The Skylab Rescue Mission (also SL-R)
Mission Requirements, Skylab Rescue Mission, SL-R
NASA, 24 August 1973. was an unflown rescue mission, planned as a contingency in the event of astronauts being stranded aboard the American

Skylab Skylab was the first United States space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three separate three-astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Major operations in ...

space station.Wade, Mark.
Skylab Rescue
". ''

Encyclopedia Astronautica The ''Encyclopedia Astronautica'' is a reference web site on space travel. A comprehensive catalog of vehicles, technology, astronauts, and flights, it includes information from most countries that have had an active rocket research program, f ...

''. Retrieved 2009-04-10. If flown, it would have used a modified

Apollo Command Module The Apollo command and service module (CSM) was one of two principal components of the United States Apollo spacecraft, used for the Apollo program, which landed astronauts on the Moon between 1969 and 1972. The CSM functioned as a mother ship ...

that could be launched with a crew of two and return a crew of five. Astronauts

Vance Brand Vance DeVoe Brand (born May 9, 1931) is an American naval officer, aviator, aeronautical engineer, test pilot, and NASA astronaut. He served as command module pilot during the first U.S.-Soviet joint spaceflight in 1975, and as commander of thr ...

and

Don Lind Don Leslie Lind (May 18, 1930 – August 30, 2022) was an American scientist, naval officer, aviator, and NASA astronaut. He graduated from the University of Utah with an undergraduate degree in physics in 1953. Following his military service o ...

were assigned as the rescue crew, in the event of the mission's necessity. A rescue mission was considered when the

Skylab 3 Skylab 3 (also SL-3 and SLM-2) was the second crewed mission to the first American space station, Skylab. The mission began on July 28, 1973, with the launch of NASA astronauts Alan Bean, Owen Garriott, and Jack Lousma in the Apollo command ...

Command/Service Module (CSM) developed problems in its

reaction control system A reaction control system (RCS) is a spacecraft system that uses thrusters to provide attitude control and translation. Alternatively, reaction wheels are used for attitude control. Use of diverted engine thrust to provide stable attitude contr ...

(RCS) thrusters while docked to the station. On the ground,

space vehicle A space vehicle is the combination of a spacecraft and its launch vehicle which carries it into space. The earliest space vehicles were expendable launch systems, using a single or multistage rocket to carry a relatively small spacecraft in p ...

s were assembled to fly rescue missions in support of both Skylab 3 and

Skylab 4 Skylab 4 (also SL-4 and SLM-3) was the third crewed Skylab mission and placed the third and final human spaceflight, crew aboard the first American space station. The mission began on November 16, 1973, with the launch of Gerald P. Carr, Edward ...

. However, no rescue mission ever proved necessary. All astronauts visiting Skylab returned safely to Earth in their original command modules.

History

Plans for outfitting an

Apollo Command/Service Module The Apollo command and service module (CSM) was one of two principal components of the United States Apollo spacecraft, used for the Apollo program, which landed astronauts on the Moon between 1969 and 1972. The CSM functioned as a mother ship ...

(CSM) as a space rescue vehicle date back to November 1965 when

North American Rockwell North American Aviation (NAA) was a major American aerospace manufacturer that designed and built several notable aircraft and spacecraft. Its products included: the T-6 Texan trainer, the P-51 Mustang fighter, the B-25 Mitchell bomber, the F-8 ...

technicians conceived the possibility of a rescue mission for astronauts trapped in

lunar orbit In astronomy, lunar orbit (also known as a selenocentric orbit) is the orbit of an object around the Moon. As used in the space program, this refers not to the orbit of the Moon about the Earth, but to orbits by spacecraft around the Moon. The ...

. After a rescue mission in Earth orbit was depicted in the 1969 film ''

Marooned Marooned may refer to: * Marooning, the intentional act of abandoning someone in an uninhabited area Film and television * ''Marooned'' (1933 film), a British drama film * ''Marooned'' (1969 film), an American science-fiction film * ''Marooned ...

'', the company revived the concept in November 1970.

Marshall Space Flight Center The George C. Marshall Space Flight Center (MSFC), located in Redstone Arsenal, Alabama (Huntsville postal address), is the U.S. government's civilian rocketry and spacecraft propulsion research center. As the largest NASA center, MSFC's first ...

issued a formal Mission Requirements document on 17 May 1972, with subsequent revisions.

astronauts

Alan Bean Alan LaVern Bean (March 15, 1932 – May 26, 2018) was an American naval officer and aviator, aeronautical engineer, test pilot, NASA astronaut and painter; he was the fourth person to walk on the Moon. He was selected to become an astron ...

and

Jack Lousma Jack Robert Lousma (born February 29, 1936) is an American astronaut, aeronautical engineer, retired United States Marine Corps, United States Marine Corps officer, former United States naval aviator, naval aviator, NASA astronaut, and politici ...

helped design the "field modification kit" to use a standard CSM for rescue, and would have flown the CSM for their mission to rescue

Skylab 2 Skylab 2 (also SL-2 and SLM-1) was the first crewed mission to Skylab, the first American orbital space station. The mission was launched on an Apollo command and service module by a Saturn IB rocket on May 25, 1973, and carried NASA astronau ...

if necessary. 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 biggest risk in a rescue was the three upper seats "stroking" or collapsing onto the two lower seats in a rough landing, but no stroking occurred in previous missions.

AS 208

Soon after Skylab 3's launch the crew's CSM developed a problem with Quad B, one of its four reaction control system thrusters. On August 2, 1973, six days later, a snowstorm-like effect outside the station startled the crew during breakfast. What appeared to be "a real blizzard" was fuel leaking from Quad D, opposite from Quad B. The malfunctions left two available quads, and while the spacecraft could operate with just one, the leaks posed a possible risk to other systems. The fuel for all quads and the main

service propulsion system The Apollo command and service module (CSM) was one of two principal components of the United States Apollo spacecraft, used for the Apollo program, which landed astronauts on the Moon between 1969 and 1972. The CSM functioned as a mother ship ...

(SPS) engine were from the same batch; if the SPS fuel was contaminated, the CSM might not be able to

deorbit Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the entr ...

. NASA considered bringing the crew home immediately, but because the astronauts were safe on the station with ample supplies and because plans for a rescue flight existed, the mission continued while the

Saturn IB The Saturn IB (also known as the uprated Saturn I) was an American launch vehicle commissioned by the NASA, National Aeronautics and Space Administration (NASA) for the Apollo program. It uprated the Saturn I by replacing the S-IV second stage (, ...

rocket AS 208 with CSM 119Wade, Mark.
Apollo Rescue CSM
". ''Encyclopedia Astronautica''. Retrieved April 10, 2009. was assembled in the

Vehicle Assembly Building The Vehicle Assembly Building (originally the Vertical Assembly Building), or VAB, is a large building at NASA's Kennedy Space Center (KSC), designed to assemble large pre-manufactured space vehicle components, such as the massive Saturn V and th ...

Launch Complex 39 Launch Complex 39 (LC-39) is a rocket launch site at the John F. Kennedy Space Center on Merritt Island in Florida, United States. The site and its collection of facilities were originally built as the Apollo program's "Moonport" and later mo ...

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

and

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,Skylab's New Crisis: A Rescue Mission?
''

TIME Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, to ...

'', August 13, 1973. Retrieved April 10, 2009.Benson, Charles Dunlap and William David Compton.
Living and Working in Space: A History of Skylab
'. NASA publication SP-4208. and would last no more than five days. The astronauts would attempt to prepare Skylab for further use but returning experimental data and diagnosing the cause of the problem were more important, with Lind choosing what would be brought back.Don L. Lind oral history transcript
NASA Johnson Space Center Oral History Project, May 27, 2005. Human urine and feces samples and

Apollo Telescope Mount The Apollo Telescope Mount, or ATM, was a crewed solar observatory that was a part of Skylab, the first American space station. It could observe the Sun in wavelengths ranging from soft X-rays, ultra-violet, and visible light. The ATM was man ...

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. While many within NASA believed that the rescue mission would occur, within hours of the failure of the second quad the agency canceled the rescue mission. Beyond NASA's conclusion that the failed quads would not disable the Skylab 3 CSM and the SPS fuel was uncontaminated, Brand and Lind had already shown during their training as backup Skylab crewmen that a reentry with failed quads was safe. They also devised a method to deorbit with the command module's attitude control system. Later joking that they were "very efficient but perfectly stupid, because we have literally worked ourselves out of the mission", Brand and Lind continued to train for a rescue mission, as well as for their backup roles, but the Skylab 3 crew was able to complete its full 59-day mission on the station and safely return to Earth using the two functional RCS thruster quads,Belew, Leland. F. (editor)
Skylab, Our First Space Station
' NASA publication SP-400. using the SPS engine once instead of twice as precaution.

AS 209

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 Skylab was the first United States space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three separate three-astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Major operations in ...

flight that would use this backup CSM. The crew, likely consisting of Brand, Lind, and Skylab backup Science Pilot

William B. Lenoir William Benjamin "Bill" Lenoir (March 14, 1939 – August 26, 2010) was an American electrical engineer and NASA astronaut. Early life and education William Benjamin Lenoir was born on March 14, 1939, in Miami, Florida as a son of Samuel Sta ...

, would have performed some scientific research and closed out the station until the

Space Shuttle The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program na ...

was operational. However, the extension of Skylab 4 from fifty-six to eighty-four days obviated the need for the additional mission. AS 209 and CSM 119 were later used as a backup to the ASTP mission. Both are now on display at the

Kennedy Space Center Visitor Complex The Kennedy Space Center Visitor Complex is the visitor center at NASA's Kennedy Space Center on Merritt Island, Florida. It features exhibits and displays, historic spacecraft and memorabilia, shows, two IMAX theaters, and a range of bus tour ...

. 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 sitting untouched for over 30 years, NASA engineers used the command module for studies on the spacecraft's life-support adapter assembly
Using History to Design the Future
NASA, retrieved March 9, 2011 – 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 Orion (officially Orion Multi-Purpose Crew Vehicle or Orion MPCV) is a Reusable spacecraft, partially reusable crewed spacecraft used in NASA's Artemis program. The spacecraft consists of a Crew Module (CM) space capsule designed by Lockheed ...

, which resembles the Skylab Rescue configuration.

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

missions:

STS-5 STS-5 was the fifth NASA Space Shuttle mission and the fifth flight of the Space Shuttle Columbia, Space Shuttle ''Columbia''. It launched on November 11, 1982, and landed five days later on November 16, 1982. STS-5 was the first Space Shuttle ...

in 1982,

STS-41-B STS-41-B was the tenth NASA Space Shuttle mission and the fourth flight of the . It launched on 3 February 1984, and landed on 11 February 1984 after deploying two communications satellites. It was also notable for including the first untethere ...

in 1984, and

STS-35 STS-35 was the tenth flight of Space Shuttle ''Columbia'', the 38th shuttle flight, and a mission devoted to astronomical observations with ASTRO-1, a Spacelab observatory consisting of four telescopes. The mission launched from Kennedy Spac ...

in 1990. Lind would wait another decade before he flew as a Mission Specialist on

STS-51-B STS-51-B was the 17th flight of NASA's Space Shuttle program, and the seventh flight of Space Shuttle ''Challenger''. The launch of ''Challenger'' on April 29, 1985, was delayed by 2 minutes and 18 seconds, due to a launch processing failure ...

in 1985.

References

External links

Skylab Rescue Space Vehicle Countdown

Skylab Rescue Space Vehicle flight readiness test

Skylab Rescue Space Vehicle OAT no. 1 plugs in test

Launch vehicle test and checkout plan – Volume 2: Saturn 1B launch vehicle Skylab R (rescue) and AS-208 flow plan and listings

Skylab hardware evaluation CSM rescue

Structural analysis Skylab spacecraft. Addendum A: Rescue vehicle
{{NASA space program Skylab program 1973 in spaceflight