The Big Falcon Rocket (officially shortened to BFR) is a privately funded, fully reusable launch vehicle and spacecraft system in development by SpaceX. In November 2018 the second stage and ship was renamed by CEO Elon Musk to Starship, while the first stage was given the moniker "Super Heavy." The overall space vehicle architecture includes both launch vehicle and spacecraft, as well as ground infrastructure for rapid launch and relaunch, and propellant transfer in space. The payload capacity to Earth orbit is cited as being at least 100,000 kg (220,000 lb), making BFR a super heavy-lift launch vehicle. The first orbital flight will occur no earlier than 2020, with a flight around the Moon slated for 2023.
Artistic rendition of the SpaceX Super Heavy booster lifting the Starship vehicle during ascent
|Country of origin||United States|
|Project cost||US$5 billion, estimated|
|Height||118 m (387 ft)|
|Diameter||9 m (30 ft)|
|Mass||4,400,000 kg (9,700,000 lb) [needs update]|
|Payload to LEO||150,000 kg |
|Payload to Moon||100,000+ kg (220,000+ lb)|
(with orbital refueling)
|Payload to Mars||100,000+ kg (220,000+ lb)|
(with orbital refueling)
|Launch sites||Test flights:|
|First flight||2020 (planned)|
|First stage – Super Heavy|
|Length||63 m (207 ft)|
|Diameter||9 m (30 ft)|
|Gross mass||3,065,000 kg (6,757,000 lb) [needs update]|
|Thrust||61,000 kN; 14,000,000 lbf (6,200 tf)|
|Specific impulse||330 s (3.2 km/s)|
4 / LOX
|Second stage – Starship|
|Length||55 m (180 ft)|
|Diameter||9 m (30 ft)|
|Empty mass||85,000 kg (187,000 lb) [needs update]|
|Gross mass||1,335,000 kg (2,943,000 lb) [needs update]|
|Thrust||12,000 kN; 2,600,000 lbf (1,200 tf)|
|Specific impulse||380 s (3.7 km/s) (vacuum)|
4 / LOX
SpaceX has been developing the technologies needed for a super heavy-lift launch vehicle for many years, with the design characteristics and nomenclature undergoing several revisions over time. Before 2016, the SpaceX super heavy-lift vehicle concept was referred to as the Mars Colonial Transporter (MCT). In 2016, Musk presented a specific design for a much larger 12-meter-diameter rocket called the ITS launch vehicle. In September 2017, a design was unveiled for a smaller 9 m (30 ft)-diameter vehicle—one that SpaceX believed would be more feasible to successfully fund and build—which was given the code name BFR. In 2018, the launch vehicle component parts were renamed to Starship (second stage and spaceship) and Super Heavy (first stage).
The launch vehicle design is dependent on the concurrent development work by SpaceX on the Raptor rocket engine, which is a cryogenic methalox-fueled engine that will be used for both stages of the BFR launch vehicle. Development on the Raptor began in 2012, leading to engine testing which began in 2016, flight testing after May 2019, and a full-up orbital flight test as early as 2020.
The BFR system is intended to completely replace SpaceX's existing space transportation hardware (the Falcon 9 and Falcon Heavy launch vehicles and the Dragon spacecraft), initially aiming at the Earth-orbit launch market, but explicitly adding substantial capability to support long-duration spaceflight in the cislunar and Mars transport flight environments.
The development of the BFR started in 2012, when in March, news accounts asserted that a Raptor upper-stage engine had begun development, although no details were released at that time. In October 2012, Musk publicly stated a high-level plan to build a second reusable rocket system with capabilities substantially beyond the Falcon 9/Falcon Heavy launch vehicles on which SpaceX had by then spent several billion US dollars. This new vehicle was to be "an evolution of SpaceX's Falcon 9 booster ... 'much bigger'." But he indicated that SpaceX would not be speaking publicly about it until 2013.
In June 2013, Musk stated that he intended to hold off any potential initial public offering of SpaceX shares on the stock market until after the "Mars Colonial Transporter is flying regularly."
In August 2014, media sources speculated that the initial flight test of the Raptor-driven super-heavy launch vehicle could occur as early as 2020, in order to fully test the engines under orbital spaceflight conditions; however, any colonization effort was reported to be "deep into the future".
In early 2015, Musk said that he hoped to release details in late 2015 of the "completely new architecture" for the system that would enable the colonization of Mars. Those plans were delayed, following a launch failure in June 2015 until after SpaceX returned to flight in late December 2015.
In September 2016, Musk unveiled substantial details of a SpaceX design concept for a much larger transport vehicle, 12 meters (39 ft) in diameter, the ITS launch vehicle, aimed specifically at the interplanetary transport use case. At the time, the system architecture was referred to as the "Interplanetary Transport System" (ITS) and included detailed discussion of the overall SpaceX Mars transportation mission architecture. This included the launch vehicle (the very large size 12-meter core diameter, vehicle construction material, number and type of engines, thrust, cargo and passenger payload capabilities) but also on-orbit propellant-tanker refills, representative transit times, and various portions of the Mars-side and Earth-side infrastructure that SpaceX would require to support a set of three flight vehicles. The three distinct vehicles that made up the 2016 ITS launch vehicle concept were the:
- ITS booster, the first-stage of the launch vehicle
- ITS spaceship, a second-stage and long-duration in-space spacecraft
- ITS tanker, an alternative second-stage designed to carry more propellant for refueling other vehicles in space
The talk included presentation of a larger systemic vision, aspirationally hoping that other interested parties (whether companies, individuals, or governments) would utilize the new and significantly lower-cost transport infrastructure that SpaceX hoped to build in order enable a sustainable human civilization on Mars.
In July 2017, Musk indicated that the architecture had "evolved quite a bit" since the 2016 articulation of the Mars architecture. A key driver of the updated architecture was to be making the system useful for substantial Earth-orbit and cislunar launches so that the system might pay for itself, in part, through economic spaceflight activities in the near-Earth space zone. In September 2018, a less drastic redesign was announced, stretching the second stage slightly and adding radially-steerable forward canards and aft fins, used for pitch control in a new reentry profile resembling a descending skydiver. The aft fins act as landing legs, with a third leg on the top that looks identical but serves no aerodynamic purpose.
In September 2017, at the 68th annual meeting of the International Astronautical Congress, SpaceX unveiled the updated vehicle design. Musk said "we are searching for the right name, but the code name, at least, is BFR." The 2017 revised design concept was a 9-meter (30 ft) diameter carbon-composite technology set of vehicles, using methalox-fueled Raptor rocket engine technology directed initially at the Earth-orbit and cislunar environment, later, being used for flights to Mars.
The 2017 design was cylindrical and included a small delta wing at the rear end which included a split flap for pitch and roll control. The delta wing and split flaps were said to be needed to expand the flight envelope to allow the ship to land in a variety of atmospheric densities (none, thin, or heavy atmosphere) with a wide range of payloads (small, heavy, or none) in the nose of the ship.:18:05–19:25 Three versions of the ship were described: BFS cargo, BFS tanker, and BFS crew. The cargo version will be used to launch satellites to low Earth orbit—delivering "significantly more satellites at a time than anything that has been done before"—as well as for cargo transport to the Moon and Mars. After retanking in a high-elliptic Earth orbit the spaceship is being designed to be able to land on the Moon and return to Earth without further refueling.:31:50
Additionally, the BFR system was shown to theoretically have the capability to carry passengers and/or cargo in rapid Earth-to-Earth transport, delivering its payload anywhere on Earth within 90 minutes.
By September 2017, Raptor engines had been tested for a combined total of 1200 seconds of test firing time over 42 main engine tests. The longest test was 100 seconds, which is limited by the size of the propellant tanks at the SpaceX ground test facility. The test engine operates at 20 MPa (200 bar; 2,900 psi) pressure. The flight engine is aimed for 25 MPa (250 bar; 3,600 psi), and SpaceX expects to achieve 30 MPa (300 bar; 4,400 psi) in later iterations. In November 2017, SpaceX president and COO Gwynne Shotwell indicated that approximately half of all development work on BFR was then focused on the Raptor engine.
The aspirational goal in 2017 was to send the first two cargo missions to Mars in 2022, with the goal to "confirm water resources and identify hazards" while putting "power, mining, and life support infrastructure" in place for future flights, followed by four ships in 2024, two crewed BFR spaceships plus two cargo-only ships bringing additional equipment and supplies with the goal of setting up the propellant production plant.
By early 2018, the first ship using carbon composite structure was under construction, and SpaceX had begun building a new permanent production facility to build the 9-meter vehicles at the Port of Los Angeles. Manufacture of the first ship was underway by March 2018 in a temporary facility at the port, with first suborbital test flights planned for no earlier than 2019. The company continued to state publicly its aspirational goal for initial Mars-bound cargo flights of BFR launching as early as 2022, followed by the first crewed flight to Mars one synodic period later, in 2024, consistent with the no-earlier-than dates mentioned in late-2017.
Back in 2015, SpaceX had been scouting for manufacturing facility locations to build the large rocket, with locations being investigated in California, Texas, Louisiana, and Florida. By September 2017, SpaceX had already started building launch vehicle components. "The tooling for the main tanks has been ordered, the facility is being built, we will start construction of the first ship [in the second quarter of 2018.]"
In March 2018, SpaceX publicly announced that it would manufacture its next-generation, 9-meter-diameter (30 ft) launch vehicle and spaceship at a new facility the company is constructing in 2018–2019 on Seaside Drive at the Port of Los Angeles. The company had leased an 18-acre site for 10 years, with multiple renewals possible, and will use the site for manufacturing, recovery from shipborne landings, and refurbishment of both the booster and the spaceship. Final regulatory approval of the new manufacturing facility came from the Board of Harbor Commissioners in April 2018, and the Los Angeles City Council in May. By that time, approximately 40 SpaceX employees were working on the design and construction of BFR. Over time, the project was expected to have 700 technical jobs. The permanent Port of Los Angeles facility was projected to be a 203,500-square-foot (18,910 m2) building that would be 105 feet (32 m) tall. The fully assembled launch vehicle was expected at that time to be "transported by barge, through the Panama Canal, to Cape Canaveral in Florida for launch."
In August 2018, for the first time, the US military publicly discussed interest in using the BFR. The head of USAF Air Mobility Command was specifically interested in BFRs ability to move up to 150 t (330,000 lb) of cargo to anywhere in the world using the projected Earth-to-Earth capability in under 30 minutes, for "less than the cost of a C-5". They projected the large transport capability "could happen within the next five to 10 years."
In a September 2018 announcement of a planned 2023 lunar circumnavigation mission—a private flight called #dearMoon—Musk showed a redesigned concept for the second stage and spaceship with three rear fins and two front canard fins added for atmospheric entry, replacing the previous delta wing and split flaps shown a year earlier. The revised BFR design was to use seven identically-sized Raptor engines in the second stage; the same engine model as would be used on the first stage. The second stage design had two small actuating canard fins near the nose of the ship, and three large fins at the base, two of which would actuate, with all three serving as landing legs. Additionally, SpaceX also stated in the second half of the month that they were "no longer planning to upgrade Falcon 9 second stage for reusability." The two major parts of the BFR launch vehicle were given descriptive names in November: Starship for the spaceship/upper stage and "Super Heavy" for the booster stage which Musk pointed out was "needed to escape Earth’s deep gravity well (not needed for other planets or moons)."
“New design approach”Edit
In December 2018, nine months after starting construction of some parts of the first test article carbon composite Starship low-altitude test vehicle, SpaceX CEO Musk announced a "counterintuitive new design approach" would be taken by the company: the primary construction material for the rocket's structure and propellant tanks would be "fairly heavy...but extremely strong" metal, subsequently revealed to be stainless steel.
Following a personal trip to the South Texas Launch Site in Boca Chica, Texas, Musk revealed on 23 December 2018 that the first test article Starship had been under construction there for several weeks, out in the open on SpaceX property. The "hopper" was being built from a 300-series stainless steel—not carbon composite as previously thought. According to Musk, the reason for using this material is that "it’s [stainless steel] obviously cheap, it’s obviously fast—but it’s not obviously the lightest. But it is actually the lightest. If you look at the properties of a high-quality stainless steel, the thing that isn’t obvious is that at cryogenic temperatures, the strength is boosted by 50 percent." The high melting point of 300-series still would mean the leeward side of Starship would need no insulation during reentry, while the much hotter windward side would be cooled by allowing fuel or water to bleed through micropores in a double-wall stainless steel skin, removing heat by evaporation. The test “hopper” Starship would be used on the initial test flights to characterize the vehicle and develop the landing and low-altitude/low-velocity control algorithms. The test vehicle will fly with only three Raptor methalox engines installed, reach an altitude of no more than 5 km, and the initial flight was expected no earlier than the first half of 2019.
By March 2019, SpaceX had scrapped millions of dollars worth of carbon-composite production tooling that they had purchased from Ascent Aerospace and had been delivered to SpaceX for use only the previous April, abandoned all Port of Los Angeles production plans, and shut down that composite manufacturing facility.
Super Heavy prototype assembly was planned to start no earlier than the second quarter of 2019. The first Super Heavy flights will likely fly with fewer than all 31 Raptor engines, simply because they will not be needed for the early test flights, and it will reduce the cost to SpaceX in the event of a booster failure during the early flights.
Testing began at the subsystem level, as it does with most launch vehicles, with rocket engine component tests, followed by tests of the complete rocket engine in ground test facilities. Raptor engine component-level testing began in May 2014 with the first full-engine test in September 2016. By September 2017, the development Raptor engine had undergone 1200 seconds of hotfire testing in ground-test stands across 42 main engine tests, with the longest test at that time being 100 seconds.
SpaceX had indicated in November 2018 that they were considering testing a heavily-modified Falcon 9 second stage that would look like a "mini-BFR Ship" and be used for atmospheric reentry testing of a number of technologies needed for the full-scale spaceship, including a high-Mach control surfaces. However, several weeks later, Musk clarified that SpaceX would not build a mini-BFR but would accelerate development of the full-sized BFR instead.
From October 2017, the month after the BFR concept was unveiled, flight tests of the rocket were expected to begin with short suborbital hops of the full-scale second stage, with initial test flights proposed to be as early as 2019. By September 2018, it was clear that hops of the upper stage spaceship would be conducted from the SpaceX South Texas Launch Site near Brownsville, Texas. SpaceX filed an application with the FCC in November 2018 for an experimental radio communications license to support the test flight program, with all test flights on that permit slated to remain under 5 kilometers (16,000 ft) in altitude. Both the test article Starship and the Texas launch site were under construction by late 2018.
The primary structure of the first test "Starhopper", a cut-down version of the Starship meant for low altitude tests, was complete by 10 January 2019. Later in January, while the nose and tail sections of the Starhopper were separated, high winds toppled and damaged the nose structure. The tank structure and vehicle legs remained intact.  SpaceX subsequently indicated they would not rebuild the nose cone for the first Starhopper as it was not needed for the low-velocity flight testing.
Super Heavy testsEdit
Initial flight testing of the Super Heavy booster stage will follow Starship testing. As of May 2019, SpaceX projected that the construction of the first Super Heavy would not start before August.
At least as early as 2005, SpaceX had used the descriptor "BFR" for a conceptual heavy-lift vehicle "far larger than the Falcon family of vehicles," with a goal of 100 t (220,000 lb) to orbit. Beginning in mid-2013, SpaceX referred to both the mission architecture and the vehicle as the Mars Colonial Transporter. By the time the large 12-meter diameter design was unveiled in September 2016, SpaceX had begun referring to the overall system as the Interplanetary Transport System and the launch vehicle itself as the ITS launch vehicle.
With the announcement of a new 9-meter design in September 2017, SpaceX resumed referring to the vehicle as "BFR". Musk said in the announcement "we are searching for the right name, but the code name, at least, is BFR." SpaceX President Gwynne Shotwell subsequently stated that BFR stands for "Big Falcon Rocket". However, Elon Musk had explained in the past that although BFR is the official name, he drew inspiration from the BFG weapon in the Doom video games. The BFR has also occasionally been referred to informally by the media and internally at SpaceX as "Big Fucking Rocket". The upper stage is also the spaceship, or for a time in 2017–18 was referred to as "BFS".[a] The booster first stage was also at times referred to as the "BFB".[b] In November 2018, the spaceship was renamed Starship, and the first stage booster was named Super Heavy.
Notably, in the fashion of SpaceX, even that term super heavy had been previously used by SpaceX in a different context. In February 2018, at about the time of the first Falcon Heavy launch, Musk had "suggested the possibility of a Falcon Super Heavy—a Falcon Heavy with extra boosters. 'We could really dial it up to as much performance as anyone could ever want. If we wanted to we could actually add two more side boosters and make it Falcon Super Heavy.'"
The SpaceX next-generation launch vehicle design combines several elements that, according to Musk, will make long-duration, beyond Earth orbit (BEO) spaceflights possible. The design is projected by SpaceX to reduce the per-ton cost of launches to low Earth orbit (LEO) and of transportation between BEO destinations. It will also serve all use cases for the conventional LEO market. This will allow SpaceX to focus the majority of their development resources on the next-generation launch vehicle.
The fully reusable super-heavy-lift Big Falcon Rocket (BFR) will consist of two main parts: a reusable booster stage, named Super Heavy, and a reusable second stage with an integrated payload section, named Starship.
Combining the second-stage of a launch vehicle with a long-duration spaceship will be a unique type of space mission architecture. This architecture is dependent on the success of orbital refueling.
- Both stages are being designed to be completely reusable, with the booster returning to land on the launch mount while the second-stage/spaceship will have the ability to return to near the launch mount. Both will use retropropulsive landing and the reusable launch vehicle technologies developed earlier by SpaceX.
- The full Starship-Super Heavy stack will stretch 118 m (387 ft), 25 m (82 ft) taller than the Statue of Liberty.
First stage: Super HeavyEdit
Super Heavy, the first stage, or booster, of the SpaceX next-generation launch vehicle is 63 meters (207 ft) long and 9 m (30 ft) in diameter and expected to have a gross liftoff mass of 3,065,000 kg (6,757,000 lb) It is to be constructed of stainless steel tanks and structure, holding subcooled liquid methane and liquid oxygen (CH
4/LOX) propellants, powered by 31 Raptor rocket engines providing 61.8 MN (13,900,000 lbf) total liftoff thrust. The booster is projected to return to land on the launch mount, although it might land on legs initially.
Second stage and spaceship: StarshipEdit
Starship is a reusable spacecraft that also serves as the launch vehicle second stage with an integrated payload section. It is planned to be built in at least three operational versions, with a number of limited-function prototype test articles will also be built. Starship will eventually be built in at least three operational versions:
- spaceship: a large, long-duration spacecraft capable of carrying passengers or cargo to interplanetary destinations, to LEO, or between destinations on Earth.
- tanker: a cargo-only propellant tanker to support the refilling of propellants in Earth orbit. The tanker will enable launching a heavy spacecraft to interplanetary space as the spacecraft being refueled can use its tanks twice, first to reach LEO and afterwards to leave Earth orbit.
- satellite delivery spacecraft: a vehicle with a large cargo bay door that can open in space to facilitate the placement of spacecraft into orbit, or the recovery of spacecraft and space debris.
- being designed such that the ship can return from Earth orbit and land near the launch mount using retropropulsive landing and the reusable launch vehicle technologies developed earlier by SpaceX
- landing reliability is projected by SpaceX to ultimately be able to achieve "airline levels" of safety due to engine-out capability.
- rendezvous and docking operations will be automated
- on-orbit propellant transfers from Starship tankers to Starship spaceships or cargo spaceships[c]
- a Starship and its payload will be able to transit to the Moon or fly to Mars after on-orbit propellant loading
- stainless steel structure and tank construction. Its strength-to-mass ratio is comparable to or better than the earlier SpaceX design alternative of carbon fiber composites across the anticipated temperature ranges, from the low temperatures of cryogenic propellants to the high temperatures of atmospheric reentry
- some parts of the craft will be built with a stainless steel alloy that "has undergone [a type of] cryogenic treatment, in which metals are ... cold-formed/worked [to produce a] cryo-treated steel ... dramatically lighter and more wear-resistant than traditional hot-rolled steel."
- the thermal protection system against the harsh conditions of atmospheric reentry will utilize a double stainless-steel skin with active coolant flowing in between the two layers. Hexagonal stainless steel tiles will blanket the windward side of Starship, and some areas will additionally contain multiple small pores that will allow for transpiration cooling.
- as envisioned in the 2017 design unveiling, the Starship is to have a pressurized volume of approximately 1,000 m3 (35,000 cu ft), which could be configured for up to 40 cabins, large common areas, central storage, a galley, and a solar flare shelter for Mars missions plus 12 unpressurized aft cargo containers of 88 m3 (3,100 cu ft) total.
- flexible design options; for example, a possible design modification to the base Starship—expendable 3-engine Starship with no fairing, canards, rear fins, nor landing legs—to optimize mass ratio for interplanetary exploration with robotic probes.
Launch vehicle specifications and performanceEdit
|Overall launch vehicle
(booster + ship)
|Super Heavy (booster)||Starship (spaceship/tanker/|
|LEO payload||100,000 kg (220,000 lb)-150,000 kg (330,000 lb)|
|Return payload||50,000 kg (110,000 lb)[needs update?]|
|Cargo volume||1,088+ m3 (38,400+ cu ft)||N/A||1,000+ m3 (35,000+ cu ft)|
88 m3 (3,100 cu ft)
|Diameter||9 m (30 ft)|
|Length||118 m (387 ft)||63 m (207 ft)[needs update?]||55 m (180 ft)|
|Maximum mass||4,400,000 kg (9,700,000 lb)[needs update?]||1,335,000 kg (2,943,000 lb)|
4 – 240,000 kg (530,000 lb)[needs update?]
2 – 860,000 kg (1,900,000 lb)[needs update?]
|Empty mass||85,000 kg (187,000 lb)[needs update?]|
|Engines||31 × Sea level Raptors||3 × Sea level Raptors, |
3 × vacuum optimized Raptors
|Thrust||52.7 MN (11,800,000 lbf)||11.9 MN (2,700,000 lbf) total|
The Raptor engine design chamber pressure is 25 MPa (250 bar; 3,600 psi), although SpaceX plans to increase that to 30 MPa (300 bar; 4,400 psi) in later iterations of the engine. Musk states that the engine "will be designed with an extreme focus on reliability for any single engine", and that redundant engines means it is "definitely capable of [mitigating an] engine out at any time, including two engine out, in almost all circumstances. So you could lose two engines and still be totally safe." In this way, the ship is being designed to achieve "landing reliability that is on par with the safest commercial airliners." The comments were made before SpaceX reduced the number of total engines to six.
SpaceX is building at least two Starship prototype vehicles to use as test articles for integrated system testing of various aspects of the technology that makes up Starship. The low-altitude, low-velocity Starship test flight rocket will be used for initial integrated testing of the Raptor rocket engine with a flight-capable propellant structure, and will test the newly-designed autogenous pressurization system that is replacing traditional helium tank pressurization as well as initial launch and landing algorithms for the much larger 9-meter-diameter rocket. SpaceX originally developed their reusable booster technology for the 3-meter-diameter Falcon 9 in 2012–2018. It will also be the platform for the first flight tests of the full-flow staged combustion methalox Raptor engines, where the hopper vehicle is expected to be flight tested with up to three engines to facilitate engine-out tolerance testing.
The high-altitude, high-velocity Starship orbital prototype will be used to develop and flight test novel thermal protection systems and hypersonic reentry control surfaces. The orbital prototype is expected to be outfitted with more than three Raptor engines.
The construction of the initial test article—the "Starship test flight rocket" or "test hopper" or "Starhopper"—was begun in early December 2018 and the external frame and skin was complete by 10 January 2019. The test article will be used to flight test a number of subsystems of the Starship and will be used to expand the flight envelope as this radically unusual reusable Starship second stage and spaceship continues in design, build and test for the next several years. Testing will commence at the SpaceX South Texas Launch Site near Boca Chica, Texas, with the initial testing of the low-velocity prototype anticipated as early as March, approximately one year ahead of schedule. All test flights of the "test hopper" will be low altitude, under 5 kilometers (16,000 ft).
A Starship orbital prototype test article, also referred to as the "Starship Mk I orbital design," is currently being built, with component build starting in December 2018, and vehicle structure construction starting in February 2019. Planned for high-altitude and high-velocity testing, it is expected to be completed by June 2019. The orbital prototype will be taller than the suborbital hopper, have thicker skins, and a smoothly curving nose section.
The Big Falcon Rocket launch vehicle is designed to replace all existing SpaceX vehicles and spacecraft: Falcon 9 and Falcon Heavy launch vehicles, and also the Dragon capsule. SpaceX estimates that BFR launches will be cheaper than the existing fleet, and even cheaper than the retired Falcon 1, due to full reusability and precision landing of the booster on its launch mount for simplified launch logistics. SpaceX intends to fully replace its vehicle fleet with BFRs during the early 2020s.:24:50–27:05
- existing Earth-orbit satellite delivery market
- Mars transportation, both as cargo ships as well as passenger-carrying transport
- long-duration spaceflights in the cislunar region
- (eventually) long-duration flights to the outer planets
- (possibly) commercial long-haul transport on Earth, competing with long-range aircraft.
Although both Musk and Shotwell, SpaceX's CEO and COO, have mentioned the potential of BFR to carry passengers on suborbital flights between any two points on Earth in under one hour, SpaceX has announced no concrete plans to pursue this use case. Nevertheless, the technology possibilities shown by SpaceX have surfaced theoretical transportation options that could potentially fill previously unfilled niches of transport across the globe, and analysts continue to debate the economic value of such high-speed, high-capacity cargo and passenger transportation means.
Lunar flyby tourEdit
In September 2018, SpaceX announced that it signed a contract to fly a group of private passengers around the Moon aboard Starship. In addition of the pilots, this lunar flyby will be crewed by Yusaku Maezawa, who will invite 6 to 8 artists to travel with him around the Moon in 2023. The expected travel time would be about 6 days.
Transport to Mars and Mars surface ship useEdit
Any Mars expeditions would refuel Starships in low Earth orbit before departing for Mars. Early ships would be left on Mars to house equipment, store propellant, or provide spare parts. Eventually, once humans travel to Mars, at least one of the reusable Starships from earlier flights would be capable of being refueled to provide a redundant spare spacecraft for a return journey to Earth. 
- Big Falcon Spaceship
- Big Falcon Booster
- Also known as "butt to butt" transfer
- Elon Musk (29 September 2017). Becoming a Multiplanet Species (video). 68th annual meeting of the International Astronautical Congress in Adelaide, Australia: SpaceX. Retrieved 14 December 2017 – via YouTube.
- Musk, Elon (17 September 2018). First Private Passenger on Lunar BFR Mission. SpaceX. Retrieved 18 September 2018 – via YouTube.
- Gaynor, Phillip (9 August 2018). "The Evolution of the Big Falcon Rocket". NASASpaceFlight.com. Retrieved 17 August 2018.
- Elon Musk [@elonmusk] (23 May 2019). "Aiming for 150 tons useful load in fully reusable configuration, but should be at least 100 tons, allowing for mass growth" (Tweet) – via Twitter.
- "Mars". SpaceX. Retrieved 20 September 2016.
- Foust, Jeff (12 March 2018). "Musk reiterates plans for testing BFR". SpaceNews. Retrieved 15 March 2018.
Construction of the first prototype spaceship is in progress. 'We're actually building that ship right now,' he said. 'I think we'll probably be able to do short flights, short sort of up-and-down flights, probably sometime in the first half of next year.'
- Eric Ralph (19 March 2019). "SpaceX will build and launch Starship/Super Heavy in Texas and Florida, says Musk". Retrieved 25 March 2019.
- "The first SpaceX BFR should make orbital launches by 2020". 19 March 2018. Retrieved 14 October 2018.
Boyle, Alan (19 November 2018). "Goodbye, BFR … hello, Starship: Elon Musk gives a classic name to his Mars spaceship". GeekWire. Retrieved 22 November 2018.
Starship is the spaceship/upper stage & Super Heavy is the rocket booster needed to escape Earth’s deep gravity well (not needed for other planets or moons)
- SpaceX Aims to Begin BFR Spaceship Flight Tests as Soon as Next Year. Jay Bennett, Popular Mechanics. 7 February 2018.
- Musk, Elon (28 May 2019). "3 sea level optimized Raptors, 3 vacuum optimized Raptors (big nozzle)". twitter.com. Retrieved 28 May 2019.
- "Elon Musk Says SpaceX Will Send Yusaku Maezawa (and Artists!) to the Moon". Wired. 18 September 2018. Retrieved 27 May 2019.
- Eric Berger (18 September 2016). "Elon Musk scales up his ambitions, considering going "well beyond" Mars". Ars Technica. Retrieved 19 September 2016.
- Jeff Foust (29 September 2017). "Musk unveils revised version of giant interplanetary launch system". SpaceNews. Retrieved 1 October 2017.
- William Harwood (29 September 2017). "Elon Musk revises Mars plan, hopes for boots on ground in 2024". Spaceflight Now. Retrieved 30 September 2017.
The new rocket is still known as the BFR, a euphemism for 'Big (fill-in-the-blank) Rocket.' The reusable BFR will use 31 Raptor engines burning densified, or super-cooled, liquid methane and liquid oxygen to lift 150 tons, or 300,000 pounds, to low Earth orbit, roughly equivalent to NASA’s Saturn 5 moon rocket.
- Zach Rosenberg (16 March 2012). "SpaceX readies upgraded engines". Flightglobal. Retrieved 17 January 2018.
SpaceX is in the midst of a variety of ambitious engine programmes, including the Merlin 2, a significant modification of the Merlin 1 series, and the Raptor upper stage engine. Details of both projects are tightly held.
- Gray, Tyler (28 May 2019). "SpaceX ramps up operations in South Texas as Hopper tests loom". NASASpaceFlight.com. Retrieved 9 June 2019.
- Tribou, Richard (1 May 2019). "Elon Musk shares new renderings of SpaceX Starship on moon, Mars". OrlandoSentinel.com. Retrieved 3 May 2019.
- Steve Dent (29 September 2017). "Elon Musk's Mars dream hinges on a giant new rocket". Engadget. Retrieved 9 December 2017.
- Zach Rosenberg (15 October 2012). "SpaceX aims big with massive new rocket". Flight Global. Retrieved 28 October 2015.
- "Huge Mars Colony Eyed by SpaceX Founder". Discovery News. 13 December 2012. Archived from the original on 15 November 2014. Retrieved 14 March 2014.CS1 maint: Unfit url (link)
- Rod Coppinger (23 November 2012). "Huge Mars Colony Eyed by SpaceX Founder Elon Musk". Space.com. Retrieved 10 June 2013.
The fully reusable rocket that Musk wants to take colonists to Mars is an evolution of SpaceX's Falcon 9 booster.... 'It's going to be much bigger [than Falcon 9], but I don’t think we’re quite ready to state the payload. We’ll speak about that next year,' Musk said. ... 'Vertical landing is an extremely important breakthrough — extreme, rapid reusability.'
- Steve Schaefer (6 June 2013). "SpaceX IPO Cleared For Launch? Elon Musk Says Hold Your Horses". Forbes. Retrieved 10 June 2013.
- Chris Ciaccia (6 June 2013). "SpaceX IPO: 'Possible in the Very Long Term'". The Street. Retrieved 10 June 2013.
- Alan Boyle (5 January 2015). "Coming Soon From SpaceX's Elon Musk: How to Move to Mars". NBC News. Retrieved 8 January 2015.
The Mars transport system will be a completely new architecture. Am hoping to present that towards the end of this year. Good thing we didn't do it sooner, as we have learned a huge amount from Falcon and Dragon.
- Chris Bergin (29 August 2014). "Battle of the Heavyweight Rockets -- SLS could face Exploration Class rival". NASAspaceflight.com. Retrieved 30 August 2014.
- Chris Heath (12 December 2015). "How Elon Musk Plans on Reinventing the World (and Mars)". GQ. Retrieved 12 December 2015.
- 2016 StartmeupHK Venture Forum - Elon Musk on Entrepreneurship and Innovation. StartmeupHK Venture Forum--2016 (video). Invest Hong Kong. 26 January 2016. Event occurs at 30:15-31:40. Retrieved 26 January 2016 – via YouTube.
We'll have the next generation rocket and spacecraft, beyond the Falcon and Dragon series... I'm hoping to describe that architecture later this year at the International Astronautical Congress. which is the big international space event every year. ... first flights to Mars? we're hoping to do that in around 2025 ... nine years from now or thereabouts.
- Alan Boyle (27 January 2016). "SpaceX's Elon Musk wants to go into space by 2021 and start Mars missions by 2025". GeekWire. Retrieved 29 January 2016.
- Christian Davenport (13 June 2016). "Elon Musk provides new details on his 'mind blowing' mission to Mars". Washington Post. Retrieved 14 June 2016.
- Alan Boyle (27 September 2016). "SpaceX's Elon Musk makes the big pitch for his decades-long plan to colonize Mars". GeekWire. Retrieved 3 October 2016.
- Kenneth Chang (27 September 2016). "Elon Musk's Plan: Get Humans to Mars, and Beyond". New York Times. Retrieved 27 September 2016.
- Eric Berger (28 September 2016). "Musk's Mars moment: Audacity, madness, brilliance—or maybe all three". Ars Technica. Retrieved 13 October 2016.
- Jeff Foust (10 October 2016). "Can Elon Musk get to Mars?". SpaceNews. Retrieved 12 October 2016.
- Elon Musk (19 July 2017). Elon Musk, ISS R&D Conference (video). ISS R&D Conference, Washington DC, USA. Event occurs at 49:48–51:35. Retrieved 13 September 2017 – via YouTube.
the updated version of the Mars architecture: Because it has evolved quite a bit since that last talk. ... The key thing that I figured out is how do you pay for it? If we downsize the Mars vehicle, make it capable of doing Earth-orbit activity as well as Mars activity, maybe we can pay for it by using it for Earth-orbit activity. That is one of the key elements in the new architecture. It is similar to what was shown at IAC, but a little bit smaller. Still big, but this one has a shot at being real on the economic front.
- Musk, Elon (1 March 2018). "Making Life Multi-Planetary". New Space. 6 (1): 2–11. Bibcode:2018NewSp...6....2M. doi:10.1089/space.2018.29013.emu.
- Henry, Caleb (21 November 2017). "SpaceX aims to follow a banner year with an even faster 2018 launch cadence". SpaceNews. Retrieved 15 January 2018.
Shotwell estimated that around 50 percent of the work on BFR is focused on the Raptor engines.
- Elon Musk (6 February 2018). 'Crazy things can come true': Elon Musk discusses Falcon Heavy launch: Full presser. Event occurs at 17:00. Retrieved 22 March 2019 – via YouTube.
If we get lucky, we'll be able to do short hopper flights with the spaceship part of BFR maybe next year.
- Masunaga, Samantha (19 April 2018). "SpaceX gets approval to develop its BFR rocket and spaceship at Port of Los Angeles". Los Angeles Times. Retrieved 21 April 2018.
- Berger, Eric (19 March 2018). "SpaceX indicates it will manufacture the BFR rocket in Los Angeles". Ars Technica. Retrieved 21 March 2018.
- "Fireside Chat with SpaceX President Gwynne Shotwell". Flickr.com. 11 October 2017. Retrieved 7 March 2018.
- Seemangal, Robin (1 February 2018). "SpaceX Gears Up to Finally, Actually Launch the Falcon Heavy". Wired. Retrieved 7 March 2018.
SpaceX is actively considering expanding its San Pedro, California facility to begin manufacturing its interplanetary spacecraft. This would allow SpaceX to easily shift personnel from headquarters in Hawthorne.
- Masunaga, Samantha (8 May 2018). "All systems are go for SpaceX's BFR rocket facility at Port of Los Angeles after City Council OKs plan". Los Angeles Times. Retrieved 24 May 2018.
- "Regular Meeting, Planning & Strategy, Resolution" (PDF). Port of Los Angeles. Archived from the original (PDF) on 12 June 2018. Retrieved 6 June 2018.
- Insinnia, Valerie (2 August 2018). "One possible job for SpaceX's BFR rocket? Taking the Air Force's cargo in and out of space". DefenseNews. Retrieved 9 June 2019.
- Air Mobility Command Chief Looks Toward Supplying Forces From Space, US Department of Defense, 2 August 2018.
- Eric Ralph (14 September 2018). "SpaceX has signed a private passenger for the first BFR launch around the Moon". Retrieved 14 September 2018.
- Foust, Jeff (17 November 2018). "Musk hints at further changes in BFR design". SpaceNews. Retrieved 22 March 2019.
- Elon Musk [@elonmusk] (8 December 2018). "The new design is metal" (Tweet) – via Twitter.
- Elon Musk [@elonmusk] (8 December 2018). "Fairly heavy metal, but extremely strong" (Tweet) – via Twitter.
- Ralph, Eric (9 December 2018). "SpaceX CEO Elon Musk teases new Starship photos and "heavy metal" BFR". Teslarati. Retrieved 9 December 2018.
wide-reaching changes to BFR’s general structural composite, Musk at long last confirmed what some had suspected – now known as the Starship/Super Heavy — the BFR program has officially moved away from carbon fiber composites as the primary material of choice for the rocket’s structure and propellant tanks, instead pivoting to what Musk described as a “fairly heavy metal”.
- D'Agostino, Ryan (22 January 2019). "Elon Musk: Why I'm Building the Starship out of Stainless Steel". popularmechanics.com. Popular Mechanics. Retrieved 22 January 2019.
- Ralph, Eric (24 December 2018). "SpaceX CEO Elon Musk: Starship prototype to have 3 Raptors and "mirror finish"". Teslarati. Retrieved 24 December 2018.
- Foust, Jeff (24 December 2018). "Musk teases new details about redesigned next-generation launch system". SpaceNews. Retrieved 25 December 2018.
- Ralph, Eric (20 March 2019). "SpaceX goes all-in on steel Starship, scraps expensive carbon fiber BFR tooling". Teslarati. Retrieved 22 March 2019.
- Ralph, Eric (1 February 2019). "SpaceX CEO Elon Musk reveals photos of Starship's first completed Raptor engine". TESLARATI.com. Retrieved 1 February 2019.
- Guess, Natalie (21 April 2014). "NASA, SpaceX Cut Ribbon To Launch Testing Partnership". MS EIGS. Archived from the original on 8 July 2015. Retrieved 22 April 2014.
- Belluscio, Alejandro G. (3 October 2016). "ITS Propulsion – The evolution of the SpaceX Raptor engine". NASASpaceFlight.com. Retrieved 24 November 2018.
Foust, Jeff (7 November 2018). "SpaceX to modify Falcon 9 upper stage to test BFR technologies". SpaceNews. Retrieved 8 November 2018.
Falcon 9 second stage will be upgraded to be like a mini-BFR Ship," Musk said. The BFR’s upper stage is sometimes referred to as a "spaceship
- SpaceX to build small version of BFR's spaceship for use on Falcon 9, says Elon Musk. Eric Ralph, Teslarati. 7 November 2018.
- SpaceX plans shortcut to test a mini version of its Big Falcon Rocket. Mariella Moon, EnGadget. 7 November 2018.
- SpaceX CEO Elon Musk kills mini BFR spaceship 12 days after announcing it. Eric Ralph, Teslarati. 20 November 2018.
- Jeff Foust (15 October 2017). "Musk offers more technical details on BFR system". SpaceNews. Retrieved 15 October 2017.
[The] spaceship portion of the BFR, which would transport people on point-to-point suborbital flights or on missions to the moon or Mars, will be tested on Earth first in a series of short hops. ... a full-scale Ship doing short hops of a few hundred kilometers altitude and lateral distance ... fairly easy on the vehicle, as no heat shield is needed, we can have a large amount of reserve propellant and don’t need the high area ratio, deep space Raptor engines.
- Murphy, Mike (10 January 2019). "Elon Musk shows off SpaceX's massive Starship test rocket". MarketWatch. Retrieved 12 January 2019.
- Grush, Loren. "SpaceX's new test rocket topples over thanks to strong Texas winds". theverge.com. Vox Media, Inc. Retrieved 23 January 2019.
- Ralph, Eric (22 January 2019). "SpaceX fits Starship prototype with tank bulkheads as hop test pad progresses". TESLARATI.com. Retrieved 23 January 2019.
- Ralph, Eric (17 January 2019). "SpaceX separates Starship prototype's nose and tail to install giant propellant tanks". TESLARATI.com. Retrieved 23 January 2019.
- Gebhardt, Chris (3 April 2019). "Starhopper conducts Raptor Static Fire test". NASASpaceFlight.com. Retrieved 4 April 2019.
- Jeff Foust (14 November 2005). "Big plans for SpaceX". The Space Review.
- SPACEX set maiden flight – goals, NASASpaceFlight.com, 18 November 2005, accessed 31 January 2019.
- Steve Schaefer (6 June 2013). "SpaceX IPO Cleared For Launch? Elon Musk Says Hold Your Horses". Forbes.
- "Artist's Rendering Of The BFR". SpaceX. 12 April 2017. Retrieved 3 October 2017.
- Mike Wall. "What's in a Name? SpaceX's 'BFR' Mars Rocket Acronym Explained". space.com. Retrieved 11 February 2018.
- Heath, Chris (12 December 2015). "Elon Musk Is Ready to Conquer Mars". GQ. Retrieved 14 February 2018.
- Fernholz, Tim (20 March 2018). Rocket Billionaires: Elon Musk, Jeff Bezos, and the New Space Race. Boston: Houghton Mifflin Harcourt. p. 244. ISBN 978-1328662231.
SpaceX would build a huge rocket: the BFR, or Big Falcon Rocket—or, more crudely among staff, the Big Fucking Rocket
- Slezak, Michael; Solon, Olivia (29 September 2017). "Elon Musk: SpaceX can colonise Mars and build moon base". The Guardian. London. Retrieved 21 May 2018.
- Burgess, Matt (29 September 2017). "Elon Musk's Big Fucking Rocket to Mars is his most ambitious yet". Wired UK. London: Condé Nast Publications. Retrieved 21 May 2018.
- Space tourists will have to wait as SpaceX plans bigger rocket. Stu Clark, The Guardian. 8 February 2018.
- "Making Life Multiplanetary: Abridged transcript of Elon Musk's presentation to the 68th International Astronautical Congress in Adelaide, Australia" (PDF). SpaceX. September 2017.
- SpaceX signs its first passenger to fly aboard the Big Falcon Rocket Moon mission. CatchNews. 14 September 2018.
- Dave Mosher (24 December 2018). "Elon Musk: SpaceX to launch a Starship spaceship prototype this spring". Business Insider.
- Dave Mosher (19 November 2018). "NASA 'will eventually retire' its new mega-rocket if SpaceX, Blue Origin can safely launch their own powerful rockets". New Haven Register.
- Matthew Broersma (28 December 2018). "SpaceX Starts Construction Of Mars Rocket Prototype". Silicon.co.uk.
- Lawler, Richard (20 November 2018). "SpaceX BFR has a new name: Starship". Engadget. Retrieved 21 November 2018.
- "Here are four things we learned from Elon Musk before the first Falcon Heavy launch". 5 February 2018.
- Elon Musk (27 September 2016). Making Humans a Multiplanetary Species (video). Guadalajara, Mexico: SpaceX. Event occurs at 9:20–10:10. Retrieved 10 October 2016.
So it is a bit tricky. Because we have to figure out how to improve the cost of the trips to Mars by five million percent ... [which] translates to an improvement of approximately 4 1/2 orders of magnitude. These are the key elements that are needed ... to achieve ...[this] improvement. Most of the improvement would come from full reusability—somewhere between 2 and 2 1/2 orders of magnitude—and then the other 2 orders of magnitude would come from refilling in orbit, propellant production on Mars, and choosing the right propellant.
- Jeff Foust (15 October 2017). "Musk offers more technical details on BFR system". SpaceNews. Retrieved 15 October 2017.
[Musk wrote,] "The flight engine design is much lighter and tighter, and is extremely focused on reliability."
- "8 things Elon Musk wants you to know about SpaceX's monster BFR spaceship". USA TODAY. Retrieved 27 September 2018.
- Elon Musk on Twitter: Prob wise for version 1 to have legs or we will frag a lot of launch pads, 7 February 2019
- SpaceX Starship Will "Bleed Water" From Tiny Holes, Says Elon Musk. Kristin Houser, Futurism. 22 January 2019.
- SpaceX CEO Elon Musk explains Starship's "transpiring" steel heat shield in Q&A. Eric Ralph, Teslarati News. 23 January 2019.
- Ralph, Eric (1 April 2019). "SpaceX CEO Elon Musk proposes Starship, Starlink tech for Solar System tour". Teslarati. Retrieved 3 April 2019.
- Elon Musk on Twitter: Aiming for 150 tons useful load in fully reusable configuration, but should be at least 100 tons, allowing for mass growth
- Elon Musk on Twitter: 3 sea level optimized Raptors, 3 vacuum optimized Raptors (big nozzle)
- Elon Musk (17 September 2018). First Private Passenger on Lunar Starship Mission (video). SpaceX Headquarters, Hawthorne, CA. Event occurs at 1:37:09–1:37:35. Retrieved 6 February 2019 – via YouTube.
Seven engines means it's definitely capable of [mitigating] engine out at any time, including two engine out, in almost all circumstances. So you could lose two engines and still be totally safe. In fact, [in] some cases you can lose up to four engines and still be totally fine. So it only needs three engines for landing; three out of seven.
- Berger, Eric (8 January 2019). "Here's why Elon Musk is tweeting constantly about a stainless-steel starship". Ars Technica. Retrieved 12 January 2019.
- Ralph, Eric (12 March 2019). "SpaceX begins static Starhopper tests as Raptor engine arrives on schedule". Teslarati. Retrieved 22 March 2019.
- Gebhardt, Chris (18 March 2019). "Starhopper first flight as early as this week; Starship/Superheavy updates". NASASpaceFlight.com. Retrieved 22 March 2019.
- Ralph, Eric (9 March 2019). "SpaceX's Starship prototype moved to launch pad on new rocket transporter". Teslarati. Retrieved 22 March 2019.
- @elonmusk (5 January 2019). "Aiming for 4 weeks [until the first hopper test], which probably means 8 weeks, due to unforeseen issues" (Tweet) – via Twitter.
- Kanter, Jake (11 January 2019). "Elon Musk released a photo of his latest rocket, and it already delivers on his promise of looking like liquid silver". Business Insider. Retrieved 13 January 2019.
- Elon Musk [@elonmusk] (22 December 2018). "We're building subsections of the Starship Mk I orbital design there [in San Pedro]" (Tweet) – via Twitter.
- Elon Musk [@elonmusk] (10 January 2019). "Should be done with first orbital prototype around June" (Tweet) – via Twitter.
- Chris Gebhardt (29 September 2017). "The Moon, Mars, & around the Earth – Musk updates BFR architecture, plans". NASASpaceflight.com. Retrieved 2 October 2017.
In a move that would have seemed crazy a few years ago, Mr. Musk stated that the goal of BFR is to make the Falcon 9 and the Falcon Heavy rockets and their crew/uncrewed Dragon spacecrafts redundant, thereby allowing the company to shift all resources and funding allocations from those vehicles to BFR. Making the Falcon 9, Falcon Heavy, and Dragon redundant would also allow BFR to perform the same Low Earth Orbit (LEO) and Beyond LEO satellite deployment missions as Falcon 9 and Falcon Heavy – just on a more economical scale as multiple satellites would be able to launch at the same time and on the same rocket thanks to BFR's immense size.
- Elon Musk [@elonmusk] (12 May 2018). "SpaceX will prob build 30 to 40 rocket cores for ~300 missions over 5 years. Then BFR takes over & Falcon retires. Goal of BFR is to enable anyone to move to moon, Mars & eventually outer planets" (Tweet) – via Twitter.
- Sheetz, Michael (18 March 2019). "Super fast travel using outer space could be $20 billion market, disrupting airlines, UBS predicts". CNBC. Retrieved 26 March 2019.
- Elon Musk (28 September 2017). BFR Earth to Earth (video). SpaceX. Event occurs at 1:45. Retrieved 23 December 2017 – via YouTube.
- Neil Strauss (15 November 2017). "Elon Musk: The Architect of Tomorrow". Rolling Stone. Retrieved 17 February 2018.
- Dinkin, Sam (25 March 2019). "Could suborbital point-to-point really be worth $20 billion a year in 2030?". The Space Review. Retrieved 26 March 2019.
- First Private Passenger on Lunar BFR Mission. Press conference streamed live at YouTube by SpaceX. 17 September 2018.
- "Dear Moon". Accessed: 17 September 2018.
- "SpaceX wants to use the first Mars-bound BFR spaceships as Martian habitats". Eric Ralph, TeslaRati. 27 August 2018.
- "We're going to Mars by 2024 if Elon Musk has anything to say about it". Elizabeth Rayne, SyFy Wire. 15 August 2018.
- Berger, Eric (28 September 2016). "Musk's Mars moment: Audacity, madness, brilliance—or maybe all three". Ars Technica. Retrieved 13 October 2016.
- Foust, Jeff (10 October 2016). "Can Elon Musk get to Mars?". SpaceNews. Retrieved 12 October 2016.
- Boyle, Alan (27 September 2016). "SpaceX's Elon Musk makes the big pitch for his decades-long plan to colonize Mars". GeekWire. Retrieved 3 October 2016.
- "Everything SpaceX revealed about its updated plan to reach Mars by 2022". Darrell Etherington, TechCrunch. 29 September 2017, accessed 14 September 2018.
- Paul Wooster (29 August 2018). SpaceX's Plans for Mars. 21st Annual International Mars Society Convention. Mars Society. Retrieved 2 September 2018.