- Transposition, docking, and extraction
Transposition, docking, and extraction (abbreviated to TD&E, often just transposition and docking) is a
space rendezvous maneuver performed during the Apollo lunar missions of the1960 s and 70s. It was performed after thetrans lunar injection burn that placed theApollo spacecraft on the trajectory towards the moon, but before reaching theMoon or attaininglunar orbit .Performing TD&E
It was performed by the Command Module pilot (although as a contingency, the Lunar Module pilot and commander were also trained to perform the maneuver), and involved separating the CSM from the Lunar Module, yawing the CSM 180° to reattach the two spacecraft, by inserting a probe on the CSM into the Lunar Module. Then, the Apollo spacecraft stack would separate from the LM container of on the
S-IVB , which would then either continue on to aheliocentric orbit or be deliberately steered into a crash landing on the Moon.Missions
[
TD&E onApollo 15 , performed by Al Worden]TD&E was performed on all Apollo missions from
Apollo 9 onward, as these flights carried the LM. The maneuver was first practiced on the earth-orbitingApollo 7 flight, but the S-IVB utlized 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 withApollo 8 when the fairing "petals" would fall away from the S-IVB. [cite web|url=http://answers.yahoo.com/question/index?qid=20080204180730AAOZMKu|title=Why did the Apollo 7 and 8 missions not have to make the 'transposition and docking manoeuvre'?|publisher=Yahoo! Answers |date=February 2008|accessdate=2008-05-29]The last mission to use the TD&E maneuver was the
Apollo-Soyuz Test Project mission in which the Apollo CSM used the procedure to extract the docking adapter used to link up the Apollo and Soyuz 19 spacecraft in the first, and only joint mission between the U.S. and theSoviet Union (although there would be much future cooperation in space between the "post-Soviet"Roskosmos andNASA ).References
ee also
*
Manned Venus Flyby - a TD&E maneuver would also have been required on this missionExternal links
* [http://history.nasa.gov/ap15fj/03tde.htm Apollo 15 Flight Journal: Transposition, Docking and Extraction]
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