Transposition, docking, and extraction
Encyclopedia
Transposition, docking, and extraction (abbreviated to TD&E, often just transposition and docking) is a space rendezvous
Space rendezvous
A space rendezvous is an orbital maneuver during which two spacecraft, one of which is often a space station, arrive at the same orbit and approach to a very close distance . Rendezvous requires a precise match of the orbital velocities of the two spacecraft, allowing them to remain at a constant...

 maneuver
Orbital maneuver
In spaceflight, an orbital maneuver is the use of propulsion systems to change the orbit of a spacecraft.For spacecraft far from Earth—for example those in orbits around the Sun—an orbital maneuver is called a deep-space maneuver .-delta-v:...

 performed during the Apollo lunar missions of the 1960s and 70s. It was performed after the trans lunar injection
Trans Lunar Injection
A Trans Lunar Injection is a propulsive maneuver used to set a spacecraft on a trajectory which will arrive at the Moon.Typical lunar transfer trajectories approximate Hohmann transfers, although low energy transfers have also been used in some cases, as with the Hiten probe...

 burn that placed the Apollo spacecraft
Apollo spacecraft
The Apollo spacecraft was composed of five combined parts designed to accomplish the American Apollo program's goal of landing astronauts on the Moon by the end of the 1960s and returning them safely to Earth...

 on the trajectory towards the moon, but before reaching the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 or attaining lunar orbit
Lunar orbit
In astronomy, lunar orbit refers to 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 various manned or unmanned spacecraft around the Moon...

.

Performing TD&E

It was performed by the Command Module
Apollo Command/Service Module
The Command/Service Module was one of two spacecraft, along with the Lunar Module, used for the United States Apollo program which landed astronauts on the Moon. It was built for NASA by North American Aviation...

 pilot (although as a contingency, the Lunar Module
Apollo Lunar Module
The Apollo Lunar Module was the lander portion of the Apollo spacecraft built for the US Apollo program by Grumman to carry a crew of two from lunar orbit to the surface and back...

 pilot and commander were also trained to perform the maneuver), and involved separating the CSM
Apollo Command/Service Module
The Command/Service Module was one of two spacecraft, along with the Lunar Module, used for the United States Apollo program which landed astronauts on the Moon. It was built for NASA by North American Aviation...

 from the S-IVB
S-IVB
The S-IVB was built by the Douglas Aircraft Company and served as the third stage on the Saturn V and second stage on the Saturn IB. It had one J-2 engine...

, pitching
Flight dynamics
Flight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle's center of mass, known as pitch, roll and yaw .Aerospace engineers develop control systems for...

 the CSM 180° and proceeding to dock with the Lunar Module
Apollo Lunar Module
The Apollo Lunar Module was the lander portion of the Apollo spacecraft built for the US Apollo program by Grumman to carry a crew of two from lunar orbit to the surface and back...

, by inserting a probe at the top the CSM into a drogue at the top of the Lunar Module. Then, the Apollo spacecraft stack would separate from the S-IVB
S-IVB
The S-IVB was built by the Douglas Aircraft Company and served as the third stage on the Saturn V and second stage on the Saturn IB. It had one J-2 engine...

, which would then either continue on to a heliocentric orbit
Heliocentric orbit
A heliocentric orbit is an orbit around the Sun. All planets, comets, and asteroids in our Solar System are in such orbits, as are many artificial probes and pieces of debris. The moons of planets in the Solar System, by contrast, are not in heliocentric orbits as they orbit their respective planet...

 or be deliberately steered into a crash landing on the Moon.

Missions

TD&E was performed on all Apollo missions from Apollo 9
Apollo 9
Apollo 9, the third manned mission in the American Apollo space program, was the first flight of the Command/Service Module with the Lunar Module...

 onward, as these flights carried the LM. The maneuver was first practiced on the earth-orbiting Apollo 7
Apollo 7
Apollo 7 was the first manned mission in the American Apollo space program, and the first manned US space flight after a cabin fire killed the crew of what was to have been the first manned mission, AS-204 , during a launch pad test in 1967...

 flight, but the S-IVB utilized a LM fairing adapter that did not separate from the S-IVB, thus the crew could not approach the S-IVB in fear that the adapter "petals" would strike the Apollo CSM. This was corrected with all flights commencing with Apollo 8
Apollo 8
Apollo 8, the second manned mission in the American Apollo space program, was the first human spaceflight to leave Earth orbit; the first to be captured by and escape from the gravitational field of another celestial body; and the first crewed voyage to return to Earth from another celestial...

 when the fairing "petals" would fall away from the S-IVB.

The last mission to use the TD&E maneuver was the Apollo-Soyuz Test Project
Apollo-Soyuz Test Project
-Backup crew:-Crew notes:Jack Swigert had originally been assigned as the command module pilot for the ASTP prime crew, but prior to the official announcement he was removed as punishment for his involvement in the Apollo 15 postage stamp scandal.-Soyuz crew:...

 mission in which the Apollo CSM used the procedure to extract the docking adapter used to link up the Apollo and Soyuz 19
Soyuz spacecraft
Soyuz , Union) is a series of spacecraft initially designed for the Soviet space programme by the Korolyov Design Bureau in the 1960s, and still in service today...

 spacecraft in the first, and only joint mission between the U.S. and the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 (although there would be much future cooperation in space between the post-Soviet Roskosmos and NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

).

See also

  • Manned Venus Flyby
    Manned Venus Flyby
    A manned Venus flyby was considered by NASA in the mid 1960s as part of the Apollo Applications Program, using hardware derived from the Apollo program...

    - a TD&E maneuver would also have been required on this mission

External links

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