thumb|The Skylab 4 rescue vehicle at Launch Pad 39B (3 December 1973)
The Skylab Rescue Mission (also SL-R) was an unflown rescue mission, planned as a contingency in the event of astronauts being stranded aboard the American Skylab space station. After a rescue mission in Earth orbit was depicted in the 1969 film Marooned, the company revived the concept in November 1970. The standard Skylab Command Module accommodated a crew of three with storage lockers on the aft bulkhead for resupply of experiment film and other equipment, as well as the return of exposed film, data tapes and experiment samples. To convert the standard CSM to a rescue vehicle, the storage lockers were removed and replaced with two crew couches to seat a total of five crewmen. The fuel for all quads and the main service propulsion system (SPS) engine were from the same batch; if the SPS fuel was contaminated, the CSM might not be able to deorbit.
NASA considered bringing the crew home immediately, was assembled in the Vehicle Assembly Building at Launch Complex 39 for possible use. It was at one point rolled out to LC-39B.
NASA announced on August 4 that Skylab 3 and Skylab 4 backup crewmen Vance Brand and Don Lind would fly any rescue mission; they had immediately begun training for the flight once the second quad had failed on August 2. After engineers found that the leaks would not disable the spacecraft, the two men used simulators to test reentry using two quads. If ground personnel worked 24 hours a day and skipped some tests, the mission could launch on September 10, and would last no more than five days. Human urine and feces samples and Apollo Telescope Mount and other film were the priorities. Although Skylab had two docking ports the primary one would be used if possible, jettisoning the Skylab crew's CSM if necessary. using the SPS engine once instead of twice as precaution.
AS 209
thumb|alt=Black-and-white picture from inside a tall building with a space capsule being lifted from the top of a rocket|Skylab Rescue [[Apollo CSM|CSM being removed from its Saturn IB following the successful recovery of Skylab 4 (19 February 1974)]]
After the Skylab 4 launch, another rescue flight was assembled as a backup contingency. The Saturn IB rocket AS 209 was assembled in the Vehicle Assembly Building at Launch Complex 39 for possible use. It also used the CSM 119 Command Module that was to be launched with Brand and Lind.
There were also plans for a short 20-day Skylab 5 flight that would use this backup CSM. The crew, likely consisting of Brand, Lind, and Skylab backup Science Pilot William B. Lenoir, would have performed some scientific research and closed out the station until the Space Shuttle was operational. However, the extension of Skylab 4 from fifty-six to eighty-four days obviated the need for the additional mission.
Crew
Brand and Lind were assigned as the rescue mission's crew, had it proven necessary. Although the rescue contingency was not flown, both astronauts made later spaceflights. Brand flew in 1975 as the Command Module Pilot of the Apollo–Soyuz Test Project before commanding three Space Shuttle missions: STS-5 in 1982, STS-41-B in 1984, and STS-35 in 1990. Lind would wait another decade before he flew as a mission specialist on STS-51-B in 1985.
Current location
Skylab Rescue hardware in now on display at the Kennedy Space Center Visitor Complex. CSM 119 is located in the Apollo/Saturn V Center. The Saturn IB booster for AS 209 is currently located in the Visitor Complex's Rocket Garden. It is displayed horizontally, mated to an Apollo FVV (Facilities Verification Vehicle) which was formerly displayed at the VAB's Visitor Complex circa October 1968.
In 2007, after the command module had sat untouched for over 30 years, NASA engineers used it for studies on the spacecraft's life-support adapter assembly – the projecting aerodynamic fairing that allows oxygen, water, and electricity to flow from the Service Module to the Command Module. This was in support of the design and construction of a similar system on the new Orion spacecraft, which resembles the Skylab Rescue configuration.
See also
- STS-3xx
- Soyuz 32, Soyuz 33, and Soyuz 34. The crew of Soyuz 32 boarded the Soviet Salyut 6 space station, taking up residence. It was planned that the crew which launched aboard Soyuz 32 would return to Earth using the Soyuz 33 spacecraft, while the crew launching with Soyuz 33 would visit briefly and return using the older Soyuz 32 spacecraft, the latter nearing the end of its design life. However, Soyuz 33 was unable to dock, endangering the cosmonauts aboard the station. As a contingency, the Soyuz 34 spacecraft was launched to the station without a crew aboard. The crew which had docked with Salyut 6 aboard Soyuz 32 returned safely to Earth via the Soyuz 34 spacecraft.
- SpaceX Crew-9