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Answers Your Questions

From: Edwin Proctor, of McFarland, Wis.
To: Kelly Beck, flight director


Question: On launch, I hear the calls "Press to MECO." I understand MECO is Main Engine Cut Off. I have looked in the file and can not find "PRESS." What does "PRESS" (PRS, PRSS or whatever) stand for? Thanks.

Answer: Good question! During the short-duration, highly dynamic launch phase, the crew receives information from the ground concerning, among other things, abort boundaries -- points at which certain abort options become or are no longer available. To speed this communication, many of these standard calls are abbreviated to short phrases and acronyms. "Press to MECO" is one of these abort boundary calls and is defined as the point in the ascent at which the shuttle can still attain the minimum MECO targets (altitude and velocity) needed for reaching orbit after sustaining loss of one of the three main engines. You may also have heard the call "Single Engine Press to MECO," which, similar to the above call, means that orbit can now be reached on only one main engine.

Kevin McCluney
Ascent/Entry Mechanical Systems


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Curator: Kim Dismukes | Responsible NASA Official: John Ira Petty | Updated: 06/11/2002
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