In the early decades of the Space Age, the government space agencies of the Soviet Union and United States pioneered space technology augmented by collaboration with affiliated design bureaus in the USSR and private companies in the US. The European Space Agency was formed in 1975, largely following the same model of space technology development.
Later on, large defense contractors began to develop and operate space launch systems, derived from government rockets and commercial satellites. Private spaceflight in Earth orbit includes communications satellites, satellite television, satellite radio, astronaut transport and sub-orbital and orbital space tourism.
Entrepreneurs have begun designing and deploying competitive space systems to the national-monopoly governmental systems of the early decades of the space age. Successes to date include flying suborbital spaceplanes, launching orbital rockets, and flying a couple of orbital expandable test modules (Genesis I and II). Planned private spaceflights beyond Earth orbit include personal spaceflights around the Moon. Two private orbital habitat prototypes are already in Earth orbit, with larger versions to follow. Planned private spaceflights beyond Earth orbit include solar sailing prototypes (LightSail-3).
- 1 History of commercial space transportation
- 2 Private spaceflight companies
- 3 Plans
- 4 Failed spaceflight ventures
- 5 See also
- 6 References
- 7 External links
History of commercial space transportation
In a 2012 article in Bloomberg, author Michael Burgan asserted that there is a "grand tradition of private wealth furthering advances in rocketry and space exploration" dating back to the early rocketry experiments of Robert Goddard.
Despite those earlier private undertakings, during the principal period of spaceflight in the mid-twentieth century, only nation states developed and flew spacecraft above the Kármán line, the nominal boundary of space. Spaceflight was thus the monopoly province of a small group of national governments.
Both the U.S. civilian space program and Soviet space program were operated using mainly military pilots as astronauts. During this period, no commercial space launches were available to private operators, and no private organization was able to offer space launches. Eventually, private organizations were able to both offer and purchase space launches, thus beginning the period of private spaceflight.
The first phase of private space operation was the launch of the first commercial communications satellites. The U.S. Communications Satellite Act of 1962 opened the way to commercial consortia owning and operating their own satellites, although these were still launched on state-owned launch vehicles.
History of full private space transportation includes early efforts by Germany OTRAG company in the 20th century and numerous modern projects of orbital and suborbital launch systems in the 21st century. Last ones counts the manned programs also - most famous and important of them are suborbital flights of Virgin Galactic and orbital flights of SpaceX and other COTS participants.
Development of alternatives to government-provided space launch services began in earnest in the 2000s. Private interests began funding limited development programs, but the US government later sponsored a series of programs to incentivize and encourage private companies to begin offering both cargo, and later, crew space transportation services.
By 2012, a private company had begun transporting cargo to and from the International Space Station (ISS), while a second private company was scheduled to begin making deliveries in 2013, ushering in a time of regular private space cargo delivery to and return from the government-owned space facility in low-Earth orbit (LEO). In this new paradigm for LEO cargo transport, the government contracts for and pays for cargo services on substantially privately developed space vehicles rather than the government operating each of the cargo vehicles and cargo delivery systems. As of 2013[update], there is a mix of private and government resupply vehicles being used for the ISS, as the Russian Soyuz and Progress vehicles, and the European Space Agency (ESA) ATV (through 2014) and the Japanese HTV (through 2014) remain in operation after the 2011 retirement of the US Space Shuttle.
Wired magazine went so far as to say that 2012 was "the year of private space," recounting the success of SpaceX in conducting two launches to the International Space Station, with progress toward emerging competition in that industry sector, while also highlighting the well-funded capital and experienced engineering teams behind the startup companies Planetary Resources–asteroid mining–and Golden Spike–private human Lunar surface excursions.
In June 2013, British newspaper The Independent' claimed that "the space race is flaring back into life, and it's not massive institutions such as Nasa that are in the running. The old view that human space flight is so complex, difficult and expensive that only huge government agencies could hope to accomplish it is being disproved by a new breed of flamboyant space privateers, who are planning to send humans out beyond the Earth's orbit for the first time since 1972," particularly noting projects underway by Mars One, Inspiration Mars Foundation, Bigelow Aerospace and SpaceX.
On March 26, 1980, the European Space Agency created Arianespace, a company to be operated commercially after initial hardware and launch facilities were developed with government funding. Arianespace produces, operates and markets the Ariane launcher family. By 1995 Arianespace lofted its 100th satellite and by 1997 the Ariane rocket had its 100th launch. Arianespace's 23 shareholders represent scientific, technical, financial and political entities from 10 different European countries.
From the beginning of the Shuttle program until the Challenger disaster in 1986, it was the policy of the United States that NASA be the public-sector provider of U.S. launch capacity to the world market.
On October 30, 1984, United States President Ronald Reagan signed into law the Commercial Space Launch Act. This enabled an American industry of private operators of expendable launch systems. Prior to the signing of this law, all commercial satellite launches in the United States were restricted by Federal regulation to NASA's Space Shuttle.
On November 5, 1990, United States President George H. W. Bush signed into law the Launch Services Purchase Act. The Act, in a complete reversal of the earlier Space Shuttle monopoly, ordered NASA to purchase launch services for its primary payloads from commercial providers whenever such services are required in the course of its activities.
In 1992, Resurs-500 capsule containing gifts was launched from Plesetsk Cosmodrome in what was a private spaceflight called Europe-America 500. The flight was conceived by the Russian Foundation for Social Inventions and TsSKB-Progress, a Russian rocket-building company, to increase trade between Russia and USA, and promote use of technology once reserved only for military forces. Money for the launch was raised from a collection of Russian companies. The capsule parachuted into the Pacific Ocean and was brought to Seattle by a Russian missile-tracking ship.
The Russian government sold part of its stake in RSC Energia to private investors in 1994. Energia together with Khrunichev constituted most of the Russian manned space program. In 1997, the Russian government sold off enough of its share to lose the majority position.
In 1996 the United States government selected Lockheed Martin and Boeing to each develop Evolved Expendable Launch Vehicles (EELV) to compete for launch contracts and provide assured access to space. The government's acquisition strategy relied on the strong commercial viability of both vehicles to lower unit costs. This anticipated market demand did not materialize, but both the Delta IV and Atlas V EELVs remain in active service.
In 2003 Arianespace joined with Boeing Launch Services and Mitsubishi Heavy Industries to create the Launch Services Alliance. In 2005, continued weak commercial demand for EELV launches drove Lockheed Martin and Boeing to propose a joint venture called the United Launch Alliance to service the United States government launch market.
Since the late 1990s, various private initiatives have started up to pursue the private use of space. In the early 2000s, several public-private partnerships have been established in the United States to take advantage of entrepreneurial companies to accelerate spaceflight technology development and reduce the cost of access to space, both for cargo and passenger transport. In addition, several purely private initiatives have begun in the 2010s to develop reusable spaceflight technology as well as to begin various private spaceflight endeavors to the inner solar system.
On February 1, 2010, United States President Barack Obama proposed in a speech that NASA exit the business of flying astronauts from Earth to low-Earth orbit—the locus of human spaceflight ever since the last Lunar manned mission in 1972—and move it to private companies who contract with the government to provide cargo resupply services to the ISS. The proposal acted on the findings of the 2009 Augustine Commission and built on the success of the Commercial Resupply Services that outsourced American cargo delivery to the International Space Station.'
In June 2012, private Dutch non-profit Mars One announced a private one-way (no return) human mission to Mars with the aim to establish a permanent human colony on Mars. The plan is to send a communication satellite and path finder lander to the planet by 2016 and, after several stages, land four humans on the Martian surface for permanent settlement in 2023. A new set of four astronauts would then arrive every two years.
In December 2012, a private US company, Golden Spike, announced plans for commercial human spaceflight missions to the Moon by no earlier than 2020. Their plan projects development budget of between $7 and $8 billion, followed by around $1.5 billion per each "two-human lunar surface mission".
In February 2013, the US nonprofit Inspiration Mars Foundation announced a plan to send a married couple on a 2018 mission to travel to Mars and back to Earth on a 501-day round trip, with no landing planned on Mars. The mission will take advantage of an infrequently-occurring free return trajectory—a unique orbit opportunity which occurs only once every fifteen years—and will allow the space capsule to use the smallest possible amount of fuel to get it to Mars and back to Earth. The two-person American crew – a man and a woman – will orbit around Mars at a distance of 100 miles (160 km) of the surface. "If anything goes wrong, the spacecraft should make its own way back to Earth — but with no possibility of any short-cuts home."
Private spaceflight companies
Today many commercial space transportation companies offer launch services to satellite companies and government space organizations around the world. In 2005 there were 18 total commercial launches and 37 non-commercial launches. Russia flew 44% of commercial orbital launches, while Europe had 28% and the United States had 6%.
In recent years, the funding to support private spaceflight has begun to be raised from a larger pool of sources than the relatively more limited sources of the 1990s. For example, as of June 2013[update] and in the United States alone, ten billionaires have made "serious investments in private spaceflight activities" at six companies, including Stratolaunch Systems, Planetary Resources, Blue Origin, Virgin Galactic, SpaceX, and Bigelow Aerospace. The ten investors are Paul Allen, Larry Page, Eric E. Schmidt, Ram Shriram, Charles Simony, Ross Perot, Jr., Jeff Bezos, Richard Branson, Elon Musk, and Robert Bigelow.
It is not yet clear to what extent these entrepreneurs see "legitimate business opportunity, [for example,] space tourism and other commercial activities in space, or [are] wealthy men seeking the exclusivity that space offers innovators and investors." These investments are a "gamble", and may, or may not pay off.
The space transport business serves primarily national government and large commercial customer segments. Launches of government payloads, including military, civilian and scientific satellites, is the largest market segment at nearly $100 billion a year. This segment is dominated by domestic favorites such as the United Launch Alliance for U.S. government payloads and Arianespace for European satellites. The commercial payload segment, valued at under $3 billion a year, is dominated by Arianespace, with over 50% of the market segment, followed by Russian launchers. See a complete list of launch systems.
US government commercial cargo services
The US government determined to begin a process to purchase orbital launch services for cargo deliveries to the International Space Station (ISS) beginning in the mid-2000s, rather than operate the launch and delivery services as they had with the Space Shuttle, which was to retire in less than half a decade, and ultimately did retire in 2011. On January 18, 2006, NASA announced an opportunity for US commercial providers to demonstrate orbital transportation services. As of 2008, NASA planned to spend $500 million through 2010 to finance development of private sector capability to transport payloads to the International Space Station (ISS).[dated info] This was considered more challenging than then-available commercial space transportation because it would require precision orbit insertion, rendezvous and possibly docking with another spacecraft. The commercial vendors competed in specific service areas.
In August 2006, NASA announced that two relatively young aerospace companies, SpaceX and Rocketplane Kistler, had been awarded $278m and $207m, respectively, under the COTS program. In 2008, NASA anticipated that commercial cargo delivery services to and return services from the ISS would be necessary through at least 2015. The NASA Administrator suggested that space transportation services procurement may be expanded to orbital fuel depots and lunar surface deliveries should the first phase of COTS prove successful.
After it transpired that Rocketplane Kistler was failing to meet its contractual deadlines, NASA terminated their contract in August 2008, after only $32m had been spent. Several months later, in December 2008, NASA announced that they have awarded the remaining $170m to the Orbital Sciences Corporation to develop resupply services to the ISS.
Commercial Space Station
Bigelow Aerospace is developing the Next-Generation Commercial Space Station, a private orbital space complex. The space station will be constructed of both Sundancer and BA 330 expandable spacecraft modules as well as a central docking node, propulsion, solar arrays, and attached crew capsules. As of July 2010[update], initial launch of space station components was planned for 2014, with portions of the station projected to be available for leased use as early as 2015.
Lunar private ventures
Robotic Lunar-surface missions
Private Lunar-surface crewed expeditions
- Shackleton Energy Company intends to undertake human tended lunar prospecting for water ice. If significant reserves of ice are located, they plan to establish a network of "refueling service stations" in low Earth orbit and on the moon to process and provide fuel and consumables for commercial and government customers. If the prospecting is successful—ice deposits are located, the appropriate legal regime is in place to support commercial development, and the ice can be extracted — Shackleton proposes to establish a fuel-processing operation on the lunar surface and in propellant depots in Low Earth Orbit. Equipment would melt the ice and purify the water, "electrolyze the water into gaseous hydrogen and oxygen, and then condense the gases into liquid hydrogen and liquid oxygen and also process them into hydrogen peroxide, all of which could be used as rocket fuels.
Emerging personal spaceflight
Before 2004 no privately operated manned spaceflight had ever occurred. The only private individuals to journey to space went as space tourists in the Space Shuttle or on Russian Soyuz flights to Mir or the International Space Station.
All private individuals who flew to space before Dennis Tito's self-financed International Space Station visit in 2001 had been sponsored by their home governments. Those trips include US Congressman Bill Nelson's January 1986 flight on the Space Shuttle Columbia and Japanese television reporter Toyohiro Akiyama's 1990 flight to the Mir Space Station.
The Ansari X PRIZE was intended to stimulate private investment in the development of spaceflight technologies. The June 21, 2004, test flight of SpaceShipOne, a contender for the X PRIZE, was the first human spaceflight in a privately developed and operated vehicle.
On September 27, 2004, following the success of SpaceShipOne, Richard Branson, owner of Virgin and Burt Rutan, SpaceShipOne's designer, announced that Virgin Galactic had licensed the craft's technology, and were planning commercial space flights in 2.5 to 3 years. A fleet of five craft (SpaceShipTwo, launched from the WhiteKnightTwo carrier airplane) is to be constructed, and flights will be offered at around $200,000 each, although Branson has said he plans to use this money to make flights more affordable in the long term.[dated info]
XCOR Aerospace also planned to initiate a suborbital commercial spaceflight service with the Lynx rocketplane in 2014 at $95,000 each through a partnership with Space Expedition Corporation (SXC). First test flights were planned for 2013.
In December 2004, United States President George W. Bush signed into law the Commercial Space Launch Amendments Act. The Act resolved the regulatory ambiguity surrounding private spaceflights and is designed to promote the development of the emerging U.S. commercial human space flight industry.
On July 12, 2006, Bigelow Aerospace launched the Genesis I, a subscale pathfinder of an orbital space station module. Genesis II was launched on June 28, 2007, and there are plans for additional prototypes to be launched in preparation for the production model BA 330 spacecraft.[dated info]
On September 28, 2006, Jim Benson, SpaceDev founder, announced he was founding Benson Space Company with the intention of being first to market with the safest and lowest cost suborbital personal spaceflight launches, using the vertical takeoff and horizontal landing Dream Chaser vehicle based on the NASA HL-20 Personnel Launch System vehicle.[dated info]
In December 2012, the Golden Spike Company announced plans to privately transport space exploration participants to the surface of the Moon and return, beginning as early as 2020, for US$750 million per passenger.
Many have speculated on where private spaceflight may go in the near future. Numerous projects of orbital and suborbital launch systems for satellites and manned flights exist. Some orbital manned missions would be state-sponsored like most COTS participants. (that develop their own launch systems). Another possibility is for paid suborbital tourism on craft like those from Virgin Galactic, Space Adventures, XCOR Aerospace, RocketShip Tours, ARCASPACE, PlanetSpace-Canadian Arrow, British Starchaser Industries or non-commercial like Copenhagen Suborbitals. Additionally, suborbital spacecraft have applications for faster intercontinental package delivery and passenger flight.
Private orbital spaceflight, space stations
Plans and a full-scale prototype for the SpaceX Dragon, a capsule capable of carrying up to 7 passengers, were announced in March 2006, and Dragon version 2 flight hardware was unveiled in May 2014. As of September 2014[update], both SpaceX and Boeing have received contracts from NASA to complete building, testing, and flying up to six flights of human-rated space capsules to the International Space Station beginning in 2017.
In December 2010, SpaceX launched the second Falcon 9 and the first operational Dragon spacecraft. The mission was deemed fully successful, marking the first launch to space, atmospheric reentry and recovery of a rocket by a private company. Subsequent COTS missions includee increasingly complex orbital tasks, culminating in Dragon first docking to the ISS in 2012.
An early flight of the Falcon 9 is planned to carry Sundancer, the prototype expandable and habitable space module (based on the former NASA TransHab design) constructed by Bigelow Aerospace. Bigelow Aerospace expects modules like Sundancer and the larger BA 330 to be used for activities like microgravity research, space manufacturing, and space tourism (with modules serving as orbital hotels). To promote private manned launch efforts, Bigelow offered the US$50 million America's Space Prize for the first US-based privately funded team to launch a manned reusable spacecraft to orbit on or before January 10, 2010, though no company was able to meet this deadline.
Excalibur Almaz plans to launch a modernized TKS Spacecraft (for Almaz space station), for tourism and other uses. It will feature the largest window ever on a spacecraft. The British Government has recently partnered with the ESA to promote a possibly commercial single-stage to orbit spaceplane concept called Skylon. This design was pioneered by the privately held Reaction Engines Limited, a company founded by Alan Bond after HOTOL was canceled.
As of 2012, there is commercial/private access to the U.S. National Laboratory space on the International Space Station (ISS) through the private company NanoRacks. Science experiments can be conducted on a variety of standard rack-sized experimental platforms with standard interfaces for power and data acquisition.
On-orbit propellant depots
In a presentation given November 15, 2005, to the 52nd Annual Conference of the American Astronautical Society, NASA Administrator Michael D. Griffin suggested that establishing an on-orbit propellant depot is, "Exactly the type of enterprise which should be left to industry and to the marketplace." At the Space Technology and Applications International Forum in 2007, Dallas Bienhoff of Boeing made a presentation detailing the benefits of propellant depots. Shackleton Energy Company has established operational plans, an extensive teaming and industrial consortium for developing LEO Propellant Depots supplied by Lunar polar sourced water ice.
Some have speculated on the profitability of mining metal from asteroids. According to some estimates, a one kilometer-diameter asteroid would contain 30 million tons of nickel, 1.5 million tons of metal cobalt and 7,500 tons of platinum; the platinum alone would have a value of more than $150 billion at 2008 terrestrial prices.
Energy from space
Future energy development may use energy sources in space and on other planets. Examples include Helium-3 extraction from the Moon, and solar power satellite systems. See space manufacturing for more on extraterrestrial economic development.
A space elevator system is a possible launch system, currently under investigation by at least one private venture. There are concerns over cost, general feasibility and some political issues. On the plus side the potential to scale the system to accommodate traffic would (in theory) be greater than some other alternatives. Some factions contend that a space elevator — if successful — would not supplant existing launch solutions but complement them.
Failed spaceflight ventures
After earlier first effort of OTRAG, in the 1990s the projection of a significant demand for communications satellite launches attracted the development of a number of commercial space launch providers. The launch demand largely vanished when some of the largest satellite constellations, such as 288 satellite Teledesic network, were never built. The historic tendency of NASA to compete against the private sector and the Department of Defense's preference for the traditional military industrial complex has discouraged many new space launch ventures.
In 1996 NASA selected Lockheed Martin Skunk Works to build the X-33 VentureStar prototype for a single stage to orbit (SSTO) reusable launch vehicle. In 1999, the subscale X-33 prototype's composite liquid hydrogen fuel tank failed during testing. At project termination on March 31, 2001, NASA had funded $912 million of this wedge shaped spacecraft while Lockheed Martin financed $357 million of it. The VentureStar was to have been a full-scale commercial space transport operated by Lockheed Martin.
In 1997 Beal Aerospace proposed the BA-2, a low-cost heavy-lift commercial launch vehicle. On March 4, 2000, the BA-2 project tested the largest liquid rocket engine built since the Saturn V. In October 2000, Beal Aerospace ceased operations citing a decision by NASA and the Department of Defense to commit themselves to the development of the competing government-financed EELV program.
In 1998 Rotary Rocket proposed the Roton, a Single Stage to Orbit (SSTO) piloted Vertical Take-off and Landing (VTOL) space transport. A full scale Roton Atmospheric Test Vehicle flew three times in 1999. After spending tens of millions of dollars in development the Roton failed to secure launch contracts and Rotary Rocket ceased operations in 2001.
- Armadillo Aerospace
- Astrobotic Technology
- Beal Aerospace
- Blue Origin
- Commercial Spaceflight Federation
- Copenhagen Suborbitals
- Effect of spaceflight on the human body
- Garvey Spacecraft
- Health threat from cosmic rays
- Heinlein Prize for Advances in Space Commercialization
- Human spaceflight
- Inspiration Mars Foundation
- L5 Society
- Mars One
- Masten Space Systems
- Orbital Sciences Corporation
- Rocketplane Kistler
- RocketShip Tours
- Rotary Rocket
- Shackleton Energy Company
- Space Adventures
- Space Frontier Foundation
- Space medicine
- Starchaser Industries
- Virgin Galactic
- X Prize Foundation
- XCOR Aerospace
- Armadillo Aerospace Black Armadillo - Suborbital Capsule
- ARCASPACE Stabilo and ORIZONT - Suborbital Capsule and Spaceplane
- Blue Origin New Shepard - Suborbital Capsule
- Boeing CST-100 - Orbital Capsule
- Copenhagen Suborbitals HEAT1X and Tycho Brahe - Suborbital Capsule
- Excalibur Almaz - Orbital Capsule
- PlanetSpace Canadian Arrow - Suborbital Capsule
- PlanetSpace Silver Dart - Orbital Spaceplane
- Reaction Engines Skylon - Single-Stage-To-Orbit Spaceplane
- Scaled Composites SpaceShipOne - Suborbital Spaceplane
- Scaled Composites/Virgin Galactic SpaceShipTwo - Suborbital Spaceplane
- SpaceDev Dream Chaser - Orbital Spaceplane
- SpaceX Dragon - Orbital Capsule
- Starchaser Industries Thunderbird and Thunderstar - Suborbital Capsule
- XCOR Lynx - Suborbital Spaceplane
- Szondy, David (2012-02-05). "SpaceX Dragon's ultimate mission is Mars colonization". Gizmag. Retrieved 2012-02-13. "For decades after that first launch, space flight was a government monopoly. Even when private companies started going into space in the 1990s, it was only as providers of launch services to send commercial and government satellites into orbit. Now, all that is changing as private enterprise takes over space exploration in a manner not seen since the early days of the Hudson's Bay Company."
- Oberg, James (January 2012). "Private Spaceflight: Up, Up, and Away". IEEE Spectrum. Retrieved 2011-12-31.
- "Special Announcement". bigelowaerospace.com. Retrieved 2008-04-01.
- Burgan, Michael (2012-07-18). "Private Space Exploration a Long and Thriving Tradition". Bloomberg L.P. Retrieved 2012-07-20.
- Mann, Adam (2012-12-27). "The Year’s Most Audacious Private Space Exploration Plans". Wired. Retrieved 2013-01-20.
- Hanlon, Michael (2013-06-11). "Roll up for the Red Planet". The Telegraph. Retrieved 2013-06-14.
- Engel, Max (2013-03-01). "Launch Market on Cusp of Change". Satellite Today. Retrieved 2013-02-15. "Although some governments funded vehicle development in different ways, there were no vehicles that were not the product of some form of fairly direct governmental support. Even Ariane, the most “commercial” of launch vehicles, was commercial in operation only, not in inception and development, and could easily call on government support when things went wrong."
- "Milestones". Arianespace.com. Archived from the original on 2008-01-13. Retrieved 2008-02-14.
- "Arianespace shareholders represent scientific, technical, financial and political entities from 10 different European countries". Arianespace.com. Archived from the original on 2008-02-06. Retrieved 2008-02-14.
- "Setting Space Transportation Policy for the 1990s" (PDF). cbo.gov. Retrieved 2008-02-14.
- "Statement on Signing the Commercial Space Launch Act". reagan.utexas.edu. Retrieved 2008-02-14.
- "$ 2465d. Requirement of US Federal government to procure commercial launch services". space-frontier.org. Retrieved 2008-02-14.
- "Streamlining Space Launch Range Safety - Executive Summary". National Academy of Sciences. Retrieved 2008-02-13.
- "Boeing, Lockheed Martin to Form Launch Services Joint Venture". spaceref.com. Retrieved 2008-02-13.
- Pittman, Bruce; Rasky, Dan; Harper, Lynn (2012). "Infrastructure Based Exploration – An Affordable Path To Sustainable Space Development". IAC - 12, D3, 2, 4 , x14203: IAC. Retrieved 2014-10-14.
- Chang, Kenneth (2010-02-02). "Obama Calls for End to NASA’s Moon Program" (PDF). nytimes.com. Retrieved 2010-02-01.
- Anne Sewell (1 June 2012). "Mars One: Human settlement on Mars in 2023". Digital Journal. Retrieved 6 June 2012.
- Adario Strange (1 June 2012). "Dutch Group Planning for Mars Settlement by 2023". PC Mag. Retrieved 6 June 2012.
- Dario Borghino (4 June 2012). "Mission to Mars meets reality TV". Gizmag. Retrieved 8 June 2012.
- Man, Adam (2012-12-06). "Golden Spike Company Unveils Plans to Fly Commercial Crews to the Moon". Wired. Retrieved 2012-12-26.
- Belfiore, Michael (27 February 2013). "The Crazy Plan to Fly Two Humans to Mars in 2018". Popular Mechanics. Retrieved 28 February 2013.
- Morring, Frank, Jr. (2013-03-04). "Serious Intent About 2018 Human Mars Mission". Aviation Week and Space Technology. Retrieved 2013-03-07.
- Connor, Steve (26 February 2013). "The millionaire Dennis Tito and his mission to Mars". The Independent. Retrieved 28 February 2013.
- "Commercial Space Transportation: 2005 Year In Review" (PDF). faa.gov. Retrieved 2008-02-13.
- Berger, Eric (2013-06-28). "Ten billionaires are betting on private spaceflight: Smart or squandered money?". Houston Chronicle. Retrieved 2013-06-30.
- "Changing Trajectory: French Firms Vaults Ahead in Civilian Rocket Market". The Wall Street Journal (Dow Jones & Company, Inc.): A1. June 25, 2007.
- "NASA Seeks Proposals for Crew and Cargo Transportation to Orbit". spaceref.com. Retrieved 2008-02-11.
- "GUIDANCE_FOR_THE_PREPARATION_AND_SUBMISSION_OF_UNSOLICITED_PROPOSALS". nasa.gov. Retrieved 2008-02-13.[dead link]
- "NASA Invests in Private Sector Space Flight with SpaceX, Rocketplane-Kistler". nasa.gov. Retrieved 2008-02-14.
- "Human_Space_Flight_Transition_Plan" (PDF). nasa.gov. Archived from the original on 2008-02-27. Retrieved 2008-02-14.
- "NASA Awards Space Station Commercial Resupply Services Contracts". nasa.gov. Retrieved 2008-12-24.
- Bigelow Aerospace — Next-Generation Commercial Space Stations: Orbital Complex Construction, Bigelow Aerospace, accessed 2010-07-15.
- "SpaceX Lands Contract To Fly To Moon". Aviation Week. 2011-02-08. Retrieved 2011-02-08. "Pittsburgh-based Astrobotic Technology, a Carnegie Mellon University spin-off company, has signed a launch services contract with Space Exploration Technologies (SpaceX) for a Falcon 9 rocket to deliver a lander, small rover and up to about 240 lb. of payload to the surface of the Moon"
- Jason Paur (2012-08-09). "China to Launch Spanish Team’s Lunar X PRIZE Robot". Wired. Retrieved 2013-0-21. "after signing a contract with a Chinese company to launch its lunar robot to the moon in 2014." Check date values in:
- "MoonEx aims to scour moon for rare materials". Los Angeles Times. 2011-04-08. Retrieved 2011-08-20. "The company is among several teams hoping to someday win the Google Lunar X Prize competition, a $30-million race to the moon in which a privately-funded team must successfully place a robot on the moon's surface and have it explore at least 1/3 of a mile. It also must transmit high definition video and images back to Earth before 2016. ... should be ready to land on the lunar surface by 2013"
- Mining the Moon: How the extraction of lunar hydrogen or ice could fuel humanity's expansion into space, IEEE Spectrum, June 2009, accessed 2011-01-05.
- "Golden Spike Company Unveils Plans to Fly Commercial Crews to the Moon", Wired Magazine, 6 Dec 2012, accessed 7 Dec 2012.
- Hindman, Nate C. (23 October 2012) XCOR Lynx: Supersonic Plane To Fly Between NYC And Tokyo In 90 Minutes The Huffington Post, Retrieved 19 February 2013
- Chow, Denise (8 June 2012) Space tourists can hop on a flight in 2014, XCOR says NBC news, Retrieved 19 February 2013
- "House Approves H.R. 3752, The Commercial Space Launch Amendments Act of 2004". spaceref.com. Retrieved 2008-02-14.
- "Golden Spike Company Unveils Plans to Fly Commercial Crews to the Moon"
- "The Foundation". B612 Foundation. Retrieved September 13, 2012.
- "The Sentinel Mission". B612 Foundation. Retrieved September 19, 2012.
- "Falcon 9 booster rockets into orbit on dramatic first launch". SpaceflightNOW. June 4, 2010. Retrieved June 4, 2010.
- Cowing, Keith (2006-03-06). "The SpaceX Dragon: America's First Privately Financed Manned Orbital Spacecraft?". SpaceRef.com. Retrieved 2008-02-12.
- Norris, Guy (2014-05-30). "SpaceX Unveils ‘Step Change’ Dragon ‘V2’". Aviation Week. Retrieved 2014-09-18.
- "NASA Chooses American Companies to Transport U.S. Astronauts to International Space Station". Retrieved 16 September 2014.
- Reaction Engines Limited FAQ
- Reaction Engines Ltd 2006
- Knapp, Alex (2013-03-04). "The Space Station Is The Final Frontier Of Bio Research". Forbes. Retrieved 2013-02-18.
- "NASA and the Business of Space" (PDF). NASA. Retrieved 2008-02-12.
- "The Potential Impact of a LEO Propellant Depot on the NASA ESAS Architecture" (PDF). Boeing. Retrieved 2008-02-12.
- Shackleton Energy's cislunar economic development plans David Livingston interview with James Keravala, The Space Show, 14 Dec 2012, accessed 2013-01-03.
- "How Asteroid Mining Will Work". howstuffworks.com. Retrieved 2008-02-12.
- "The LiftPort Space Elevator". liftport.com. Retrieved 2008-02-11.
- "NASA Reaches Milestone in Space Launch Initiative Program". nasa.gov. Retrieved 2008-02-14.
- "Beal BA-2". astronautix.com. Retrieved 2008-02-14.
- "Beal Aerospace regrets to announce that it is ceasing all business operations effective October 23, 2000" (Press release). spaceprojects.com. 2000-03-23. Retrieved 2007-06-21.
- "Roton". astronautix.com. Retrieved 2008-02-14.
- Messier, Doug (2013-04-04). "Garvey Nanosat Launcher Selected for NASA SBIR Funding". Parabolic Arc. Retrieved 2013-04-05.
- Belfiore, Michael. Rocketeers: How a Visionary Band of Business Leaders, Engineers, and Pilots is Boldly Privatizing Space. Harper Paperbacks, 2008.
- Bizony, Piers. How to Build Your Own Spaceship: The Science of Personal Space Travel. Plume, 2009.
- Climbing a Commercial Stairway to Space: A Plausible Timeline RLV News, February 2, 2006
- An Introduction to Private Spaceflight Space Liberates Us!, March 20, 2007
- Study defining personal spaceflight industry Space Fellowship, May 29, 2008
- Starchaser Industries
- Space Services, Inc.
- Commercial Space Companies at the Space Frontier Foundation
- A Word from the Know-Nothing Bureaucrats NASA union viewpoint on private spaceflight
- Private Industry Can Help NASA Open the Space Frontier Space Frontier Foundation, February 14, 2005