The Crew Return Vehicle (CRV), sometimes referred to as the Assured Crew Return Vehicle (ACRV), was the proposed lifeboat or escape module for the International Space Station (ISS). A number of different vehicles and designs had been considered over the past two decades – with several flying as developmental test prototypes – but no one single design had been built as the dedicated CRV. In the original space station design, emergencies were intended to be dealt with by having a "safe area" on the station that the crew could evacuate to, pending a rescue from a U.S. Space Shuttle. However, the 1986 Space Shuttle Challenger disaster and the subsequent grounding of the shuttle fleet caused station planners to rethink this concept.^[1] Planners foresaw the need for a CRV to address three specific scenarios: Severn class lifeboat in Poole Harbour, Dorset, England. ... “ISS” redirects here. ... NASAs Space Shuttle, officially called Space Transportation System (STS), is the United States governments current manned launch vehicle. ... For further information about Challengers mission and crew, see STS-51-L. The iconic image of Space Shuttle Challengers smoke plume after its breakup 73 seconds after launch. ...

• Crew return if a space shuttle or Soyuz capsule was unavailable;
• An escape vehicle from a major time-critical space station emergency;
• Full or partial crew return in case of a medical emergency.^[2]

Soyuz is Russian for Union. Depending on the context, Soyuz may also refer to either of the following: The originally Soviet (now Russian) Soyuz program of human spaceflight The Soyuz spacecraft, used in that program The Soyuz launch vehicle that is used to launch those and other spacecraft This is...

Medical considerations

The ISS is equipped with a Health Maintenance Facility (HMF) to handle a certain level of medical situations, which are broken into three main classifications:

• Class I: non-life-threatening illnesses and injuries (headache, lacerations).
• Class II: moderate to severe, possibly life-threatening (appendicitis, kidney stones).
• Class III: severe, incapacitating, life-threatening (major trauma, toxic exposure).

However, the HMF is not designed to have general surgical capability, so a means of evacuating a crew member in case of a medical situation that is beyond the HMF's capabilities is essential.^[2]

A number of studies have attempted to assess the medical risks for long-term space station habitation, but the results are inconclusive, as epidemiological data is lacking. It is, however, understood that longer periods in space increase the risk of serious problems. The closest estimates show an illness/injury rate of 1:3 per year, with 1% estimated to require emergency evacuation by means of a CRV. For an eight-person ISS crew, this results in an expected need for a CRV flight once every four to 12 years. These estimates have been partially corroborated by experiences onboard the Soviet Union's Mir space station. In the 1980s, the Soviets had at least three incidents where cosmonauts had to be returned under urgent medical conditions.^[2] Mir insignia Mir Statistics Crew: 3 Call sign Mir Launch February 19, 1986 21:28:23 UTC Baikonur, USSR Re-entry March 23, 2001 05:50:00 UTC Perigee: 385 km (239 NM) Apogee: 393 km (244 NM) Orbital period: 89. ... U.S. Space Shuttle astronaut Bruce McCandless II using a manned maneuvering unit. ...

Because of its potential use as a medical evacuation method, the CRV design was required to address a number of issues that are not factors for a standard manned space vehicle. Foremost of these are the g-loadings as influenced by reentry profiles and deceleration/landing methods upon patients with hemorrhagic shock issues. Patient security issues are more critical for injured astronauts than for uninjured personnel. Additionally, depending on the nature of the injury, it may be unlikely that the patient could be placed in an environmentally contained space suit or minicapsule, therefore the CRV needs to have the capability to provide a "shirt sleeve" environment. The ability to address air purity issues is included in this requirement, as air purity is especially critical in medical as well as toxic exposure situations.^[2] The term g force or gee force refers to the symbol g, the force of acceleration due to gravity at the earths surface. ...

Early NASA concepts

NASA planners developed a number of early concepts for a space station lifeboat: The National Aeronautics and Space Administration (NASA) is an agency of the United States federal government, responsible for the nations public space program. ...

Capsule systems

• The Station Crew Return Alternative Module (SCRAM) was a capsule which could hold up to six astronauts. Reentry heat protection was provided by the use of a heat shield designed for the NASA Viking Mars probe. Costing US$600 million, the primary drawback to this design was high g-loadings on landing, which were not ideal in case of a medically necessitated evacuation.^[1][2]
• As a follow-on to the Viking-based concept, NASA considered a 1986 proposal by General Electric and NIS Space Ltd. for a commercially developed derivative of the U.S. Air Force Discoverer recovery capsule called MOSES. These capsules were being planned for unmanned microgravity experiments, and initially were planned for up to four occupants, but the idea of scaling the capsule up to accommodate eight crew members was considered for a time before also being dropped.^[3][1] However, g-loads of up to 8-g's make this vehicle unsuitable for critical medical situations.^[2]
• In 1989, NASA engineers patented a capsule-type ACRV concept.^[4]

GE redirects here. ... Seal of the Air Force. ... KH-4B Corona satellite Recovery of Discoverer 14 return capsule (typical for the Corona series Diagram of J-1 type stereo / panoramic reciprocating Corona reconnaissance satellite camera system used on KH-4A missions from 1963 to 1969. ...

HL-20 PLS

The HL-20 Crew Rescue Vehicle was based on the Personnel Launch System (PLS) concept being developed by NASA as an outgrowth of earlier lifting body research. In October 1989, Rockwell International (Space Systems Division) began a year-long contracted effort managed by Langley Research Center to perform an in-depth study of PLS design and operations with the HL-20 concept as a baseline for the study. In October 1991, the Lockheed Advanced Development Company (better known as the Skunk Works) began a study to determine the feasibility of developing a prototype and operational system. A cooperative agreement between NASA, North Carolina State University and North Carolina A&T University led to the construction of a full-scale model of the HL-20 PLS for further human factors research on this concept.^[1][5] Of all the options, a lifting body presents the most ideal medical environment in terms of controlled environment as well as low g-loading during reentry and landing.^[2] However, the price tag for the HL-20 project was US$2 billion, and Congress cut the program from NASA's budget in 1990.^[1] The HL-20 Personnel Launch System was a NASA concept being studied by NASAs Langley Research Center in Hampton, Virginia, based on an enhanced lifting body candidate for manned orbital missions. ... The lifting body is an aircraft configuration where the body itself produces lift. ... Rockwell International was the ultimate incarnation of a series of companies under the sphere of influence of Willard Rockwell, who had made his fortune after the invention and successful launch of a new bearing system for truck axles in 1919. ... Langley Research Center NASA Langley 14 x 22 foot Subsonic Wind Tunnel. ... A modern Skunk works project leverages an older: LASRE and SR-71 Blackbird. ... North Carolina State University is a public, coeducational, extensive research university located in Raleigh, North Carolina, United States. ...

European Space Agency concepts

As a part of their wide ranging studies of potential manned spaceflight programs, the European Space Agency (ESA) began a six-month, first-phase ACRV study in October 1992. Prime contractors for the study were Aerospatiale, Alenia Spazio and Deutsche Aerospace.^[6] ESA redirects here. ... The Aerospatiale Corvette first flew in 1970 and went into service in 1974. ... Alcatel Alenia Space was established on July 1 2005 by the merger of Alcatel Space and Alenia Spazio and is owned by Alcatel (67%) and Finmeccanica (33%). The company is Europes largest satellite manufacturer. ... Luftwaffe Tornado ECR DASA was the aerospace subsidiary of Daimler-Benz AG (later DaimlerChrysler) from 1989. ...

The ESA studied several concepts for a CRV:

• Apollo-type capsule: This would have been a scaled-up version of the 1960s Apollo capsule capable of carrying eight astronauts. A tower that sat on top of the capsule would contain a docking tunnel as well as the capsule's rocket engines, again similar to the Apollo configuration. The tower would be jettisoned just before reentry. Landing would be via deceleration parachutes and air bags.^[6][7]
• Also during Phase 1 studies, the ESA looked at a conical capsule known as the "Viking". Like the Apollo-style concept, it would have reentered base-first, but it had a more aerodynamic shape. The rocket engines for the "Viking" module were derivatives of the Ariane Transfer Vehicle. The design work continued until the end of Phase 1 in March 1995.^[6][8]
• A Blunt Biconic concept was studied in 1993-1994. This design was expected to be more maneuverable, but would have been heavier and more expensive.^[6][9]

The ESA's US$1.7 billion ACRV program was cancelled in 1995, although French protests resulted in a two-year contract to perform further studies, which led to a scaled-down Atmospheric Reentry Demonstrator capsule, which was flown in 1997.^[6][10] The ESA instead elected to join NASA's X-38 CRV program in May 1996, after that program finished its Phase A study.^[6] Apollo Spacecraft: Command Module, Service Module, Lunar Module. ... The Advanced Reentry Demonstrator (ARD) was a suborbital reentry test flown on the third Ariane 5 flight. ...

Lifeboat Alpha

The idea of using a Russian-built craft as a CRV dates back to March 1993, when President Clinton directed NASA to redesign Space Station Freedom and consider including Russian elements. The design was revised that summer, resulting in Space Station Alpha (later the International Space Station). One of the Russian elements considered as a part of the redesign was the use of Soyuz "lifeboats." It was estimated that using the Soyuz capsules for CRV purposes would save NASA US$500 million over the cost expected for Freedom.^[11] William Jefferson Bill Clinton (born William Jefferson Blythe III[1] on August 19, 1946) was the 42nd President of the United States, serving from 1993 to 2001. ... Space Station Freedom was the name given to NASAs project to construct a permanently-manned earth-orbiting space station. ... “ISS” redirects here. ...

However, in 1995, a joint venture between Energia, Rockwell International and Khrunichev proposed the Lifeboat Alpha design, derived from the Zarya reentry vehicle. The reentry motor was a solid propellant, and maneuvering thrusters utilized cold gas, so that it would have had a five-year on-station life cycle. The design was rejected, though, in June 1996 in favor of the NASA CRV/X-38 program.^[12] This article or section does not cite its references or sources. ... Rockwell International was the ultimate incarnation of a series of companies under the sphere of influence of Willard Rockwell, who had made his fortune after the invention and successful launch of a new bearing system for truck axles in 1919. ... Khrunichev State Space Scientific Production Center is a Moscow-based producer of space-launch systems. ... Zarya module as seen from STS-88 (NASA) Zarya (meaning sunrise), also known as the Functional Cargo Block or the FGB (the Russian Acronym), was the first module launched of the International Space Station. ...

The Crew Return Vehicle and the X-38

Besides referring to a generalized role within the ISS program, the name Crew Return Vehicle also refers to a specific design program initiated by NASA and joined by the ESA. The concept was to produce a spaceplane that was dedicated to the CRV role only. As such, it was to have three specific missions: medical return, crew return in case of the ISS becoming uninhabitable, and crew return if the ISS cannot be resupplied.^[13]

CRV overview and concept development

As a follow-on to the HL-20 program, the NASA intent was to apply Administrator Dan Goldin's concept of "better, faster, cheaper" to the program.^[14] The CRV design concept incorporated three main elements: the lifting-body reentry vehicle, the international berthing/docking module, and the Deorbit Propulsion Stage. The vehicle was to be designed to accommodate up to seven crew members in a shirt-sleeve environment. Because of the need to be able to operate with incapacitated crew members, flight and landing operations were to be performed autonomously.^[13] The CRV design had no space maneuvering propulsion system.^[15] Daniel Saul Goldin (born July 23, 1940) served as the 9th and longest-tenured Administrator of NASA from April 1, 1992, to November 17, 2001. ...

NASA and ESA agreed that the CRV would be designed to be launched on top of an expendable launch vehicle (ELV) such as the Ariane 5.^[15] The program envisioned the construction of four CRV vehicles and two berthing/docking modules. The vehicles and berthing/docking modules were to be delivered to the ISS by the Space Shuttle, and each would remained docked for three years.^[13] An expendable launch system or expendable launch vehicle, ELV, is a single-use launch vehicle usually used to launch a payload into space. ... Ariane 5 mock-up Ariane 5 is a European expendable launch system designed to deliver satellites into geostationary transfer orbit and to send payloads to Low Earth orbit. ...

Depending on which mission was being operated, maximum mission duration was intended to be up to nine hours. If the mission was related to emergency medical return, the mission duration could be reduced to three hours, given optimum sequencing between ISS departure and the deorbit/reentry burn.^[13] Under normal operations, the undocking process would take up to 30 minutes, but in an emergency the CRV could separate from the ISS in as little as three minutes.^[16]

The CRV was to have a length of 29.8 ft (9.1 m) and a cabin volume of 416.4 ft³ (11.8 m³). Maximum landing weight was to be 22,046 lb (10,000 kg). The autonomous landing system was intended to place the vehicle on the ground within 3,000 ft (0.9 km) of its intended target.^[13]

The Deorbit Propulsion Stage was designed by Aerojet GenCorp under contract to the Marshall Space Flight Center. The module was to be attached to the aft of the spacecraft at six points, and is 15.5 ft (4.72 m) long and 6 ft (1.83 m) wide. Fully fueled, the module would weigh about 6,000 lb (2721.5 kg). The module was designed with eight 100-lb-thrust (45.35 kg) rocket engines fueled by hydrazine, which would burn for ten minutes to deorbit the CRV. Eight reaction control thrusters would then control the ship's attitude during deorbit. Once the burn was completed, the module was to be jettisoned, and would burn most of its mass up as it reentered the atmosphere.^[16] Aerojet is a major rocket and missile propulsion manufacturer based primarily in Sacramento, California with divisions in Redmond, Washington, Orange, VA, Gainesville, VA, and Camden, AK. Their products include a wide range of propulsion, from main engines used on a number of NASA vehicles and ballistic missiles, down to stationkeeping... Aerial view of the test area at Marshall Space Flight Center The George C. Marshall Space Flight Center (MSFC) is a lead NASA center for propulsion, Space Shuttle propulsion, external fuel tank, crew training and payloads, International Space Station (ISS) design and construction, for computers, networks, and information management. ... Hydrazine is the chemical compound with formula N2H4. ...

The cabin of the CRV was designed to be a "windowless cockpit", as windows and windshields add considerable weight to the design and pose additional flight risks to the spacecraft. Instead, the CRV was to have a "virtual cockpit window" system that used synthetic vision tools to provide an all-weather, day/night, real-time, 3-D visual display to the occupants.^[17]

X-38 Advanced Technology Demonstrator

Main article: X-38 Crew Return Vehicle

In order to develop the design and technologies for the operational CRV at a fraction of the cost of other space vehicles, NASA launched a program to develop a series of low-cost, rapid-prototype vehicles that were designated the X-38 Advanced Technology Demonstrators.^[18] As described in EAS Bulletin 101, the X-38 program "is a multiple application technology demonstration and risk mitigation programme, finding its first application as the pathfinder for the operational Crew Return Vehicle (CRV) for the International Space Station (ISS)."^[13][19] The X-38 Crew Return Vehicle (CRV) was a prototype for a wingless lifting body reentry vehicle that was to be used as a Crew Return Vehicle for the International Space Station (ISS). ...

NASA acted as its own prime contractor for the X-38 program, with the Johnson Space Center taking the project lead. All aspects of construction and development were managed in-house, although specific tasks were contracted out.^[19] For the production CRV, NASA intended to select an outside prime contractor to build the craft.^[20] An aerial view of the complete Johnson Space Center facility in Houston, Texas in 1989. ...

Four test vehicles were planned, but only two were built, both atmospheric test vehicles. The airframes, which were largely built of composite materials, were constructed under contract by Scaled Composites. The first flew its maiden flight on March 12, 1998. The X-38 utilized a unique parafoil landing system designed by Pioneer Aerospace. The ram-air inflated parafoil used in the flight test program was the largest in the world, with a surface area of 7,500 ft² (700 m²). The parafoil was actively controlled by an on-board guidance system that was based on GPS navigation.^[21] Scaled Composites (often abbreviated as Scaled) was founded in 1982 in Mojave, California by famous aircraft designer Burt Rutan out of what used to be the Rutan Aircraft Factory. ... The Maiden flight of an aircraft is the first occasion on which an aircraft leaves the ground of its own accord. ... March 12 is the 71st day of the year in the Gregorian calendar (72nd in leap years). ... This is a list of aviation-related events from 1998: Events Cirrus Aircraft successfully flight-tests the CAPS ballistic emergency aircraft parachute. ... A parafoil is a nonrigid airfoil, designed with an aerodynamically inflated cell structure. ...

Controversy

NASA's plans for the development program did not include an operational test of the actual CRV, which would have involved it being launched to the ISS, remaining docked there for up to three months, and then conducting an "empty" return to Earth. Instead, NASA had planned to "human rate" the spacecraft based on the results of the X-38's orbital testing. Three independent review groups, as well as NASA's Inspector General's office, expressed concerns about the wisdom and safety of this plan.^[20]

The rapid-prototyping method of development, as opposed to the approach of sequential design, development, test and engineering evaluation also raised some concerns about program risk.^[19]

Funding issues

In 1999, NASA projected the cost of the X-38 program at US$96 million (Space Flight Advanced Projects funds) and the actual CRV program at US$1.1 billion (ISS Program funds).^[20] A year later, the X-38 costs had risen to US$124.3 million, with the increased cost being paid for by ISS funds.^[19] Part of the increased cost was the result of the need to operationally test the CRV with at least one, and possibly more, shuttle launches.^[22]

The ESA chose not to fund the CRV program directly, but instead decided to allow ESA-participating governments to fund the program individually, starting in 1999.^[15] Belgium, France, Germany, The Netherlands, Italy, Spain, Sweden, and Switzerland all indicated that they would make substantial contributions.^[13]

U.S. funding for the NASA/ESA CRV was never a settled issue. In the Fiscal Year (FY) 2002 funding bill, Congress recommended a funding amount of US$275 million, but made it clear that this was conditional: "[T]he Committee does not anticipate providing additional funds for this purpose unless it is made clear that the Administration and the international partners are committed to the International Space Station as a research facility. For this reason, the language included in the bill would rescind the $275,000,000 unless the Administration requests at least $200,000,000 for the crew return vehicle in the fiscal year 2003 NASA budget request." Furthermore, funding of the CRV program was tied to Administration justification of the mission of the ISS: "By March 1, 2002, the President shall submit to the Committees on Appropriations of the House and Senate a comprehensive plan that meets the following terms and conditions: First, a clear and unambiguous statement on the role of research in the International Space Station program. Second, a detailed outline of the efforts being pursued to provide habitation facilities for a full-time crew of no less than six persons.... Third, the anticipated costs of the crew return vehicle program by fiscal year.... Fourth, the relative priority of the crew return vehicle development program in the context of the International Space Station. The Committee does not intend to provide any additional funds or approve the release of any of the $275,000,000 provided in this bill, until all conditions are fully satisfied."^[23]

Cancellation

On April 29, 2002, NASA announced that it was cancelling the CRV and X-38 programs, due to budget pressures associated with other elements of the ISS.^[24] The agency had been faced with a US$4 billion shortfall, and so radically redesigned the scope of the ISS, calling the new version U.S. Core Complete. This scaled-down station did not include the X-38-based CRV. Although the FY 2002 House budget had proposed US$275 million for the CRV, this was not included in the final budget bill. House-Senate conferees, however, saw the need to keep the CRV options open, believing that NASA's redesign and consequent deletion of the CRV premature, and so directed NASA to spend up to US$40 million to keep the X-38 program alive.^[25]

The cancellation created its own controversy, with Congressman Ralph Hall (D-TX) taking NASA to task in an open letter.^[26] Hall offered the following criticsms of NASA's CRV cancellation: Ralph Moody Hall (born May 3, 1923) is a United States Representative from the Fourth Congressional District in Texas (map). ...

• "No quantitative analysis of the costs and benefits of X-38/CRV alternatives was conducted prior to the decision to terminate the program."
• "2010 is estimated to be the "earliest" availability date for a Crew Transfer Vehicle (CTV) to support crew return functions on the International Space Station."
• "No estimates of the cost to develop and operate a CTV are provided."
• "NASA has no plans to purchase Soyuz crew return vehicles from Russia. The letter does not address the limits on Russian cooperation imposed by the Iran Nonproliferation Act, nor does it describe how a crew return capability will be provided for either a 3-person or larger crew-size Station once the Russian obligation to provide Soyuz vehicles ends in 2006."
• "NASA now estimates the cost of a CRV fleet at $3 billion, which constitutes a massive increase from the $1.3-1.4 billion estimate consistently provided to Congress prior to the Administrator's termination announcement. NASA's new position is that a CRV would not be available until 2008, which appears to be due to OMB's decision last year to defer work on the program rather than any technical or management problems. Mr. O'Keefe's June 2002 announcement of the cancellation of the X-38/CRV program did not raise cost growth or schedule as factors in that decision. It seems clear to me that the new cost and schedule estimates for the CRV are not based on a thorough technical analysis, but rather on a desire to portray CTV development in a more favorable light."^[27]

Orbital Space Plane

Main article: Orbital Space Plane

As a part of NASA's Integrated Space Transportation Plan (ISTP) which restructured the Space Launch Initiative (SLI), focus moved in 2002 to developing the Orbital Space Plane (OSP) (early on referred to as the Crew Transfer Vehicle, or CTV),^[28] which would serve as both crew transport and as the CRV. In the restructuring, program priorities were changed, as NASA declared: "NASA's needs for transporting US crew to and from the Space Station is a driving space transportation requirement and must be addressed as an agency priority. It is NASA's responsibility to ensure that a capability for emergency return of the ISS crew is available. The design and development of an evolvable and flexible vehicle architecture that will initially provide crew return capability and then evolve into a crew transport vehicle is now the near-term focus of SLI."^[28] // Background The Orbital Space Plane program (now defunct and replaced by the Spiral series of CEV — Crew Exploration Vehicles) was designed to support the International Space Station requirements for crew rescue, crew transport and contingency cargo such as supplies, food and other needed equipment. ...

A Crew Transfer Vehicle/Crew Rescue Vehicle Study, conducted by the SLI program in 2002, concluded that a multi-purpose Orbital Space Plane that can perform both the crew transfer and crew return functions for the Space Station is viable and could provide the greatest long-term benefit for NASA's investment. One of the key missions for the OSP, as defined by NASA in 2002, was to provide "rescue capability for no fewer than four Space Station crew members as soon as practical, but no later than 2010." As a part of the flight evaluation program that was to explore and validate technologies to be used in the OSP, NASA initiated the X-37 program, selecting Boeing Integrated Defense Systems as the prime contractor.^[29] An artists rendition of the X-37. ... Boeing Integrated Defense Systems (Boeing IDS), based in St. ...

However, the OSP received heavy congressional criticism for being too limited in mission ("...the primary shortcoming of the OSP is that, as currently envisioned, it leads nowhere besides the space station")^[30] and for costing as much as US$3 to $5 billion.

Then, in 2004, NASA's focus changed yet again, from the OSP to the Crew Exploration Vehicle (CEV), and the X-37 project was transferred to DARPA, where some aspects of technology development were continued, but only as an atmospheric test vehicle.^[31] Orion is a spacecraft currently under development by the United States National Aeronautics and Space Administration (NASA). ... The Defense Advanced Research Projects Agency (DARPA) is an agency of the United States Department of Defense responsible for the development of new technology for use by the military. ...

Apollo-derivative capsule

With the cancellation of the OSP, the Apollo capsule was once again looked at for use as a CRV, this time by NASA in March 2003. In the initial study of the concept, "the Team concluded unanimously that an Apollo-derived Crew Return Vehicle (CRV) concept, with a 4 to 6 person crew, appears to have the potential of meeting most of the OSP CRV Level 1 requirements. An Apollo derived Crew Transport Vehicle (CTV) would also appear to be able to meet most of the OSP CTV Level 1 requirements with the addition of a service module. The team also surmised that there would be an option to consider the Apollo CSM concept for a common CRV/CTV system. It was further concluded that using the Apollo Command Module (CM) and Service Module (SM) as an ISS CRV and CTV has sufficient merit to warrant a serious detailed study of the performance, cost, and schedule for this approach, in comparison with other OSP approaches, to the same Level 1 requirements."^[32] Apollo Spacecraft: Command Module, Service Module, Lunar Module. ...

The study identified a number of issues with development of this option: "On the one hand, the Apollo system is well understood, and proved to be a highly successful, rugged system with a very capable launch abort system. Documentation would be very helpful in leading the designers. On the other hand, nearly every system would have to be redesigned, even if it were to be replicated. None of the existing hardware (such as CMs in Museums) was thought to be usable, because of age, obsolescence, lack of traceability, and water immersion. There would be no need for fuel cells or cryogenics, and modern guidance and communications would be lighter and less expensive. Although the flight hardware would be less expensive, and its impact on the Expendable Launch Vehicles would be minimal (it’s just another axisymmetrical payload), the landing sites for the CRV may drive the Life Cycle costs high. By adding a Service Module (smaller than the one required to go to the moon), orbital cross-range of 3000 to 5000 ft/sec, might be gained, and the number of landing sites radically reduced. If land landings can be added to the system safely, another major reduction in life cycle costs would result, because the team believed that the system could be made re-usable."^[32]

Due to the capsule's somewhat aerodynamic design, g-loadings are in the moderate range, (2.5 to 3.5g). From a medical perspective, though, the Apollo-type capsule presents several disadvantages. The Apollo capsule would have an internal atmospheric operating pressure of only 5 PSI, as opposed to the station's 14.5 PSI. In addition, a water landing on short notice presents some significant delays in capsule recovery.^[2]

Soyuz TMA

Main article: Soyuz spacecraft

With the cancellation of the X-38 and CRV programs in 2001, it was clear that the interim use of Soyuz capsules would be a longer term necessity. To make them more compatible with the needs of the ISS, Energia was contracted to modify the standard Soyuz TM capsule to the TMA configuration.^[33][34] The main modifications involve the interior layout, with new, improved seats to accommodate larger American astronaut anthropometric standards.^[35] A series of test drops of the improved capsule were made in 1998 and 1999 from an Ilyushin Il-76 cargo plane to validate the landing capabilities of the TMA.^[36] Soyuz (Russian: Союз, pronounced sah-YOUS, meaning union) is a series of spacecraft designed by Sergey Korolyov for the Soviet Unions space program. ... This article or section does not cite its references or sources. ... Ilyushin Il-76T An Indian Air Force IL-76 in Hawaii, with IAF and US personnel. ...

A Soyuz TMA capsule is always attached to the ISS in "standby" mode, in case of emergencies. Operated in this configuration, the TMA has a lifespan of about 200 days before it has to be rotated out.^[37] Because of this limitation, the vehicle is planned for a typical six-month changeout cycle. The first flight of the TMA to the ISS occurred on October 29, 2002 with the flight of the Soyuz TMA-1.^[38]. October 29 is the 302nd day of the year (303rd in leap years) in the Gregorian calendar. ... For album titles with the same name, see 2002 (album). ...

Because the TMA is limited to three occupants, the ISS is also likewise restricted to that number of occupants, which drastically reduces the amount of research that can be done onboard the ISS to 20 person-hours per week, far lower than what was anticipated when the station was designed.^[39]

Soyuz TMAT version that is planed to be introduced in 2008/9 will extend it's lifespan to one year. That along with expanded production rate will enable the ISS to increase the crew size.

References

1. ^ ^{a b c d e} NASA ACRV history from Astronautix.com
2. ^ ^{a b c d e f g h} Stepaniak, Philip, MD; Hamilton, Glenn; Stizza, Denis; Garrison, Richard; Gerstner, David (July 2001). Considerations for Medical Transport From the Space Station via an Assured Crew Return Vehicle (ACRV) (PDF). NASA Johnson Space Center. Retrieved on 2006-11-06.
3. ^ Mark Wade. MOSES. Astronautix.com. Retrieved on 2006-11-03.
4. ^ U.S. Patent 5,064,151  NASA patent for a capsule-type CRV (First page)
5. ^ NASA HL-20 web site
6. ^ ^{a b c d e f} ESA ACRV review
7. ^ Image of Apollo-type capsule
8. ^ Image of Viking ACRV
9. ^ Image of Blunt Biconic capsule
10. ^ EADS ARD page
11. ^ GAO (June 1994). Space Station: Impact of the Expanded Russian Role on Funding and Research (PDF). GAO. Retrieved on 2006-11-03.
12. ^ Mark Wade. Alpha Lifeboat. Astronautix. Retrieved on 2006-11-03.
13. ^ ^{a b c d e f g} E. D. Graf (February 2000). The X-38 and Crew Return Vehicle Programmes (PDF). ESA Bulletin 101. European Space Administration. Retrieved on 2006-10-31.
14. ^ NASA Developing Crew-Return Vehicle. Retrieved on 2006-10-31.
15. ^ ^{a b c} X-38 Crew Return Vehicle. GlobalSecurity.org. Retrieved on 2006-10-27.
16. ^ ^{a b} Marshall Space Flight Center (December 2000). X-38 Deorbit Propulsion System (PDF). NASA Facts. NASA. Retrieved on 2006-11-01.
17. ^ Delgado, Frank; Altman Scott; Abernathy, Michael F.; White, Janis; Verly, Jacques G.. Virtual cockpit window for the X-38 crew return vehicle. International Society for Optical Engineering proceedings series. Society of Photo-Optical Instrumentation Engineers. Retrieved on 2006-11-01.
18. ^ X-38 TECHNOLOGY DEMONSTRATOR ARRIVES AT DRYDEN. Retrieved on 2006-10-27.
19. ^ ^{a b c d} NASA Office of Inspector General (2000-02-06). Audit Report: X-38/Crew Return Vehicle Project Management (PDF). Retrieved on 2006-11-02.
20. ^ ^{a b c} NASA Office of Inspector General (1999-09-20). Audit Report: X-38/Crew Return Vehicle Operational Testing (PDF). Retrieved on 2006-11-02.
21. ^ Pioneer Aerospace. Retrieved on 2006-10-31.
22. ^ NASA House testimony
23. ^ Update on NASA Appropriations; Language on Space Station Overruns
24. ^ X-38. Federation of American Scientists' Space Policy Project. Retrieved on 2006-10-31.
25. ^ Public Law 107-73, Departments of Veterans Affairs and Housing and Urban Development, and Independent Agencies Appropriations Act, 2002. Retrieved on 2006-11-06.
26. ^ Ralph Hall. Rep. Hall Letter to NASA Administrator (PDF). US Government. Retrieved on 2006-11-07.
27. ^ Rep. Hall Releases O'Keefe's Responses on Crew Return Plans for the Space Station. Spaceref.com (2002-10-22). Retrieved on 2006-11-07.
28. ^ ^{a b} The New Integrated Space Transportation Plan (ISTP). NASA Aeronautics News (2003-01-23). Retrieved on 2006-11-07.
29. ^ Statement of Frederick D. Gregory, Deputy Administrator, NASA, before the Subcommittee on Space and Aeronautics Committee on Science House of Representatives
30. ^ Brian Berger (2003-05-27). Space News Business Report. Space.com. Retrieved on 2006-11-07.
31. ^ Space.com news
32. ^ ^{a b} Dale Myers (2003-05-08). Testimony to the House Subcommittee on Space and Aeronautics On the Assessment of Apollo Hardware for CRV and CTV. Retrieved on 2006-10-31.
33. ^ Energia Soyuz TMA webpage
34. ^ Sepahbam, S. F., and Williams, R. J., The Soyuz Assured Crew Return Vehicle operations concept, Operations Integrations Office, ACRV Project Office, NASA Johnson Space Center, 1993
35. ^ Energia Soyuz modification listing
36. ^ Energia drop test information
37. ^ NASA 2003 ISS goals
38. ^ NASA press release, October 29, 2002
39. ^ AAAS (2001-07-27). House Boosts NASA R&D, Adds Crew Return Vehicle to Station. AAAS. Retrieved on 2006-11-07.

For the Manfred Mann album, see 2006 (album). ... November 6 is the 310th day of the year (311th in leap years) in the Gregorian calendar, with 55 days remaining. ... For the Manfred Mann album, see 2006 (album). ... November 3 is the 307th day of the year (308th in leap years) in the Gregorian calendar, with 58 days remaining. ... For the Manfred Mann album, see 2006 (album). ... November 3 is the 307th day of the year (308th in leap years) in the Gregorian calendar, with 58 days remaining. ... For the Manfred Mann album, see 2006 (album). ... November 3 is the 307th day of the year (308th in leap years) in the Gregorian calendar, with 58 days remaining. ... For the Manfred Mann album, see 2006 (album). ... October 31 is the 304th day of the year (305th in leap years) in the Gregorian calendar, with 61 days remaining. ... For the Manfred Mann album, see 2006 (album). ... October 31 is the 304th day of the year (305th in leap years) in the Gregorian calendar, with 61 days remaining. ... For the Manfred Mann album, see 2006 (album). ... October 27 is the 300th day of the year (301st in leap years) in the Gregorian calendar, with 65 days remaining. ... For the Manfred Mann album, see 2006 (album). ... November 1 is the 305th day of the year (306th in leap years) in the Gregorian calendar, with 60 days remaining. ... For the Manfred Mann album, see 2006 (album). ... November 1 is the 305th day of the year (306th in leap years) in the Gregorian calendar, with 60 days remaining. ... For the Manfred Mann album, see 2006 (album). ... October 27 is the 300th day of the year (301st in leap years) in the Gregorian calendar, with 65 days remaining. ... For the Manfred Mann album, see 2006 (album). ... November 2 is the 306th day of the year (307th in leap years) in the Gregorian calendar, with 59 days remaining. ... For the Manfred Mann album, see 2006 (album). ... November 2 is the 306th day of the year (307th in leap years) in the Gregorian calendar, with 59 days remaining. ... For the Manfred Mann album, see 2006 (album). ... October 31 is the 304th day of the year (305th in leap years) in the Gregorian calendar, with 61 days remaining. ... For the Manfred Mann album, see 2006 (album). ... October 31 is the 304th day of the year (305th in leap years) in the Gregorian calendar, with 61 days remaining. ... For the Manfred Mann album, see 2006 (album). ... November 6 is the 310th day of the year (311th in leap years) in the Gregorian calendar, with 55 days remaining. ... For the Manfred Mann album, see 2006 (album). ... November 7 is the 311th day of the year (312th in leap years) in the Gregorian Calendar, with 54 days remaining. ... For the Manfred Mann album, see 2006 (album). ... November 7 is the 311th day of the year (312th in leap years) in the Gregorian Calendar, with 54 days remaining. ... For the Manfred Mann album, see 2006 (album). ... November 7 is the 311th day of the year (312th in leap years) in the Gregorian Calendar, with 54 days remaining. ... For the Manfred Mann album, see 2006 (album). ... November 7 is the 311th day of the year (312th in leap years) in the Gregorian Calendar, with 54 days remaining. ... For the Manfred Mann album, see 2006 (album). ... October 31 is the 304th day of the year (305th in leap years) in the Gregorian calendar, with 61 days remaining. ... For the Manfred Mann album, see 2006 (album). ... November 7 is the 311th day of the year (312th in leap years) in the Gregorian Calendar, with 54 days remaining. ...

See also

• Space Station Freedom
• International Space Station
• Lifting body

Space Station Freedom was the name given to NASAs project to construct a permanently-manned earth-orbiting space station. ... “ISS” redirects here. ... The lifting body is an aircraft configuration where the body itself produces lift. ...

External links

• ESA CRV specifications
• Burgio, Fabrizio; Ferro, Claudio; Russo, Adofo (1993). Thermal control issues of the assured crew return vehicle (ACRV). Retrieved on 2006-10-31.
• Assured crew return vehicle post landing configuration design and test. Retrieved on 2006-10-31.
• CRV interior mockup. Retrieved on 2006-10-31.
• Cockpit Virtual Vision paper
• MSNBC Flash presentation showing construction of the ISS and placement of the CRV
• 3D Modeling for CRV design
• Timing Analysis and Scheduling of the X-38 Space Station Crew Return Vehicle and Other Space Vehicles
• CRV Interior Design
• NASA Tech Paper 3101: Numerical Analysis and Simulation of an Assured Crew Return Vehicle Flow Field
• Historic overview of space lifeboats
• AAAS FY 2002 budget review and commentary on CRV issues