Mars to Stay

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https://en.wikipedia.org/wiki/Mars_to_Stay 

 

Concept for NASA Design Reference Mission Architecture 5.0 (2009)

Mars to Stay missions propose astronauts sent to Mars for the first time should intend to stay. Unused emergency return vehicles would be recycled into settlement construction as soon as the habitability of Mars becomes evident to the initial pioneers. Mars to Stay missions are advocated both to reduce cost and to ensure permanent settlement of Mars. Among many notable Mars to Stay advocates, former Apollo astronaut Buzz Aldrin has been particularly outspoken, suggesting in numerous forums "Forget the Moon, Let’s Head to Mars!" and, in June 2013, Aldrin promoted a crewed mission "to homestead Mars and become a two-planet species". In August 2015, Aldrin, in association with the Florida Institute of Technology, presented a "master plan", for NASA consideration, for astronauts, with a "tour of duty of ten years", to colonize Mars before the year 2040. The Mars Underground, Mars Homestead Project / Mars Foundation, Mars One (defunct in 2019), and Mars Artists Community advocacy groups and business organizations have also adopted Mars to Stay policy initiatives.

The earliest formal outline of a Mars to Stay mission architecture was given at the Case for Mars VI Workshop in 1996, during a presentation by George Herbert titled "One Way to Mars".

Proposals

Arguments for settlement missions

Since returning the astronauts from the surface of Mars is one of the most difficult parts of a Mars mission, the idea of a one-way trip to Mars has been proposed several times. Space activist Bruce Mackenzie, for example, proposed a one-way trip to Mars in a presentation "One Way to Mars – a Permanent Settlement on the First Mission" at the 1998 International Space Development Conference, arguing that since the mission could be done with less difficulty and expense if the astronauts were not required to return to Earth, the first mission to Mars should be a settlement, not a visit.

Paul Davies, writing in the New York Times in 2004, made similar arguments. Under Davies' plan, an initial colony of four astronauts equipped with a small nuclear reactor and a couple of rover vehicles would make their own oxygen, grow food, and even initiate building projects using local raw materials. Supplemented by food shipments, medical supplies, and replacement gadgets from Earth, the colony would be indefinitely sustained.

Original Aldrin plan

Under Mars to Stay mission architectures, the first humans to travel to Mars would typically be in six-member teams. After this initial landing, subsequent missions would raise the number of persons on Mars to 30, thereby beginning a Martian settlement. Since the Martian surface offers some of the natural resources and elements necessary to sustain a robust, mature, industrialized human settlement—unlike, for example the Moon—a permanent Martian settlement is thought to be the most effective way to ensure that humanity becomes a space-faring, multi-planet species. Through the use of digital fabricators and in vitro fertilisation it is assumed a permanent human settlement on Mars can grow organically from an original thirty to forty pioneers.

A Mars to Stay mission following Aldrin's proposal would enlist astronauts in the following timeline:

• Age 30: an offer to help settle Mars is extended to select pioneers
• Age 30–35: training and social conditioning for long-duration isolation and time-delay communications
• Age 35: launch three married couples to Mars; followed in subsequent years by a dozen or more couples
• Age 35–65: development of sheltered underground living spaces; artificial insemination ensures genetic diversity
• Age 65: an offer to return to Earth or retire on Mars is given to first-generation settlers

As Aldrin has said, "who knows what advances will have taken place. The first generation can retire there, or maybe we can bring them back."

"To Boldly Go: A One-Way Human Mission to Mars"

An article by Dirk Schulze-Makuch (Washington State University) and Paul Davies (Arizona State University) from the book The Human Mission to Mars: Colonizing the Red Planet highlights their mission plans as:

• No base on the Moon is needed. Given the broad variety of resources available on Mars, the long-term survival of Martian settlers is much more feasible than Lunar settlers.
• Since Mars affords neither an ozone shield nor magnetospheric protection, robots would prepare a basic modular base inside near-surface lava tubes and ice caves for the human settlers.
• A volunteer signing up for a one-way mission to Mars would do so with the full understanding that they will not return to Earth; Mars exploration would proceed for a long time on the basis of outbound journeys only.
• The first human contingent would consist of a crew of four, ideally (if budget permits) distributed between two two-man spacecraft for mission redundancy.
• Over time humans on Mars will increase with follow-up missions. Several subsurface biospheres would be created until there were 150+ individuals in a viable gene pool. Genetic engineering would further contribute to the health and longevity of settlers.

The astronauts would be sent supplies from Earth regularly. This proposal was picked up for discussion in a number of public sources.

Mars One

A proposal for a one-way human settlement mission to Mars was put forward in 2012 by the Mars One, a private spaceflight project led by Dutch entrepreneur Bas Lansdorp to establish a permanent human colony on Mars. Mars One was a Dutch not-for-profit foundation, a Stichting. The proposal was to send a communication satellite and pathfinder lander to the planet by 2018 and, after several stages, land four humans on Mars for permanent settlement in 2027. A new set of four astronauts would then arrive every two years. 200,000 applications were started; about 2,500 were complete enough for consideration, from which one hundred applicants were chosen. Further selections were planned to narrow this down to six groups of four before training began in 2016. It was hoped that a reality television show, participant fees, and donations would generate the funding for the project.

The project was criticized by experts as a 'scam' and as 'delusional'. On January 15, 2019, a court decision was settled to liquidate the organization, sending it into bankruptcy administration.

Strive to Stay: Emergency Return Only

In response to feedback following the EarthLight Institute's "Mars Colony 2030" project at NewSpace 2012 and the announcement of Mars One, Eric Machmer proposed conjunction-class missions be planned with a bias to stay (if low gravity, radiation, and other factors present no pressing health issues), so that, if at the end of each 550-day period during a conjunction-class launch window no adverse health effects were observed, settlers would continue research and construction through another 550-day period. In the meantime, additional crews and supplies would continue to arrive, starting their own 550-day evaluation periods. Health tests would be repeated during subsequent 550-day periods until the viability of human life on Mars was proven. Once settlers determine that humans can live on Mars without negative health effects, emergency return vehicles would be recycled into permanent research bases.

Initial and permanent settlement

Initial explorers leave equipment in orbit and at landing zones scattered considerable distances from the main settlement. Subsequent missions therefore are assumed to become easier and safer to undertake, with the likelihood of back-up equipment being present if accidents in transit or landing occur.

Large subsurface, pressurized habitats would be the first step toward human settlement; as Dr. Robert Zubrin suggests in the first chapter of his book Mars Direct, these structures can be built as Roman-style atria in mountainsides or underground with easily produced Martian brick. During and after this initial phase of habitat construction, hard-plastic radiation and abrasion-resistant geodesic domes could be deployed on the surface for eventual habitation and crop growth. Nascent industry would begin using indigenous resources: the manufacture of plastics, ceramics and glass could be easily achieved.

The longer-term work of terraforming Mars requires an initial phase of global warming to release atmosphere from the Martian regolith and to create a water-cycle. Three methods of global warming are described by Zubrin, who suggests they are best deployed in tandem: orbital mirrors to heat the surface; factories on the ground to pump halocarbons into the atmosphere; and the seeding of bacteria that can metabolize water, nitrogen and carbon to produce ammonia and methane (these gases would aid in global warming). While the work of terraforming Mars is on-going, robust settlement of Mars would continue.

Zubrin, in his 1996 book (revised 2011) The Case for Mars, acknowledges any Martian colony will be partially Earth-dependent for centuries. However, Zubrin suggests Mars may be profitable for two reasons. First, it may contain concentrated supplies of metals equal to or of greater value than silver, which have not been subjected to millennia of human scavenging; it is suggested such ores may be sold on Earth for profit. Secondly, the concentration of deuterium—an extremely expensive but essential fuel for the as-yet non-existent nuclear fusion power industry—is five times greater on Mars. Humans emigrating to Mars, under this paradigm, are presumed to have an industry; it is assumed the planet will be a magnet for settlers as wage costs will be high. Because of the labor shortage on Mars and its subsequent high pay-scale, Martian civilization and the value placed upon each individual's productivity is proposed as a future engine of both technological and social advancement.

Risks

Artist's conception of a human mission on Mars
1989 painting by Les Bossinas of Lewis Research Center for NASA

In the fifth chapter of "Mars Direct", Zubrin addresses the idea that radiation and zero-gravity are unduly hazardous. He claims cancer rates do increase for astronauts who have spent extensive time in space, but only marginally. Similarly, while zero-gravity presents challenges, near total recovery of musculature and immune system vitality is presumed by all Mars to Stay mission plans once settlers are on the Martian surface. Several experiments, such as the Mars Gravity Biosatellite, have been proposed to test this hypothetical assumption, but until humans have lived in Martian gravity conditions (38% of Earth's), human long-term viability in such low gravity will remain only a working assumption. Back-contamination—humans acquiring and spreading hypothetical Martian viruses—is described as "just plain nuts", because there are no host organisms on Mars for disease organisms to have evolved.

In the same chapter, Zubrin rejects suggestions the Moon should be used as waypoint to Mars or as a preliminary training area. "It is ultimately much easier to journey to Mars from low Earth orbit than from the Moon and using the latter as a staging point is a pointless diversion of resources." While the Moon may superficially appear a good place to perfect Mars exploration and habitation techniques, the two bodies are radically different. The Moon has no atmosphere, no analogous geology and a much greater temperature range and rotational period of illumination. It is argued Antarctica, deserts of Earth, and precisely controlled chilled vacuum chambers on easily accessible NASA centers on Earth provide much better training grounds at lesser cost.

Public reception

Artist's conception of a Mars Habitat
1993 by John Frassanito and Associates for NASA

"Should the United States space program send a mission to Mars, those astronauts should be prepared to stay there," said Lunar astronaut Buzz Aldrin during an interview on "Mars to Stay" initiative. The time and expense required to send astronauts to Mars, argues Aldrin, "warrants more than a brief sojourn, so those who are on board should think of themselves as pioneers. Like the Pilgrims who came to the New World or the families who headed to the Wild West, they should not plan on coming back home." The Moon is a shorter trip of two or three days, but according to Mars advocates it offers virtually no potential for independent settlements. Studies have found that Mars, on the other hand, has vast reserves of frozen water, all of the basic elements, and more closely mimics both gravitational (roughly ​¹⁄₃ of Earth's while the moon is ​¹⁄₆) and illumination conditions on Earth. "It is easier to subsist, to provide the support needed for people there than on the Moon." In an interview with reporters, Aldrin said Mars offers greater potential than Earth's satellite as a place for habitation:

If we are going to put a few people down there and ensure their appropriate safety, would you then go through all that trouble and then bring them back immediately, after a year, a year and a half? ... They need to go there more with the psychology of knowing that you are a pioneering settler and you don't look forward to go back home again after a couple of years.

A comprehensive statement of a rationale for "Mars to Stay" was laid out by Buzz Aldrin in a May 2009 Popular Mechanics article, as follows:

The agency's current Vision for Space Exploration will waste decades and hundreds of billions of dollars trying to reach the Moon by 2020—a glorified rehash of what we did 40 years ago. Instead of a steppingstone to Mars, NASA's current lunar plan is a detour. It will derail our Mars effort, siphoning off money and engineering talent for the next two decades. If we aspire to a long-term human presence on Mars—and I believe that should be our overarching goal for the foreseeable future—we must drastically change our focus. Our purely exploratory efforts should aim higher than a place we've already set foot on six times. In recent years my philosophy on colonizing Mars has evolved. I now believe that human visitors to the Red Planet should commit to staying there permanently. One-way tickets to Mars will make the missions technically easier and less expensive and get us there sooner. More importantly, they will ensure that our Martian outpost steadily grows as more homesteaders arrive. Instead of explorers, one-way Mars travelers will be 21st-century pilgrims, pioneering a new way of life. It will take a special kind of person. Instead of the traditional pilot/scientist/engineer, Martian homesteaders will be selected more for their personalities—flexible, inventive and determined in the face of unpredictability. In short, survivors.

The Mars Artists Community has adopted Mars to Stay as their primary policy initiative. During a 2009 public hearing of the U.S. Human Space Flight Plans Committee at which Dr. Robert Zubrin presented a summary of the arguments in his book The Case for Mars, dozens of placards reading "Mars Direct Cowards Return to the Moon" were placed throughout the Carnegie Institute. The passionate uproar among space exploration advocates—both favorable and critical—resulted in the Mars Artists Community creating several dozen more designs, with such slogans as, "Traitors Return to Earth" and "What Would Zheng He Do?"

Mars Artists design, August 2009.

In October 2009, Eric Berger of the Houston Chronicle wrote of "Mars to Stay" as perhaps the only program that can revitalize the United States' space program:

What if NASA could land astronauts on Mars in a decade, for not ridiculously more money than the $10 billion the agency spends annually on human spaceflight? It's possible ... relieving NASA of the need to send fuel and rocketry to blast humans off the Martian surface, which has slightly more than twice the gravity of the moon, would actually reduce costs by about a factor of 10, by some estimates.

Hard Science Fiction writer Mike Brotherton has found "Mars to Stay" appealing for both economic and safety reasons, but more emphatically, as a fulfillment of the ultimate mandate by which "our manned space program is sold, at least philosophically and long-term, as a step to colonizing other worlds". Two-thirds of the respondents to a poll on his website expressed interest in a one-way ticket to Mars "if mission parameters are well-defined" (not suicidal).

In June 2010, Buzz Aldrin gave an interview to Vanity Fair in which he restated "Mars to Stay":

Did the Pilgrims on the Mayflower sit around Plymouth Rock waiting for a return trip? They came here to settle. And that's what we should be doing on Mars. When you go to Mars, you need to have made the decision that you're there permanently. The more people we have there, the more it can become a sustaining environment. Except for very rare exceptions, the people who go to Mars shouldn't be coming back. Once you get on the surface, you're there.

An article by Dirk Schulze-Makuch (Washington State University) and Paul Davies (Arizona State University) from the book The Human Mission to Mars: Colonizing the Red Planet summarizes their rationale for Mars to Stay:

[Mars to stay] would obviate the need for years of rehabilitation for returning astronauts, which would not be an issue if the astronauts were to remain in the low-gravity environment of Mars. We envision that Mars exploration would begin and proceed for a long time on the basis of outbound journeys only.

In November 2010, Keith Olbermann started an interview with Derrick Pitts, Planetarium Director at the Franklin Institute in Philadelphia, by quoting from the Dirk Schulze-Makuch and Paul Davies article, saying, "The Astronauts would go to Mars with the intention of staying for the rest of their lives, as trailblazers of a permanent human Mars colony." In response to Olbermann's statement that "the authors claim a one-way ticket to Mars is no more outlandish than a one-way ticket to America was in 1620", Pitts defends Mars to Stay initiatives by saying "they begin to open the doors in a way that haven't been opened before".

In a January 2011 interview, X Prize founder Peter Diamandis expressed his preference for Mars to Stay research settlements:

Privately funded missions are the only way to go to Mars with humans because I think the best way to go is on "one-way" colonization flights and no government will likely sanction such a risk. The timing for this could well be within the next 20 years. It will fall within the hands of a small group of tech billionaires who view such missions as the way to leave their mark on humanity.

In March 2011, Apollo 14 pilot Edgar Mitchell and Apollo 17's geologist Harrison Schmitt, among other noted Mars exploration advocates published an anthology of Mars to Stay architectures titled, A One Way Mission to Mars: Colonizing the Red Planet". From the publisher's review:

Answers are provided by a veritable who's who of the top experts in the world. And what would it be like to live on Mars? What dangers would they face? Learn first hand, in the final, visionary chapter about life in a Martian colony, and the adventures of a young woman, Aurora, who is born on Mars. Exploration, discovery, and journeys into the unknown are part of the human spirit. Colonizing the cosmos is our destiny. The Greatest Adventure in the History of Humanity awaits us. Onward to Mars!

August 2011, Professor Paul Davies gave a plenary address to the opening session of the 14th Annual International Mars Society Convention on cost-effective human mission plans for Mars titled "One-Way Mission to Mars".

New York Times op-eds

"Mars to Stay" has been explicitly proposed by two op-ed pieces in the New York Times.

Following a similar line of argument to Buzz Aldrin, Lawrence Krauss asks in an op-ed, "Why are we so interested in bringing the Mars astronauts home again?" While the idea of sending astronauts aloft never to return may be jarring upon first hearing, the rationale for one-way exploration and settlement trips has both historical and practical roots. For example, colonists and pilgrims seldom set off to the New World with the expectation of a return trip. As Lawrence Krauss writes, "To boldly go where no one has gone before does not require coming home again."

If it sounds unrealistic to suggest that astronauts would be willing to leave home never to return ... consider the results of several informal surveys I and several colleagues have conducted recently. One of my peers in Arizona recently accompanied a group of scientists and engineers from the Jet Propulsion Laboratory on a geological survey. He asked how many would be willing to go on a one-way mission into space. Every member of the group raised their hand.

Additional immediate and pragmatic reasons to consider one-way human space exploration missions are explored by Krauss. Since much of the cost of a voyage to Mars will be spent on returning to Earth, if the fuel for the return is carried on board, this greatly increases the mission mass requirement – that in turn requires even more fuel. According to Krauss, "Human space travel is so expensive and so dangerous ... we are going to need novel, even extreme solutions if we really want to expand the range of human civilization beyond our own planet." Delivering food and supplies to pioneers via uncrewed spacecraft is less expensive than designing an immediate return trip.

In an earlier 2004 op-ed for the New York Times, Paul Davies says motivation for the less expensive, permanent "one-way to stay option" arises from a theme common in "Mars to Stay" advocacy: "Mars is one of the few accessible places beyond Earth that could have sustained life [... and] alone among our sister planets, it is able to support a permanent human presence."

Why is going to Mars so expensive? ... It takes a lot of fuel to blast off Mars and get back home. If the propellant has to be transported there from Earth, costs of a launching soar. Without some radical improvements in technology, the prospects for sending astronauts on a round-trip to Mars any time soon are slim, whatever the presidential rhetoric. What's more, the president's suggestion of using the Moon as a base — a place to assemble equipment and produce fuel for a Mars mission less expensively — has the potential to turn into a costly sideshow. There is, however, an obvious way to slash the costs and bring Mars within reach of early human exploration. The answer lies with a one-way mission.

Davies argues that since "some people gleefully dice with death in the name of sport or adventure [and since] dangerous occupations that reduce life expectancy through exposure to hazardous conditions or substances are commonplace", we ought to not find the risks involved in a Mars to Stay architecture unusual. "A century ago, explorers set out to trek across Antarctica in the full knowledge that they could die in the process, and that even if they succeeded their health might be irreversibly harmed. Yet governments and scientific societies were willing sponsors of these enterprises." Davies then asks, "Why should it be different today?"

 

SpaceX Starship

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/SpaceX_Starship 

 

Starship

SpaceX Starship SN8 prototype during a flight test at Boca Chica, Texas, December 2020
Function	Reusable launch system Intercontinental transport Space tourism Earth–lunar transport Mars colonization Multiplanetary transport
Manufacturer	SpaceX
Country of origin	United States
Cost per launch	US$2 million (aspirational)
Size
Height	120 m (390 ft) (not including landing legs)
Diameter	9 m (30 ft)
Mass	5,000 t (11,000,000 lb) (with maximum payload)(estimated)
Stages	2
Capacity
Payload to LEO
Mass	+100 t (220,000 lb)
Volume	1,100 m3 (39,000 cu ft)
Associated rockets
Family	SpaceX launch vehicles
Comparable	Saturn V N1 Space Launch System Long March 9 Falcon Heavy Energia Space Shuttle
Launch history
Status	In development
Launch sites	Boca Chica Floating launch platform
First stage – Super Heavy
Length	72 m (236 ft) (including landing legs)
Diameter	9 m (30 ft)
Propellant mass	3,400 t (7,500,000 lb)
Engines	~28 Raptors
Thrust	c. 76,000 kN (17,000,000 lbf)
Specific impulse	330 s (3.2 km/s)
Fuel	Subcooled CH 4 / LOX
Second stage – Starship
Length	50 m (160 ft)
Diameter	9 m (30 ft)
Empty mass	(goal) 120 t (260,000 lb)
Gross mass	1,320 t (2,910,000 lb)
Propellant mass	1,200 t (2,600,000 lb)
Engines	6 Raptor
Thrust	c. 12,000 kN (2,700,000 lbf)
Specific impulse	380 s (3.7 km/s) (vacuum)
Fuel	Subcooled CH 4 / LOX

The SpaceX Starship system is a proposed fully reusable, two-stage-to-orbit super heavy-lift launch vehicle under development by SpaceX. The system is composed of a booster stage, named Super Heavy, and a second stage, also referred to as "Starship".The second stage is being designed as a long-duration cargo, and eventually, passenger-carrying spacecraft. The spacecraft will serve as both the second stage and the in-space long-duration orbital spaceship.

Engine development started in 2012, and Starship development began in 2016 as a self-funded private spaceflight project. Testing of the second stage Starship began in 2019 as part of an extensive development program to prove out launch-and-landing and iterate on a variety of design details, particularly with respect to the vehicle's atmospheric reentry. The first prototypes made low-altitude, low-velocity flight testing of vertical launches and landings in 2019-2020. On 9 December 2020, Starship prototype SN8 performed the first high-altitude test flight, demonstrating most of the atmospheric re-entry maneuvers. The test was deemed a success, although a hard landing caused the explosion of the prototype. More prototype Starships have been built and more are under construction as the iterative design progresses. All test articles have a 9 m (30 ft)-diameter stainless steel hull.

In June 2019, SpaceX indicated they could potentially launch commercial payloads using Starship as early as 2021. In April 2020, NASA selected a modified crew-rated Starship system as one of three potential lunar landing system design concepts to receive funding for a 10-month-long initial design phase for the NASA Artemis program. As of March 2021, SpaceX is conducting atmospheric flights to 10 km altitude with Starship prototypes.

Nomenclature

The name of the vehicle changed many times after its first announcement and during the first several years of development. At least as early as 2005, SpaceX used the codename, "BFR", for a conceptual heavy-lift vehicle, "far larger than the Falcon family of vehicles", with a goal of 100 t (110 tons) to orbit. Beginning in mid-2013, SpaceX referred to both the mission architecture and the vehicle as the Mars Colonial Transporter. By the time a large 12-meter diameter design concept was unveiled in September 2016, SpaceX had begun referring to the overall system as the Interplanetary Transport System.

With the announcement of a new 9-meter design in September 2017, SpaceX resumed referring to the vehicle as "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 had also occasionally been referred to informally by the media and internally at SpaceX as "Big Fucking Rocket". At the time, the second stage/spacecraft was referred to as "BFS" (Big Falcon Ship or Big Fucking Ship). The booster first stage was also at times referred to as the "BFR" (Big Falcon Rocket or Big Fucking Rocket).

In November 2018, the spaceship was renamed Starship, and the first stage booster was named Super Heavy. The whole system, with the booster stage and spaceship, is also referred to as "Starship". The combination of Starship spacecraft and Super Heavy booster is called the "Starship system" by SpaceX in their payload users guide. The term "Super Heavy" had also 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.

History

Early concepts

The launch vehicle was initially mentioned in public discussions by SpaceX CEO Elon Musk in 2012 as part of a description of the company's overall Mars system architecture, then known as "Mars Colonial Transporter" (MCT). By 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 then reported to continue to be "deep into the future".

In mid-September 2016, Musk noted that the Mars Colonial Transporter name would not continue, as the system would be able to "go well beyond Mars", and that a new name would be needed. The name selected was "Interplanetary Transport System" (ITS). In September 2017, at the 68th annual meeting of the International Astronautical Congress, SpaceX unveiled an updated vehicle design.

In September 2018 Musk showed another 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. He also announced a planned 2023 lunar circumnavigation mission, a private spaceflight called dearMoon project. The two major parts of the launch vehicle were given descriptive names in November 2018: "Starship" for the 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)".

Shift to steel and early testing

In January 2019, Musk announced that Starship would no longer be constructed out of carbon fiber, and that stainless steel would be used instead, citing several reasons including cost, strength, and ease of production. Later in May, the Starship design changed back to just six Raptor engines, with three optimized for sea-level and three optimized for vacuum. Later that month, an initial test article, Starhopper, was being finished for untethered flight tests at the SpaceX South Texas launch site, while two "orbital prototypes" without aerodynamic control surfaces were under construction, one in South Texas and one on the Florida Space Coast. The following month, SpaceX publicly announced that discussions had begun with three telecommunications companies for using Starship, rather than Falcon 9, for launching commercial satellites for paying customers in 2021. No specific companies or launch contracts were announced at that time.

Starhopper made its initial flight test in July 2019, a "hop" of around 20 m (66 ft) altitude, and a second and final "hop" in August 2019, reached an altitude of ~150 m (490 ft) and landing around 100 m (330 ft) from the launchpad. In September 2019 Musk unveiled Starship Mk1, a more advanced test article. The Mk1 was destroyed in a tank pressure test in November, and SpaceX ceased construction on the Mk2 prototype in Florida and moved on to work on the Mk3 article.

Adopting a new "serial number" nomenclature, the Mk3 article was renamed Starship SN1 by SpaceX to signify the major evolution in building techniques: the rings were now taller and each was made of one single sheet of steel, drastically reducing the welding lines (thus failure points). The worksite in Texas was also significantly expanded. In February 2020, SN1 was also destroyed during pressurization. The company then focused on resolving the problem that led to SN1's failure by assembling a stripped-down version of their next planned prototype, SN2; SN2 ended up being basically a test tank. This time the pressure test was successful and SpaceX began work on SN3. However, in April 2020, SN3 was also destroyed during testing due to a test configuration error. At that time, construction of SN4 was underway.

Prototypes testing

On 26 April 2020, Starship SN4 became the first full-scale prototype to pass a cryogenic proof test. On 5 May 2020, SN4 completed a single engine static fire with one mounted Raptor engine and became the first full Starship tank to pass a Raptor static fire. SN4 would complete a total of 4 short static fires (2 to 5 seconds long) before being destroyed in a massive explosion due to a propellant leak from the quick disconnect mechanism. On 4 August 2020 Starship SN5 completed a 150 meter flight test, landing at an adjacent landing site, thus becoming the first full-scale prototype to perform a successful flight test.

Musk declared in June 2020 that Starship was by then the top SpaceX priority, except for anything related to reduction of Crew Dragon return risk for the upcoming Crew Dragon Demo-2 flight to the ISS, and remained so in September 2020. In September 2020, Musk clarified that SpaceX intends to exclusively fly cargo transport missions initially, and that passenger flights would come only much later.

In July 2020, SpaceX procured two deepwater oil rigs from Valaris plc for $3.5 million each. These semi-submersible platforms, renamed Deimos and Phobos after the two moons of Mars, will be modified into two floating launch platforms for Super Heavy/Starship orbital launches. As of January 2021, refit is underway on Deimos at the Port of Brownsville, and Phobos at the Port of Galveston. Current plans are for both the first stage (Super Heavy) booster and the second stage (Starship) to be landed on land, unlike the many sea landings seen with their Falcon 9 boosters.

On 9 December 2020, SN8 flew a largely successful 12.5 km (41,000 ft) flight test, which included the first 3-engine flight test, the first test of the body flaps during its novel "bellyflop" descent, and the first test of the "flip maneuver" landing burn at the end of the free-fall phase. However the fuel header tank pressure was low during the landing burn, and SN8 landed at a higher speed than intended and exploded. On 2 February 2021, SN9 attempted a 10 km (33,000 ft) flight, but once again exploded on landing after one of the Raptor engines failed to ignite.

On 3 March 2021, SN10 successfully completed the first landing of Starship after a 10km ascent. However, the landing was harder than expected due to unexpected low thrust. Immediately after the landing, there was a fire visible near the vehicle's skirt, prompting the deployment of the landing site's fire suppression system. Approximately eight minutes after the landing, the vehicle's liquid oxygen and methane tanks ruptured catastrophically, resulting in the fiery explosion of SN10 on the landing pad before it could be made safe and recovered.

Starship upper stage

Artist's concept of the 2018 version of Starship upper stage following stage separation

The upper stage of Starship is intended to function both as a second stage to reach orbital velocity on launches from Earth, and also be used in outer space as an on-orbit long-duration spacecraft. This is in contrast to most previous launch vehicle and spacecraft designs. Starship is being designed to be capable of reentering Earth's atmosphere from orbital velocities and landing vertically, with a design goal of rapid re-usability without the need for extensive refurbishment.

According to Musk, when Starship is used for beyond Earth orbit (BEO) launches to Mars, the functioning of the overall expedition system will necessarily include propellant production on the Mars surface. This is necessary for the return trip and to reuse the spaceship to keep costs as low as possible. Lunar destinations (circumlunar 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 dearMoon project.

The SpaceX approach is to tackle the hardest problems first, and Musk sees the hardest problem for getting to sustainable human civilization on Mars to be building a fully-reusable orbital Starship, so that is the major focus of SpaceX resources as of 2020. For example, it is planned for the spacecraft to eventually incorporate life support systems, but as of September 2019, Musk has stated that it is yet to be developed, as the early flights will all be cargo only.

General characteristics

As of September 2019, the Starship upper stage is expected to be a 9 m (30 ft) diameter, 50 m (160 ft) tall, fully reusable spacecraft with a dry mass of 120 t (120 long tons; 130 short tons) or less, powered by six Raptor engines.

Starship is designed with the ability to re-enter Earth's atmosphere and retropropulsively land on a designated landing pad. Landing reliability is projected by SpaceX to ultimately be able to achieve "airline levels" of safety due to engine-out capability. The spacecraft is also designed to be able to perform automatic rendezvous and docking operations, and perform on-orbit propellant transfers between Starships.

Starship is also designed with the goal to reach other planets and moons in the solar system after on-orbit propellant loading. While retropropulsion is intended to be used for the final landing maneuver on the Earth, Moon, or Mars, 99.9% of the energy dissipation on Earth reentry is to be removed aerodynamically, and on Mars, 99% aerodynamically even using the much thinner Martian atmosphere, where "body flaps" are used to control attitude during descent and optimize both trajectory and energy dissipation during descent.

As envisioned in the 2017 design unveiling, the Starship is to have a pressurized volume of approximately 825 m³ (29,100 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.

Propulsion

The methane/oxygen-propellant Raptor engines will be the main propulsion system on Starship. Starship will use three sea-level optimized Raptor engines and three vacuum-optimized Raptor engines. The sea-level engines are identical to the engines on the Super Heavy booster. Transport use in space is expected to use a vacuum-optimized Raptor engine variant to optimize specific impulse (I_sp) to approximately 380 s (8,300 mph; 3.7 km/s). Total Starship thrust will be approximately 11,500 kN (2,600,000 lbf).

Starship will use pressure fed hot gas reaction control system (RCS) thrusters using methane gas for attitude control, including the final pre-landing pitch-up maneuver from belly flop to tail down, and stability during high-wind landings up to 60 km/h (37 mph). Initial prototypes are using nitrogen cold gas thrusters, which are substantially less mass efficient, but are expedient for quick building to support early prototype flight testing.

Variants

Starship is planned to eventually be built in at least these operational variants:

• Spaceship: a large, long-duration spacecraft capable of carrying passengers or cargo to interplanetary destinations, to LEO, or Earth-to-Earth spaceflight.
• Satellite delivery spacecraft: a vehicle able to transport and place spacecraft into orbit, or handle the in-space recovery of spacecraft and space debris for return to Earth or movement to another orbit. In the March 2020 users guide, this was shown with a large cargo bay door that can open in space to facilitate delivery and pickup of cargo.
• 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. The tanker variant, also required for high-payload lunar flights, is expected to come only later; initial in-space propellant transfer will be from one standard Starship to another.
• Lunar-surface-to-orbit transport: a variant of Starship without airbrakes or heat shielding that is required for in-atmosphere-operations. Additionally, the ship will be equipped with a docking port on the nose, additional landing engines (installed much higher up to reduce dust clouds during landing) and have white paint (as opposed to the bare steel planned for regular Starships). On 30 April 2020, NASA selected SpaceX to develop a human-rated lunar lander for the Artemis program, therefore requiring SpaceX to develop an approach for a direct lunar landing.

The spaceship design is expected to be flexible. For example, a possible design modification to the base Starship – expendable three-engine Starship with no fairing, rear fins, nor landing legs in order to optimize its mass ratio for an interplanetary exploration with robotic probes.

Materials and construction

Starship has a stainless steel structure and tank construction. Its strength-to-mass ratio should be 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 spacecraft will also have a thermal protection system against the harsh conditions of atmospheric reentry. This will include hexagonal ceramic tiles that will be used on the windward side of Starship. Earlier designs included a double stainless-steel skin with active coolant flowing in between the two layers, or with some areas additionally containing multiple small pores that would allow for transpiration cooling.

Starship Human Landing System

A modified version known as the Starship Human Landing System (Starship HLS) was selected by NASA in April 2020 for potential use for long-duration crewed lunar landings as part of NASA's Artemis program. The Starship HLS variant is being designed to stay on and around the Moon and as such both the heat shield and air-brakes—integral parts of the main Starship design—are not included in the Starship HLS design. The variant will use high-thrust methox RCS thrusters located mid-body on Starship HLS during the final "tens of meters" of the terminal lunar descent and landing, and will also include a smaller crew area and a much larger cargo bay, be powered by a solar array located on its nose below the docking port. SpaceX intends to use the same high-thrust RCS thrusters for liftoff from the lunar surface. If built, the HLS variant would be launched to Earth orbit via the Super Heavy booster and would use orbital refueling to reload propellants into Starship HLS for the lunar transit and lunar landing operations. In the 2020 mission concept, a NASA Orion spacecraft would carry a NASA crew to the lander where they would depart and descend to the surface in Starship HLS. After Lunar surface operations, it would ascend using the same Starship HLS vehicle and return the crew to the Orion. Although not confirmed yet, the vehicle in theory could be refueled in orbit to carry more crews and cargo to the surface.

SpaceX is one of three organizations developing their lunar lander designs for the Artemis program over a 10-month period in 2020–2021, starting in May 2020. If SpaceX completes the milestone-based requirements of the design contract, then NASA will pay SpaceX US$135 million in design development funding. The other teams selected were the 'National Team'—led by Blue Origin but including Lockheed Martin, Northrop Grumman, and Draper (with US$579 million in NASA design funding) and Dynetics, including SNC and other unspecified companies (with US$253 million in NASA funding). At the end of the ten-month program on 28 February 2021, NASA had planned to evaluate which contractors would be offered contracts for initial demonstration missions and select firms for development and maturation of their lunar lander system designs. However, on 27 January 2021, NASA informed each of the HLS contractors that the original ten-month program would be extended two months to end on or before 30 April 2021.

Prototypes and testing

The SpaceX testing philosophy, referred to as "test, fly, fail, fix, repeat", is evident in the Starship development and testing program. SpaceX is willing to regularly test prototypes to destruction, counting the data gathered as a successful part of the overall process. This allowance for failures, willingness to build flight articles in view of the public, and fast cadence of prototype construction makes the Starship design process unique in the spaceflight industry.

In the first two years of development, from December 2018 to December 2020, SpaceX built and tested 13 (12 if the unfinished MK4 is not counted) prototypes. These include MK4 whose development was suspended mid-construction; MK1, SN1, SN3, SN4, SN7 (test tank), SN7.1 (test tank) and SN8 which were tested to destruction; MK2 and SN2 (test tank) which were retired before flight; Starhopper, SN5 and SN6 which were flight tested and retired. In 2021 SpaceX has continued building and testing prototypes including SN7.2 (test tank) and SN9 with SN10.

Starhopper

Starhopper before test flight

The construction of the initial test article—the Starship Hopper or Starhopper—began in early December 2018 and the external frame and skin was complete by 10 January 2019. Constructed outside in the open on a SpaceX property just 3.2 km (2.0 mi) from Boca Chica Beach in South Texas, the external body of the rocket rapidly came together in less than six weeks from half-inch (12.5 mm) steel. Originally thought by onlookers at the SpaceX South Texas Launch Site to be the initial construction of a large water tower, the stainless steel vehicle was built by welders and construction workers in more of a shipyard form of construction than traditional aerospace manufacturing. The full Starhopper vehicle is 9 m (30 ft) in diameter and was originally 39 m (128 ft) tall in January 2019. Subsequent wind damage to the nose cone of the vehicle resulted in a SpaceX decision to scrap the nose section, and fly the low-velocity hopper tests with no nose cone, resulting in an 18 m (59 ft) tall test vehicle.

The low-altitude, low-velocity Starhopper was used for initial integrated testing of the Raptor rocket engine with a flight-capable propellant structure, and was slated to also 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-metre (30 ft) diameter rocket. SpaceX originally developed their reusable booster technology for the 3-meter-diameter Falcon 9 from 2012 to 2018. The Starhopper prototype was also the platform for the first flight tests of the full-flow staged combustion methalox Raptor engine. Only one engine was installed but Starhopper could have been fitted with up to three engines to facilitate engine-out tolerance testing. Starhopper was also used to flight test a number of subsystems of Starship to begin to expand the flight envelope of the Starship design. Starhopper testing ran from March to August 2019 with all Starhopper test flights at low altitude.

The maiden flight test of the Starhopper test vehicle, and also the maiden flight test of any full-flow staged combustion rocket engine, was on 25 July 2019, and attained a height of 18 m (59 ft). This was not a full-duration burn but a 22-second test. SpaceX is developing their next-generation rocket to be reusable from the beginning, just like an aircraft, and thus needs to start with narrow flight test objectives, while still aiming to land the rocket successfully to be used subsequently in further tests to expand the flight envelope. The second and final untethered test flight of the Starhopper test article was carried out on 27 August 2019, to a VTVL altitude of 150 m (490 ft).

Low-altitude prototypes

SN5 being moved by a crane onto a stand before test flight

Construction of the Mark 1 (Mk1) in Boca Chica, Texas and Mark 2 (Mk2) in Cocoa, Florida began in December 2018. Planned for high-altitude and high-velocity testing, the prototypes were described to be taller than the Starhopper, have thinner skins, and a smoothly curving nose section. Like Starhopper, the vehicles measured 9 m (30 ft) in diameter but were full-height at approximately 50 m (160 ft), making them the first full-size Starship prototypes. On 20 November 2019, the Starship Mk1 was partially destroyed during max pressure tank testing, when the forward LOX tank ruptured along a weld line of the craft's steel structure, propelling the bulkhead several meters upwards. The upper bulkhead went airborne and landed some distance away from the craft. No injuries were reported. After the incident, SpaceX decided not to repair and retest Mk1. Both Mk1 and Mk2 were retired and focus turned to the Mk3 and Mk4 builds which were designed for orbit.

The prototype in Texas (Mk3) was renamed to SN1 (serial number 1). It was destroyed in February 2020 during a pressure test when the tank ruptured near the thrust puck. The thrust puck serves as both the lower dome of the fuel tank and the mount for the raptor engines. After this incident, SpaceX built SN2 as a scaled down test tank to focus testing on the structure of the thrust puck. SN2 successfully passed the pressure and cryogenic tests proving the design changes. SpaceX returned to full size prototype testing with SN3 which failed the cryogenic proof test. During testing the LOX (Liquid Oxygen) Tank experienced a loss of pressure and collapsed due to bad commanding in the test sequence. SN4 successfully completed a cryogenic pressure test on 26 April 2020. but exploded a few weeks later after a successful engine test when SpaceX tested a new "quick disconnect" design as part of ground support equipment testing. After passing all pad tests, SN5 completed a 150 m hop on 4 August 2020, descending to a nearby landing pad. This marked the first successful launch and landing of a prototype with full-height propellant tanks. SN6 performed the same flight test plan just one month later.

High-altitude prototypes

Starship SN9 sitting on the launch pad awaiting its test flight

High-altitude prototypes include installation of the nose cone and aerodynamic surfaces allowing testing of ascent, controlled engine cutoff, vehicle reorientation, controlled descent, the flip maneuver and landing. SN8 was the first high-altitude prototype to perform a test flight. On 9 December 2020, SN8 launched and ascended to an altitude of 12.5 km (41,000 ft). During ascent, the three raptor engines were cut one by one allowing the rocket to performed a successful and novel skydiver-like horizontal descent. As the vehicle neared the ground, it used a combination of aerodynamic surfaces and engine gimbaling to rotate back to a vertical position for a propulsive landing attempt. Lower than expected pressure in the methane header tank following the rapid rotation caused inadequate final deceleration and a hard landing resulted in an explosion on the landing pad and total destruction of the test vehicle. SN9 and SN10 both followed the same general test flight plan. SN9's flight took it to 10 km (33,000 ft), on 2 February 2021. The flight went well up until the landing, where one of the raptor engines did not relight causing a failure to counteract the momentum of the landing flip maneuver. This failure caused SN9 to slam into the ground diagonally and explode. SN10 performed the same test profile, but used all three engines for the final flip maneuver successfully decelerating enough to land intact. Several minutes after the landing the Starship exploded and was tossed in the air, before slamming down on its side on the landing pad. SpaceX CEO Elon Musk later revealed that the single Raptor engine that was used for the final landing burn couldn't reach high thrust despite being commanded to do so, thus SN10's landing was harder than intended.

Testing program

Starship prototypes are subjected to several tests on the launch stand before flight testing. These include the ambient pressure test, cryogenic proof test, and static fire of the engines. During the ambient pressure test the test article's propellant tanks are filled with benign air-temperature nitrogen gas. This test checks for leaks, verifies basic vehicle valve and plumbing performance, and ensure a basic level of structural integrity. The ambient pressure test is followed by the cryogenic proof test where the vehicle's oxygen and methane tanks are loaded with liquid nitrogen. This also tests structural integrity but adds the challenge of thermal stresses to ensure that Starship can safely load, hold, and offload supercool liquids. SN9 was the first prototype to arrive at the test stand with engines already installed. For previous test articles with thrust structures, a hydraulic ram was attached to the thrust puck to simulate the thrust of one, two, or three Raptor engines. SN4 was the first full scale prototype to pass the cryogenic proof test. Finally a static fire test is performed by loading liquid oxygen and liquid methane and firing the raptor engines briefly while Starship is held down on the test stand.

Since 2019, prototypes of the upper stage of Starship have been flown 7 times. Prototypes of Starship that performed suborbital flights include Starhopper, SN5, SN6, SN8, SN9, and SN10. All test flights launched from the Boca Chica launch site in Texas.

Despite making an intact landing and beginning the detanking procedures, the vehicle suffered an explosion several minutes later destroying the vehicle in the process. SpaceX has claimed it as a successful landing but later admitted problems with engine thrust and that the vehicle exploded.

Super Heavy booster

Comparison of super heavy-lift launch vehicles. Masses listed are the maximum payload to low Earth orbit in metric tons.

The booster stage Super Heavy is expected to be 72 m (236 ft) long and 9 m (30 ft) in diameter with a gross liftoff mass of 3,680 t (8,110,000 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 ~28 Raptor rocket engines that will provide 72,000 kN (16,000,000 lb_f) total liftoff thrust. The specification propellant capacity of Super Heavy was shown as 3,400 t (7,500,000 lb) in May 2020, 3% more than estimated in September 2019.

The initial prototype Super Heavy will be full size. It is expected however, to initially fly with less than the full complement of 28 engines, perhaps approximately 20.

The Super Heavy external design changed throughout 2019/2020 as the detailed design was iterated and the Raptor engines were tested and achieved higher power levels. In September 2019, a design change for the booster stage to have six fins that serve exclusively as fairings to cover the six landing legs, and four diamond-shaped welded steel grid fins to provide aerodynamic control on descent, was discussed. In August 2020, as the first build of "booster prototype 1" was to get underway, Musk noted that the leg design had been modified to just four landing legs and fins, to improve supersonic engine plume re-circulation margins.

Landing

In September 2016, Elon Musk described the possibility of landing the ITS booster on the launch mount. He re-described this concept in September 2017 with the Big Falcon Booster (BFB). In 2019, Musk announced that the booster would initially have landing legs to support the early VTVL development testing of Super Heavy. More recently, Musk had again expressed the long term goal of landing on the launch mount. In December 2020, Musk added the possibility of catching the booster by the grid fins using the launch tower arm, eliminating the need for landing legs entirely and simplifying recovery processes.

Prototypes

In late 2020, the segments of the first booster, codenamed BN1 were observed at Boca Chica. In March 2021, Elon Musk indicated that the goal for the first orbital flight is in July 2021. The two segments of BN1 were stacked together in the High Bay for the first time on 18 March 2021. The first booster is a production pathfinder and will also help develop transport processes from the Boca Chica build area to the launch/landing area.

Intended uses

Orbital launches

Starship is intended to become the primary SpaceX orbital vehicle. SpaceX intends to eventually replace its existing Falcon 9 and SpaceX Dragon 2 fleet with Starship, which is expected to take cargo to orbit at far lower cost than any other existing launch vehicle. In November 2019, Elon Musk estimated that fuel will cost US$900,000 per launch and total launch costs could drop as low as US$2 million.

In addition to the commercial launch market that SpaceX has been servicing since 2013, the company intends to use Starship to launch the largest portion of its own internet satellite constellation, Starlink, with more than 12,000 satellites intended to be launched by 2026, more than six times the total number of active satellites on orbit in 2018. An orbital launch of Starship could place ~400 Starlink satellites into orbit with a single launch, whereas the Falcon 9 flights in 2019-2020 can launch only ~60.

Other space missions

Starship is an architecture designed to do many diverse spaceflight missions, principally due to the very low marginal cost per mission that the fully-reusable spaceflight vehicles bring to spaceflight technology that were absent in the first six decades after humans put technology into space. Specifically, in addition to orbital launches, Starship is designed to be used for:

• Long-duration spaceflights to outer space, beyond the earth-moon system.
• Sending crew such as space tourists to the International Space Station, the Lunar Gateway, and other orbital installations.
• Mars transportation, both as cargo ships as well as passenger-carrying transport.
• Long-duration flights to the outer planets of the Solar System, for cargo and astronauts.
• Reusable lunar lander, for use transporting astronauts and cargo to and from the Moon's surface and Gateway in lunar orbit via Starship Human Landing System (Starship HLS); as well as more advanced heavy cargo lunar use cases that are envisioned by SpaceX but are not any part of the HLS variant that NASA has contracted with SpaceX for early design work.

Long-haul Earth transport

In 2017, SpaceX mentioned the theoretical possibility of using Starship to carry passengers on suborbital flights between two points on Earth. Any two points on Earth could be connected in under one hour, providing commercial long-haul transport competing with long-range aircraft. SpaceX however announced no concrete plans to pursue the two stage "Earth-to-Earth" use case.

Over two years later, in May 2019, Musk floated the idea of using single-stage Starship to travel up to 10,000 km (6,200 mi) on Earth-to-Earth flights at speeds approaching Mach 20 (25,000 km/h; 15,000 mph) with an acceptable payload saying it "dramatically improves cost, complexity and ease of operations". In June 2020, Musk estimated that Earth-to-Earth test flights could begin in "2 or 3 years", i.e. 2022 or 2023, and that planning was underway for "floating superheavy-class spaceports for Mars, Moon and hypersonic travel around Earth".

Funding

SpaceX has been developing the Starship partially with private funding, including the Raptor rocket engine used on both stages of the vehicle, since 2012. Some of the funding came from public grants. In January 2016 the US Airforce awarded SpaceX a US$33.7m grant to optimise the Raptor engine for use in the upper atmosphere with a further US$61.4m available for stretch goals.

Beginning in 2019, SpaceX began to offer specific services to potential future customers using Starship/Super Heavy/Raptor technology, and such product offerings have resulted in revenue to the company from this line of technologies. In June 2019, SpaceX indicated they could potentially launch commercial payloads using Starship as early as 2021, which often results in the recognition of revenue before a flight is launched. By late 2019, SpaceX projected that, with company private investment funding, including contractual funds from Yusaku Maezawa who had recently contracted for a private lunar mission in 2023, they have sufficient funds to advance the Earth-orbit and lunar-orbit extent of flight operations, although they may raise additional funds in order "to go to the Moon or landing on Mars".

In April 2020, NASA announced they would pay SpaceX US$135 million for initial design work of a variation of the Starship second-stage vehicle and spaceship—a "Starship Human Landing System", or Starship HLS—as one of three potential Lunar human landing systems for the NASA Artemis program In October 2020, NASA awarded SpaceX US$53.2 million to conduct a large scale flight demonstration to transfer 10 metric tons of cryogenic propellant between the tanks of two Starship vehicles.

Criticism

The Starship vehicle design has been criticized for not adequately protecting astronauts from ionizing radiation on Mars missions; Musk has stated that he thinks the transit time to Mars will be too brief to lead to an increased risk of cancer, saying "it's not too big of a deal". The lifetime cancer risk increase caused by the dose incurred on a multi-year Mars mission has been estimated to amount to a 5% increase in total cancer risk, a number which can be greatly reduced through simple shielding measures.