SpaceX launch vehicles

Falcon Heavy

Falcon Heavy (FH) is a super heavy lift space launch vehicle designed and manufactured by SpaceX. The Falcon Heavy is a variant of the Falcon 9 launch vehicle comprising three Falcon 9 first stages: a reinforced center core, and two additional side boosters. All three boosters are capable of being recovered and reused, although most flights use unrecoverable stripped-down center cores to increase performance. The side boosters assigned to Falcon Heavy's first flight were recovered from two prior Falcon 9 missions. SpaceX successfully launched the Falcon Heavy on February 6, 2018, delivering a payload comprising Musk's personal Tesla Roadster onto a trajectory reaching the orbit of Mars.[3]

Falcon 9 "Full Thrust"

The "Full Thrust" version of Falcon 9 is an upgraded version of the Falcon 9 v1.1. It was used the first time on December 22, 2015, for the ORBCOMM-2 launch at Cape Canaveral SLC-40 launch pad.[4]

The first stage was upgraded with a larger liquid oxygen tank, loaded with subcooled propellants to allow a greater mass of fuel in the same tank volume. The second stage was also extended for greater fuel tank capacity. These upgrades brought a 33% increase to the previous rocket performance.[5] Five sub-variants have been flown; only Falcon 9 Block 5 is still active.[6]

By default the first stage lands and gets reused, although it can be expended to increase the payload capacity.[7]

Starship

Falcon 1

The Falcon 1 was a small, planned to be partially reusable rocket capable of placing several hundred kilograms into low earth orbit.[8] It also functioned as a testbed for developing concepts and components for the larger Falcon 9.[8] Initial Falcon 1 flights were launched from the US government's Reagan Test Site on the island atoll of Kwajalein in the Pacific Ocean, and represented the first attempt to fly a ground-launched rocket to orbit from that site.[9]

On March 26, 2006, the Falcon 1's maiden flight failed only seconds after leaving the pad due to a fuel line rupture.[10][11] After a year, the second flight was launched on March 22, 2007, and it also ended in failure, due to a spin stabilization problem that automatically caused sensors to turn off the Kestrel 2nd-stage engine.[9] The third Falcon 1 flight used a new regenerative cooling system for the first-stage Merlin engine, and the engine development was responsible for the almost 17-month flight delay. The new cooling system turned out to be the major reason the mission failed; because the first stage rammed into the second-stage engine bell at staging, due to excess thrust provided by residual propellant left over from the higher-propellant-capacity cooling system.[12] On September 28, 2008, the Falcon 1 succeeded in reaching orbit on its fourth attempt, becoming the first privately funded, liquid-fueled rocket to do so.[13] The Falcon 1 carried its first and only successful commercial payload into orbit on July 13, 2009, on its fifth launch.[14] No launch attempts of the Falcon 1 have been made since 2009, and SpaceX is no longer taking launch reservations for the Falcon 1 in order to concentrate company resources on its larger Falcon 9 launch vehicle and other development projects.

Falcon 9 v1.0

The first version of the Falcon 9 launch vehicle, Falcon 9 v1.0, was developed in 2005–2010, and was launched for the first time in 2010. Falcon 9 v1.0 made five flights in 2010–2013, when it was retired.

Falcon 9 v1.1

On September 8, 2005, SpaceX announced the development of the Falcon 9 rocket, which has nine Merlin engines in its first stage. The design is an EELV-class vehicle, intended to compete with the Delta IV and the Atlas V, along with launchers of other nations as well. Both stages were designed for reuse. A similarly designed Falcon 5 rocket was also envisioned to fit between[15] the Falcon 1 and Falcon 9, but development was dropped to concentrate on the Falcon 9.[16]

The first version of the Falcon 9, Falcon 9 v1.0, was developed in 2005–2010, and flew five orbital missions in 2010–2013. The second version of the launch system—Falcon 9 v1.1—has been retired meanwhile.

Falcon 9 v1.1 was developed in 2010–2013, and made its maiden flight in September 2013. The Falcon 9 v1.1 is 60 percent heavier, with 60 percent more thrust than the v1.0 version of the Falcon 9. It includes realigned first-stage engines[17] and 60 percent longer fuel tanks, making it more susceptible to bending during flight.[18] The engines themselves have been upgraded to the more powerful Merlin 1D. These improvements increased the payload capability from 10450 to 13150 kg.

The stage separation system has been redesigned and reduces the number of attachment points from twelve to three,[18] and the vehicle has upgraded avionics and software.[18]

The new first stage was also supposed to be used as side boosters on the Falcon Heavy launch vehicle.[19]

The company purchased the McGregor, Texas, testing facilities of defunct Beal Aerospace, where it refitted the largest test stand at the facilities for Falcon 9 testing. On November 22, 2008, the stand tested the nine Merlin 1C engines of the Falcon 9, which deliver 350 tf of thrust, well under the stand's capacity of 1,500 tf.[20]

The first Falcon 9 vehicle was integrated at Cape Canaveral on December 30, 2008. NASA was planning for a flight to take place in January 2010;[21] however the maiden flight was postponed several times and took place on June 4, 2010.[22] At 2:50pm EST (14:50 ET), the Falcon 9 rocket successfully reached orbit.

The second flight for the Falcon 9 vehicle was the COTS Demo Flight 1, the first launch under the NASA Commercial Orbital Transportation Services (COTS) contract designed to provide "seed money" for development of new boosters.[23] The original NASA contract called for the COTS Demo Flight 1 to occur the second quarter of 2008;[24] this flight was delayed several times, occurring at 15:43 GMT on December 8, 2010.[25] The rocket successfully deployed an operational Dragon spacecraft at 15:53 GMT.[25] Dragon orbited the Earth twice, and then made a controlled reentry burn that put it on target for a splashdown in the Pacific Ocean off the coast of Mexico.[26] With Dragon's safe recovery, SpaceX became the first private company to launch, orbit, and recover a spacecraft; prior to this mission only government agencies had been able to recover orbital spacecraft.[26] The first flight of the Falcon 9 v1.1 was September 29, 2013, from Vandenberg Air Force Base carrying several payloads including Canada's CASSIOPE technology demonstration satellite.[27] The Falcon 9 v1.1 features stretched first and second stages, and a new octagonal arrangement of the 9 Merlin-1D engines on the first stage (replacing the square pattern of engines in v1.0). SpaceX notes that the Falcon 9 v1.1 is cheaper to manufacture, and longer than v1.0. It also has a larger payload capacity: 13,150 kilograms to low Earth orbit or 4,850 kg to geosynchronous transfer orbit.[27]

Grasshopper

Grasshopper was an experimental technology-demonstrator, suborbital reusable launch vehicle (RLV), a vertical takeoff, vertical landing (VTVL) rocket.[28] The first VTVL flight test vehicle—Grasshopper, built on a Falcon 9 v1.0 first-stage tank—made a total of eight test flights between September 2012 and October 2013.[29] All eight flights were from the McGregor, Texas, test facility.

Grasshopper began flight testing in September 2012 with a brief, three-second hop. It was followed by a second hop in November 2012, which consisted of an 8-second flight that took the testbed approximately 5.4 m off the ground. A third flight occurred in December 2012 of 29 seconds duration, with extended hover under rocket engine power, in which it ascended to an altitude of 40 m before descending under rocket power to come to a successful vertical landing.[30] Grasshopper made its eighth and final test flight on October 7, 2013, flying to an altitude of 744 m before making its eighth successful vertical landing.[31] The Grasshopper test vehicle is now retired.[29]

Falcon 1e

The Falcon 1e was a proposed upgrade of the SpaceX Falcon 1. The Falcon 1e would have featured a larger first stage with a higher thrust engine, an upgraded second stage engine, a larger payload fairing, and was intended to be partially reusable. Its first launch was planned for mid-2011,[32] but the Falcon 1 and Falcon 1e were withdrawn from the market, with SpaceX citing "limited demand," before its debut.[33][34] Payloads that would have flown on the Falcon 1 were instead to be flown on the Falcon 9 using excess capacity.[35]

The Falcon 1e was to be 6.1 m longer than the Falcon 1, with an overall length of 27.4 m, but with the same 1.68 m diameter. Its first stage had a dry mass of 5680 lb, and was powered by an upgraded[36] pump-fed Merlin 1C engine burning 87000 lb of RP-1 and liquid oxygen. The first stage burn time was around 169 seconds. The second stage had a dry mass of 1200 lb and its pressure-fed Kestrel 2 engine burned 8900 lb of propellant. The restartable Kestrel 2 could burn for up to a total of 418 seconds.[37]

The Falcon 1e planned to use Aluminum Lithium alloy 2195 in the second stage, a change from the 2014 Aluminum used in the Falcon 1 second stages.[38]

Falcon 1e launches were intended to occur from Omelek Island, part of Kwajalein Atoll in the Marshall Islands, and from Cape Canaveral, however SpaceX had announced that they would consider other locations as long as there is a "business case for establishing the requested launch site".[37] Following a demonstration flight, the Falcon 1e was intended to make a series of launches carrying Orbcomm O2G spacecraft, with a total of eighteen satellites being launched, several per rocket.[39] EADS Astrium had been responsible for marketing the Falcon 1e in Europe.[32]

Falcon 5

The Falcon 5 was a proposed two-stage-to-orbit partially reusable launch vehicle designed by SpaceX.[40]

The first stage of Falcon 5 was to be powered by five Merlin engines, and the upper stage by one Merlin engine, both burning RP-1 with a liquid oxygen oxidizer. Along with the Falcon 9, it would have been the world's only launch vehicle with its first stage designed for reuse.[41]

The Falcon 5 would have been the first American rocket since the Saturn V to have full engine-out capability, meaning that with the loss of one engine, it can still meet mission requirements by burning the other four engines longer to achieve the correct orbit.[42] In comparison, the Space Shuttle only had partial engine-out capability, meaning that it was not able to achieve proper orbit by burning the remaining engines longer.[42]

In 2006, SpaceX stated that the Falcon 5 was a Falcon 9 with four engines removed.[42] Since the launchers were being co-developed, work on the Falcon 9 was also applicable to the Falcon 5.[42][43]

Falcon 9 Air

Falcon 9 Air would have been an air-launched multi-stage launch vehicle under development by SpaceX in 2011–2012. Falcon 9 Air was to be carried to launch position and launch altitude by a Stratolaunch Systems carrier aircraft, the world's largest aircraft by wingspan. Payload to low Earth orbit was projected to be 6100 kg.

Propulsion for the rocket was planned to be provided by four Merlin 1D rocket engines, engines that were also to be used in the Falcon 9 v1.1 beginning in 2013, and also on the Falcon Heavy in 2014. Its first flight was notionally planned for 2016.

In December 2011 Stratolaunch Systems announced that it would contract with SpaceX to develop an air-launched, multiple-stage launch vehicle, as a derivative of Falcon 9 technology, called the Falcon 9 Air,[44] as part of the Stratolaunch project.[45] As initially conceived with the SpaceX Falcon 9 Air (F9A) launch vehicle, Stratolaunch was to initially place satellites of up to 6100 kg into low Earth orbit; and once established as a reliable system, announced that it would explore a human-rated version.[46] The system can take off from airfields with a minimum 3700 m length, and the F9A carrier aircraft was proposed to travel to a launch point up to 2200 km away from the airfield and fly at a launch altitude of 9100 m.[45]

A month after the initial announcement, Stratolaunch confirmed that the first stage of the F9A launch vehicle would have only four engines, not the five that were shown in the mission video in December, and that they would be SpaceX Merlin 1D engines.[47]

As initially announced, Stratolaunch Systems was a collaborative project that included subcontractors SpaceX, Scaled Composites, and Dynetics, with funding provided by Microsoft co-founder Paul G. Allen's Vulcan investment and project management company.[48] Stratolaunch set out to build a mobile launch system with three primary components: a carrier aircraft (aircraft concept was designed by Burt Rutan, but the aircraft will be designed and built by Scaled Composites); a multi-stage launch vehicle to be developed and built by SpaceX; and a mating and integration system—allowing the carrier aircraft to safely carry and release the booster—to be built by Dynetics, a Huntsville, Alabama-based engineering company.[46] The whole system will be the largest aircraft ever built; with the first test flight of the carrier aircraft originally expected in 2015 from Scaled Composites' facilities in Mojave, California,[46] while the first test launch of the rocket was not expected before 2016 at the time of the project getting underway.[49]

As the Stratolaunch development program progressed, it became clear that Stratolaunch and the system integrator, Dynetics, wanted modifications to the SpaceX basic launch-vehicle design that SpaceX felt were not strategic to the direction they were growing the company. These included requested modifications to the launch vehicle to add chines.

Development ceased in the fourth quarter of 2012, as SpaceX and Stratolaunch "amicably agreed to end [their] contractual relationship because the [Stratolaunch] launch vehicle design [had] departed significantly from the Falcon derivative vehicle envisioned by SpaceX and does not fit well with [SpaceX's] long-term strategic business model".

On November 27, 2012, Stratolaunch announced that they would partner with Orbital Sciences Corporation—initially on an air-launched vehicle study contract—instead of SpaceX, effectively ending development of the Falcon 9 Air.[50]

In May 2013, the Falcon 9 Air was eventually replaced in the development plan by the Orbital Sciences Pegasus II air-launched rocket.[51]