In-flight aborts and rescue options

In-flight aborts and rescue options

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.

In-flight abort

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.

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.

pace rescue

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 new generation of universal docking systems 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 "Launch On Need" rescue flights, would then be launched and if undamaged, would dock with the ISS. At that time, the crew would have 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.

In the event the damage to the Orion spacecraft is severe enough to prevent docking with the ISS, or fails to reach the ISS at all, NASA would then rush an unmanned Orion/Ares I stack and launch it in a manner similar to that "Launch on Need" rescue to be planned for the upcoming STS-125 flight to the Hubble Space Telescope. Once the "rescue Orion" reaches the damaged Orion spacecraft, a physical docking would take place, allowing a crew transfer without the need to perform an EVA like those required for Shuttle-to-Shuttle rescues. In the event of a failed capture, ship-to-ship EVAs will then be required, but would not pose any problems as the Constellation Space Suit system, which unlike the current ACES pressure suit worn by Shuttle crews, will then be in place by the first manned Orion flight in 2015, and are capable of emergency microgravity EVAs.

Lunar missions

Although the "Apollo 13" was called a "successful failure" due to the fact that the crew returned safely to Earth using the onboard resources of the Apollo Lunar Module, part of that success was due to the design of the Apollo Service Module. Design around the use of a fuel cell architecture, the cylindrical service module housed the fuel cells, which powered the spacecraft and produced the crew's drinking water, while the liquid oxygen and liquid hydrogen tanks, located almost at the module's mid-section, provided the ingredients to make the cells work. That architecture, along with the decision made by legendary flight director Gene Kranz to use the engine on the LM "Aquarius", lead to the crew's safe return to Earth.

With the design of the Orion spacecraft's service module around the use of solar panels, an onboard explosion in the magnitude as that of "Apollo 13" would most likely lead to the entire Orion spacecraft, including its heat shield, to become damaged to the point a "Columbia"-like scenario may occur. In such cases, the Orion/Altair combination will then continue on and enter orbit around the Moon, while NASA will rush and launch a modified "rescue Orion" on either an Ares IV or Ares V rocket.

As the Altair spacecraft is capable of a 7 to 10 day stay on the lunar surface, both it, and any resources on the damaged Orion spacecraft will allow the astronauts to both stay safe, and even carry out some limited surveys of the lunar surface until the "rescue Orion" reaches orbit, upon which the damaged Orion is then jettisoned and the crew, flying the Altair, rendezvous and docks with the "rescue Orion." Once the crew transfers to the "rescue Orion," the Altair is jettisoned and the "rescue Orion" than takes the crew back to Earth in the same manner as that of a normal Orion lunar mission. Both the damaged Orion and the Altair are than programmed by Mission Control to crash onto the lunar farside.

In a situation in which the Altair 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 Altair to the launch pad, and like the unmanned Lunar Outpost supply missions (similar to the "LM Truck" flights of the cancelled AAP missions), fly the unmanned Altair directly out to the Moon. Upon touching down in a pre-determined area (between 2 to 4 km. away from the stranded Altair), the crew will then transfer, via rover or on foot, to the "rescue Altair" and then fly back into lunar orbit for a rendezvous with the circling Orion CEV.

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