In-flight aborts and rescue options
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In the context of the Orion spacecraft, in-flight aborts and rescue options are activities which might take place if there were an emergency during a mission. Like all previous U.S. manned spacecraft, an in-flight abort can occur when a major component fails (such as a malfunctioning altitude-control thruster on Gemini 8) or when a crew member becomes dangerously ill (such as that on the Soyuz T-14 flight to Salyut 7 in 1985, when the commander became seriously ill).
In most cases, NASA Mission Control in Houston will immediately abort the flight and instruct the crew to return home on the next orbit, and because the Orion crew module was designed to touch down on both land and water, NASA can direct the spacecraft to either a ground landing in California or New Mexico, or a water splashdown near major U.S. Naval forces.
The only case in which an in-flight abort occurred in which astronauts or cosmonauts could not return to Earth on a short notice was that of the flight of Apollo 13 in 1970. On that flight, an oxygen tank in the spacecraft's Service Module exploded, crippling the onboard life-support systems and forcing astronauts Jim Lovell, Fred Haise, and Jack Swigert to use the Lunar Module as a "lifeboat" until the crew, after swinging around the Moon, was just three hours away from a splashdown in the Pacific Ocean. Although the crew endured an ordeal of little water, cold temperatures, and a decaying trajectory that had to be corrected twice during the return trip, the biggest concern was the spacecraft's heat shield, which may have been cracked by the onboard explosion. If such a crack did occur, it would have resulted in a scenario similar in nature to the Columbia Disaster in 2003.
As such, NASA is currently developing both in-flight abort and rescue proceduces that date back to the Apollo-Soyuz flight in 1975 and highlighted by the Columbia Accident Investigation Board (CAIB). These scenarios would allow NASA to bring a crew home within two hours on a low-Earth orbit flight and in seven days on a lunar sortie flight.
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[edit] In-flight abort
[edit] Low-Earth orbit
On an in-flight abort, such as the early flights to the International Space Station, Mission Control in Houston will direct the crew to leave the ISS and use the Orion CEV for a ground landing at either Edwards Air Force Base in California or White Sands Space Harbor in New Mexico, where any injured or sick crew members can receive immediate care in a manner similar to that of a wounded combatant in either Vietnam or Iraq. Such an in-flight abort would have to occur when the Orion CEV is intact and undamaged, and the cause of the in-flight abort lies within the ISS itself or when a crew member becomes ill. For an ill crew member, the ISS can remained manned by a skeleton crew until another Orion or a private spaceflight is launched.
[edit] Lunar missions
In the event of a malfunction of lunar flight hardware that does not jeopardize the crew or spacecraft, Mission Control will abort the lunar flight and depending on the phase of the mission, would require the crew to make a lunar flyby (as done on Apollo 13), enter orbit around the Moon (as done on Apollo 8), or perform, using both LSAM and Orion SM engines, a "direct abort," in which the Orion/LSAM combination is turned around so that the LSAM's descent and ascent engines face the Moon, and in a manner similar to the RTLS abort maneuver on the Space Shuttle, fires its engines so that the spacecraft reverses course and heads straight back to Earth, using the onboard Orion engine for minor course refinements. Using the skip entry techniques first demonstrated by the former Soviet Union for their failed lunar program, the Orion CEV would then either land in California or New Mexico in a manner similar to that for a near-Earth abort.
[edit] Space rescue
[edit] Low-Earth orbit
Because of the stigma placed by the Columbia Accident Investigation Board (CAIB) to provide the needs for an in-flight rescue, all Orion spacecraft will utilize a universal docking system first demonstrated on Apollo-Soyuz and is now a standard part of the U.S. docking system on the ISS. In the event the Orion spacecraft is damaged during launch, but is able to reach the ISS, the crew would use the ISS as a "safe haven" and an unmanned "rescue Orion," similar to that of the Skylab Rescue and STS-3xx rescue flights, would then be launched and if undamaged, would dock with the ISS. At that time, the crew would jettison the damaged Orion CEV with Mission Control deorbiting the spacecraft to a crash landing in the Pacific Ocean away from known shipping lanes in a manner used for the unmanned Progress cargo ships used by the Russian space program.
For an in-flight rescue in which the Orion fails to reach the ISS, the unmanned Orion will be launched, and with the universal docking system, will allow a hard dock and crew transfer without having to perform an EVA, although all crew members by then will have Apollo-style pressure suits for both internal and external use. Procedures after crew transfer will be the same as that for ISS flights.
[edit] Lunar missions
Although Apollo 13 was deemed a "successful failure," primarily due to the construction of the spacecraft's service module (which was centered around a fuel cell architecture), an Apollo 13-style explosion would most likely damage the Orion spacecraft, due to the shorter length of the Orion SM (due to the elimination of liquid hydrogen "slush tanks" needed for fuel cell operation), which will require Mission Control to direct the Orion/LSAM combination into an orbit around the Moon while a modified unmanned "rescue Orion" is rushed to the pad and launched on an Ares IV rocket on a direct trajectory to the Moon. Once in lunar orbit, the crew, flying in the LSAM, would abandon the damaged Orion CEV and then dock with the "rescue Orion," abandoning the LSAM in lunar orbit. Once the crew is on their way back to Earth, Mission Control will then control both the Orion CEV and the LSAM to crash landings on the lunar far side.
In a situation in which the LSAM is damaged and unable to take off from the Moon (a scenario going back to the planned lunar base of the Apollo Applications Program), NASA would rush a standard Ares V rocket and an unmanned LSAM to the launch pad, and like the "Cargo LSAM" for lunar base supply mission, fly the unmanned LSAM directly out to the Moon. Upon touching down in a pre-determined area (between 4 and 6 miles away from the stranded LSAM), the crew will then transfer, via rover or on foot, to the rescue LSAM and then fly the rescue LSAM back into lunar orbit for a rendezvous with the circling Orion CEV.
