Space tourism

From Wikipedia, the free encyclopedia

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

The first space tourist, Dennis Tito (left) aboard the ISS

Space tourism is human space travel for recreational purposes. There are several different types of space tourism, including orbital, suborbital and lunar space tourism. To date, orbital space tourism has been performed only by the Russian Space Agency. Work also continues towards developing suborbital space tourism vehicles. This is being done by aerospace companies like Blue Origin and Virgin Galactic. In addition, SpaceX (an aerospace manufacturer) announced in 2018 that they are planning on sending space tourists, including Yusaku Maezawa, on a free-return trajectory around the Moon on the Starship.

During the period from 2001 to 2009, 7 space tourists made 8 space flights aboard a Russian Soyuz spacecraft brokered by Space Adventures to the International Space Station. The publicized price was in the range of US$20–25 million per trip. Some space tourists have signed contracts with third parties to conduct certain research activities while in orbit. By 2007, space tourism was thought to be one of the earliest markets that would emerge for commercial spaceflight. Space Adventures is the only company that has sent paying passengers to space. In conjunction with the Roscosmos and RSC Energia, Space Adventures facilitated the flights for all of the world's first private space explorers. The first three participants paid in excess of $20 million (USD) each for their 10-day visit to the ISS.

Russia halted orbital space tourism in 2010 due to the increase in the International Space Station crew size, using the seats for expedition crews that would previously have been sold to paying spaceflight participants. Orbital tourist flights were set to resume in 2015 but the one planned was postponed indefinitely and none have occurred since 2009.

On June 7, 2019, NASA announced that starting in 2020, the organization aims to start allowing private astronauts to go on the International Space Station, with the use of SpaceX's Crew Dragon spacecraft and Boeing Starliner spacecraft for public astronauts, which is planned to be priced at 35,000 USD per day for one astronaut and an estimated 50 million USD for the ride there and back.

Precursors

The Soviet space program was successful in broadening the pool of cosmonauts. The Soviet Intercosmos program included cosmonauts selected from Warsaw Pact member countries (Czechoslovakia, Poland, East Germany, Bulgaria, Hungary, Romania) and later from allies of the USSR (Cuba, Mongolia, Vietnam) and non-aligned countries (India, Syria, Afghanistan). Most of these cosmonauts received full training for their missions and were treated as equals, but were generally given shorter flights than Soviet cosmonauts. The European Space Agency (ESA) also took advantage of the program.

The US space shuttle program included payload Specialist positions which were usually filled by representatives of companies or institutions managing a specific payload on that mission. These payload specialists did not receive the same training as professional NASA astronauts and were not employed by NASA. In 1983, Ulf Merbold from ESA and Byron Lichtenberg from MIT (engineer and Air Force fighter pilot) were the first payload specialists to fly on the Space Shuttle, on mission STS-9.

In 1984, Charles D. Walker became the first non-government astronaut to fly, with his employer McDonnell Douglas paying US$40,000 (equivalent to $98,437 in 2019) for his flight. NASA was also eager to prove its capability to Congressional sponsors. During the 1970s, Shuttle prime contractor Rockwell International studied a $200–300 million removable cabin that could fit into the Shuttle's cargo bay. The cabin could carry up to 74 passengers into orbit for up to three days. Space Habitation Design Associates proposed, in 1983, a cabin for 72 passengers in the bay. Passengers were located in six sections, each with windows and its own loading ramp, and with seats in different configurations for launch and landing. Another proposal was based on the Spacelab habitation modules, which provided 32 seats in the payload bay in addition to those in the cockpit area. A 1985 presentation to the National Space Society stated that, although flying tourists in the cabin would cost $1 to 1.5 million per passenger without government subsidy, within 15 years 30,000 people a year would pay US$25,000 (equivalent to $59,429 in 2019) each to fly in space on new spacecraft. The presentation also forecast flights to lunar orbit within 30 years and visits to the lunar surface within 50 years.

As the shuttle program expanded in the early 1980s, NASA began a Space Flight Participant program to allow citizens without scientific or governmental roles to fly. Christa McAuliffe was chosen as the first Teacher in Space in July 1985 from 11,400 applicants. 1,700 applied for the Journalist in Space program. An Artist in Space program was considered, and NASA expected that after McAuliffe's flight two to three civilians a year would fly on the shuttle. After McAuliffe was killed in the Challenger disaster in January 1986, the programs were canceled. McAuliffe's backup, Barbara Morgan, eventually got hired in 1998 as a professional astronaut and flew on STS-118 as a mission specialist. A second journalist-in-space program, in which NASA green-lighted Miles O'Brien to fly on the space shuttle, was scheduled to be announced in 2003. That program was canceled in the wake of the Columbia disaster on STS-107 and subsequent emphasis on finishing the International Space Station before retiring the Space Shuttle.

Initially, senior figures at NASA strongly opposed space tourism on principle; from the beginning of the ISS expeditions, NASA stated it was not interested in accommodating paying guests. The Subcommittee on Space and Aeronautics Committee on Science of the House of Representatives held in June 2001 revealed the shifting attitude of NASA towards paying space tourists wanting to travel to the ISS in its statement on the hearing's purpose:

"Review the issues and opportunities for flying nonprofessional astronauts in space, the appropriate government role for supporting the nascent space tourism industry, use of the Shuttle and Space Station for Tourism, safety and training criteria for space tourists, and the potential commercial market for space tourism."

The subcommittee report was interested in evaluating Dennis Tito's extensive training and his experience in space as a nonprofessional astronaut.

With the realities of the post-Perestroika economy in Russia, its space industry was especially starved for cash. The Tokyo Broadcasting System (TBS) offered to pay for one of its reporters to fly on a mission. Toyohiro Akiyama was flown in 1990 to Mir with the eighth crew and returned a week later with the seventh crew. Cost estimates vary from $10 million up to $37 million. Akiyama gave a daily TV broadcast from orbit and also performed scientific experiments for Russian and Japanese companies.

In 1991, British chemist Helen Sharman was selected from a pool of 13,000 applicants to be the first Briton in space. The program was known as Project Juno and was a cooperative arrangement between the Soviet Union and a group of British companies. The Project Juno consortium failed to raise the funds required, and the program was almost canceled. Reportedly Mikhail Gorbachev ordered it to proceed under Soviet expense in the interests of international relations, but in the absence of Western underwriting, less expensive experiments were substituted for those in the original plans. Sharman flew aboard Soyuz TM-12 to Mir and returned aboard Soyuz TM-11.

Sub-orbital space tourism

Successful projects

• Scaled Composites won the $10 million X Prize in October 2004 with SpaceShipOne, as the first private company to reach and surpass an altitude of 100 km (62 mi) twice within two weeks. The altitude is beyond the Kármán Line, the arbitrarily defined boundary of space. The first flight was flown by Michael Melvill in June 2004, to a height of 100 km (62 mi), making him the first commercial astronaut. The prize-winning flight was flown by Brian Binnie, which reached a height of 112.0 km (69.6 mi), breaking the X-15 record.

Ongoing projects

• Virgin Galactic aspires to be the first to offer regular suborbital spaceflights to paying passengers, aboard a fleet of five SpaceShipTwo-class spaceplanes. The first of these spaceplanes, VSS Enterprise, was intended to commence its first commercial flights in 2015, and tickets were on sale at a price of $200,000 (later raised to $250,000). However, the company suffered a considerable setback when the Enterprise broke up over the Mojave Desert during a test flight in October 2014. Over 700 tickets had been sold prior to the accident. A second spaceplane, VSS Unity, has begun testing.
• As of 2018, Blue Origin is developing the New Shepard reusable suborbital launch system specifically to enable short-duration space tourism. Blue Origin plans to ferry a maximum of six persons on a brief journey to space on board the New Shepard. The capsule is attached to the top portion of an 18-meter rocket. The rocket reached 66 miles during a test flight on April 29, 2018. This was the eighth test flight of the New Shepard as part of its entire developmental program. Blue Origin has not yet started selling tickets for this flight carrying passengers.

Canceled projects

• Armadillo Aerospace was developing a two-seat vertical takeoff and landing (VTOL) rocket called Hyperion, which will be marketed by Space Adventures. Hyperion uses a capsule similar in shape to the Gemini capsule. The vehicle will use a parachute for descent but will probably use retrorockets for final touchdown, according to remarks made by Armadillo Aerospace at the Next Generation Suborbital Researchers Conference in February 2012. The assets of Armadillo Aerospace were sold to Exos Aerospace and while SARGE is continuing to be developed, it is unclear whether Hyperion is still being developed.
• XCOR Aerospace was developing a suborbital vehicle called Lynx until development was halted in May 2016. The Lynx would take off from a runway under rocket power. Unlike SpaceShipOne and SpaceShipTwo, Lynx would not require a mothership. Lynx was designed for rapid turnaround, which would enable it to fly up to four times per day. Because of this rapid flight rate, Lynx had fewer seats than SpaceShipTwo, carrying only one pilot and one spaceflight participant on each flight. XCOR expected to roll out the first Lynx prototype and begin flight tests in 2015, but as of late 2017, XCOR was unable to complete their prototype development and filed for bankruptcy.
  • Citizens in Space, formerly the Teacher in Space Project, is a project of the United States Rocket Academy. Citizens in Space combines citizen science with citizen space exploration. The goal is to fly citizen-science experiments and citizen explorers (who travel free) who will act as payload operators on suborbital space missions. By 2012, Citizens in Space had acquired a contract for 10 suborbital flights with XCOR Aerospace and expected to acquire additional flights from XCOR and other suborbital spaceflight providers in the future. In 2012 Citizens in Space reported they had begun training three citizen astronaut candidates and would select seven additional candidates over the next 12 to 14 months.
  • Space Expedition Corporation was preparing to use the Lynx for "Space Expedition Curaçao", a commercial flight from Hato Airport on Curaçao, and planned to start commercial flights in 2014. The costs were $95,000 each.
  • Axe Apollo Space Academy promotion of Unilever which planned to provide 23 people suborbital spaceflights on board the Lynx.
• EADS Astrium, a subsidiary of European aerospace giant EADS, announced its space tourism project in June 2007.

Orbital space tourism

As of 2020, Space Adventures is the only company to have coordinated tourism flights to Earth's orbit. The Virginia-based company has worked with Russia to use its Soyuz spacecraft to fly ultra-wealthy individuals to the International Space Station. The tourists included entrepreneur and space investor Anousheh Ansari and Cirque du Soleil co-founder Guy Laliberté. Those missions were priced at around $20 million each. The space industry could soon be headed for a tourism revolution if SpaceX and Boeing make good on their plans to take tourists to orbit.

Successful projects

Space tourist Mark Shuttleworth

At the end of the 1990s, MirCorp, a private venture that was by then in charge of the space station, began seeking potential space tourists to visit Mir in order to offset some of its maintenance costs. Dennis Tito, an American businessman and former JPL scientist, became their first candidate. When the decision was made to de-orbit Mir, Tito managed to switch his trip to the International Space Station (ISS) aboard a Russian Soyuz spacecraft through a deal between MirCorp and US-based Space Adventures, Ltd. Dennis Tito visited the ISS for seven days in April–May 2001, becoming the world's first "fee-paying" space tourist. Tito paid a reported $20 million for his trip.

Tito was followed in April 2002 by South African Mark Shuttleworth (Soyuz TM-34). The third was Gregory Olsen in October 2005 (Soyuz TMA-7). In February 2003, the Space Shuttle Columbia disintegrated on re-entry into the Earth's atmosphere, killing all seven astronauts aboard. After this disaster, space tourism on the Russian Soyuz program was temporarily put on hold, because Soyuz vehicles became the only available transport to the ISS. After the Shuttle return to service in July 2005, space tourism was resumed. In September 2006, an Iranian American businesswoman named Anousheh Ansari became the fourth space tourist (Soyuz TMA-9).) In April 2007, Charles Simonyi, an American businessman of Hungarian descent, joined their ranks (Soyuz TMA-10). Simonyi became the first repeat space tourist, paying again to fly on Soyuz TMA-14 in March 2009. British-American Richard Garriott became the next space tourist in October 2008 aboard Soyuz TMA-13. As of 2020, Canadian Guy Laliberté is the most recent tourist to visit the ISS, flying in September 2009 aboard Soyuz TMA-16. Originally the third member aboard Soyuz TMA-18M should have been the British singer Sarah Brightman as a space tourist, but on May 13, 2015, she announced she had withdrawn from training.

Since the Space Shuttle was retired in 2011, Soyuz once again became the only means of accessing the ISS, and so tourism was once again put on hold. On June 7, 2019, NASA announced a plan to open ISS to the space tourism again.

Ongoing projects

• The Boeing Starliner capsule is being developed as part of the NASA's Commercial Crew Program. Part of the agreement with NASA allows Boeing to sell seats for space tourists. Boeing proposed including one seat per flight for a spaceflight participant at a price that would be competitive with what Roscosmos charges tourists.
• Bigelow Aerospace plan to extend their successes with the Genesis modules by launching the B330, an expandable habitation module with 330 cubic meters of internal space, aboard a Vulcan rocket. The Vulcan, which is the only rocket under development with sufficient performance and a large enough payload fairing, is contracted to boost BA 330 to low lunar orbit by the end of 2022.
• Aurora Space Station A United States startup firm, Orion Span announced during the early part of 2018 it plans to launch and position a luxury space hotel to orbit within several years. This project remains in the preliminary stages. Aurora Station, the name of this hotel, will offer guests (maximum of six individuals) 12 days of staying in a pill-shaped space hotel for $9.5 million floating in the unexplored universe. The hotel's cabin measures approximately 43 feet by 14 feet in width. Guests can enjoy non-space food and drinks for a small fee.
• SpaceX Axiom Space-1 (AX-1): Axiom Space and SpaceX plan to send tourists to the ISS in January 2022 using a Dragon 2 spacecraft.
• Space Adventures Crew Dragon mission: Space Adventures and SpaceX plan to send up to four tourists to low Earth orbit for a few days in late 2021 or early 2022.

Canceled projects

• In 2004, Bigelow Aerospace established a competition called America's Space Prize, which offered a $50 million prize to the first US company to create a reusable spacecraft capable of carrying passengers to a Nautilus space station. The prize expired in January 2010 without anyone making a serious effort to win it.
• The Space Island Group proposed having 20,000 people on their "space island" by 2020.
• Galactic Suite Design
• Orbital Technologies Commercial Space Station
• Space Industries Incorporated
• Space Islands

Tourism beyond Earth orbit

Ongoing projects

• In February 2017, Elon Musk announced that substantial deposits from two individuals had been received by SpaceX for a Moon loop flight using a free return trajectory and that this could happen as soon as late 2018. Musk said that the cost of the mission would be "comparable" to that of sending an astronaut to the International Space Station, about US$70 million in 2017. In February 2018, Elon Musk announced the Falcon Heavy rocket would not be used for crewed missions. The proposal changed in 2018 to use the Starship launch system instead. In September 2018, Elon Musk revealed the passenger for the trip, Yusaku Maezawa during a livestream. Yusaku Maezawa described the plan for his trip in further detail, dubbed the #dearMoon project, intending to take 6–8 artists with him on the journey to inspire the artists to create new art.
• Elon Musk said that the Starship will be ready for an unpiloted trip to Mars in 2022. The crewed flight will follow in 2024.
• Space Adventures Ltd. have announced that they are working on DSE-Alpha, a circumlunar mission to the Moon, with the price per passenger being $100,000,000.

Canceled projects

• Excalibur Almaz proposed to take three tourists in a flyby around the Moon, using modified Almaz space station modules, in a low-energy trajectory flyby around the Moon. The trip would last around 6 months. However, their equipment was never launched and is to be converted into an educational exhibit.
• The Golden Spike Company was an American space transport startup active from 2010 to 2013. The company held the objective to offer private commercial space transportation services to the surface of the Moon. The company's website was quietly taken offline in September 2015.
• The Inspiration Mars Foundation is an American nonprofit organization founded by Dennis Tito that proposed to launch a crewed mission to flyby Mars in January 2018, or 2021 if they missed the first deadline. Their website became defunct by late 2015 but it is archived by the Internet Archive. The Foundation's future plans are unclear.

Legality

Under the Outer Space Treaty signed in 1967, the launch operator's nationality and the launch site's location determine which country is responsible for any damages occurred from a launch.

After valuable resources were detected on the Moon, private companies began to formulate methods to extract the resources. Article II of the Outer Space Treaty dictates that "outer space, including the Moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means". However, countries have the right to freely explore the Moon and any resources collected are property of that country when they return.

United States

In December 2005, the US government released a set of proposed rules for space tourism. These included screening procedures and training for emergency situations, but not health requirements.

Under current US law, any company proposing to launch paying passengers from American soil on a suborbital rocket must receive a license from the Federal Aviation Administration's Office of Commercial Space Transportation (FAA/AST). The licensing process focuses on public safety and safety of property, and the details can be found in the Code of Federal Regulations, Title 14, Chapter III. This is in accordance with the Commercial Space Launch Amendments Act passed by Congress in 2004.

In March 2010, the New Mexico legislature passed the Spaceflight Informed Consent Act. The SICA gives legal protection to companies who provide private space flights in the case of accidental harm or death to individuals. Participants sign an Informed Consent waiver, dictating that spaceflight operators cannot be held liable in the "death of a participant resulting from the inherent risks of space flight activities". Operators are however not covered in the case of gross negligence or willful misconduct.

Criticism and alternatives of the term "space tourist"

Many private space travelers have objected to the term "space tourist", often pointing out that their role went beyond that of an observer, since they also carried out scientific experiments in the course of their journey. Richard Garriott additionally emphasized that his training was identical to the requirements of non-Russian Soyuz crew members, and that teachers and other non-professional astronauts chosen to fly with NASA are called astronauts. He has said that if the distinction has to be made, he would rather be called "private astronaut" than "tourist". Mark Shuttleworth described himself as a "pioneer of commercial space travel". Gregory Olsen prefers "private researcher", and Anousheh Ansari prefers the term "private space explorer". Other space enthusiasts object to the term on similar grounds. Rick Tumlinson of the Space Frontier Foundation, for example, has said: "I hate the word tourist, and I always will ... 'Tourist' is somebody in a flowered shirt with three cameras around his neck." Russian cosmonaut Maksim Surayev told the press in 2009 not to describe Guy Laliberté as a tourist: "It's become fashionable to speak of space tourists. He is not a tourist but a participant in the mission."

"Spaceflight participant" is the official term used by NASA and the Russian Federal Space Agency to distinguish between private space travelers and career astronauts. Tito, Shuttleworth, Olsen, Ansari, and Simonyi were designated as such during their respective space flights. NASA also lists Christa McAuliffe as a spaceflight participant (although she did not pay a fee), apparently due to her non-technical duties aboard the STS-51-L flight.

The US Federal Aviation Administration awards the title of "commercial astronaut" to trained crew members of privately funded spacecraft. The only people currently holding this title are Mike Melvill and Brian Binnie, the pilots of SpaceShipOne in 2004; pilots Mark P. Stucky and Frederick W. Sturckow in 2018, and pilots Dave Mackay, Michael Masucci, and trainer Beth Moses in 2019 aboard SpaceShipTwo on two separate missions.

Attitudes towards space tourism

A web-based survey suggested that over 70% of those surveyed wanted less than or equal to 2 weeks in space; in addition, 88% wanted to spacewalk, of whom 14% would pay a 50% premium for the experience, and 21% wanted a hotel or space station.

The concept has met with some criticism; Günter Verheugen, vice-president of the European Commission, said of the EADS Astrium Space Tourism Project: "It's only for the super-rich, which is against my social convictions".

Environmental effects

A 2010 study published in Geophysical Research Letters raised concerns that the growing commercial spaceflight industry could accelerate global warming. The study, funded by NASA and The Aerospace Corporation, simulated the impact of 1,000 suborbital launches of hybrid rockets from a single location, calculating that this would release a total of 600 tonnes of black carbon into the stratosphere. They found that the resultant layer of soot particles remained relatively localized, with only 20% of the carbon straying into the southern hemisphere, thus creating a strong hemispherical asymmetry. This unbalance would cause the temperature to decrease by about 0.4 °C (0.72 °F) in the tropics and subtropics, whereas the temperature at the poles would increase by between 0.2 and 1 °C (0.36 and 1.80 °F). The ozone layer would also be affected, with the tropics losing up to 1.7% of ozone cover, and the polar regions gaining 5–6%. The researchers stressed that these results should not be taken as "a precise forecast of the climate response to a specific launch rate of a specific rocket type", but as a demonstration of the sensitivity of the atmosphere to the large-scale disruption that commercial space tourism could bring.

Education and advocacy

Several organizations have been formed to promote the space tourism industry, including the Space Tourism Society, Space Future, and HobbySpace. UniGalactic Space Travel Magazine is a bi-monthly educational publication covering space tourism and space exploration developments in companies like SpaceX, Orbital Sciences, Virgin Galactic and organizations like NASA.

Classes in space tourism are currently taught at the Rochester Institute of Technology in New York, and Keio University in Japan.

Economic potential

A 2010 report from the Federal Aviation Administration, titled "The Economic Impact of Commercial Space Transportation on the U. S Economy in 2009", cites studies done by Futron, an aerospace and technology-consulting firm, which predict that space tourism could become a billion-dollar market within 20 years. Eight tourists reached orbit between 2001 and 2009. In 2011 Space Adventures suggested that this number could reach 140 by 2020, but there has yet to be any increase with commercial crewed rockets only just beginning to enter service.

 

Space architecture

From Wikipedia, the free encyclopedia

A 1990 artist rendering of Space Station Freedom, a project that eventually evolved into the International Space Station

Space architecture is the theory and practice of designing and building inhabited environments in outer space. The architectural approach to spacecraft design addresses the total built environment. It is mainly based on the field of engineering (especially aerospace engineering), but also involves diverse disciplines such as physiology, psychology, and sociology. Like architecture on Earth, the attempt is to go beyond the component elements and systems and gain a broad understanding of the issues that affect design success. Space architecture borrows from multiple forms of niche architecture to accomplish the task of ensuring human beings can live and work in space. These include the kinds of design elements one finds in “tiny housing, small living apartments/houses, vehicle design, capsule hotels, and more.”

Much space architecture work has been in designing concepts for orbital space stations and lunar and Martian exploration ships and surface bases for the world's space agencies, chiefly NASA.

The practice of involving architects in the space program grew out of the Space Race, although its origins can be seen much earlier. The need for their involvement stemmed from the push to extend space mission durations and address the needs of astronauts including but beyond minimum survival needs. Space architecture is currently represented in several institutions. The Sasakawa International Center for Space Architecture (SICSA) is an academic organization with the University of Houston that offers a Master of Science in Space Architecture. SICSA also works design contracts with corporations and space agencies. In Europe, The Vienna University of Technology and the International Space University are involved in space architecture research. The International Conference on Environmental Systems meets annually to present sessions on human spaceflight and space human factors. Within the American Institute of Aeronautics and Astronautics, the Space Architecture Technical Committee has been formed. Despite the historical pattern of large government-led space projects and university-level conceptual design, the advent of space tourism threatens to shift the outlook for space architecture work.

Etymology

The word space in space architecture is referring to the outer space definition, which is from English outer and space. Outer can be defined as "situated on or toward the outside; external; exterior" and originated around 1350–1400 in Middle English. Space is "an area, extent, expanse, lapse of time," the aphetic of Old French espace dating to 1300. Espace is from Latin spatium, "room, area, distance, stretch of time," and is of uncertain origin. In space architecture, speaking of outer space usually means the region of the universe outside Earth's atmosphere, as opposed to outside the atmospheres of all terrestrial bodies. This allows the term to include such domains as the lunar and Martian surfaces.

Architecture, the concatenation of architect and -ure, dates to 1563, coming from Middle French architecte. This term is of Latin origin, formerly architectus, which came from Greek arkhitekton. Arkitekton means "master builder" and is from the combination of arkhi- "chief" and tekton "builder". The human experience is central to architecture – the primary difference between space architecture and spacecraft engineering.

There is some debate over the terminology of space architecture. Some consider the field to be a specialty within architecture that applies architectural principles to space applications. Others such as Ted Hall of the University of Michigan see space architects as generalists, with what is traditionally considered architecture (Earth-bound or terrestrial architecture) being a subset of a broader space architecture. Any structures that fly in space will likely remain for some time highly dependent on Earth-based infrastructure and personnel for financing, development, construction, launch, and operation. Therefore, it is a matter of discussion how much of these earthly assets are to be considered part of space architecture. The technicalities of the term space architecture are open to some level of interpretation.

Origins

Ideas of people traveling to space were first published in science fiction stories, like Jules Verne's 1865 From the Earth to the Moon. In this story several details of the mission (crew of three, spacecraft dimensions, Florida launch site) bear striking similarity to the Apollo moon landings that took place more than 100 years later. Verne's aluminum capsule had shelves stocked with equipment needed for the journey such as a collapsing telescope, pickaxes and shovels, firearms, oxygen generators, and even trees to plant. A curved sofa was built into the floor and walls and windows near the tip of the spacecraft were accessible by ladder. The projectile was shaped like a bullet because it was gun-launched from the ground, a method infeasible for transporting man to space due to the high acceleration forces produced. It would take rocketry to get humans to the cosmos.

An illustration of von Braun's rotating space station concept

The first serious theoretical work published on space travel by means of rocket power was by Konstantin Tsiolkovsky in 1903. Besides being the father of astronautics he conceived such ideas as the space elevator (inspired by the Eiffel Tower), a rotating space station that created artificial gravity along the outer circumference, airlocks, space suits for extra-vehicular activity (EVA), closed ecosystems to provide food and oxygen, and solar power in space. Tsiolkovsky believed human occupation of space was the inevitable path for our species. In 1952 Wernher von Braun published his own inhabited space station concept in a series of magazine articles. His design was an upgrade of earlier concepts, but he took the unique step in going directly to the public with it. The spinning space station would have three decks and was to function as a navigational aid, meteorological station, Earth observatory, military platform, and way point for further exploration missions to outer space. It is said that the space station depicted in 2001: A Space Odyssey traces its design heritage to Von Braun's work. Wernher von Braun went on to devise mission schemes to the Moon and Mars, each time publishing his grand plans in Collier's Weekly.

The flight of Yuri Gagarin on April 12, 1961 was humanity's maiden spaceflight. While the mission was a necessary first step, Gagarin was more or less confined to a chair with a small view port from which to observe the cosmos – a far cry from the possibilities of life in space. Following space missions gradually improved living conditions and quality of life in low Earth orbit. Expanding room for movement, physical exercise regimens, sanitation facilities, improved food quality, and recreational activities all accompanied longer mission durations. Architectural involvement in space was realized in 1968 when a group of architects and industrial designers led by Raymond Loewy, over objections from engineers, prevailed in convincing NASA to include an observation window in the Skylab orbital laboratory. This milestone represents the introduction of the human psychological dimension to spacecraft design. Space architecture was born.

Theory

The subject of architectural theory has much application in space architecture. Some considerations, though, will be unique to the space context.

Ideology of building

Louis Sullivan famously coined the phrase 'form ever follows function'

In the first century BC, the Roman architect Vitruvius said all buildings should have three things: strength, utility, and beauty. Vitruvius's work De Architectura, the only surviving work on the subject from classical antiquity, would have profound influence on architectural theory for thousands of years to come. Even in space architecture these are some of the first things we consider. However, the tremendous challenge of living in space has led to habitat design based largely on functional necessity with little or no applied ornament. In this sense space architecture as we know it shares the form follows function principle with modern architecture.

Some theorists link different elements of the Vitruvian triad. Walter Gropius writes:

'Beauty' is based on the perfect mastery of all the scientific, technological and formal prerequisites of the task ... The approach of Functionalism means to design the objects organically on the basis of their own contemporary postulates, without any romantic embellishment or jesting.

As space architecture continues to mature as a discipline, dialogue on architectural design values will open up just as it has for Earth.

Analogs

The Mars Desert Research Station is located in the Utah desert because of its relative similarity to the Martian surface

A starting point for space architecture theory is the search for extreme environments in terrestrial settings where humans have lived, and the formation of analogs between these environments and space. For example, humans have lived in submarines deep in the ocean, in bunkers beneath the Earth's surface, and on Antarctica, and have safely entered burning buildings, radioactively contaminated zones, and the stratosphere with the help of technology. Aerial refueling enables Air Force One to stay airborne virtually indefinitely. Nuclear powered submarines generate oxygen using electrolysis and can stay submerged for months at a time. Many of these analogs can be very useful design references for space systems. In fact space station life support systems and astronaut survival gear for emergency landings bear striking similarity to submarine life support systems and military pilot survival kits, respectively.

Space missions, especially human ones, require extensive preparation. In addition to terrestrial analogs providing design insight, the analogous environments can serve as testbeds to further develop technologies for space applications and train astronaut crews. The Flashline Mars Arctic Research Station is a simulated Mars base, maintained by the Mars Society, on Canada's remote Devon Island. The project aims to create conditions as similar as possible to a real Mars mission and attempts to establish ideal crew size, test equipment "in the field", and determine the best extra-vehicular activity suits and procedures. To train for EVAs in microgravity, space agencies make broad use of underwater and simulator training. The Neutral Buoyancy Laboratory, NASA's underwater training facility, contains full-scale mockups of the Space Shuttle cargo bay and International Space Station modules. Technology development and astronaut training in space-analogous environments are essential to making living in space possible.

In space

Fundamental to space architecture is designing for physical and psychological wellness in space. What often is taken for granted on Earth – air, water, food, trash disposal – must be designed for in fastidious detail. Rigorous exercise regimens are required to alleviate muscular atrophy and other effects of space on the body. That space missions are (optimally) fixed in duration can lead to stress from isolation. This problem is not unlike that faced in remote research stations or military tours of duty, although non-standard gravity conditions can exacerbate feelings of unfamiliarity and homesickness. Furthermore, confinement in limited and unchanging physical spaces appears to magnify interpersonal tensions in small crews and contribute to other negative psychological effects. These stresses can be mitigated by establishing regular contact with family and friends on Earth, maintaining health, incorporating recreational activities, and bringing along familiar items such as photographs and green plants. The importance of these psychological measures can be appreciated in the 1968 Soviet 'DLB Lunar Base' design:

...it was planned that the units on the Moon would have a false window, showing scenes of the Earth countryside that would change to correspond with the season back in Moscow. The exercise bicycle was equipped with a synchronized film projector, that allowed the cosmonaut to take a 'ride' out of Moscow with return.

Mir was a 'modular' space station. This approach allows a habitat to function before assembly is complete and its design can be changed by swapping modules.

The challenge of getting anything at all to space, due to launch constraints, has had a profound effect on the physical shapes of space architecture. All space habitats to date have used modular architecture design. Payload fairing dimensions (typically the width but also the height) of modern launch vehicles limit the size of rigid components launched into space. This approach to building large scale structures in space involves launching multiple modules separately and then manually assembling them afterward. Modular architecture results in a layout similar to a tunnel system where passage through several modules is often required to reach any particular destination. It also tends to standardize the internal diameter or width of pressurized rooms, with machinery and furniture placed along the circumference. These types of space stations and surface bases can generally only grow by adding additional modules in one or more direction. Finding adequate working and living space is often a major challenge with modular architecture. As a solution, flexible furniture (collapsible tables, curtains on rails, deployable beds) can be used to transform interiors for different functions and change the partitioning between private and group space. For more discussion of the factors that influence shape in space architecture, see the Varieties section.

Eugène Viollet-le-Duc advocated different architectural forms for different materials. This is especially important in space architecture. The mass constraints with launching push engineers to find ever lighter materials with adequate material properties. Moreover, challenges unique to the orbital space environment, such as rapid thermal expansion due to abrupt changes in solar exposure, and corrosion caused by particle and atomic oxygen bombardment, require unique materials solutions. Just as the industrial age produced new materials and opened up new architectural possibilities, advances in materials technology will change the prospects of space architecture. Carbon-fiber is already being incorporated into space hardware because of its high strength-to-weight ratio. Investigations are underway to see whether carbon-fiber or other composite materials will be adopted for major structural components in space. The architectural principle that champions using the most appropriate materials and leaving their nature unadorned is called truth to materials.

A notable difference between the orbital context of space architecture and Earth-based architecture is that structures in orbit do not need to support their own weight. This is possible because of the microgravity condition of objects in free fall. In fact much space hardware, such as the Space Shuttle ''s robotic arm, is designed only to function in orbit and would not be able to lift its own weight on the Earth's surface. Microgravity also allows an astronaut to move an object of practically any mass, albeit slowly, provided he or she is adequately constrained to another object. Therefore, structural considerations for the orbital environment are dramatically different from those of terrestrial buildings, and the biggest challenge to holding a space station together is usually launching and assembling the components intact. Construction on extraterrestrial surfaces still needs to be designed to support its own weight, but its weight will depend on the strength of the local gravitational field.

Ground infrastructure

Human spaceflight currently requires a great deal of supporting infrastructure on Earth. All human orbital missions to date have been government-orchestrated. The organizational body that manages space missions is typically a national space agency, NASA in the case of the United States and Roscosmos for Russia. These agencies are funded at the federal level. At NASA, flight controllers are responsible for real-time mission operations and work onsite at NASA Centers. Most engineering development work involved with space vehicles is contracted-out to private companies, who in turn may employ subcontractors of their own, while fundamental research and conceptual design is often done in academia through research funding.

Varieties

Suborbital

Structures that cross the boundary of space but do not reach orbital speeds are considered suborbital architecture. For spaceplanes, the architecture has much in common with airliner architecture, especially those of small business jets.

SpaceShip

A mockup of the SpaceShipTwo interior

On June 21, 2004, Mike Melvill reached space funded entirely by private means. The vehicle, SpaceShipOne, was developed by Scaled Composites as an experimental precursor to a privately operated fleet of spaceplanes for suborbital space tourism. The operational spaceplane model, SpaceShipTwo (SS2), will be carried to an altitude of about 15 kilometers by a B-29 Superfortress-sized carrier aircraft, WhiteKnightTwo. From there SS2 will detach and fire its rocket motor to bring the craft to its apogee of approximately 110 kilometers. Because SS2 is not designed to go into orbit around the Earth, it is an example of suborbital or aerospace architecture.

The architecture of the SpaceShipTwo vehicle is somewhat different from what is common in previous space vehicles. Unlike the cluttered interiors with protruding machinery and many obscure switches of previous vehicles, this cabin looks more like something out of science fiction than a modern spacecraft. Both SS2 and the carrier aircraft are being built from lightweight composite materials instead of metal. When the time for weightlessness has arrived on a SS2 flight, the rocket motor will be turned off, ending the noise and vibration. Passengers will be able to see the curvature of the Earth. Numerous double-paned windows that encircle the cabin will offer views in nearly all directions. Cushioned seats will recline flat into the floor to maximize room for floating. An always-pressurized interior will be designed to eliminate the need for space suits.

Orbital

Orbital architecture is the architecture of structures designed to orbit around the Earth or another astronomical object. Examples of currently-operational orbital architecture are the International Space Station and the re-entry vehicles Space Shuttle, Soyuz spacecraft, and Shenzhou spacecraft. Historical craft include the Mir space station, Skylab, and the Apollo spacecraft. Orbital architecture usually addresses the condition of weightlessness, a lack of atmospheric and magnetospheric protection from solar and cosmic radiation, rapid day/night cycles, and possibly risk of orbital debris collision. In addition, re-entry vehicles must also be adapted both to weightlessness and to the high temperatures and accelerations experienced during atmospheric reentry.

International Space Station

Astronaut (upper center) works on the Integrated Truss Structure of the ISS

The International Space Station (ISS) is the only permanently inhabited structure currently in space. It is the size of an American football field and has a crew of six. With a living volume of 358 m³, it has more interior room than the cargo beds of two American 18-wheeler trucks. However, because of the microgravity environment of the space station, there are not always well-defined walls, floors, and ceilings and all pressurized areas can be utilized as living and working space. The International Space Station is still under construction. Modules were primarily launched using the Space Shuttle until its deactivation and were assembled by its crew with the help of the working crew on board the space station. ISS modules were often designed and built to barely fit inside the shuttle's payload bay, which is cylindrical with a 4.6 meter diameter.

An interior view of the Columbus module

Life aboard the space station is distinct from terrestrial life in some very interesting ways. Astronauts commonly "float" objects to one another; for example they will give a clipboard an initial nudge and it will coast to its receiver across the room. In fact, an astronaut can become so accustomed to this habit that they forget that it doesn't work anymore when they return to Earth. The diet of ISS spacefarers is a combination of participating nations' space food. Each astronaut selects a personalized menu before flight. Many food choices reflect the cultural differences of the astronauts, such as bacon and eggs vs. fish products for breakfast (for the US and Russia, respectively). More recently such delicacies as Japanense beef curry, kimchi, and swordfish (Riviera style) have been featured on the orbiting outpost. As much of ISS food is dehydrated or sealed in pouches MRE-style, astronauts are quite excited to get relatively fresh food from shuttle and Progress resupply missions. Food is stored in packages that facilitate eating in microgravity by keeping the food constrained to the table. Spent packaging and trash must be collected to load into an available spacecraft for disposal. Waste management is not nearly as straight forward as it is on Earth. The ISS has many windows for observing Earth and space, one of the astronauts' favorite leisure activities. Since the Sun rises every 90 minutes, the windows are covered at "night" to help maintain the 24-hour sleep cycle.

When a shuttle is operating in low Earth orbit, the ISS serves as a safety refuge in case of emergency. The inability to fall back on the safety of the ISS during the latest Hubble Space Telescope Servicing Mission (because of different orbital inclinations) was the reason a backup shuttle was summoned to the launch pad. So, ISS astronauts operate with the mindset that they may be called upon to give sanctuary to a Shuttle crew should something happen to compromise a mission. The International Space Station is a colossal cooperative project between many nations. The prevailing atmosphere on board is one of diversity and tolerance. This does not mean that it is perfectly harmonious. Astronauts experience the same frustrations and interpersonal quarrels as their Earth-based counterparts.

A typical day on the station might start with wakeup at 6:00 am inside a private soundproof booth in the crew quarters. Astronauts would probably find their sleeping bags in an upright position tied to the wall, because orientation does not matter in space. The astronaut's thighs would be lifted about 50 degrees off the vertical. This is the neutral body posture in weightlessness – it would be excessively tiring to "sit" or "stand" as is common on Earth. Crawling out of his booth, an astronaut may chat with other astronauts about the day's science experiments, mission control conferences, interviews with Earthlings, and perhaps even a space walk or space shuttle arrival.

Bigelow Aerospace (out of business since March 2020)

Bigelow Aerospace took the unique step in securing two patents NASA held from development of the Transhab concept in regard to inflatable space structures. The company now has sole rights to commercial development of the inflatable module technology. On July 12, 2006 the Genesis I experimental space habitat was launched into low Earth orbit. Genesis I demonstrated the basic viability of inflatable space structures, even carrying a payload of life science experiments. The second module, Genesis II, was launched into orbit on June 28, 2007 and tested out several improvements over its predecessor. Among these are reaction wheel assemblies, a precision measurement system for guidance, nine additional cameras, improved gas control for module inflation, and an improved on-board sensor suite.

While Bigelow architecture is still modular, the inflatable configuration allows for much more interior volume than rigid modules. The BA-330, Bigelow's full-scale production model, has more than twice the volume of the largest module on the ISS. Inflatable modules can be docked to rigid modules and are especially well suited for crew living and working quarters. In 2009 NASA began considering attaching a Bigelow module to the ISS, after abandoning the Transhab concept more than a decade before. The modules will likely have a solid inner core for structural support. Surrounding usable space could be partitioned into different rooms and floors. The Bigelow Expandable Activity Module (BEAM) was transported to ISS arriving on April 10, 2016, inside the unpressurized cargo trunk of a SpaceX Dragon during the SpaceX CRS-8 cargo mission.

Bigelow Aerospace may choose to launch many of their modules independently, leasing their use to a wide variety of companies, organizations, and countries that can't afford their own space programs. Possible uses of this space include microgravity research and space manufacturing. Or we may see a private space hotel composed of numerous Bigelow modules for rooms, observatories, or even a recreational padded gymnasium. There is the option of using such modules for habitation quarters on long-term space missions in the Solar System. One amazing aspect of spaceflight is that once a craft leaves an atmosphere, aerodynamic shape is a non-issue. For instance it's possible to apply a Trans Lunar Injection to an entire space station and send it to fly by the Moon. Bigelow has expressed the possibility of their modules being modified for lunar and Martian surface systems as well.

Lunar

Lunar architecture exists both in theory and in practice. Today the archeological artifacts of temporary human outposts lay untouched on the surface of the Moon. Five Apollo Lunar Module descent stages stand upright in various locations across the equatorial region of the Near Side, hinting at the extraterrestrial endeavors of mankind. The leading hypothesis on the origin of the Moon did not gain its current status until after lunar rock samples were analysed. The Moon is the furthest any humans have ever ventured from their home, and space architecture is what kept them alive and allowed them to function as humans.

Apollo

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Lunar Module ascent stage blasts off the Moon in 1972, leaving the descent stage behind. View from TV camera on Lunar rover.

On the cruise to the Moon, Apollo astronauts had two "rooms" to choose from – the Command Module (CM) or the Lunar Module (LM). This can be seen in the film Apollo 13 where the three astronauts were forced to use the LM as an emergency life boat. Passage between the two modules was possible through a pressurized docking tunnel, a major advantage over the Soviet design, which required donning a spacesuit to switch modules. The Command Module featured five windows made of three thick panes of glass. The two inner panes, made of aluminosilicate, ensured no cabin air leaked into space. The outer pane served as a debris shield and part of the heat shield needed for atmospheric reentry. The CM was a sophisticated spacecraft with all the systems required for successful flight but with an interior volume of 6.17 m³ could be considered cramped for three astronauts. It had its design weaknesses such as no toilet (astronauts used much-hated 'relief tubes' and fecal bags). The coming of the space station would bring effective life support systems with waste management and water reclamation technologies.

The Lunar Module had two stages. A pressurized upper stage, termed the Ascent stage, was the first true spaceship as it could only operate in the vacuum of space. The Descent stage carried the engine used for descent, landing gear and radar, fuel and consumables, the famous ladder, and the Lunar Rover during later Apollo missions. The idea behind staging is to reduce mass later in a flight, and is the same strategy used in an Earth-launched multistage rocket. The LM pilot stood up during the descent to the Moon. Landing was achieved via automated control with a manual backup mode. There was no airlock on the LM so the entire cabin had to be evacuated (air vented to space) in order to send an astronaut out to walk on the surface. To stay alive, both astronauts in the LM would have to get in their space suits at this point. The Lunar Module worked well for what it was designed to do. However, a big unknown remained throughout the design process – the effects of lunar dust. Every astronaut who walked on the Moon tracked in lunar dust, contaminating the LM and later the CM during Lunar Orbit Rendezvous. These dust particles can't be brushed away in a vacuum, and have been described by John Young of Apollo 16 as being like tiny razor blades. It was soon realized that for humans to live on the Moon, dust mitigation was one of many issues that had to be taken seriously.

Constellation program

The Exploration Systems Architecture Study that followed the Vision for Space Exploration of 2004 recommended the development of a new class of vehicles that have similar capabilities to their Apollo predecessors with several key differences. In part to retain some of the Space Shuttle program workforce and ground infrastructure, the launch vehicles were to use Shuttle-derived technologies. Secondly, rather than launching the crew and cargo on the same rocket, the smaller Ares I was to launch the crew with the larger Ares V to handle the heavier cargo. The two payloads were to rendezvous in low Earth orbit and then head to the Moon from there. The Apollo Lunar Module could not carry enough fuel to reach the polar regions of the Moon but the Altair lunar lander was intended to access any part of the Moon. While the Altair and surface systems would have been equally necessary for Constellation program to reach fruition, the focus was on developing the Orion spacecraft to shorten the gap in US access to orbit following the retirement of the Space Shuttle in 2010.

Even NASA has described Constellation architecture as 'Apollo on steroids'. Nonetheless, a return to the proven capsule design is a move welcomed by many.

Martian

Martian architecture is architecture designed to sustain human life on the surface of Mars, and all the supporting systems necessary to make this possible. The direct sampling of water ice on the surface, and evidence for geyser-like water flows within the last decade have made Mars the most likely extraterrestrial environment for finding liquid water, and therefore alien life, in the Solar System. Moreover, some geologic evidence suggests that Mars could have been warm and wet on a global scale in its distant past. Intense geologic activity has reshaped the surface of the Earth, erasing evidence of our earliest history. Martian rocks can be even older than Earth rocks, though, so exploring Mars may help us decipher the story of our own geologic evolution including the origin of life on Earth. Mars has an atmosphere, though its surface pressure is less than 1% of Earth's. Its surface gravity is about 38% of Earth's. Although a human expedition to Mars has not yet taken place, there has been significant work on Martian habitat design. Martian architecture usually falls into one of two categories: architecture imported from Earth fully assembled and architecture making use of local resources.

Von Braun and other early proposals

Wernher von Braun was the first to come up with a technically comprehensive proposal for a manned Mars expedition. Rather than a minimal mission profile like Apollo, von Braun envisioned a crew of 70 astronauts aboard a fleet of ten massive spacecraft. Each vessel would be constructed in low Earth orbit, requiring nearly 100 separate launches before one was fully assembled. Seven of the spacecraft would be for crew while three were designated as cargo ships. There were even designs for small "boats" to shuttle crew and supplies between ships during the cruise to the Red Planet, which was to follow a minimum-energy Hohmann transfer trajectory. This mission plan would involve one-way transit times on the order of eight months and a long stay at Mars, creating the need for long-term living accommodations in space. Upon arrival at the Red Planet, the fleet would brake into Mars orbit and would remain there until the seven human vessels were ready to return to Earth. Only landing gliders, which were stored in the cargo ships, and their associated ascent stages would travel to the surface. Inflatable habitats would be constructed on the surface along with a landing strip to facilitate further glider landings. All necessary propellant and consumables were to be brought from Earth in von Braun's proposal. Some crew remained in the passenger ships during the mission for orbit-based observation of Mars and to maintain the ships. The passenger ships had habitation spheres 20 meters in diameter. Because the average crew member would spend much time in these ships (around 16 months of transit plus rotating shifts in Mars orbit), habitat design for the ships was an integral part of this mission.

Von Braun was aware of the threat posed by extended exposure to weightlessness. He suggested either tethering passenger ships together to spin about a common center of mass or including self-rotating, dumbbell-shaped "gravity cells" to drift alongside the flotilla to provide each crew member with a few hours of artificial gravity each day. At the time of von Braun's proposal, little was known of the dangers of solar radiation beyond Earth and it was cosmic radiation that was thought to present the more formidable challenge. The discovery of the Van Allen belts in 1958 demonstrated that the Earth was shielded from high energy solar particles. For the surface portion of the mission, inflatable habitats suggest the desire to maximize living space. It is clear von Braun considered the members of the expedition part of a community with much traffic and interaction between vessels.

The Soviet Union conducted studies of human exploration of Mars and came up with slightly less epic mission designs (though not short on exotic technologies) in 1960 and 1969. The first of which used electric propulsion for interplanetary transit and nuclear reactors as the power plants. On spacecraft that combine human crew and nuclear reactors, the reactor is usually placed at a maximum distance from the crew quarters, often at the end of a long pole, for radiation safety. An interesting component of the 1960 mission was the surface architecture. A "train" with wheels for rough terrain was to be assembled of landed research modules, one of which was a crew cabin. The train was to traverse the surface of Mars from south pole to north pole, an extremely ambitious goal even by today's standards. Other Soviet plans such as the TMK eschewed the large costs associated with landing on the Martian surface and advocated piloted (manned) flybys of Mars. Flyby missions, like the lunar Apollo 8, extend the human presence to other worlds with less risk than landings. Most early Soviet proposals called for launches using the ill-fated N1 rocket. They also usually involved fewer crew than their American counterparts. Early Martian architecture concepts generally featured assembly in low Earth orbit, bringing all needed consumables from Earth, and designated work vs. living areas. The modern outlook on Mars exploration is not the same.

Recent initiatives

In every serious study of what it would take to land humans on Mars, keep them alive, and then return them to Earth, the total mass required for the mission is simply stunning. The problem lies in that to launch the amount of consumables (oxygen, food and water) even a small crew would go through during a multi-year Mars mission, it would take a very large rocket with the vast majority of its own mass being propellant. This is where multiple launches and assembly in Earth orbit come from. However even if such a ship stocked full of goods could be put together in orbit, it would need an additional (large) supply of propellant to send it to Mars. The delta-v, or change in velocity, required to insert a spacecraft from Earth orbit to a Mars transfer orbit is many kilometers per second. When we think of getting astronauts to the surface of Mars and back home we quickly realize that an enormous amount of propellant is needed if everything is taken from the Earth. This was the conclusion reached in the 1989 '90-Day Study' initiated by NASA in response to the Space Exploration Initiative.

The NASA Design Reference Mission 3.0 incorporated many concepts from the Mars Direct proposal

Several techniques have changed the outlook on Mars exploration. The most powerful of which is in-situ resource utilization. Using hydrogen imported from Earth and carbon dioxide from the Martian atmosphere, the Sabatier reaction can be used to manufacture methane (for rocket propellant) and water (for drinking and for oxygen production through electrolysis). Another technique to reduce Earth-brought propellant requirements is aerobraking. Aerobraking involves skimming the upper layers of an atmosphere, over many passes, to slow a spacecraft down. It's a time-intensive process that shows most promise in slowing down cargo shipments of food and supplies. NASA's Constellation program does call for landing humans on Mars after a permanent base on the Moon is demonstrated, but details of the base architecture are far from established. It is likely that the first permanent settlement will consist of consecutive crews landing prefabricated habitat modules in the same location and linking them together to form a base.

In some of these modern, economy models of the Mars mission, we see the crew size reduced to a minimal 4 or 6. Such a loss in variety of social relationships can lead to challenges in forming balanced social responses and forming a complete sense of identity. It follows that if long-duration missions are to be carried out with very small crews, then intelligent selection of crew is of primary importance. Role assignments is another open issue in Mars mission planning. The primary role of 'pilot' is obsolete when landing takes only a few minutes of a mission lasting hundreds of days, and when that landing will be automated anyway. Assignment of roles will depend heavily on the work to be done on the surface and will require astronauts to assume multiple responsibilities. As for surface architecture inflatable habitats, perhaps even provided by Bigelow Aerospace, remain a possible option for maximizing living space. In later missions, bricks could be made from a Martian regolith mixture for shielding or even primary, airtight structural components. The environment on Mars offers different opportunities for space suit design, even something like the skin-tight Bio-Suit.

A number of specific habitat design proposals have been put forward, to varying degrees of architectural and engineering analysis. One recent proposal—and the winner of NASA's 2015 Mars Habitat Competition—is Mars Ice House. The design concept is for a Mars surface habitat, 3d-printed in layers out of water ice on the interior of an Earth-manufactured inflatable pressure-retention membrane. The completed structure would be semi-transparent, absorbing harmful radiation in several wavelengths, while admitting approximately 50 percent of light in the visible spectrum. The habitat is proposed to be entirely set up and built from an autonomous robotic spacecraft and bots, although human habitation with approximately 2–4 inhabitants is envisioned once the habitat is fully built and tested.

Robotic

It is widely accepted that robotic reconnaissance and trail-blazer missions will precede human exploration of other worlds. Making an informed decision on which specific destinations warrant sending human explorers requires more data than what the best Earth-based telescopes can provide. For example, landing site selection for the Apollo landings drew on data from three different robotic programs: the Ranger program, the Lunar Orbiter program, and the Surveyor program. Before a human was sent, robotic spacecraft mapped the lunar surface, proved the feasibility of soft landings, filmed the terrain up close with television cameras, and scooped and analysed the soil.

A robotic exploration mission is generally designed to carry a wide variety of scientific instruments, ranging from cameras sensitive to particular wavelengths, telescopes, spectrometers, radar devices, accelerometers, radiometers, and particle detectors to name a few. The function of these instruments is usually to return scientific data but it can also be to give an intuitive "feel" of the state of the spacecraft, allowing a subconscious familiarization with the territory being explored, through telepresence. A good example of this is the inclusion of HDTV cameras on the Japanese lunar orbiter SELENE. While purely scientific instruments could have been brought in their stead, these cameras allow the use of an innate sense to perceive the exploration of the Moon.

The modern, balanced approach to exploring an extraterrestrial destination involves several phases of exploration, each of which needs to produce rationale for progressing to the next phase. The phase immediately preceding human exploration can be described as anthropocentric sensing, that is, sensing designed to give humans as realistic a feeling as possible of actually exploring in person. More, the line between a human system and a robotic system in space is not always going to be clear. As a general rule, the more formidable the environment, the more essential robotic technology is. Robotic systems can be broadly considered part of space architecture when their purpose is to facilitate the habitation of space or extend the range of the physiological senses into space.

Future

The future of space architecture hinges on the expansion of human presence in space. Under the historical model of government-orchestrated exploration missions initiated by single political administrations, space structures are likely to be limited to small-scale habitats and orbital modules with design life cycles of only several years or decades. The designs, and thus architecture, will generally be fixed and without real time feedback from the spacefarers themselves. The technology to repair and upgrade existing habitats, a practice widespread on Earth, is not likely to be developed under short term exploration goals. If exploration takes on a multi-administration or international character, the prospects for space architecture development by the inhabitants themselves will be broader. Private space tourism is a way the development of space and a space transportation infrastructure can be accelerated. Virgin Galactic has indicated plans for an orbital craft, SpaceShipThree. The demand for space tourism is one without bound. It is not difficult to imagine lunar parks or cruises by Venus. Another impetus to become a spacefaring species is planetary defense.

The classic space mission is the Earth-colliding asteroid interception mission. Using nuclear detonations to split or deflect the asteroid is risky at best. Such a tactic could actually make the problem worse by increasing the amount of asteroid fragments that do end up hitting the Earth. Robert Zubrin writes:

If bombs are to be used as asteroid deflectors, they cannot just be launched willy-nilly. No, before any bombs are detonated, the asteroid will have to be thoroughly explored, its geology assessed, and subsurface bomb placements carefully determined and precisely located on the basis of such knowledge. A human crew, consisting of surveyors, geologists, miners, drillers, and demolition experts, will be needed on the scene to do the job right.

Robotic probes have explored much of the solar system but humans have not yet left the Earth's influence

If such a crew is to be summoned to a distant asteroid, there may be less risky ways to divert the asteroid. Another promising asteroid mitigation strategy is to land a crew on the asteroid well ahead of its impact date and to begin diverting some its mass into space to slowly alter its trajectory. This is a form of rocket propulsion by virtue of Newton's third law with the asteroid's mass as the propellant. Whether exploding nuclear weapons or diversion of mass is used, a sizable human crew may need to be sent into space for many months if not years to accomplish this mission. Questions such as what the astronauts will live in and what the ship will be like are questions for the space architect.

When motivations to go into space are realized, work on mitigating the most serious threats can begin. One of the biggest threats to astronaut safety in space is sudden radiation events from solar flares. The violent solar storm of August 1972, which occurred between the Apollo 16 and Apollo 17 missions, could have produced fatal consequences had astronauts been caught exposed on the lunar surface. The best known protection against radiation in space is shielding; an especially effective shield is water contained in large tanks surrounding the astronauts. Unfortunately water has a mass of 1000 kilograms per cubic meter. A more practical approach would be to construct solar "storm shelters" that spacefarers can retreat to during peak events. For this to work, however, there would need to be a space weather broadcasting system in place to warn astronauts of upcoming storms, much like a tsunami warning system warns coastal inhabitants of impending danger. Perhaps one day a fleet of robotic spacecraft will orbit close to the Sun, monitoring solar activity and sending precious minutes of warning before waves of dangerous particles arrive at inhabited regions of space.

Nobody knows what the long-term human future in space will be. Perhaps after gaining experience with routine spaceflight by exploring different worlds in the Solar System and deflecting a few asteroids, the possibility of constructing non-modular space habitats and infrastructure will be within capability. Such possibilities include mass drivers on the Moon, which launch payloads into space using only electricity, and spinning space colonies with closed ecological systems. A Mars in the early stages of terraformation, where inhabitants only need simple oxygen masks to walk out on the surface, may be seen. In any case, such futures require space architecture.