SpaceX Starship

Starship

Starship rocket with the launch tower
Function	sub-orbital spaceflight orbital spaceflight interplanetary spaceflight
Manufacturer	SpaceX
Country of origin	United States
Size
Height	122 m 400 ft
Diameter	9 m 29.5 ft
Mass	5,000 t 11,000,000 lb
Launch history
Launch sites	Starbase Launch Site Kennedy Space Center Launch Complex 39A
Capacity with refueling Payload to low Earth orbit Mass 150 t 330,000 lb Volume 1,000 m³ 35,000 ft³ Payload to Moon Mass 100 t 220,000 lb Volume 1,000 m³ 35,000 ft³ Payload to Mars Mass 100 t 220,000 lb Volume 1,000 m³ 35,000 ft³
Stages information First stage – Super Heavy Height 71 m 232 ft Diameter 9 m 30 ft Empty mass 200 t 440,000 lb Gross mass 3,600 t 7,900,000 lb Propellant mass 3,400 t 7,500,000 lb Powered by Raptor engine (33) Maximum thrust 74,500,000 N 7,590 Tf 16,700,000 lbf Propellant liquid oxygen liquid methane Second stage – Starship Height 50 m 164 ft Diameter 9 m 30 ft Empty mass 100 t 220,000 lb Gross mass 1,300 t 2,900,000 lb Propellant mass 1,200 t 2,650,000 lb Powered by Raptor engine (3) Raptor Vacuum (3) Maximum thrust 14,700,000 N 1,500 Tf 3,300,000 lbf Propellant liquid oxygen liquid methane

Starship is a two-stage and super heavy-lift launch vehicle in development by SpaceX, with the main goal of being fully reusable with low operating costs. Generally, the rocket uses liquid oxygen and liquid methane, with its structure divided into two stages: Super Heavy booster and Starship spacecraft. Notably, the latter has four extruding flaps, which are used for its atmospheric entry and descent phase. The spacecraft can be made into many variants, each optimized to serve a particular type of mission. As a direct result, Starship is selected for many space programs, such as the Artemis program or the dearMoon project. It is integral to SpaceX's ambitions of colonizing Mars and making rapid transport between locations on Earth possible.

The launch of Starship begins at either Starbase, Kennedy Space Center, or one of two SpaceX offshore launch platforms. With the rocket pointed upright, the Super Heavy booster fires thirty-three Raptor engines, lifting the whole rocket to space. After separation, the Starship spacecraft fires three of its Raptor Vacuum engines and inserts itself into orbit. Meanwhile, the booster descends through the atmosphere and takes control via its four grid fins. The booster is later caught by the launch tower's arms, which would reposition the booster to the launch mount. At the end of the mission, the Starship spacecraft enters the atmosphere, glides toward the landing site, and lands vertically on a pad.

The rocket was first outlined by SpaceX as early as 2005, with frequent design and name changes as the concept matured. In July 2019, Starhopper, a prototype vehicle with extended fins acting as fixed landing legs, performed a 150 m (490 ft) low altitude test flight under the power of a single Raptor engine. In May 2021, Starship SN15 successfully flew to 10 km (6 mi), transitioning to horizontal free-fall before successfully landing for the first time after four failed attempts by previous prototypes. As of February 2022, the Super Heavy BN4 and Starship SN20 are scheduled for the first full-stack flight in early 2022, though this schedule is subjected to change.

Development

Main article: SpaceX Starship development

See also: List of SpaceX Starship launches

Starship's development approach is iterative and incremental, with the owner company SpaceX mostly self-funds the project. The development approach is exemplified by building and launching many prototypes of Starship, which is similar to Falcon 9's reusability development. To be more specific, before launching onto different test flight trajectories, these prototypes are going to be subjected to proof pressure tests and static fires. Due to the company's openness to space news correspondents, these rocket tests have received significant coverage, one of which is spaceflight news site NASASpaceFlight.com.

The reception of Starship development has been mixed among local communities, especially at cities near the Starbase spaceport. Proponents of SpaceX's arrival claimed the company would provide money, education and job opportunities aid to Brownville, Texas, one of the poorest United States's cities. Opponents of the plan, meanwhile, claimed that the company's operation encourages inequality, gentrification, and extensive environmental harm nearby the spaceport.

Concepts

SpaceX illustration of the 2016 Interplanetary Transport System

SpaceX illustration of the 2018 Big Falcon Rocket in flight

In November 2005, SpaceX first referenced a concept with some capabilities of Starship. The rocket was going to have a larger version of the Merlin engine called Merlin 2, could lift about 100 t (220,000 lb) to low Earth orbit, and was not mentioned to be reusable. The company also had another plan for a rocket called the Mars Colonial Transporter. Although little information had been made public, it was known that the rocket would be powered by the liquid methane fueled Raptor engine. The rocket would have been able to carry one hundred people or 100 t (220,000 lb) of cargo to Mars.

Just before the 67th International Astronautical Congress in September 2016, the first sea-level-optimized Raptor engine was fired. At the presentation, SpaceX CEO and Chief Engineer Elon Musk announced the Interplanetary Transport System. The rocket was to be fully reusable and made of carbon composite, able to put 300 t (660,000 lb) to low Earth orbit. It would use the same Raptor engines to combust liquid methane and oxygen, launching the spacecraft on top into orbit. Then another could be sent up with more fuel, giving the first enough propellant to go on to further destinations. Even though the Interplanetary Transport System had many features to reduce its launch cost, funding for it was not explained satisfactorily. The only mentioned use of the rocket was ferrying crew to Mars for exploration and colonization.

In September 2017, Musk announced a revision to the rocket design and renamed it the Big Falcon Rocket. It was planned to be 106 m (348 ft) tall and 9 m (30 ft) wide, able to launch a reduced 150 t (330,000 lb) to low Earth orbit. The booster engine count was reduced to thirty-one, and the spacecraft to six. Finance for the rocket development was clarified, as the Big Falcon Rocket could clean up space debris, land on the Moon, and travel between locations on Earth. Nevertheless, its ultimate purpose was still to ferry crew to Mars. After the talk, Musk clarified on Reddit that the spacecraft's heat shield was not used to induce lift, but for orientation control.

In September 2018, the dearMoon project funded by Japanese billionaire Yusaku Maezawa was announced. Maezawa, along with six to eight other artists, would fly a free-return trajectory around the Moon, and create artworks in the process. There, Musk presented a revised design for the rocket that was 106 m (348 ft) tall and the same 9 m (30 ft) wide. Its spacecraft would have two forward flaps at the top and three aft flaps at the bottom, along with seven Raptor engines. The flaps are used to control the spacecraft's descent and the bottom ones can be used as landing legs. Two months later, in November 2018, the booster was first termed "Super Heavy", and the spacecraft was renamed to "Starship".

Low-altitude flights

Starhopper while in construction

A crane lifting Starship SN5

The first prototype to run a Raptor engine was the Starhopper. It had three large non-retractable legs and was noticeably shorter than a normal Starship spacecraft. The craft performed two tethered hops in early April 2019 and hopped untethered up to 20–30 m (70–100 ft) two months later, doing a controlled hover at a low speed. In August 2019, the vehicle hopped to 150 m (500 ft) and traveled to the landing pad 100 m (300 ft) away. As of August 2021, the vehicle has been retired and repurposed as a water tank and a mounting point for radio communication, weather, and ground station equipment.

SpaceX then constructed Starship Mk1 and Starship Mk2, located at Starbase and the SpaceX facility in Cocoa, Florida, respectively. In late September 2019, Musk presented more details about the booster, the spacecraft's method to control its descent, its heat shield, orbital refilling feature, and potential destinations outside Mars. The spacecraft design was once again changed, reducing the number of aft flaps from three to two. Musk mentioned the switch of Starship material from carbon composites to stainless steel formally, claiming its lower cost, high melting point, cryogenic temperature strength, and ease of manufacturing. After the presentation, Mk1 was destroyed during a pressure stress test two months later and Mk2 did not fly because the Florida facility was deconstructed throughout 2020.

In January 2020, SpaceX bought two drilling rigs from Valaris plc for $3.5 million each during its bankruptcy proceedings and planned to repurpose them as offshore spaceports. After the "Mk" prefix, SpaceX from here named later prototypes with the prefix "SN". No prototypes between SN1 and SN4 flew, as SN1 and SN3 collapsed during a proof pressure test and SN4 exploded after its fifth engine firing. During the interval, the company accelerated the construction of infrastructure at Starbase, which uses large tents, stations, and repurposed intermodal containers. When linked together, these facilities function as a production line, hastening the rocket construction.

In June 2020, SpaceX began construction of an orbital launch pad. Around that time, Starship SN5 was built, the lack of flaps or nose cone giving it a distinctive cylindrical shape. The test vehicle only consisted of one Raptor engine, full-size propellant tanks, and a mass on top. SN5 performed a 150 m (500 ft)-high flight on 5 August 2020, successfully landing on a nearby pad. On 3 September, Starship SN6 with a similar structure to Starship SN5 repeated the hop. A week later, SpaceX stress tested SN7.1 tank that first made use of SAE 304L stainless steel grade, instead of the old SAE 301 stainless steel grade in prior prototypes. In the same September, the company first fired its Raptor Vacuum engine.

High-altitude flights

Starship SN9 on a mount with its flaps closed

Play media
Animation depicting a successful test flight, following flight profile of SN8 to SN15

SN8 was the first complete Starship prototype and underwent four static fire tests between October and November 2020. The third test ingested fragments of pad material into engine internals, causing an earlier shutdown. The fourth test was successful, and on 9 December 2020 SN8 flew, reaching an altitude of 12.5 km (7.8 mi). However, just before touchdown, an issue related to propellant flow caused the prototype to lose thrust and impact the pad. The test provoked condemnation from FAA Associate Administrator Wayne Monteith, as SpaceX had ignored FAA warnings that weather conditions at the time could have worsened damage from a possible in-flight explosion to nearby homes. Two months later, on 2 February 2021, Starship SN9 launched on an almost identical flight path and crashed on landing.

In March 2021, the company sent a public construction plan to the United States Army Corps of Engineers, which has two sub-orbital launch pads, two orbital launch pads, two landing pads, two test stands, and a large tank farm that stores propellant. The company proposed the incorporation of surrounding Boca Chica Village into a city named Starbase, raising concerns about SpaceX's authority, power, and potential abuse for eviction. On 3 March 2021, after an initially aborted launch, Starship SN10 traveled the same flight path. The vehicle then landed hard and crushed its landing legs. Minutes later, SN10 exploded, due to a propellant tank rupture.

After approval from the FAA, on 30 March 2021, Starship SN11 flew into thick fog along the same flight path. The vehicle exploded during descent, scattering debris up to 8 km (5 mi) away. In early April 2021, the first tank was placed into the fuel farm for the first orbital launch pad. Around the same time, despite a few earlier misgivings about its complexity, NASA selected Starship HLS as the crewed lunar lander. The decision was disputed by Blue Origin and sparked a six-month-long dispute, titled Blue Origin v. United States & Space Exploration Technologies Corp. Returning to Starbase, Starship SN12, SN13, and SN14 were not fully assembled, and Starship SN15 was selected to fly instead. On 5 May 2021, SN15 flew, did the same maneuvers as older prototypes and landed, completing the first successful mission.

Planned orbital launches

Examination of Starship SN20's heat shield

Engine firing of Starship SN20 near Super Heavy boosters and launch tower

In July 2021, Super Heavy BN3 first fired three of its engines. Super Heavy BN4 was the first that can mate to Starships, while Starship SN20 was the first to feature a body-tall heat shield, mostly made of black hexagonal heat tiles. A month later, Starship SN20 was stacked atop of Super Heavy BN4, the first pair of vehicles to be so stacked. In October 2021, the catching mechanical arm was installed onto the first launch tower, forming the recovery system, and the last tank insulation cover was installed, marking the completion of the first tank farm. On 26 November 2021, a day after Thanksgiving in the United States, Musk sent an internal email to all SpaceX employees saying that the Raptor engine's production line was not sufficiently mature, thus creating a risk of bankruptcy for the company.

Two weeks later, just north of Launch Complex 39B, NASA announced the new Launch Complex 49 that will launch Starship at the Kennedy Space Center. In February 2022, Musk gave a presentation on Starship development at Starbase. There, he clarified much of the information provided in the past, as well as giving updates on Starship HLS, Raptor engines, the environmental assessment of Starbase, and a reopening of the Florida facility.

SpaceX explained the planned trajectory of the first orbital flight of the Starship system in a report sent to the Federal Communications Commission. The rocket is planned to launch from Starbase, then Super Heavy will separate and perform a soft water landing around 30 km (20 mi) from the Texan shoreline. The spacecraft will continue flying with its ground track passing through the Straits of Florida, and then softly land in the Pacific Ocean around 100 km (60 mi) northwest of Kauai in the Hawaiian Islands. The whole spaceflight will last ninety minutes.

Description

Starship is designed to be a fully reusable orbital rocket, with the aim of reducing launch costs drastically. One launch may deliver more than 100 t (220,000 lb) to low Earth orbit, which would formally classify the rocket as a super heavy-lift launch vehicle. When stacked and fueled, Starship may be about 5,000 t (11,000,000 lb) by mass, 9 m (30 ft) wide, and 120 m (390 ft) high, taller than the Saturn V by 9 m (30 ft). The rocket will consist of a Super Heavy first stage or booster and a Starship second stage or spacecraft. powered by many Raptor and Raptor Vacuum engines. These rocket stages' reusability and stainless-steel construction has influenced other rockets such as the Terran R and Project Jarvis.

Raptor engine

Main article: SpaceX Raptor

Sea level-optimized Raptor engine

First test firing of the sea-level Raptor engine, with methane combusted to produce a purple-orange flame

Raptor is a family of rocket engines used in the Starship rocket, combusting liquid oxygen and methane in a full-flow staged combustion cycle. The whole family uses a new alloy and can obtain 300 bar (4,400 psi) inside the main combustion chamber. These engines can fire many times, with their nozzles cooled by surrounding running propellant, called regenerative cooling. In the future, the engine family may be mass-produced, costing about $230,000 per engine and $100 per kilonewton.

The Raptor family is the only full-flow staged combustion cycle engine currently in production. In the past, the Soviet Union and the United States tried to construct such an engine, but both products have never been put in use. A general full-flow staged combustion cycle engine has two preburners connected to their matching turbopumps. One of the preburners is fed with an oxygen-rich mixture and the other is fed with a propellant-rich mixture, combusting a small amount to spin the matching turbines. The cycle then feeds all gaseous propellant mixture into the combustion chamber, unlike other engine cycles that waste some propellant. This increases the engine's chamber pressure, making more thrust and being more efficient overall.

Methane was chosen for the Raptor engines since it may be cheaper, does not accumulate soot, and can be produced on Mars via the Sabatier reaction, among other reasons. The engines run at an oxygen to methane mass ratio of 3.6 : 1, as combusting a stoichiometric mixture of 4 : 1 would overheat and damage them. The exhaust contains carbon dioxide and water, with a trace amount of carbon monoxide and nitric oxide. The plume stretches about 65 m (213 ft) at full power, longer than the Starship spacecraft by about 15 m (49 ft). When clustered inside a rocket stage, the inner engines' plumes do not interact with the air right away, so the cluster's plume may be much longer.

SpaceX builds multiple other variants of Raptor. The company specifies the Raptor engine has a ratio of throat area to exit area of 1:34. Another is the Raptor Vacuum, designed to be fired in space. It is equipped with a nozzle extension made from brazed steel tubes, increasing the throat area to exit area to 1:90 and specific impulse or fuel efficiency to 380 seconds. The Raptor 2 is the next generation in the family; the engine may produce 2.3 MN (520,000 lb_f) of thrust, with its specific impulse reduced by 3 seconds. The new generation of Raptor simplified the design of the earlier version. In the long term, SpaceX plans to make three variants of Raptor: sea level-optimized engine with gimbaled thrust, sea level-optimized engine without gimbaled thrust, and vacuum-optimized engine without gimbaled thrust.

Super Heavy booster

Underside of the Super Heavy booster

Super Heavy is a booster or first stage, located at the bottom of the rocket. The booster measures 70 m (230 ft) tall, housing up to thirty-three sea level-optimized Raptor engines. The engine cluster may be more than twice as powerful as the Saturn V. The booster's tanks can hold 3,600 t (7,900,000 lb) of propellant, consisting of 2,800 t (6,200,000 lb) of liquid oxygen and 800 t (1,800,000 lb) of liquid methane. Without propellant, Super Heavy's dry mass is estimated to range between 160 t (350,000 lb) to 200 t (440,000 lb). Of which, the tanks weigh 80 t (180,000 lb), the interstage between the booster and spacecraft weigh 20 t (44,000 lb), and all the engines and mounts weigh 2 t (4,400 lb).

The booster is equipped with four grid fins, each with a mass of 3 t (6,600 lb). These grid fins are not spaced evenly for obtaining more pitch control and can only rotate in the roll axis. They may control the booster's descent and work as a mounting point for a touchdown into the tower's mechanical arms. Though catching Super Heavy requires great precision, this may reduce the turnaround time after landing and enable more frequent launches. To control the booster's orientation, it may fire cold gas thrusters fed by evaporated propellant inside tanks. While Super Heavy and Starship are attached in space, the booster can move its engines and separates from the spacecraft.

Starship spacecraft

Non-tiled view of Starship SN16 spacecraft

Starship is a spacecraft and a second stage, located at the top of the booster. The spacecraft is 50 m (160 ft) tall, with a dry mass of less than 100 t (220,000 lb). By refueling the Starship spacecraft using tanker spacecraft, Starship may carry payloads and astronauts to higher Earth orbits, the Moon, Mars, and other destinations in the Solar System. The spacecraft has two main and two header tanks, for a total of 1,200 t (2,600,000 lb) capacity. Each of its main and header tanks hold a type of propellant, either liquid oxygen or methane, with the header tanks being reserved to flip and land the spacecraft. At the bottom of Starship are six Raptor engines, with three operating in the atmosphere while the other three Raptor Vacuum may run in space.

The spacecraft has four body flaps to control the spacecraft's falling velocity and orientation, with two forward flaps mounted near the nose cone and two aft flaps mounted near the bottom. The hinges that mount them are sealed with metal, as they are the most easily damaged part during reentry. Starship's heat shield is designed to be used multiple times with no maintenance between flights. It is composed of thousands of hexagonal tiles, each mounted and spaced to counteract expansion due to heat. The shape of these tiles prevents hot plasma from causing damage, allowing it to withstand temperatures of 1,400 °C (2,600 °F). Starship payload volume may be as large as 1,000 m³ (35,000 cu ft), far larger than any other spacecraft. The spacecraft nose cone as of August 2021 is made from two rows of stretch-formed steel.

Variants

Further information: Starship HLS

The cargo Starship spacecraft variant may feature a large door replacing conventional payload fairings, which can launch, store, capture, and return payloads. The payload door would be closed during launch, opened to release its payload once in orbit, and closed again during reentry. It may be possible to mount the payload on the inside of the payload bay's sidewalls using trunnions, more suitable for payloads on ride-share missions. Payloads may be integrated into a vertical rocket inside temperature-controlled, ISO class 8 clean air.

The crew variant can be adapted for missions to the Moon, Mars, point-to-point flights, and other destinations. Each spacecraft can carry one hundred people, with "private cabins, large communal areas, centralized storage, solar storm shelters, and a viewing gallery". Starship's life-support system is expected to be closed, where resources are constantly recycled. Other than that, little information about it is provided to the public.

The tanker variant can be used to refuel another spacecraft in orbit. According to Musk, up to seven launches of the tanker are needed to send a spacecraft to the Moon. The concept was detailed by Musk in September 2019, by docking the ends of both spacecraft to each other. They then accelerate slightly toward the tanker using control thrusters, settling propellant to the fueled Starship. In October 2020, NASA awarded SpaceX US$53.2 million to conduct a large-scale flight demonstration, transferring 10 t (22,000 lb) of propellant between the tanks of two Starship spacecraft.

Starship HLS is a crewed lunar lander variant of the Starship spacecraft for NASA's Artemis program. The lunar lander may have windows and airlocks near the top, along with an elevator and a set of thrusters to land on the Moon's surface. The lunar lander may be able to carry a large amount of payload between outer space and the Moon. On an Artemis mission, it may launch ahead of the crew by up to a hundred days, accompanied with many other launches of refueling Starship tankers. Another variant of the lunar lander may be used for the Commercial Lunar Payload Services program, where scientific, explorational, and commercial payloads are tasked with being sent to the Moon.

Launch profile

Artemis 3 launch profile of a human landing on the Moon, involving Starship HLS, Starship tanker variant, and Orion spacecraft

Before launch, Super Heavy and Starship are stacked onto a launch mount and loaded with propellant. When the rocket launches at Starbase, it may make more than 115 dBA at up to a 3.7 km (2.3 mi) radius, and up to 90 dBA throughout most of Brownsville, a nearby city, comparable to a lawnmower. For providing context, the Occupational Safety and Health Administration defines 115 dB as the upper limit for exposure within 15 minutes, beyond which hearing damage may occur.

Then, after some time during launch, the stages separate via the conservation of angular momentum. The booster flips its orientation and turns on its center engine cluster returning to the launch site, followed by a controlled descent, and a landing burn. It is then caught by a pair of mechanical arms, arresting any remaining velocity, and repositioning the booster onto the mount, allowing another launch cycle to begin. Super Heavy would have 20 t (44,000 lb) of propellant left after launching and landing. Landings of the booster may be quieter than launches, as residents of Brownsville may experience noise levels in the range of 60 dBA, comparable to the volume of a human conversation.

Meanwhile, the Starship spacecraft accelerates to orbital velocity and circularizes its orbit. There, the spacecraft may be refueled by the Starship tanker variants, by docking both spacecraft to each other. Both then accelerate slightly toward the tanker using control thrusters, settling propellant into the fueled Starship. The refueled Starship then fires its engines and coasts to the destination.

For landing on bodies without an atmosphere like the Moon, Starship turns on its engines and thrusters to slow down and land. For other bodies with an atmosphere like Mars, Starship slows down by entering the atmosphere, protected by a heat shield. After atmospheric entry, Starship performs a belly flop maneuver, defined in a whitepaper as the control of its surface area, leading to the control of aerodynamic drag and terminal velocity. Tim Dodd, American space and science communicator, analyzed the maneuver and highlighted its large propellant saving compared to the Falcon 9 first stage's landing.

During landing, both liquid methane and oxygen header tank are used to feed the Raptor engines. A pseudospectral optimal control algorithm predicted that the landing flip may make Starship overshoot the landing point by 100 m (300 ft). The simulation further predicted that the spacecraft would intentionally tilt 20° further from the ground's normal line and then reduce to zero on touchdown. The spacecraft's landing may make more than 60 dBA at Brownsville, similar to Super Heavy landing's noise level and lower than rocket liftoff.

Applications

Starship launch cost estimates vary widely, ranging from Musk's $2 million per launch to a satellite market analyst's $10 million. It is hoped that this lower launch cost would be accomplished by Starship's reusability, expanding space access to more types of payloads and entities. On the contrary, Pierre Lionnet, director of research at Eurospace, said that launch cost may not play a key role in certain science payloads.

Satellites and probes

Illustration of 1584 Starlink satellites around Earth, where Starship is expected to launch four hundred at a time, compared to Falcon 9's limit of sixty

Starship may enable the launching of larger space telescopes, such as the Habitable Exoplanet Imaging Mission that can directly image planets outside the Solar System. Some planetary science researchers started incorporating Starship into their projects, citing low launch cost and high launch capacity. An analyst at the Australian Strategic Policy Institute think-tank wrote possible military-use cases of Starship. One of them is the deployment of military satellites, replacing ones destroyed by anti-satellite weapons. Another is the launch of many reconnaissance satellites to fill gaps if larger satellites in a higher orbit were destroyed. Waleed Abdalati, a former NASA Chief Scientist, said the rocket may enable recovery of space debris, which are defunct artificial objects in space.

Starship is intended to launch the next generation of SpaceX's Starlink communication satellites. A space analyst at Morgan Stanley, a financial services company, said that both Starship and Starlink are very intertwined with each other. This is because improvements in launch capacity and cost aid Starlink satellite launches and Starlink profits can be fed back into Starship development. A single orbital launch of Starship could place up to four hundred Starlink satellites into orbit, whereas the Falcon 9 flights in 2019 and 2020 launched a maximum of 60 satellites per flight.

According to NASA's Ames Research Center, since Starship may have a large capacity, it may bring heavy machinery to destinations in space, such as drilling rigs on the surface of bodies. The mission may enable much more comprehensive research of their interiors and underground resources, which earlier rockets would not be able to do so at a reasonable cost. Starship may enable large experiments and sample-return missions of Moon and Mars rock. These missions could be integrated into SpaceX's test landings of the spacecraft and designed to go to locations of interest. Such a mission may answer many unsolved problems in astronomy, such as past volcanism on the Moon or extraterrestrial life.

A scouting mission proposed to deliver a probe for the Neptunian system, with a lander on its moon Triton. The probe would be equipped with a telescope to study the outer Solar System and exoplanets in other stars. Another was proposed to launch a space probe orbiting around Io, a moon of Jupiter, which is difficult because of the mission's demand for shielding from intense radiation and large delta-v budget or range. Even further, the Max Planck Institute for Solar System Research, who experiment with using solar sails to travel between the stars, proposed a mission riding on a Starship cruising to Mars.

Human travel

Illustration of a Rocket Cargo operation, with a rocket similarly shaped to Starship

One potential use for Starship is space tourism. An example is the dearMoon project announced by Japanese entrepreneur Yusaku Maezawa. The project consists of a flight around the Moon with Starship, with its crew consisting of Maezawa and eight others. The other crews are selected via video submissions with applicants ranging from dancers, actors, photographers, artists, to athletes. Another example is the Polaris program announced by Jared Issacman, Mission Commander for the Inspiration4 mission, aimed to raise funds for St. Jude Children's Research Hospital.

The spacecraft may host point-to-point flights – coined "Earth to Earth" by SpaceX – by traveling between spaceports on Earth. For example, via this mode of transport, a flight between New York City and Shanghai is estimated to take about 39 minutes. SpaceX president and chief operating officer, Gwynne Shotwell, predicted it could become cost-competitive with business class travel. John Logsdon, an academic on space policy and history, said point-to-point travel would have a high acceleration, thus making it impractical for civilians. The Rocket Cargo program by the United States Space Force as of December 2021 is researching this mode of transport.

Space colonization

Further information: SpaceX Mars program

SpaceX has said its goal is to colonize Mars for the long-term survival of the human species. Musk himself has been pursuing the goal since 2001 with the Mars Oasis program, where a rocket would launch a greenhouse to Mars. At the time, its purpose was to stimulate the space market and increase NASA's budget. The final possible goal of the program is to send a million people to Mars by 2050, with a thousand Starships sent during a Mars launch window.

Although Musk said that the company may land the first humans on Mars before 2026, the goal is considered optimistic. Greg Autry, a space policy expert, said that such a mission might not happen before 2029, even with aid from NASA. Likewise, SpaceX rated Starship HLS's propulsion, communications, and life-support system as technology readiness level 6 and 7 respectively, meaning the technology has been shown by prototypes. Super Heavy booster and propellant fueling function were rated technology readiness levels 4 and 5 respectively, meaning the technology has only reached validated status. SpaceX has not detailed plans for life-support systems, radiation protection, and in situ resource utilization, even though they are essential for colonizing space.

The Sabatier reaction may be used to create liquid methane and liquid oxygen on Mars in a power-to-gas plant, fueling return missions. The reaction works by exposing carbon dioxide and hydrogen to a catalyst at temperatures above 375 °C (700 °F) at high pressure. Carbon dioxide and hydrogen gas can be obtained from Mars's atmosphere and ice, while the catalyst used may be nickel or ruthenium. The reaction is very energy inefficient, requiring an extensive thermal management system, and the resultant methane must be purified before use.

Facilities

SpaceX is building many launch sites, including Launch Complex 39A of the Kennedy Space Center in Florida, its offshore platforms, and the Starbase facility. Starbase, located east of Brownsville in southern Texas, serves as Starship's primary spaceport, factory, and host of all Starship test flights as of December 2021. As of August 2021, Shyamal Patel is the Director of Starship Operations.

Starbase

Main article: SpaceX Starbase

Sites at Starbase

Starbase build site being visited by Elon Musk, Gwynne Shotwell, and others

STAR­GATE facility

Starbase launch site, with the fuel farm, launch tower, and cranes visible

Starbase consists of a manufacturing facility and launch site at Boca Chica, Texas. Both operate around the clock, with at most 450 full-time employees who may be onsite. The site hosted the STARGATE facility of the University of Texas Rio Grande Valley. SpaceX uses part of the facility for Starship development, while most is used by the university for the study and research of space technologies. The site is planned to consist of two launch complexes, two payload processing facilities, a desalination plant, a natural gas power plant, a natural gas purifier, a liquefier, and a solar farm.

Manufacturing of the Starship rocket starts with rolls of stainless steel of SAE 304L grade. These rolls are unrolled, cut, and welded along the cut edge to create a cylinder. Each of these cylinders is 9 m (30 ft) in diameter, 2 m (7 ft) in height, and around 1,600 kg (4,000 lb) in mass. To make the outer layer of the Starship spacecraft, seventeen of these cylinders and nose cones are stacked and welded along their edges. Inside the body are many domes, separating liquid methane and oxygen tanks at high pressure. These domes are made by robots and welded at the rate of ten minutes per seam. Afterwards, they are inspected by an X-ray machine.

A launch complex at Starbase consists of a launch pad, a launch tower, and a tank farm. The launch pad has a water sound suppression system and twenty clamps, holding down the booster until launch. The launch tower consists of steel truss sections, a lightning rod on top, and a pair of mechanical arms that may catch and recover the booster. Each tank farm consists of eight tanks: three for liquid oxygen, two for liquid methane, two for liquid nitrogen, and one for water. Other tanks surrounding the area contain all other commodities, such as methane, oxygen, nitrogen, helium, and hydraulic fluid.

Others

Further information: SpaceX Starship offshore platforms, Kennedy Space Center, and SpaceX McGregor

Aerial view of the Rocket Development facility in 2008

SpaceX facility at Cocoa, Florida on August 2019

Phobos and Deimos are offshore platforms under construction for launching Starship at sea. They were previously Valaris 8501 and Valaris 8500 respectively—oil drilling rigs owned by Valaris plc. Their main decks measure 78 m (260 ft) long by 73 m (240 ft) wide, with a helicopter deck on top of one of their corners. Four columns extrude at each corner at the bottom, measuring 15 m (49 ft) long and 14 m (46 ft) wide each.

The Kennedy Space Center is planned to have Starship launch pads at Launch Complex 39A and Launch Complex 49, north of Launch Complex 39C. Launch Complex 39A had hosted Saturn V and Space Shuttle flights, while Launch Complex 39C was planned to be built north of Launch Complex 39A and 39B to support Saturn V flights. Launch Complex 49 has been under consideration since at least 2014 and as of December 2021, under environmental review by NASA. If either launch site is to be built, Starship may need space inside the Vehicle Assembly Building. The building is divided into four high bays, with three reserved for the Space Launch System. The remaining high bay may be used to build Super Heavy and Starship, with both stages stacked at the launch pad.

The Rocket Development facility at McGregor, Texas is used to test Raptor engines before delivery to Starbase. It has a vertical test stand for firing the Raptor engine, along with a horizontal test stand for firing Raptor and Raptor Vacuum. The facility has other stands for testing Falcon rocket's stages, Merlin engines, and future reaction control thrusters on Starship. In the past, the McGregor facility hosted test flights of Grasshopper and F9R Dev1, the first stages used for landing tests. SpaceX's main factory at Hawthorne, California is producing the Raptor Vacuum and experimental designs. Another factory near the McGregor facility is under construction as of September 2021, which will make Raptor 2 engines.

Another SpaceX facility at Cocoa, Florida near the Cape Canaveral Space Force Station, in the past hosted the construction of Starship Mk2, a prototype built in competition with Starbase. As of February 2022, the facility has been processing raw materials to make the spacecraft's heat shield. Nearby the facility are hangars for Falcon rocket boosters and a large swath of land, dedicated for another Starship launch complex. The Florida facility's construction is motivated partly by the uncertain environmental review result at Starbase.

External links

• Official website