SpaceX Starship

Starship

Left: Starship spacecraft SN16 on display Right: Super Heavy booster BN4
Function	Intercontinental transport Orbital launch and re-entry Extraterrestial lander
Manufacturer	SpaceX
Country of origin	United States
Size
Height	120 m (390 ft)
Diameter	9 m (30 ft)
Mass	5,000 t 11,000,000 lb
Stages	2
Launch history
Status	In development
Launch sites	Boca Chica launch site LC-39A Phobos and Deimos
Payload to low Earth orbit
Altitude	500 km (310 mi)
Orbital inclination	98.9°
Mass	>100 metric tons (220,000 lb) reusable
Volume	c. 1,100 m3 (39,000 cu ft)
Payload to higher Earth orbits, the Moon or Mars
Mass	>100 metric tons (220,000 lb) after one or multiple refuellings
Volume	c. 1,100 m3 (39,000 cu ft)
First stage – Super Heavy
Height	70 m (230 ft)
Propellant mass	3,400 metric tons (7,500,000 lb)
Powered by	33 Raptor
Maximum thrust	c. 72 MN (16,000,000 lbf)
Propellant	Liquid CH4 and O2
Second stage – Starship
Height	50 m (160 ft)
Propellant mass	1,200 metric tons (2,600,000 lb)
Powered by	3 Raptor 3 Raptor Vacuum
Propellant	Liquid CH4 and O2

Starship is a fully reusable launch system in development by American private aerospace company SpaceX as of October 2021. Starship launch system consists of a first stage named Super Heavy and a second stage named Starship; both are made from stainless steel and designed to hold liquid oxygen alongside liquid methane. During liftoff, 33 Raptor rocket engines mounted under Super Heavy produce 72 MN (16,000,000 lb_f) of thrust, twice that of a Saturn V rocket. The spacecraft has three Raptors optimized for the vacuum of space, three other Raptors used to land itself vertically, and two pairs of flaps to control its descent. Launch pads and towers for Starship are designed to lift Starship's stages to position, as well as aid its launch and recovery operations. A Starship launch can place more than 100 metric tons (220,000 lb) of payload to low Earth orbit and to higher Earth orbits, the Moon, and Mars after refueled by tanker Starships.

In 2005, the first publicly known rocket concept with Starship lifting capabilities from SpaceX is BFR, burning a mixture of RP-1 and liquid oxygen for thrust. After major changes to these concepts, on 25 July 2019, Starhopper performed the first successful flight by any Starship test article at the Boca Chica launch site, which as of October 2021 is the main build and launch site. The first complete Starship test article was SN8, which launched and crashed to the ground on 9 December 2020. On 5 May 2021, SN15 became the first test article to launch and land successfully. As of October 2021, SN20 and BN4 are expected to become the first test article to go to orbit. Starship launch system is incorporated to upcoming and envisioned space missions, such as the dearMoon project, NASA's Artemis program, and SpaceX's Mars program.

Description

Super Heavy and Starship

Starship's body is made from welded 9 m (30 ft) diameter rings. They are 3.97 mm (0.156 in) thick, 1.8 m (5 ft 11 in) tall, and composed of SAE 304L stainless steel. The Starship launch system consists of two stages: a Super Heavy booster and a Starship spacecraft. Both stages are equipped with complex liquid methane and oxygen full-flow staged combustion cycle Raptor engines that each can produce approximately 2 MN (450,000 lb_f) of thrust. Generally, a kind of full-flow staged combustion cycle engine operates by flowing liquid methane and oxygen into its turbopumps, which are then pressurize, mixed, and heated in two preburners, with one receiving more methane and the other more oxygen. Both the high pressure and high temperature cause the liquids to evaporate, spinning the turbines, which in turn spin the turbopumps; this process repeats, until the hot gas is ignited in a combustion chamber. The resultant gas quickly moves, and the engine nozzle redirects it to produce thrust. The Raptor Vacuum variant is equipped with a nozzle extension to increase its specfic impulse in the vacuum of space.

Super Heavy booster's primary goal is to accelerate the spacecraft to Mach 8 or 9 and land itself on the launch tower's arms. The booster measures 70 m (230 ft) tall and 9 m (30 ft) in diameter. The bottom of the booster houses up to 33 sea‑level optimized Raptors that produce 72 MN (16,000,000 lb_f) of thrust during liftoff. Above the engines sit 3,400 metric tons (7,500,000 lb) of propellant in tanks. Four grid fins, installed above the booster, are designed to control Super Heavy descent and caught the launch tower's pair of mechanical arms. The booster is topped with a stage adapter for attaching the Starship spacecraft.

After separation, the Starship spacecraft will accelerate itself to orbit and perform mission tasks and objectives. It is 50 m (160 ft) tall, 9 m (30 ft) in diameter and has a total propellant capacity of 1,200 metric tons (2,600,000 lb). The bottom section houses six Raptors and composite overwrapped pressure vessels which store gas used to spin the engines' turbopumps. Three of them are optimized for atmospheric pressure, and three for the vacuum of space. Positioned above are the liquid oxygen and liquid methane propellant tanks, separated by a dome containing a small, spherical liquid methane header tank. On top of the tanks is the payload section houses a liquid oxygen header tank and payload. For Starship cargo, a large clamshell door replaces conventional payload fairings, which can capture, store, and return payload to Earth. The door will close during launch, open to release payload once in orbit, then close again during reentry. In the Starship crewed variant, the payload bay will house cabins and other facilities.

To control the spacecraft attitude during reentry and descent, Starship moves two pairs of flaps install perpendicular to its body. They are composed of a larger pair of aft flaps that sit at the bottom of Starship, and a smaller pair of forward flaps are placed on the nose cone. The windward side of the spacecraft is covered by a heat shield made from hexagon tiles designed to withstand up to 1,350 °C (2,460 °F) and prevent plasma to accelerate through the gap. Simulations from SpaceX showed that 99.9% of Starship's kinetic energy can dissipate upon reentry to Earth, but the thinner Mars atmosphere can dissipate only 99% of its kinetic energy. From its horizontal position moving at terminal velocity, Starship fires its engines to flip back up and slow itself down using propellant from its propellant header tanks.

Ground infrastructure

Starship launch tower at the Boca Chica launch site

Starship may launch at SpaceX's Boca Chica launch site, offshore platforms, and Kennedy Space Center Launch Complex 39A (LC-39A). The Boca Chica launch site, referred to by SpaceX as Starbase, is likely to be the first site to launch Starship to orbit. The offshore platforms, named Phobos and Deimos after the moons of Mars, were former oil drilling rigs owned by Valaris. As of October 2021, SpaceX is actively constructing the Boca Chica launch site and offshore platforms.

The launch and landing pad might at least consist of a launch mount, a tower, and tanks. The launch tower in Boca Chica measures 146 m (479 ft) tall, consisting of 143 m (469 ft) tall steel truss sections and a 3 m (9.8 ft) tall lightning rod on top. The launch tower has a pair of quick-disconnect claws and a large crane. These components allow the launch tower to lift, fuel, and stabilize Starships on the launch pad. For landing, the rocket stages might touch down on drone ships or landing pads near the launch site. In the future, the launch tower might recover the Super Heavy booster, by having a cable system that matches the incoming booster's velocity and pair of mechanical steel arms that move around pivots. The tower's arms catch the booster by closing and letting the booster's grid fins touch down on them.

Future variants

SpaceX plans to build variants of Starship optimized for its tasks. The original spacecraft design will be used to transport cargo on missions, and in the future, it may be spun off into a separate cargo variant. This variant is used to deliver, deploy and pick up cargo in orbit by a large cargo bay door that could open in space. Another variant named Starship tanker can transfer its propellant to rendezvoused spacecraft. By receiving fuel from tanker Starships, the spacecraft could travel to higher orbits or further destinations in the Solar System. SpaceX has mentioned another Starship variant that could carry passengers on sub-orbital transport flights across continents, which its president Gwynne Shotwell has predicted could be cost-competitive against business class airlines. The spacecraft can go between spaceports on Earth, with a goal of 40 minutes flight time from New York City to Shanghai. At the 67th International Astronautical Congress, SpaceX's CEO Elon Musk outlined that Starship Mars's variant might carry 100 passengers and cargo to Mars.

In April 2021, NASA contracted SpaceX to design and manufacture the Starship Human Landing System (Starship HLS), a modified Starship spacecraft. It serves as the crewed lunar lander for the Artemis program. Starship HLS has significant differences from the main design, for example, the lack of heat shield and body flaps. This spacecraft will have a docking system, solar panels, and extra landing thrusters placed at the middle of the ship to minimize thrown lunar dust. Another unrelated Starship variant is also envisioned by SpaceX, capable of launching heavy payloads to the Moon's surface for the Commercial Lunar Payload Services program.

Operations

Planned missions

Artist depiction of a large white lunar lander on the Moon, with the crews nearby

Artist depiction by SpaceX of Starship HLS offloading astronauts and cargo onto the lunar surface

SpaceX aims for Starship to replace its current Falcon 9, Falcon Heavy, and Dragon 2 fleet and take cargo to orbit cheaply. In November 2019, Musk estimated that a Starship launch might cost US$2 million, US$900,000 of propellant cost. Starship could place up to four hundred Starlink satellites into orbit, whereas the Falcon 9 can only carry up to 60 satellites into orbit per flight. On 14 September 2018, the first private contract was announced by Japanese entrepreneur Yusaku Maezawa, a private space tourism mission called the dearMoon project. Starship in this mission would perform a trans-lunar injection, circle the Moon, and return to Earth. As of October 2021, the mission's crew might consist of Maezawa and ten to twelve other people.

In October 2020, NASA provided US$53.2 million to SpaceX to demonstrate 10 metric tons (9.8 long tons) of cryogenic propellant transfer between two Starships. On 16 April 2021, NASA selected Starship HLS and awarded SpaceX a US$2.89 billion contract over Integrated Lander Vehicle and Dynetics HLS. Starship HLS will perform an uncrewed landing demonstration and an Artemis 3 crewed lunar landing mission. In June 2021, the United States Air Force updated the Rocket Cargo program and began assessing the use of rockets to transport payload between spaceports on Earth. Although the Air Force does not specify what rocket is under the program, media sources speculated that Starship might be the launch system that matches the proposal.

Envisioned space colonization programs

Main article: SpaceX Mars program

Artist depiction by SpaceX of ITS in close approach to Mars

SpaceX has stated that its goal is to kick-start Mars colonization and terraforming by its launch vehicles. Musk has stated that the main reason for the goal is for the long-term survival of the human species and to inspire legislators to fund spaceflight more. From 2011 to 2017, the company conceived a spacecraft concept capable of transporting crew and cargo to Mars called Red Dragon, a modified Dragon capsule. If such a program ever existed, it likely uses Starship as the main launch vehicle, funded by both the public and private entities as well as using Mars resources. Musk estimated that a Mars city containing a million people would be self-sustaining, which need at least ten thousand crewed Starship and a hundred thousand Starship carrying cargo excluding local population growth.

Before astronauts go to Mars, cargo Starships launch requisite equipment to Mars' surface, including a fertilizer factory, a propellant factory, and construction materials for assembling geodesic domes covering farmland. The propellant factory takes in carbon dioxide from Mars's atmosphere and hydrogen from underground ice. Afterward, the factory uses the Sabatier reaction to create liquid methane and liquid oxygen. The spacecraft can launch from Mars to Earth, provided it is refueled by propellant produced on Mars by the factory.

At the 67th International Astronautical Congress, Musk outlined that the Mars Starship's variant might carry cargo and 100 passengers to Mars. It might have 825 m³ (29,100 cu ft) of pressurized space, about forty cabins, storage space, a galley, an entertainment area, and a solar storm shelter to protect against ionizing radiation. At that conference, Musk presented conceptual missions to further destinations such as Enceladus, Europa, Pluto, and the Oort cloud, that may launch from Mars.

Reception to Starship development

Starship SN8 remains after it crashed to the ground

Some residents of Boca Chica Village, Brownsville, and environmental activists have criticized the Starship development program, stating that SpaceX has harmed local wildlife, conducted unauthorized test flights along with infrastructure's construction, and polluted the area with noise. Environmental groups have warned that SpaceX's Starship program threatens wildlife in the area, including 18 vulnerable and endangered species.

A U.S. Fish and Wildlife Service employee complained of "unauthorized encroachments and trespass on the refuge" by SpaceX employees. The Fish and Wildlife Service also claimed that SpaceX exceeded 1,000 hours of highway closures in 2019, well above the 300 hours they were permitted. In June 2021, Cameron County District Attorney Luis Saenz threatened to prosecute SpaceX for unauthorized road and beach closures, as well as employing security officers who may not be licensed to carry handguns.

SpaceX proceeded with SN8 launch and ignored Federal Aviation Administration's (FAA) warnings that the flight profile posed an unacceptable risk to the uninvolved public in the event of an explosion. FAA space division chief Wayne Monteith said SpaceX's violation was “inconsistent with a strong safety culture", and criticized the company for proceeding with the launch "based on ‘impressions’ and ‘assumptions,’ rather than procedural checks and positive affirmations". Members of Congress voiced concerns about the FAA's response to SpaceX's launch license violations, calling on the FAA to "resist any potential undue influence on launch safety decision-making".

Responding to these environmental concerns, as of October 2021, the FAA allows the public to comment until 1 November on the Boca Chica launch site's environmental impact statement draft, released on 19 September. Experts commented that SpaceX's programmatic environmental assessment is missing important details about where its fuel will come from such as how SpaceX is planning to build a 250-megawatt gas-fired power plant without specifying how SpaceX plans to get tens of millions of cubic feet of gas to the plant per day. Pat Parenteau, a law professor and senior counsel for the Environmental Advocacy Clinic at Vermont Law School, noted how unusual it was for such details to not get mentioned in the programmatic environmental assessment and thus could violate the U.S. National Environmental Policy Act.

On the other side, spaceflight enthusiasts and space news correspondents have applauded SpaceX's transparency because the public can be very close to the launch site. Notable people and entities that cover Starship development extensively include Tim Dodd and NASASpaceFlight.com.

Development

For further information, see [[:SpaceX Starship development history]]. For a list of test articles flights, see [[:List of SpaceX Starship launches]].

Design process

Artist depiction by SpaceX of Big Falcon Rocket in flight

The first reference by SpaceX of a rocket concept which has Starship lifting capabilities was in 2005. In a student conference, Musk briefly mentioned a theoretical heavy‑lift launch vehicle code-named BFR, later known as the Falcon XX. It would be powered by a larger version of the Merlin engine, called Merlin 2 and has a lifting capability of 140 metric tons (310,000 lb) to low Earth orbit. In 2012, in a public discussion about a conceptual Mars colonization program, Musk described the Mars Colonial Transporter. It is envisioned as a reusable super heavy-lift launch vehicle that could deliver approximately 150 to 200 metric tons (330,000 to 440,000 lb) to low Earth orbit. The Mars Colonial Transporter might be powered by Raptors, consuming liquid methane and liquid oxygen.

In September 2016, at the 67th International Astronautical Congress, Musk announced the Interplanetary Transport System (ITS), a conceptual reusable rocket conceived to launch humans to Mars and other destinations in the Solar System. The ITS is 122 m (400 ft) tall, 12 m (39 ft) wide, and capable of lifting 300 metric tons (660,000 lb) to low Earth orbit. Both stages of the rocket are made from carbon composites. The first stage or booster named Interplanetary Transport System booster is powered by 42 Raptors, and the second stage or spacecraft named Interplanetary Spaceship is powered by nine Raptors. While in Earth orbit, if an Interplanetary Spaceship was refueled by other Interplanetary Spaceships, it can accelerate to Mars. When an Interplanetary Spaceship enters the atmosphere, it cools itself via transpiration and controls the spacecraft's descent to the ground by moving its delta wings and split flaps. At the 68th International Astronautical Congress the following September, Musk announced a replacement rocket 106 m (348 ft) tall and 9 m (30 ft) wide called the Big Falcon Rocket or informally Big Fucking Rocket. In that conference, he talked about a possible suborbital transportation feature and termed it Earth to Earth.

In November 2018, the present names of the launch vehicle were first used: Super Heavy for the booster, Starship for the spacecraft, and Starship system or just Starship for the whole launch vehicle. Around that time, Musk announced a redesigned spacecraft concept that has three aft flaps and two forward flaps. In January 2019, Musk announced on Twitter that Starship will be made from stainless steel and stated that a stainless-steel Starship might be stronger than a similar carbon composites Starship in a wide range of temperatures. In March, Musk tweeted that SpaceX opted for a heat shield composed of hexagonal ceramic tiles instead of the more complicated transpiration cooling feature. In October, the Starship spacecraft's engine configuration was changed to its present form: three Raptors optimized for atmospheric pressure and three optimized for the vacuum of space. The number of rear fins in this new design was reduced from three to two and were placed at the heat shield's edges.

Testing campaign

A steel rocket stage hovering with an engine

SN5's hop at the Boca Chica launch site, firing a Raptor

The Boca Chica launch site is the primary facility for developing and testing Starship. Starship test articles before launch are needed to pass the ambient-temperature pressure test, cryogenic proof test, and static fire test. The ambient-temperature pressure test involves the stage's tanks filling inert room-temperature nitrogen gas to highlight leaks. After that, the cryogenic proof test assesses the vessel's strength by loading, then unloading, liquid nitrogen. Finally, a static fire test confirms the engines' installation by loading propellant into a stage's tanks and firing the rocket engines. Verified test articles will launch in different flight paths, depending on their objectives.

On 27 August 2019, a simplified test article named Starhopper hopped 150 m (490 ft) high. Unveiled in a SpaceX event in September 2019, Starship Mk1 (Mark 1) was the first full‑scale Starship test article to be built, and the Mk2 in Florida was constructed five months later. Despite that, both test articles had not flown: Mk1 failed a cryogenic proof test and Mk2 was scrapped for parts. In early 2020, SpaceX changed the then-constructing Mk3's name to SN1 (serial number 1). During a cryogenic proof test on 28 February 2021, a fault in SN1's bottom tank caused it to crumble. On 8 March 2020, SN2 (Mk4) as a stripped-down test tank completed its only cryogenic proof test. On 3 April 2020, during SN3's cryogenic proof test, a valve leaked the liquid nitrogen inside its lower tank, causing the vessel to depressurize and collapse the test article. After SN4's fifth successful static fire test on 29 May 2020, the quick disconnect fuel line exploded the test article. On 4 August 2020, SN5 completed a 150 m (490 ft) hop using a single Raptor, becoming the first full-scale test article to complete a flight test and be intact. On 24 August 2020, SN6 replicated SN5's flight path successfully. SN7 was not completed, but as of October 2021, its tanks are used for various experiments.

SN8 is the first complete Starship spacecraft test article, which has three atmosphere-optimized Raptors, a nose cone, and two pairs of body flaps. In October and November 2020, SN8 underwent four static fire tests; the first, second, and fourth were successful, but the third caused an engine shutdown. According to Musk, the force from the engine destroyed parts of the launch pad and some pieces of it flew into the engine. On 9 December 2020, SN8 performed the first flight by a Starship, reaching an altitude of 12.5 km (7.8 mi). During landing, its methane header tank did not provide sufficient fuel to the Raptors, causing one of its engines to produce low thrust. The landing engine could not slow down the test article sufficiently and led to the test article's explosion on impact. On 2 February 2021, SN9 flew 10 km (6.2 mi) high. While descending, one of its engines did not function and burst itself on landing at an angle. On 3 March 2021, SN10 repeated SN9's flight path, then hard landed and set off itself 8 minutes later.

A steel rocket firing its engine with an orange plume

Liftoff of SN15 at the Boca Chica launch site, firing three Raptors

The first Super Heavy booster named BN1 (booster number 1) finished construction on 8 March 2021, but it had not flown or installed Raptors. On 30 March 2021, SN11 exploded in midair without a confirmed explanation because of the dense fog at the launch site. A possible explanation is that an engine might have burned the test article's avionics and could have caused a hard start on the engine's turbopump. After the launch, SpaceX skipped SN12, SN13, SN14, and BN2, and incorporated obsolete test articles' improvements to SN15 instead. On 5 May 2021, the test article flew the same flight path as previous test articles and soft landed on the landing pad. After the landing, SN15 did not explode and was recovered. On 20 July 2021, Super Heavy booster BN3 fired its engines for the only time. As of October 2021, SN15, SN16, and BN3 are retired and displayed. As of October 2021, skipping over SN16, SN17, SN18, and SN19, SN20 along with BN4 are assigned to an orbital flight scheduled for late 2021. Despite that, the FAA has not finalized the environmental impact statement draft released on 19 September 2021. The whole rocket is planned to launch from Boca Chica and head toward the middle of the Straits of Florida. BN4 is expected to separate about three minutes into the orbital flight and splashdown in the Gulf of Mexico, approximately 30 km (19 mi) from the shoreline. SN20 is then expected to accelerate itself close to orbital speed, then splashdown ninety minutes later at about 100 km (60 mi) northwest of Kauai.

• Picture of Starship test articles
• 
  Nose cone of Starship Mk1 near construction tents
• 
  Starhopper in construction
• 
  A crane lifting Starship SN5
• 
  Starship SN7's tank
• 
  Starship SN9 on the launchpad
• 
  A worker is examining Starship SN20's ceramic tiles

Test articles timeline

See also: List of SpaceX Starship test articles

Note: The start dates are when the test articles were first spotted by the public, and the end dates are when the test articles are destroyed, decommissioned, or retired.Template:Starship Timeline

External links

• Media related to Starship at Wikimedia Commons
• Starship's official website by SpaceX