Falcon Heavy is a reusable super heavy-lift launch vehicle being designed and manufactured by SpaceX. The Falcon Heavy (previously known as the Falcon 9 Heavy ) is a variant of the Falcon 9 launch vehicle and will consist of a strengthened Falcon 9 rocket core with two additional Falcon 9 first stages as strap-on boosters.  This will increase the low Earth orbit (LEO) maximum payload to 63.8 metric tonnes, compared to 22.8 tonnes for a Falcon 9 full thrust. Falcon Heavy was designed from the outset to carry humans into space and would enable crewed missions to the Moon or Mars.
The Falcon Heavy's design is based on the Falcon 9, and setbacks in the development of both rockets have pushed back the maiden voyage of the Falcon Heavy. The LC-39A launch pad is being modified to be the launch site for Falcon Heavy.  SpaceX Falcon Heavy's test flight occured in February 2018. According to SpaceX founder Elon Musk, its first payload will be his midnight cherry Tesla Roadster. 
Concepts for a Falcon Heavy launch vehicle were initially discussed as early as the mid-2000s. SpaceX unveiled the grand plan for the Falcon Heavy to the public at a Washington DC news conference in April 2011, with initial test flight expected in 2013.  In the event, a number of factors delayed the planned maiden flight to 2017, including two anomalies with Falcon 9 launch vehicles that put all engineering resources dedicated to failure analysis and many months of halted flight operations. The integration and structural challenges of combining three Falcon 9 cores were much more difficult than expected.  Elon Musk stated publicly in July 2017 that "It actually ended up being way harder to do Falcon Heavy than we thought. ... Really way, way more difficult than we originally thought. We were pretty naive about that."  The initial test flight is currently intended to be no earlier than January 2018  .
Conception and funding
Elon Musk first mentioned Falcon Heavy in a September 2005 news update, referring to a customer request from 18 months prior.  Various solutions using the planned Falcon 5 had been explored, but the only cost-effective, reliable iteration was one that used a 9-engine first stage - the Falcon 9. Further exploration of the capabilities of the notional Falcon 9 vehicle led to a Falcon 9 Heavy concept.
Design and development
Since the Falcon Heavy design is based on Falcon 9's fuselage and engines, the first flight of Falcon Heavy is dependent on the development of Falcon 9.
By 2008, SpaceX were aiming for the first launch of Falcon 9 in 2009, and "Falcon 9 Heavy would be in a couple of years." Speaking at the 2008 Mars Society Conference, Elon Musk also said that a hydrogen-fuelled upper stage would follow 2–3 years later (notionally 2013).  The Falcon Heavy is being developed with private capital. No government financing is being provided for its development. 
By April 2011, the capabilities of the Falcon 9 vehicle and performance were better understood, SpaceX having completed 2 successful demonstration missions to LEO, one of which included reignition of the second-stage engine. At a press conference at the National Press Club in Washington, DC. on 5 April 2011, Elon Musk stated that Falcon Heavy would "carry more payload to orbit or escape velocity than any vehicle in history, apart from the Saturn V Moon rocket […] and Soviet Energia rocket.”  In 2015, SpaceX announced a number of changes to the Falcon Heavy rocket, worked in parallel to the upgrade of the Falcon 9 v1.1 launch vehicle. 
In 2011, with the expected increase in demand for both variants, SpaceX announced plans to expand manufacturing capacity "as we build towards the capability of producing a Falcon 9 first stage or Falcon Heavy side booster every week and an upper stage every two weeks."  In December 2016, SpaceX released a photo showing the Falcon Heavy interstage at the company headquarters in Hawthorne, California. 
By May 2013, a new, partially underground test stand was being built at the SpaceX Rocket Development and Test Facility in McGregor, Texas specifically to test the triple cores and twenty-seven rocket engines of the Falcon Heavy.  By May 2017, SpaceX did the first static fire test of flight-design Falcon Heavy center core at the McGregor facility.   By September 2017, all three first stage cores had completed static fire testing on the ground test stand. 
In July 2017, Musk discussed publicly the challenges of testing a complex launch vehicle like the three-core Falcon Heavy. There is a large extent of the new design "that is really impossible to test on the ground" and cannot really be tested until flight tests begin. 
In April 2011, Elon Musk was targeting a first launch of Falcon Heavy from Vandenberg Air Force Base on the West Coast in 2013.   SpaceX refurbished Launch Complex 4E at Vandenberg AFB to accommodate Falcon 9 and Heavy. The first launch from the Cape Canaveral East Coast launch complex was planned for late 2013 or 2014. 
By September 2015, impacted by the failure of SpaceX CRS-7 that June, SpaceX rescheduled the maiden Falcon Heavy flight for April/May 2016,  but by February 2016 had moved that back again to late 2016. The flight was now to be launched from the refurbished Kennedy Space Center Launch Complex 39 A.   In August 2016, the demonstration flight was moved to early 2017,  then to summer 2017,  to late 2017  and to January 2018.  Further missions were rescheduled accordingly.
A second demonstration flight is currently scheduled for 2018 with the STP-2 US Air Force payload.  Operational GTO missions for Intelsat and Inmarsat, which were planned for late 2017, were moved to the Falcon 9 Full Thrust rocket version as it became powerful enough to lift those heavy payloads in its expendable configuration.   The first commercial GTO mission is also scheduled in 2018 for Arabsat. 
At a July 2017 meeting of the International Space Station Research and Development meeting in Washington, DC, Musk downplayed expectations for the success of the maiden flight saying "there's a real good chance the vehicle won't make it to orbit" and "I hope it makes it far enough away from the pad that it does not cause pad damage. I would consider even that a win, to be honest."  Musk went on to say the integration and structural challenges of combining 3 Falcon 9 cores were much more difficult than expected.  
The Heavy configuration consists of a structurally-strengthened Falcon 9 as the "core" component, with two additional Falcon 9 first stages acting as liquid strap-on boosters,  which is conceptually similar to EELV Delta IV Heavy launcher and proposals for the Atlas V Heavy and Russian Angara A5V. Falcon Heavy will have more lift capability than any other operational rocket, with a payload of 64,000 kilograms (141,000 lb) to low earth orbit and 16,800 kilograms (37,000 lb) to trans-Mars injection.  The rocket was designed to meet or exceed all current requirements of human rating. The structural safety margins are 40% above flight loads, higher than the 25% margins of other rockets.  Falcon Heavy was designed from the outset to carry humans into space and it would restore the possibility of flying crewed missions to the Moon or Mars. 
The first stage is powered by three Falcon 9 derived cores, each equipped with nine Merlin 1D engines. The Falcon Heavy has a total sea-level thrust at liftoff of 22,819 kN (5,130,000 lb f ), from the 27 Merlin 1D engines, while thrust rises to 24,681 kN (5,549,000 lb f ) as the craft climbs out of the atmosphere.  The upper stage is powered by a single Merlin 1D engine modified for vacuum operation, with a thrust of 934 kN (210,000 lb f ), an expansion ratio of 117:1 and a nominal burn time of 397 seconds. For added reliability of restart, the engine has dual redundant pyrophoric igniters ( TEA - TEB).  The interstage, which connects the upper and lower stage for Falcon 9, is a carbon fiber aluminum core composite structure. Stage separation occurs via reusable separation collets and a pneumatic pusher system. The Falcon 9 tank walls and domes are made from aluminium-lithium alloy. SpaceX uses an all- friction stir welded tank. The second stage tank of Falcon 9 is simply a shorter version of the first stage tank and uses most of the same tooling, material and manufacturing techniques. This approach reduces manufacturing costs during vehicle production. 
All three cores of the Falcon Heavy arrange the engines in a structural form SpaceX calls Octaweb , aimed at streamlining the manufacturing process,  and each core will include four extensible landing legs.  To control the descent of the boosters and center core through the atmosphere, SpaceX uses small grid fins which deploy from the vehicle after separation. After the side boosters separate, the center engine in each will burn for a few seconds in order to control the booster’s trajectory safely away from the rocket.   The legs will then deploy as the boosters turn back to Earth, landing each softly on the ground. The center core will continue to fire until stage separation, after which its legs will deploy and land it back on Earth as well. The landing legs are made of carbon fiber with aluminum honeycomb. The four legs stow along the sides of each core during liftoff and later extend outward and down for landing. Both the grid fins and the landing legs on the Falcon Heavy are currently undergoing testing on the Falcon 9 launch vehicle, which are intended to be used for vertical landing once the post-mission technology development effort is completed. 
The Falcon Heavy falls into the super heavy-lift range of launch systems under the classification system used by a NASA human spaceflight review panel.
The initial concept (Falcon 9-S9 2005) envisioned payloads of 24,750 kilograms (54,560 lb) to LEO, but by April 2011 this was projected to be up to 53,000 kilograms (117,000 lb)  with GTO payloads up to 12,000 kilograms (26,000 lb).  Later reports in 2011 projected higher payloads beyond LEO, including 19,000 kilograms (42,000 lb) to geostationary transfer orbit, 16,000 kilograms (35,000 lb) to translunar trajectory, and 14,000 kilograms (31,000 lb) on a trans-Martian orbit to Mars.  
By late 2013, SpaceX raised the projected GTO payload for Falcon Heavy to up to 21,200 kilograms (46,700 lb). 
In April 2017, the projected LEO payload for Falcon Heavy was raised from 54,400 kilograms (119,900 lb) (nearly 60 short tons) to 63,800 kilograms (140,700 lb) (about 70 short tons). The maximum payload is achieved when the rocket flies a fully expendable launch profile, not recovering any of the three first-stage boosters. 
|Destination||Falcon Heavy||Falcon 9|
| Aug 2013 |
to Apr 2016
| May 2016 |
to Mar 2017
|Since Apr 2017|
|LEO (28.5°)||53,000 kg||54,400 kg||63,800 kg||22,800 kg|
|GTO (27°)||21,200 kg||22,200 kg||26,700 kg||8,300 kg|
|GTO (27°) reusable||6,400 kg||6,400 kg||8,000 kg||5,500 kg|
|Mars||13,200 kg||13,600 kg||16,800 kg||4,020 kg|
|Pluto||-||2,900 kg||3,500 kg||-|
Falcon Heavy was originally designed with a unique propellant crossfeed capability, where the center core engines are supplied with fuel and oxidizer from the two side cores, up until the side cores are near empty and ready for the first separation event.  Igniting all engines from all three cores at launch and operating them at full thrust with fuel mainly from the side boosters would deplete the side boosters sooner, allowing their earlier separation, in turn leaving the central core with most of its propellant at booster separation.  The propellant crossfeed system, nicknamed "asparagus staging", comes from a proposed booster design in a book on orbital mechanics by Tom Logsdon. According to the book, an engineer named Ed Keith coined the term "asparagus-stalk booster" for launch vehicles using propellant crossfeed.  Elon Musk has stated that crossfeed is not currently planned to be implemented, at least in the first Falcon Heavy version. 
Current plans have the center booster throttling down shortly after liftoff and resuming full thrust after side boosters separate. 
Although not a part of the initial Falcon Heavy design, SpaceX is doing parallel development on a reusable rocket launching system that is intended to be extensible to the Falcon Heavy, recovering all parts of the rocket.
Early on, SpaceX had expressed hopes that all rocket stages would eventually be reusable. SpaceX has since demonstrated both land and sea recovery of the first stage of the Falcon 9 a number of times and have made attempts to recover the fairing.  This approach is 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 both moving at a lower velocity at the initial separation event.  Since late 2013, every Falcon 9 first stage has been instrumented and equipped as a controlled-descent test vehicle. For the first flight of Falcon Heavy, SpaceX is considering the possibility of recovering the second stage. 
SpaceX has indicated that the Falcon Heavy payload performance to geosynchronous transfer orbit (GTO) will be reduced due to the addition of the reusable technology, but would fly at much lower launch price. With full reusability on all three booster cores, GTO payload will be 8,000 kg (18,000 lb). If only the two outside cores fly as reusable cores while the center core is expendable, GTO payload would be approximately 16,000 kg (35,000 lb).  "Falcon 9 will do satellites up to roughly 3.5 tonnes, with full reusability of the boost stage, and Falcon Heavy will do satellites up to 7 tonnes with full reusability of the all three boost stages," [Musk] said, referring to the three Falcon 9 booster cores that will comprise the Falcon Heavy's first stage. He also said Falcon Heavy could double its payload performance to GTO "if, for example, we went expendable on the center core."
At an appearance in May 2004 before the United States Senate Committee on Commerce, Science, and Transportation, Elon Musk testified, "Long term plans call for development of a heavy lift product and even a super-heavy, if there is customer demand. We expect that each size increase would result in a meaningful decrease in cost per pound to orbit. ... Ultimately, I believe $500 per pound or less is very achievable."  This $500 per pound ($1,100/kg) goal stated by Musk in 2011 is 35% of the cost of the lowest-cost-per-pound LEO -capable launch system in a circa-2000 study: the Zenit, a medium-lift launch vehicle that can carry 14,000 kilograms (30,000 lb) into LEO. 
As of March 2013, Falcon Heavy launch prices are below $1,000 per pound ($2,200/kg) to low-Earth orbit when the launch vehicle is transporting its maximum delivered cargo weight. The published prices for Falcon Heavy launches have moved some from year to year, with announced prices for the various versions of Falcon Heavy priced at $80–125 million in 2011,  $83–128M in 2012,  $77–135M in 2013,  $85M for up to 6,400 kilograms (14,100 lb) to GTO in 2014, and $90M for up to 8,000 kilograms (18,000 lb) to GTO in 2016 (with no published price for heavier GTO or any LEO payload).  Launch contracts typically reflect launch prices at the time the contract is signed.
In 2011, SpaceX stated that the cost of reaching low Earth orbit could be as low as US$1,000/lb if an annual rate of four launches can be sustained, and as of 2011 planned to eventually launch as many as 10 Falcon Heavy and 10 Falcon 9 annually.  A third launch site, intended exclusively for SpaceX private use, is planned at Boca Chica near Brownsville, Texas. SpaceX expected to start construction on the third Falcon Heavy launch facility, after final site selection, no earlier than 2014, with the first launches from the facility no earlier than 2016.  In late 2013, SpaceX had projected Falcon Heavy's inaugural flight to be sometime in 2014, but as of October 2017 the first launch was expected to occur at the end of 2017 due to limited manufacturing capacity and the need to deliver on the Falcon 9 launch manifest.   In November 2017 the initial launch date was pushed back to January 2018. 
By late 2013, SpaceX prices for space launch were already the lowest in the industry.  SpaceX's price savings from their reused spacecraft, which could be up to 30%, could lead to a new economically driven space age.  
Scheduled launches and potential payloads
|January, 2018 ||Falcon Heavy Demo||SpaceX||Elon Musk's midnight cherry Tesla Roadster toward Mars. |
|Early 2018 ||Arabsat 6A||Arabsat||Saudi Arabian communications satellite.|
|April 30, 2018 ||USAF STP -2||DoD||The mission will support the U.S. Air Force EELV certification process for the Falcon Heavy.  Secondary payloads include LightSail, Prox-1 nanosatellite, GPIM,    the Deep Space Atomic Clock,  six COSMIC-2 satellites,   and the ISAT satellite. |
|Q4, 2018 ||Crew Dragon||Private citizens||Crewed Dragon 2 capsule with two private citizens on board. First lunar tourists, first manned Falcon Heavy. Mission will be on a free-return trajectory to the Moon.|
|2020 ||ViaSat-3 ||ViaSat|
First commercial contracts
In May 2012, SpaceX announced that Intelsat had signed the first commercial contract for a Falcon Heavy flight. It was not confirmed at the time when the first Intelsat launch would occur, but the agreement will have SpaceX delivering satellites to geosynchronous transfer orbit (GTO).   In August 2016, it emerged that this Intelsat contract had been reassigned to a Falcon 9 Full Thrust mission to deliver Intelsat 35e into orbit in the third quarter of 2017.  Performance improvements of the Falcon 9 vehicle family since the 2012 announcement, advertising 8,300 kg to GTO for its expendable flight profile,  enable the launch of this 6-tonne satellite without upgrading to a Falcon Heavy variant.
In 2014, Inmarsat booked 3 launches with Falcon Heavy,  but due to delays they switched a payload to Ariane 5 for 2017.  Similarly to the Intelsat 35e case, another satellite from this contract, Inmarsat 5-F4, was switched to a Falcon 9 Full Thrust thanks to the increased liftoff capacity.  The remaining contract covers the launch of Inmarsat 6-F1 in 2020 on a Falcon 9. 
First DoD contract: USAF
In December 2012, SpaceX announced its first Falcon Heavy launch contract with the United States Department of Defense (DoD). "The United States Air Force Space and Missile Systems Center awarded SpaceX two Evolved Expendable Launch Vehicle (EELV)-class missions" including the Space Test Program 2 (STP-2) mission for Falcon Heavy, originally scheduled to be launched in March 2017,  but later postponed to the third quarter of 2017,  to be placed at a near circular orbit at an altitude of ~700 km, with an inclination of 70°.  The Green Propellant Infusion Mission (GPIM) will be a STP-2 payload; it is a technology demonstrator project partly developed by the US Air Force.   Another secondary payload is the miniaturized Deep Space Atomic Clock. 
In April 2015, SpaceX sent the "U.S. Air Force an updated letter of intent April 14 outlining a certification process for its Falcon Heavy rocket to launch national security satellites." The process includes three successful flights of the Falcon Heavy including two consecutive successful flights, and states that Falcon Heavy can be ready to fly national security payloads by 2017.  But in July 2017, SpaceX announced that the first test flight would take place in December 2017, pushing the launch of the second launch (Space Test Program 2) to late 2018. 
Crewed circumlunar flight
On February 27, 2017, SpaceX CEO Elon Musk announced that the company will attempt to fly two private citizens on a free-return trajectory around the Moon in late 2018.  The Dragon 2 spacecraft would launch on the Falcon Heavy booster. The two private citizens, who have not yet been named, approached SpaceX about taking a trip around the Moon and have "already paid a significant deposit" for the cost of the mission, according to a statement from the company. The names of the two individuals will be announced later, pending the result of initial health tests to ensure their fitness for the mission, the statement said.  The two passengers would be the only people on board what SpaceX expects to be about a week-long trip around the Moon, according to Musk, who spoke with reporters during a phone conference. "This would be a long loop around the moon. [...] It would skim the surface of the moon, go quite a bit further out into deep space and then loop back to Earth," Musk said during the teleconference. "So I'm guessing, distance-wise, maybe [about 500,000 to 650,000 kilometers].  The Dragon spacecraft would operate, in large part, autonomously, but the passengers would have to train for emergency procedures. The Dragon 2 capsule will require some upgrades for the deep-space flight, but Musk said that those would be limited mainly to installing a long-range communications system.
Solar System transport missions
In 2011, NASA Ames Research Center proposed a Mars mission called Red Dragon that would use a Falcon Heavy as the launch vehicle and trans-Martian injection vehicle, and a variant of the Dragon capsule to enter the Martian atmosphere. The proposed science objectives were to detect biosignatures and to drill 3.3 feet (1.0 m) or so underground, in an effort to sample reservoirs of water ice known to exist under the surface. The mission cost as of 2011 was projected to be less than US$ 425,000,000, not including the launch cost.  SpaceX announced in 2017 that propulsive landing for Dragon 2 would not be developed further, and that the capsule would not receive landing legs. Consequently, the Red Dragon missions to Mars were cancelled in favor of a larger vehicle using a different landing technique. 
Beyond the Red Dragon concept, SpaceX was expecting Falcon Heavy and Dragon 2 to carry science payloads across much of the solar system, in cislunar and inner solar system regions such as the Moon and Mars, as well as to outer solar system destinations such as Jupiter's moon Europa. SpaceX planned to transport 2,000–4,000 kg (4,400–8,800 lb) to the surface of Mars, with a soft retropropulsive landing following a limited atmospheric deceleration. When the destination has no atmosphere, the Dragon variant would dispense with the parachute and heat shield and add additional propellant.  With the cancellation of the Red Dragon capsule variant, those plans are now outdated.