BFR ( Rocket )
Last Update: 20 September 2018
The Big Falcon Rocket (officially shortened to BFR) is a privately funded next-generation fully reusable launch vehicle and spacecraft system in development by SpaceX. The overall space vehicle architecture includes both launch vehicles and spacecraft, as well as ground infrastructure for rapid launch and relaunch, and zero-gravity propellant transfer technology to be deployed in low Earth orbit (LEO). The payload capacity to Earth orbit of at least 100,000 kg (220,000 lb) makes BFR a super heavy-lift launch vehicle.
SpaceX have been developing a super heavy-lift launch vehicle for many years, and the exact design (and nomenclature) of the vehicle has undergone multiple revisions over time. Before 2016, the vehicle was referred to as the Mars Colonial Transporter (MCT), though very few details about the design of the MCT were ever made public. Starting from 2016, SpaceX began sharing annual updates with the public, detailing the designs and uses of their upcoming new launch vehicle. In 2016, SpaceX CEO Elon Musk presented the vehicle at the International Astronautical Congress as the ITS launch vehicle, forming a core part of Musk's comprehensive vision for an Interplanetary Transport System (ITS).
The ITS vehicle had a 12-meter (39 ft) core diameter, but was only intended for interplanetary travel. In September 2017, the design (now known as the BFR) was scaled down to 9 meters (30 ft).
While the ITS had been solely aimed at Mars transit and other interplanetary uses, SpaceX pivoted to a plan that would support all SpaceX launch service provider capabilities with a single set of 9-meter vehicles: Earth orbit, lunar orbit, Interplanetary spaceflight, and potentially, even intercontinental passenger transport on Earth.
In September 2018, the second stage was redesigned, adding steerable canards, two radially adjustable wings also acting as landing legs, and a third leg that looks like a vertical stabilizer but has no aerodynamic function due to the special re-entry profile of the spacecraft.
The launch vehicle design is dependant on the concurrent development work on the Raptor rocket engines, which are cryogenic methalox-fueled engines to be used for both stages of the BFR launch vehicle. Development for on the Raptor began in 2012, leading to engine testing which began in 2016.
The BFR system is intended to completely replace all of SpaceX's existing space 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.
Elon Musk has long spoken of his personal goal of enabling human exploration of Mars. Disappointed at the lack of progress, Musk in 2001 conceptualized Mars Oasis, a project to land a miniature experimental greenhouse and grow plants on Mars, in an attempt to regain public interest in space exploration and increase the budget of NASA. After attempts to purchase Dnepr rockets from Russia failed, Musk in 2001 founded SpaceX with the stated aim of "enabling life to become multiplanetary".
The goal of enabling human exploration gradually transformed into colonization of Mars, and it became clear that very large launch vehicles would be required. Additional information about the mission architecture was released between 2011 and 2015, including a 2014 statement that the first crewed missions would arrive at Mars no earlier than the middle of the 2020s with the primary objective of building a propellant production depot.
Company statements in 2016 indicated that SpaceX was "being intentionally fuzzy about the timeline ... We're going to try and make as much progress as we can with a very constrained budget."
SpaceX have indicated that they only intend to create the transport system to Mars, and that other aspects of colonization (habitats, mining, etc.) will need to be contributed by third parties. A successful colonization would ultimately involve many more economic actors—whether individuals, companies, or governments—to facilitate the growth of the human presence on Mars over many decades. Work contributed by others will allow colonization to progress far beyond what SpaceX projects to build alone.
In March 2012, news accounts asserted that a Raptor upper-stage engine had begun development, although details were not 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 Musk 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, at the 67th annual meeting of the International Astronautical Congress, Musk unveiled substantial details of the design for the transport vehicles. At the time, the system architecture was referred to as the "Interplanetary Transport System" (ITS) the details announced at IAC included the very large size (12 meters (39 ft) core diameter), construction material, number and type of engines, thrust, cargo and passenger payload capabilities, in-orbit propellant-tanker refills, representative transit times, and portions of the Mars-side and Earth-side infrastructure that SpaceX intends to build to support a set of three flight vehicles. The three distinct vehicles that made up the ITS launch vehicle in the 2016 design 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
In addition, Musk spoke 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 as to build in order to help build a sustainable human civilization on Mars, and so meeting the demand that such a growing venture would occasion
In the 2016 plan, SpaceX aimed to fly its earliest research spacecraft missions to Mars using its Falcon Heavy launch vehicle and a modified Dragon spacecraft, called Red Dragon prior to the completion, and first launch, of any ITS launch vehicle. Later Mars missions using ITS were slated at that time to begin no earlier than 2022. Those plans later changed, initially with a February 2017 announcement that no SpaceX Mars mission would occur before 2020, two years later than the previously mentioned 2018 Falcon Heavy/Dragon2 exploratory mission, and then, in July 2017, by dropping the plan to use a soft lander Red Dragon spacecraft entirely.
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 2017, at the 68th annual meeting of the International Astronautical Congress, SpaceX unveiled the updated vehicle architecture. Musk said "we are searching for the right name, but the code name, at least, is BFR." The 2017 design is a 9-meter (30 ft) diameter technology, using methalox-fueled Raptor rocket engine technology directed initially at the Earth-orbit and cislunar environment, later, being used for flights to Mars.
Aerodynamics of the BFR second stage (the Big Falcon Spaceship, or BFS) changed from the 2016-design launch vehicle. The 2017 design is cylindrical with a small delta wing at the rear end which includes a split flap for pitch and roll control. The delta wing and split flaps are needed to expand the flight envelope to allow the ship to land in a variety of atmospheric densities (no, thin, or heavy atmosphere) with a wide range of payloads (small, heavy, or none) in the nose of the ship. There are three versions of the ship: 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.
Additionally, the BFR system would have the capability to carry passengers and/or cargo in rapid Earth-to-Earth transport, delivering its payload anywhere on Earth within 90 minutes.
As of 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 current development work on BFR is focused on the Raptor engine.
The aspirational goal is 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.
In an announcement held at SpaceX's Hawthorne headquarters in September 2018, Elon Musk showed a redesign of the BFS with added wings and canard fins. The new BFR concept has seven same-sized Raptor engines in the second stage. The second stage also has two small actuating fins near the nose of the ship, and three large fins at the base, two of which actuate, and all three doubling as landing legs.
As of 2018, a new production facility to build the vehicles is under construction in the Port of Los Angeles. Manufacture of the first ship was underway by March 2018 with first suborbital test flights planned for 2019. The company publicly stated an 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. Additionally, the BFR is to be used for the SpaceX lunar tourism mission, a proposed private mission to fly space tourists around the Moon, crewed by Yusaku Maezawa along with a few artists from different art backgrounds.
CONSTRUCTION OF MANUFACTURING FACILITY
Around 2015, SpaceX was 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 indicated that it would manufacture its next-generation, 9-meter-diameter (30 ft) launch vehicle and spaceship at a new facility the company will construct in 2018–2019 on Seaside Drive near Berth 240. The company has 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 BFR booster and the BFR spaceship. Final approval of the new manufacturing facility came from the Board of Harbor Commissioners in April 2018, and the Los Angeles City Council in May. At that time, around 40 SpaceX employees were working on the design and construction of BFR. Over time, the project is expected to have 700 technical jobs. The facility is expected to be a 203,500-square-foot (18,910 m2) prefabricated building that would be 105 feet (32 m) tall.
The fully assembled launch vehicle will be "transported by barge, through the Panama Canal, to Cape Canaveral in Florida for launch."
Flight tests at the subsystem level of BFR is expected to begin with short suborbital hops of the full-scale ship, likely to be just a few hundred kilometers altitude and lateral distance. In March 2018, Musk stated that "construction of the first prototype spaceship is in progress" and that initial suborbital test flights were possible as early as 2019. Hops of the upper stage spaceship (BFS) might be conducted from the SpaceX South Texas Launch Site that is currently under construction near Brownsville, Texas, or from drone ship to drone ship.
The descriptor for the large SpaceX Mars rocket has varied over the past five years that SpaceX has publicly released information about the project. Beginning in mid-2013, and prior to September 2016, SpaceX had referred to both the architecture and the vehicle as the Mars Colonial Transporter. From September 2016 through August 2017, the overall system was referred to by SpaceX as the Interplanetary Transport System and the very large 12-meter-diameter (39 ft) launch vehicle itself as the ITS launch vehicle.
"BFR" is the current code name for SpaceX's privately funded launch vehicle announced by Elon Musk in September 2017. SpaceX President Gwynne Shotwell has stated that BFR stands for "Big Falcon Rocket". However, Elon Musk has explained that although BFR is the official name, he drew inspiration from the BFG weapon in the Doom video games. The BFR has been referred to informally by the media and internally at SpaceX as "Big Fucking Rocket". The upper stage is the Spaceship, or BFS.
The BFR design combines several elements that, according to Musk, will make long-duration, beyond Earth orbit (BEO) spaceflights possible. They will reduce the per-ton cost of launches to low Earth orbit (LEO) and of transportation between BEO destinations. They will also serve all usage 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 BFR will consist of a:
- "BFR booster": a reusable booster stage.
- a reusable, integrated second-stage-with-spaceship, which will be built in at least three versions:
- "BFR spaceship": a large, long-duration spaceship capable of carrying passengers or cargo to interplanetary destinations, to LEO, or between destinations on Earth.
- "BFR tanker": an Earth-orbit, cargo-only propellant tanker to support the refilling of propellants in orbit. The tanker will enable launching a large spacecraft to interplanetary space as the spacecraft can use its tanks twice, first to reach LEO and afterwards to leave Earth orbit. This design reaches a Delta-v similar to three-stage rockets without needing the corresponding large mass fractions.
- "BFR satellite delivery spacecraft": will have a large cargo bay door that can open in space to facilitate the placement of spacecraft into orbit.
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.
The BFR spaceship, the BFR tanker, and the BFR satellite delivery spacecraft will have the same outer mold line. The second-stage-spaceship will be capable of returning to the launch location. While returning, it will be able to tolerate multiple engine-out events and land successfully with just one operating engine.
The functioning of the system during BEO launches to Mars will include propellant production on the Mars surface. This is necessary for the return trip and to reuse the spaceship at a minimal cost. Lunar destinations (some flybys, orbits and landings) will be possible without lunar-propellant depots, so long as the spaceship is refueled in a high-elliptical orbit before the lunar transit begins. Some lunar flybys will be possible without orbital refueling as evidenced by the mission profile of the SpaceX lunar tourism mission.
The major characteristics of the launch vehicle include:
- Both stages are designed to be completely reusable.
- The booster is projected to return to land on the launch mount. 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 landing reliability is projected by SpaceX to achieve "airline levels" of safety due to engine-out capability.
- Rendezvous and docking will be automated.
- There will be on-orbit propellant transfers from BFR tankers to BFR spaceships.
- A spaceship and its payload will be able to transit to the Moon or fly to Mars after on-orbit propellant loading.
- Heat-shields will be reusable.
- The BFR spaceship will have a pressurized volume of 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 storm shelter for Mars missions plus 12 unpressurized aft cargo containers of 88 m3 (3,100 cu ft) total.
|Complete||BFR booster||BFR spaceship/tanker/
|LEO Payload||100,000+ kg (220,000+ lb)|
|Return Payload||50,000 kg (110,000 lb)|
|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)||55 m (180 ft)|
|Maximum weight||4,400,000 kg (9,700,000 lb)||1,335,000 kg (2,943,000 lb)|
4 – 240,000 kg (530,000 lb)
2 – 860,000 kg (1,900,000 lb)
|Empty weight||85,000 kg (187,000 lb)|
|Engines||31 × Sea level Raptors||7 × Sea level 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. The engine will be designed with an extreme focus on reliability for any single engine and "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." In this way, the ship is being designed to achieve "landing reliability that is on par with the safest commercial airliners."
The BFR launch vehicle is designed to replace the existing SpaceX vehicles and spacecraft: Falcon 9 and Falcon Heavy rockets, and 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.
BFR is planned to execute five diverse flight use cases:
- legacy Earth-orbit satellite delivery market
- long-duration spaceflights in the cislunar region
- Mars transportation, both as cargo ships as well as passenger-carrying transport
- long-duration flights to the outer planets, for cargo and astronauts
- commercial passenger travel on Earth, competing with long-range aircraft
Musk and Shotwell have touted the ability of BFR to carry passengers on suborbital flights between any two points on Earth in under one hour.
Lunar Flyby Tour
In September 2018, SpaceX announced that it signed a contract to fly a group of private passengers around the Moon aboard the BFS. 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 between 4 and 5 days.
Mars Propellant Plant and Base
Musk plans to build a crewed base on Mars for an expanded surface presence, which he hopes will grow into a self-sufficient colony. A successful colonization would ultimately involve many more economic actors—whether individuals, companies, or governments—to facilitate the growth of the human presence on Mars over many decades.
Since the BFR spaceships (second stage) are also reusable, Musk plans on refuelling them in low Earth orbit first, and then again on the surface of Mars for their return to Earth. During the first phase, he plans to launch several BFRs to transport and assemble a propellant plant and start to build up a base. The propellant plant would produce methane (CH 4) and liquid oxygen (O2) from sub-surface water ice and atmospheric CO 2.
Two robotic cargo flights, the first of which may be named Heart of Gold, are planned to be launched in 2022 to deploy a massive array of solar panels, mining equipment, as well as deliver surface vehicles, food and life support infrastructure. In 2024 four more BFR landers will follow: two robotic cargo flights, and two crewed flights will be launched to setup the propellant production plant, solar arrays, landing pads, and greenhouses. Each landed mass will be at least 100 tons of usable payload, in addition to the spaceship's dry mass of 85 tons.
The first temporary habitats will be their own crewed BFR spaceships, as they have life-support systems. However, the robotic BFR cargo flights will be refueled for their return trip to Earth whenever possible. For a sustainable base, it is proposed that the landing zone be located at less than 40° latitude for best solar power production, relatively warm temperature, and critically: it must be near a massive sub-surface water ice deposit. The quantity and purity of the water ice must be appropriate. A preliminary study by SpaceX estimates the propellant plant is required to mine water ice and filter its impurities at a rate of 1 ton per day. The system under study is projected to produce 1 kg/day of O2/CH4 propellant while consuming 700 watts of electrical power. Overall unit conversion rate expected is one metric ton of propellant per 17 megawatt-hours energy input from solar power.
The biggest lingering questions about SpaceX's Mars colonization plans, have to do with health hazards of prolonged space travel, radiation, weightlessness, and habitation in the low gravity of Mars, which is one-third the gravity of Earth.