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Do rcs perform well in the presence of high aerodynamic forces?

nik
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    Welcome, your question seems to be lacking information that would allow it to be answered. An arbitrarily large RCS could handle 'high' aerodynamic forces. Suggest editing the question to either ask how a known craft with complex loads (EG space shuttle) achieved control or ask for details on existing RCS system mass and performance. – GremlinWranger Dec 04 '21 at 11:00
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    Before editing your question suggest checking the following https://space.stackexchange.com/a/8433/26356, https://space.stackexchange.com/q/43762/26356 and https://space.stackexchange.com/q/49772/26356 – GremlinWranger Dec 04 '21 at 11:12
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    It's been used a lot, so somebody thought so https://space.stackexchange.com/a/20759/6944 https://space.stackexchange.com/a/56035/6944 – Organic Marble Dec 04 '21 at 13:35
  • @GremlinWranger shuttle didn't use RCS "during the atmospheric phase of the launch vehicle" except in some exotic multi-engine-out and/or propellant dump scenarios. – Organic Marble Dec 04 '21 at 14:31
  • Easier to use aerodynamic surfaces and/or gimbal the main engine for thrust vectoring than use rcs for the ascent stage. – Innovine Dec 04 '21 at 19:13
  • @Innovine unless you only have one main engine, then roll is problematic. – Organic Marble Dec 04 '21 at 20:38
  • Roll isn't essential to ascent. Maybe if you have antenna only on one side of your spacecraft, or if you have aerodynamic control, but otherwise its not of much use. Pretty sure you could design around it. – Innovine Dec 05 '21 at 08:54
  • @Innovine ok https://external-preview.redd.it/I7VrWhNC1Wt_1JqUIGCw1KF4Yf3DvWzLPnJjk9JTKJ8.gif?format=mp4&s=bf91c4b46bd5e97ea3a1c7d0506daf664fb1536e – Organic Marble Dec 05 '21 at 14:55

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RCS of any sort loses ISP in atmosphere, and thus thrust, the same as any rocket engine (because that's all they are).

However they will only become completely ineffective if the apparent pressure on them is greater than their chamber pressure, which never happens.

What is more of a concern is sizing the RCS to be strong enough to overpower the sum of the aerodynamic forces on the vehicle, which can be huge.

Realistically, aerodynamically active surfaces are much more practical in the atmosphere. Whether they be fins, or gridfins, or static surfaces(wings) or dynamic surfaces like the Starship's , erm,... flaperons (or whatever they've settled on calling those things)

Example: the X-15 plane used aero surfaces for control while in enough atmosphere to do so, and only when so high that the air was too thin, did it rely on its RCS for control.

CuteKItty_pleaseStopBArking
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