Manufacturer	SpaceX
Country of origin	United States
Cost per launch	v1.1: $61.2M
Size
Height	v1.1: 68.4 m (224 ft) v1.0: 54.9 m (180 ft)
Diameter	3.66 m (12.0 ft)
Mass	v1.1: 505,846 kg (1,115,200 lb) v1.0: 333,400 kg (735,000 lb)
Stages	2
Capacity
Payload to LEO	v1.1: 13,150 kg (28,990 lb) v1.0: 10,450 kg (23,040 lb)
Payload to GTO	v1.1: 4,850 kg (10,690 lb) v1.0: 4,540 kg (10,010 lb)
Launch history
Status	V1.1: Active v1.0: Retired
Launch sites	Cape Canaveral SLC-40 Vandenberg SLC-4E
Total launches	19 (v1.1: 14, v1.0: 5)
Success(es)	17 (v1.1: 13, v1.0: 4)
Failure(s)	1 (v1.1)
Partial failure(s)	1 (v1.0)
First flight	v1.1: September 29, 2013 v1.0: June 4, 2010
First stage
Engines	v1.1: 9 Merlin 1D v1.0: 9 Merlin 1C
Thrust	v1.1: 5,885 kN (1,323,000 lbf) v1.0: 4,940 kN (1,110,000 lbf)
Specific impulse	v1.1 Sea level: 282 s Vacuum: 311 s v1.0 Sea level: 275 s Vacuum: 304 s
Burn time	v1.1: 180 seconds v1.0: 170 seconds
Propellant	LOX/RP-1
Second stage
Engines	v1.1: 1 Merlin Vacuum (1D) v1.0: 1 Merlin Vacuum (1C)
Thrust	v1.1: 801 kN (180,000 lbf) v1.0: 445 kN (100,000 lbf)
Specific impulse	Vacuum: 342 s
Burn time	v1.1: 375 seconds v1.0: 345 seconds
Propellant	LOX/RP-1

Falcon 9 is a family of two-stage-to-orbit launch vehicles designed and manufactured by SpaceX. The Falcon 9 versions are the Falcon 9 v1.0 (phased-out), Falcon 9 v1.1 (current version, expendable), and the Falcon 9-R (reusable launch system). Both stages of this two-stage-to-orbit vehicle are powered by rocket engines that burn liquid oxygen (LOX) and rocket-grade kerosene (RP-1) propellants. The current Falcon 9 (v1.1) can lift payloads of 13,150 kilograms (28,990 lb) to low Earth orbit, and 4,850 kilograms (10,690 lb) to geostationary transfer orbit. The three Falcon 9 versions are in the medium-lift range of launch systems.

The Falcon 9 and Dragon capsule combination won a Commercial Resupply Services (CRS) contract from NASA in 2008 to resupply the International Space Station (ISS) under the Commercial Orbital Transportation Services (COTS) program. The first commercial resupply mission to the International Space Station launched in October 2012. The initial version 1.0 design made a total of five flights before it was retired in 2013.

SpaceX is currently flying an improved and 60 percent heavier Falcon 9 launch vehicle—the Falcon 9 v1.1—which flew for the first time on a demonstration mission on the sixth overall launch of the Falcon 9 in September 2013.

The Falcon 9 v1.1 will be the base for the Falcon Heavy launch vehicle. Falcon 9 will also be human-rated for transporting NASA astronauts to the ISS as part of a Commercial Crew Transportation Capability contract.

Development and production

From left to right, Falcon 1, Falcon 9 v1.0, three versions of Falcon 9 v1.1, and two versions of Falcon Heavy (not all versions have flown)

Funding

While SpaceX spent its own money to develop the previous launcher, Falcon 1, development of the Falcon 9 was initiated with NASA funding from the Commercial Orbital Transportation Services (COTS) program; SpaceX received a directly-funded Space Act Agreement (SAA) in 2006 "to develop and demonstrate commercial orbital transportation service" including three demonstration flights. NASA also became an anchor tenant for the vehicle by purchasing Commercial Resupply Services launches to the International Space Station in 2008 (two years before the first launch); the contract, worth $1.6 billion, was for at least 12 missions to carry supplies to and from the station.

SpaceX's statement about the NASA contract was:

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.

In 2011, SpaceX estimated that Falcon 9 v1.0 development costs were on the order of $300 million. NASA evaluated that development costs would have been $3.6 billion if a traditional cost-plus contract approach had been used.

In 2014, SpaceX released total combined development costs for both the Falcon 9 and the Dragon capsule. NASA provided US$396 million while SpaceX provided over US$450 million to fund rocket and capsule development efforts.

Development, production and testing history

Falcon 9 rocket cores under construction at the SpaceX Hawthorne facility.

SpaceX originally intended to follow its light Falcon 1 launch vehicle with an intermediate capacity vehicle, the Falcon 5. In 2005, SpaceX announced it was instead proceeding with development of the Falcon 9, a "fully reusable heavy lift launch vehicle," and had already secured a government customer. The Falcon 9 was described as being capable of launching approximately 9,500 kg (21,000 lb) to low Earth orbit, and was projected to be priced at $27 million per flight with a 3.7 m (12 ft) fairing and $35 million with a 5.2 m (17 ft) fairing. SpaceX also announced development of a heavy version of the Falcon 9 with a payload capacity of approximately 25,000 kg (55,000 lb). The Falcon 9 was intended to enable launches to LEO, GTO, as well as both crew and cargo vehicles to the ISS.

The original NASA COTS contract called for the first demonstration flight of Falcon in September 2008, and completion of all three demonstration missions by September 2009. In February 2008, the plan for the first Falcon 9/Dragon COTS Demo flight was delayed by six months to late in the first quarter of 2009. According to Elon Musk, the complexity of the development work and the regulatory requirements for launching from Cape Canaveral contributed to the delay.

The first multi-engine test (with two engines connected to the first stage, firing simultaneously) was successfully completed in January 2008, with successive tests leading to the full Falcon 9 complement of nine engines test fired for a full mission length (178 seconds) of the first stage on November 22, 2008. In October 2009, the first flight-ready first stage had a successful all-engine test fire at the company's test stand in McGregor, Texas. In November 2009 SpaceX conducted the initial second stage test firing lasting forty seconds. This test succeeded without aborts or recycles. On January 2, 2010, a full-duration (329 seconds) orbit-insertion firing of the Falcon 9 second stage was conducted at the McGregor test site. The full stack arrived at the launch site for integration at the beginning of February 2010, and SpaceX initially scheduled a launch date of March 22, 2010, though they estimated anywhere between one and three months for integration and testing.

On February 25, 2010, SpaceX's first flight stack was set vertical at Space Launch Complex 40, Cape Canaveral, and on March 9, SpaceX performed a static fire test, where the first stage was to be fired without taking off. The test aborted at T-2 seconds due to a failure in the system designed to pump high-pressure helium from the launch pad into the first stage turbopumps, which would get them spinning in preparation for launch. Subsequent review showed that the failure occurred when a valve did not receive a command to open. As the problem was with the pad and not with the rocket itself, it didn't occur at the McGregor test site, which did not have the same valve setup. Some fire and smoke were seen at the base of the rocket, leading to speculation of an engine fire. However, the fire and smoke were the result of normal burnoff from the liquid oxygen and fuel mix present in the system prior to launch, and no damage was sustained by the vehicle or the test pad. All vehicle systems leading up to the abort performed as expected, and no additional issues were noted that needed addressing. A subsequent test on March 13 was successful in firing the nine first-stage engines for 3.5 seconds.

The first flight was delayed from March 2010 to June due to review of the Falcon 9 flight termination system by the Air Force. The first launch attempt occurred at 1:30 pm EDT on Friday, June 4, 2010 (1730 UTC). The launch was aborted shortly after ignition, and the rocket successfully went through a failsafe abort. Ground crews were able to recycle the rocket, and successfully launched it at 2:45 pm EDT (1845 UTC) the same day.

The second Falcon 9 launch, and first COTS demo flight, lifted off on December 8, 2010.

The second Falcon 9 version—v1.1—was developed in 2010–2013, and launched for the first time in September 2013.

In December 2010, the SpaceX production line was manufacturing one new Falcon 9 (and Dragon spacecraft) every three months, with a plan to double to one every six weeks. By September 2013, SpaceX total manufacturing space had increased to nearly 1,000,000 square feet (93,000 m²) and the factory had been configured to achieve a production rate of up to 40 rocket cores per year. The November 2013 production rate for Falcon 9 vehicles was one per month. The company has stated that this will increase to 18 per year in mid-2014, 24 per year by the end of 2014, and 40 rocket cores per year by the end of 2015.

Launcher versions

The original Falcon 9 flew five successful orbital launches in 2010–2013, and the much larger Falcon 9 v1.1 made its first flight—a demonstration mission with a very small 500 kilograms (1,100 lb) primary payload, the CASSIOPE satellite, that was manifested at a "cut rate price" due to the demo mission nature of the flight—on September 29, 2013. More realistic payloads have followed for v1.1 with the launch of the large SES-8 and Thaicom communications satellites, each inserted successfully into GTO. Both Falcon 9 v1.0 and Falcon 9 v1.1 are expendable launch vehicles (ELVs).

In addition, a reusable first stage is under development for the Reusable Falcon 9 launch vehicle, with initial atmospheric testing being conducted on the Grasshopper experimental technology-demonstrator reusable launch vehicle (RLV).

Common design elements

All Falcon 9 versions are two-stage, LOX/RP-1-powered launch vehicles.

The Falcon 9 tank walls and domes are made from aluminum lithium alloy. SpaceX uses an all-friction stir welded tank, the highest strength and most reliable welding technique available. The second stage tank of a Falcon 9 is simply a shorter version of the first stage tank and uses most of the same tooling, material and manufacturing techniques. This saves money during vehicle production.

Both stages use a pyrophoric mixture of triethylaluminum-triethylborane (TEA-TEB) as an engine ignitor.

SpaceX uses multiple redundant flight computers in a fault-tolerant design. Each Merlin engine is controlled by three voting computers, each of which has two physical processors that constantly check each other. The software runs on Linux and is written in C++. For flexibility, commercial off-the-shelf parts and system-wide "radiation-tolerant" design are used instead of rad-hardened parts. Each stage has stage-level flight computers, in addition to the Merlin-specific engine controllers, of the same fault-tolerant triad design to handle stage control functions.

The Falcon 9 interstage, which connects the upper and lower stage for Falcon 9, is a carbon fiber aluminum core composite structure. Reusable separation collets and a pneumatic pusher system separate the stages. The original design stage separation system had twelve attachment points, which was reduced to just three in the v1.1 launcher.

Falcon 9 v1.0

Main article: Falcon 9 v1.0

A Falcon 9 v1.0 launches with an uncrewed Dragon spacecraft, 2012

Falcon 9 booster tank at the SpaceX factory, 2008

The first version of the Falcon 9 launch vehicle, Falcon 9 v1.0, is an expendable launch vehicle (ELV) that was developed in 2005–2010, and was launched for the first time in 2010. Falcon 9 v1.0 made five flights in 2010–2013, after which it was retired.

Falcon 9 v1.0 (left) and v1.1 (right) engine configurations

The Falcon 9 v1.0 first stage was powered by nine SpaceX Merlin 1C rocket engines arranged in a 3x3 pattern. Each of these engines had a sea-level thrust of 556 kilonewtons (125,000 lb_f) for a total thrust on liftoff of about 5,000 kilonewtons (1,100,000 lb_f). The Falcon 9 v1.0 second stage was powered by a single Merlin 1C engine modified for vacuum operation, with an expansion ratio of 117:1 and a nominal burn time of 345 seconds.

Four Draco thrusters were used on the Falcon 9 v1.0 second-stage as a reaction control system. The thrusters are used to hold a stable attitude for payload separation or, as a non-standard service, could have been used to spin up the stage and payload to a maximum of 5 rotations per minute (RPM).

SpaceX expressed hopes initially that both stages would eventually be reusable. But early results from adding lightweight thermal protection system (TPS) capability to the booster stage and using parachute recovery were not successful, leading to abandonment of that approach and the initiation of a new design. In 2011 SpaceX began a formal and funded development program for a reusable Falcon 9 second stage, with the early program focus however on return of the first stage. However, by late 2014, SpaceX had apparently abandoned plans for recovering and reusing the second stage.

Falcon 9 v1.1

Main article: Falcon 9 v1.1

The launch of the first Falcon 9 v1.1 from SLC-4, Vandenberg AFB (Falcon 9 Flight 6) on September 29, 2013

The Falcon 9 v1.1 ELV is a 60 percent heavier rocket with 60 percent more thrust than the v1.0 version of the Falcon 9. It includes realigned first-stage engines and 60 percent longer fuel tanks, making it more susceptible to bending during flight. Development testing of the v1.1 first stage was completed in July 2013. The Falcon 9 v1.1 first launched on September 29, 2013, uses a longer first stage powered by nine Merlin 1D engines arranged in an "octagonal" pattern.

The v1.1 first stage has a total sea-level thrust at liftoff of 5,885 kilonewtons (1,323,000 lb_f), with the nine engines burning for a nominal 180 seconds, while stage thrust rises to 6,672 kilonewtons (1,500,000 lb_f) as the booster climbs out of the atmosphere. The engines have been upgraded to the more powerful Merlin 1D. These improvements will increase the payload capability from 9,000 kilograms (20,000 lb) to 13,150 kilograms (28,990 lb). The stage separation system has been redesigned and reduces the number of attachment points from twelve to three, and the vehicle has upgraded avionics and software as well. The new first stage will also be used as side boosters on the Falcon Heavy launch vehicle.

SpaceX President Gwynne Shotwell has stated the Falcon 9 v1.1 has about 30 percent more payload capacity than published on its standard price list, the extra margin reserved for returning of stages via powered re-entry. Though SpaceX has signed agreements with SES for two launches of satellites up to 5,330 kilograms (11,750 lb), exceeding the price list offering of 4,850 kilograms (10,690 lb) by approximately 10 percent, these satellites will be dropped off in a sub-GTO trajectory and subsequently use on board propellant to raise their orbits.

The v1.1 booster version arranges the engines in a structural form SpaceX calls Octaweb, aimed at streamlining the manufacturing process, and will eventually include four extensible landing legs, which will be used only for post-mission technology development testing in the early Falcon 9 v1.1 flights while supporting full vertical-landing capability in later flights once the technology is fully developed.

Following the September 2013 launch, the second stage igniter propellant lines were insulated to better support in-space restart following long coast phases for orbital trajectory maneuvers. Further improvements are planned for mid 2015 including uprated engine thrust, increased propellant capacity by deep chilling the propellant and propellant tank volume increase.

Payload fairing

The sixth flight (CASSIOPE, 2013) was the first launch of the Falcon 9 configured with a jettisonable payload fairing, which introduced an additional separation event – a risky operation that has doomed many previous government and commercial launch missions, including the 2009 Orbiting Carbon Observatory and 2011 Glory satellite, both on Taurus rockets.

Fairing design was done by SpaceX, with production of the 13 m (43 ft)-long, 5.2 m (17 ft)-diameter payload fairing done in Hawthorne, California at the SpaceX rocket factory. Since the first five Falcon 9 launches had a capsule and did not carry a large satellite, no fairing was required on those flights. It was required on the CASSIOPE flight, as with most satellites, in order to protect the payload during launch. Testing of the new fairing design was completed at NASA's Plum Brook Station test facility in spring 2013 where the acoustic shock and mechanical vibration of launch, plus electromagnetic static discharge conditions, were simulated on a full-size fairing test article in a very large vacuum chamber. SpaceX paid NASA US$581,300 to lease test time in the $150 million NASA simulation chamber facility. The fairing separated without incident during the launch of CASSIOPE.

Payload fairings have survived descent and splashdown in the Pacific Ocean. In June 2015, wreckage of an unidentified Falcon 9 launch vehicle was found off the coast of The Bahamas, which was confirmed by SpaceX CEO Elon Musk to be a component of the payload fairing that washed ashore. Musk also noted the concept of fairing reusability in a statement: "This is helpful for figuring out fairing reusability."

Falcon 9-R

A third version of the rocket is in development. The Falcon 9-R, a partially reusable variant of the Falcon 9—with a reusable (RLV) booster stage—is being developed using systems and software tested on the Grasshopper and F9R Dev technology demonstrators, as well as a set of technologies being developed by SpaceX to facilitate rapid reusability of both the first, and in the longer term, second stages. However, plans to reuse the Falcon 9 second-stage booster have been abandoned.

While the differences between the Falcon 9 v1.0 and the Falcon 9 v1.1 were significant, there are a much smaller set of differences between the Falcon 9 v1.1 and the emerging design of the returnable booster for the Falcon 9-R. While no changes in rocket length or thrust are planned, the principal visible change is the presence of extensible landing legs on the lower portion of the first-stage booster in the F9-R. Additional changes are less visible, including changes to the attitude control technology for the rocket and guidance control system software changes to regularly and reliably effect a ground landing.

SpaceX pricing and payload specifications published for the non-reusable Falcon 9 v1.1 rocket as of March 2014 actually include about 30 percent more performance than the published price list indicates; the additional performance is reserved for SpaceX to do reusability booster demonstration flight tests while still achieving the specified payloads for customers. Once all engineering changes to support reusability and recovery are made and testing is successful, SpaceX expects to have room to increase the payload performance for the Falcon 9-R, or decrease launch price, or both.

Comparison

Version	Falcon 9 v1.0 (retired)	Falcon 9 v1.1 (active)	Falcon 9 v1.1 Full Thrust (in testing)
Stage 1	9 × Merlin 1C	9 × Merlin 1D	9 × Merlin 1D (with minor upgrades)
Stage 2	1 × Merlin 1C Vacuum	1 × Merlin 1D Vacuum	1 × Merlin 1D Vacuum (with minor upgrades)
Max height (m)	53	68.4 (224.4 ft)	70 (229.6 ft)
Diameter (m)	3.66	3.66	3.66
Initial thrust (kN)	3,807	5,885	6,806
Takeoff mass (tonnes)	318	506	541
Fairing diameter (m)	N/A*	5.2	5.2
Payload to LEO (kg)	8,500–9,000 (launch at Cape Canaveral)	13,150 (launch at Cape Canaveral)	13,150
Payload to GTO (kg)	3,400	4,850	4,850
Success ratio	5/5**	10/11	N/A

* The Falcon 9 v1.0 only launched the Dragon spacecraft; it never launched with the clam-shell payload fairing.

** On SpaceX CRS-1, the primary payload, Dragon, was successful. A secondary payload was placed in an incorrect orbit following an engine failure on the first stage. Though enough fuel remained on the second stage for orbital insertion, NASA safety margins forbade any deviation from the original flight plan.

Features

Reliability

The company has predicted that it will have high reliability based on the philosophy that "through simplicity, reliability and low cost can go hand-in-hand," but this remains to be shown. As a comparison, the Russian Soyuz series has more than 1,700 launches to its credit, far more than any other rocket with a failure rate of 1 in 39. 75% of current launch vehicles have had at least one failure in the first three flights.

As with the company's smaller Falcon 1 vehicle, Falcon 9's launch sequence includes a hold-down feature that allows full engine ignition and systems check before liftoff. After first-stage engine start, the launcher is held down and not released for flight until all propulsion and vehicle systems are confirmed to be operating normally. Similar hold-down systems have been used on other launch vehicles such as the Saturn V and Space Shuttle. An automatic safe shut-down and unloading of propellant occurs if any abnormal conditions are detected. Prior to the launch date, SpaceX always completes a test of the Falcon 9 culminating in a firing of the first stage's Merlin 1D engines for three-and-a-half seconds to verify performance.

Falcon 9 has triple redundant flight computers and inertial navigation, with a GPS overlay for additional orbit insertion accuracy.

Engine-out capability

Like the Saturn series from the Apollo program, the presence of multiple first-stage engines can allow for mission completion even if one of the first-stage engines fails mid-flight. Detailed descriptions of several aspects of destructive engine failure modes and designed-in engine-out capabilities were made public by SpaceX in a 2007 "update" that was publicly released.

SpaceX emphasized over several years that the Falcon 9 first stage is designed for engine out capability. The SpaceX CRS-1 mission was a partial success after an engine failure in the first stage: The primary payload was inserted into the correct orbit, but due to contractual requirements of the primary payload customer, NASA, the second firing of the Falcon 9 upper stage was not allowed to insert the secondary payload into a higher orbit. This risk was understood by the secondary payload customer at time of the signing of the launch contract. As a result, the secondary payload satellite reentered the atmosphere a few days after launch.

In detail, the first stage experienced a loss of pressure in, and then shut down, engine no. 1 at 79 seconds after its October 2012 launch. To compensate for the resulting loss of acceleration, the first stage had to burn 28 seconds longer than planned, and the second stage had to burn an extra 15 seconds. That extra burn time of the second stage reduced its fuel reserves, so that the likelihood that there was sufficient fuel to reach the planned orbit above the space station with the secondary payload dropped from 99% to 95%. Because NASA had purchased the launch and therefore contractually controlled a number of mission decision points, NASA declined SpaceX's request to restart the second stage and attempt to deliver the secondary payload into the correct orbit. The secondary payload was lost in earth's atmosphere a few days after launch, and was therefore considered a loss.

Reusability

Main article: SpaceX reusable launch system development program

Although the first stages of several early Falcon flights were equipped with parachutes and were intended to be recovered to assist engineers in designing for future reusability, SpaceX was not successful in recovering the stages from the initial test launches using the original approach. The Falcon boosters did not survive post separation aerodynamic stress and heating. Although reusability of the second stage is more difficult, SpaceX intended from the beginning to eventually make both stages of the Falcon 9 reusable.

Both stages in the early launches were covered with a layer of ablative cork and possessed parachutes to land them gently in the sea. The stages were also marinized by salt-water corrosion resistant material, anodizing and paying attention to galvanic corrosion. In early 2009, Musk stated:

"By [Falcon 1] flight six we think it’s highly likely we’ll recover the first stage, and when we get it back we’ll see what survived through re-entry, and what got fried, and carry on with the process. ... That's just to make the first stage reusable, it'll be even harder with the second stage – which has got to have a full heatshield, it'll have to have deorbit propulsion and communication."

Musk said that if the vehicle does not become reusable, "I will consider us to have failed."

In late 2011, SpaceX announced a change in the approach, ditching the parachutes and going with a propulsively-powered-descent approach. On September 29, 2011, at the National Press Club, Musk indicated the initiation of a privately funded program to develop powered descent and recovery of both Falcon 9 stages – a fully vertical takeoff, vertical landing (VTVL) rocket. Included was a video said to be an approximation depicting the first stage returning tail-first for a powered descent and the second stage, with heat shield, reentering head first before rotating for a powered descent.

LC-40 at Cape Canaveral AFS, Florida, after construction of Falcon 9 launch structures in 2009.

Design was complete on the system for "bringing the rocket back to launchpad using only thrusters" in February 2012. The reusable launch system technology is under consideration for both the Falcon 9 and the Falcon Heavy, and is considered particularly well suited to the Falcon Heavy where the two outer cores separate from the rocket much earlier in the flight profile, and are therefore moving at lower velocity at stage separation.

A reusable first stage is now being flight tested by SpaceX with the suborbital Grasshopper rocket. By April 2013, a low-altitude, low-speed demonstration test vehicle, Grasshopper v1.0, had made five VTVL test flights including an 80-second hover flight to an altitude of 744 metres (2,441 ft).

In March 2013, SpaceX announced that, beginning with the first flight of the stretch version of the Falcon 9 launch vehicle—the sixth flight overall of Falcon 9, every first stage would be instrumented and equipped as a controlled descent test vehicle. SpaceX intends to do propulsive-return over-water tests and "will continue doing such tests until they can do a return to the launch site and a powered landing. ... [They] expect several failures before they 'learn how to do it right.'"

For the early-fall 2013 flight, after stage separation, the first-stage booster attempted to conduct a burn to slow it down and then a second burn just before it reaches the water. When all of the over-water testing is complete, they intend to fly back to the launch site and land propulsively, perhaps as early as mid-2014. SpaceX has been explicit that they do not expect a successful recovery in the first several powered-descent tests.

Photos of the first test of the restartable ignition system for the reusable Falcon 9—the Falcon 9-R—with the nine-engine v1.1 circular-engine configuration were released in April 2013.

By late 2014, SpaceX determined that the mass needed for a re-entry heat shield, landing engines, and other equipment to support recovery of the second stage was prohibitive, and suspended or abandoned their second-stage reusability plans.

As of March 2015, SpaceX is developing an upgraded version of the second stage that will support first-stage reusability on the more-energetic communication satellite flights to geosynchronous orbits. The modifications include increasing engine thrust by 15 percent, increasing tank volume by 10 percent, and subcooling the cryogenic oxygen to obtain greater density. This performance increase compensates for the fuel reserved by the first stage for return and landing.

Post-mission high-altitude launch vehicle testing of Falcon 9 v1.1 boosters

Main article: Falcon 9 booster landing tests

Falcon 9 Flight 17's first stage attempting a controlled landing on the Autonomous Spaceport Drone Ship following the launch of CRS-6 to the International Space Station. The stage landed hard and tipped over after landing.

The post-mission test plan calls for the first-stage booster on the sixth Falcon 9 flight, and several subsequent F9 flights, to do a burn to reduce the rocket's horizontal velocity and then effect a second burn just before it reaches the water. SpaceX announced the test program in March 2013, and their intention to continue to conduct such tests until they can return to the launch site and perform a powered landing.

Falcon 9 Flight 6's first stage performed the first propulsive-return over-water tests on 29 September 2013. Although not a complete success, the stage was able to change direction and make a controlled entry into the atmosphere. During the final landing burn, the ACS thrusters could not overcome an aerodynamically induced spin, and centrifugal force deprived the landing engine of fuel leading to early engine shutdown and a hard splashdown which destroyed the first stage. Pieces of wreckage were recovered for further study.

The next test, using the first stage from SpaceX CRS-3, led to a successful soft ocean landing, however it presumably broke up in heavy seas before it could be recovered.

After further ocean landing tests, the first stage of the CRS-5 launch vehicle attempted a landing on a floating landing platform, the Autonomous Spaceport Drone Ship. The rocket landed too hard for survival but guided itself to the ship successfully.

Launch sites

SpaceX's Falcon 9 rocket delivered the ABS 3A and EUTELSAT 115 West B satellites to a supersynchronous transfer orbit, launching from Space Launch Complex 40 at Cape Canaveral Air Force Station, Florida on Sunday, March 1, 2015.

Launch Complex 40 at Cape Canaveral Air Force Station was the Falcon 9's first launch site and is the main location for ISS cargo resupply launches and for payloads going to geostationary orbits. A second SpaceX-leased launch site is located at Vandenberg Air Force Base's SLC-4 and is used for polar-orbit launches. The Vandenberg site became active on 29 September 2013 when it launched the Canadian-built CASSIOPE satellite. Locations in Texas, Florida, Georgia, and Puerto Rico were evaluated, for a third site, intended solely for commercial launches. The Boca Chica, Texas site was selected in August 2014.

Launch prices

At the time of its retirement, the price of a Falcon 9 v1.0 launch was listed at $54 million—$59.5 million. In 2013, the list price of a Falcon 9 v1.1 was $56.5 million, and was $61.2 million as of November 2014. Dragon cargo missions to the ISS have an average cost of $133 million under a fixed price contract with NASA.The DSCOVR mission for NOAA cost $97 million

In 2004, Elon Musk stated, "long term plans call for development of a heavy lift product and even a super-heavy, if there is customer demand. [...] Ultimately, I believe $500 per pound ($1100/kg) [of payload delivered to orbit] or less is very achievable." At its 2013 launch price and at full LEO payload capacity, the Falcon 9 v1.1 cost $1,864 per pound ($4,109/kg).

In 2011, Musk estimated that fuel and oxidizer for the Falcon 9 v1.0 rocket cost a total of about $200,000. The first stage uses 39,000 US gallons (150,000 L) of liquid oxygen and almost 25,000 US gallons (95,000 L) of kerosene, while the second stage uses 7,300 US gallons (28,000 L; 6,100 imp gal) of liquid oxygen and 4,600 US gallons (17,000 L) of kerosene.

Secondary payload services

Falcon 9 payload services include secondary and tertiary payload connection via an ESPA-ring, the same interstage adapter first used for launching secondary payloads on US DoD missions that use the Evolved Expendable Launch Vehicles (EELV) Atlas V and Delta IV. This enables secondary and even tertiary missions with minimal impact to the original mission. As of 2011, SpaceX announced pricing for ESPA-compatible payloads on the Falcon 9.

Launch history

SpaceX Falcon 9 launch with COTS Demo Flight 1

Further information: List of Falcon 9 and Falcon Heavy launches

As of April 14, 2015, SpaceX had made 17 launches of the Falcon 9 since 2010, and successfully delivered their primary payloads to Earth orbit, before the failure of the 18th launch in June 2015 (see below).

The first Falcon 9 flight was launched, after several delays, from Cape Canaveral Air Force Station on June 4, 2010, at 2:45 pm EDT (18:45 UTC) with a successful orbital insertion of the Dragon Spacecraft Qualification Unit. The rocket experienced, "a little bit of roll at liftoff" as Ken Bowersox from SpaceX put it. This roll had stopped prior to the craft reaching the top of the tower. The second stage began to slowly roll near the end of its burn which was not expected.

The second launch of the Falcon 9, and the first of the SpaceX Dragon spacecraft atop it, occurred at 10:43 EST (15:43 UTC) on December 8, 2010, from Cape Canaveral. The Dragon spacecraft completed two orbits, then splashed down in the Pacific Ocean. A second NASA-contracted demonstration flight was flown in 2012, followed by the first two ISS resupply flights in late 2012 and early 2013.

In October 2012 a Falcon 9 failed to insert its secondary payload into the correct orbit due to an early engine shut down, although the primary payload was correctly delivered to the ISS.

The Falcon 9 Flight 6 successfully flew on September 29, 2013, and was the first launch of the substantially upgraded Falcon 9 v1.1 vehicle. The launch included a number of Falcon 9 "firsts":

• First use of the upgraded Merlin 1D engines, generating approximately 56 percent more sea-level thrust than the Merlin 1C engines used on all previous Falcon 9 vehicles.
• First use of the significantly longer first stage, which holds the additional propellant for the more powerful engines.
• The nine Merlin 1D engines on the first stage are arranged in an octagonal pattern with eight engines in a circle and the ninth in the center.
• First launch from SpaceX's new launch facility, Space Launch Complex 4, at Vandenberg Air Force Base, California, and the first launch over the Pacific Ocean using the facilities of the Pacific test range.
• First Falcon 9 launch to carry a satellite payload for a commercial customer, and also the first non-COTS or CRS mission. Each prior Falcon 9 launch was of a Dragon capsule or a Dragon-shaped test article, although SpaceX has previously successfully launched and deployed a satellite on the Falcon 1, Flight 5 mission.
• First Falcon 9 launch to have a jettisonable payload fairing, which introduces the risk of an additional separation event.

While a number of the new capabilities were successfully tested on the flight, there was a problem with the second stage on September 29, 2013. SpaceX was unsuccessful in reigniting the second stage Merlin 1D vacuum engine once the rocket had deployed its primary payload (CASSIOPE) and all of its nanosat secondary payloads.

On December 3, 2013, the Falcon 9 successfully lifted the SES-8 communication satellite and boosted it to a supersynchronous elliptical transfer orbit with a second burn of the upper stage.

On January 6, 2014, the launch vehicle successfully carried the Thaicom 6 communications satellite to orbit, also to a supersynchronous transfer orbit as with its previous GTO launch.

On April 18, 2014, the Falcon 9 launched the Dragon spacecraft to orbit, carrying supplies and science experiments to the International Space Station. This was the third launch under SpaceX's Commercial Resupply Services (CRS) contract with NASA. In addition, the first stage of the rocket successfully "landed" in the Atlantic ocean.

On July 14, 2014, the Falcon 9 successfully launched a constellation of six Orbcomm OG2 satellites to orbit.

On August 5, 2014, the Falcon 9 successfully launched the AsiaSat 8 satellite to geosynchronous transfer orbit.

On September 7, 2014, the Falcon 9 successfully launched the AsiaSat 6 satellite to geosynchronous transfer orbit.

On September 21, 2014, the Falcon 9 successfully launched a Dragon spacecraft carrying supplies to the International Space Station.

On January 10, 2015, the Falcon 9 successfully launched a Dragon spacecraft carrying supplies and science experiments to ISS. SpaceX also attempted to land the first stage on its autonomous spaceport drone ship in the Atlantic ocean. The first stage reached the platform but crashed due to loss of power to the fins, resulting in a hard ~45 deg angle, smashing legs and engine section, due to a lack of hydraulic fluid.

On February 11, 2015, the Falcon 9 successfully launched the Deep Space Climate Observatory (DSCOVR) a NOAA Earth observation and space weather satellite into L1 transfer orbit. The initial plan to land the first stage on the drone ship was called off due to rough seas, and the drone ship was recalled prior to launch. The first stage instead attempted a soft landing over water. The ocean landing attempt was successful, and the stage splashed down "nicely vertical" with an accuracy of 10 meters. Musk went on to state that the stage would have had a "High probability of good droneship landing in non-stormy weather."

On April 14, 2015, the Falcon 9 successfully launched Space X's Dragon spacecraft carrying scientific supplies to the International Space Station. The first stage of the Falcon 9 found its way to drone ship "Just Read the Instructions" where it came close to a successful landing. According to Elon Musk's tweet "Falcon landed fine, but excess lateral velocity caused it to tip over post landing." Later it was revealed by the owner on Twitter that "Cause of hard rocket landing confirmed as due to slower than expected throttle valve response."

On June 28, 2015, the Falcon 9 disintegrated beginning at 2 minutes and 19 seconds after launch, resulting in a total loss. SpaceX CEO Elon Musk stated it was due to an "overpressure event" in the upper stage's liquid oxygen tank, though no cause has been confirmed. The Falcon 9 was carrying the Dragon vehicle and cargo intended to resupply the International Space Station. This marked the first primary mission failure for Falcon 9, following 17 fully successful launches. Preliminary reports indicate a strut failed within the second stage liquid oxygen tank, releasing a relatively buoyant helium tank. The released helium tank apparently struck the top of the oxygen tank, ruptured, and caused the explosion. In November 2015, a 10m x 4m piece of a Falcon 9 recovered between Bryher and Tresco in the Isles of Scilly was towed ashore and thought to be from the failed launch, but was later determined to be debris from the previous year's launch of CRS-4.

The most recent launch was Falcon 9 Flight 20, on December 21st 2015. The mission payload was be 11 Orbcomm-OG2 second-generation satellites. Flight 20 will also be the first flight of the upgraded Falcon 9 v1.1 full thrust. The first stage successfully landed at landing zone 1 at Cape Canaveral, the first successful recovery of a rocket that launched a payload to orbit.

See also

• Comparison of orbital launch systems
• Falcon (rocket family)

External links

• Falcon 9 official page
• Falcon Heavy official page
• Test firing of two Merlin 1C engines connected to Falcon 9 first stage, Movie 1, Movie 2 (January 18, 2008)
• Press release announcing design (September 9, 2005)
• SpaceX hopes to supply ISS with new Falcon 9 heavy launcher (Flight International, September 13, 2005)
• SpaceX launches Falcon 9, With A Customer (Defense Industry Daily, September 15, 2005)