RCS in Prometheus

[javablue]

I have a question about the use of RCS thrusters in the film Prometheus and I thought someone on here might be able to help me.

When the spaceship is landing on the moon, it begins a touchdown sequence starting at five. So it goes:

"Bringing her down in five."

"Preparing RCS thrusters."

"Four"

Continues count until touchdown.

Is this situation appropriate for use of RCS thrusters? My reading of it says no but I also read that the Harrier Jump Jet also uses something similar to RCS. I thought RCS thruster were applied only to space craft. In the movie it sounds like the pilot is confusing RCS thrusters with the main landing thrusters.

Sorry if my question is a bit trivial for this site.

Thx.

[Grover]

Prometheus - probably inaccurate, but ive never seen the film.

Harrier - its low speed maneoivreability (when hovering and control surfaces are useless) is given by small jets around the craft which blast hot air, in a similar way that RCS is used on spacecraft, though compressed air from the engines is used rather thab monopropellant

[razark]

Haven't seen the movie, so I can't say for certain.

RCS could be used if they need to quickly adjust attitude during landing. If they were to land on a slope, or a landing leg was coming down on a large rock, RCS might be needed to keep the ship upright. The Harrier uses its system to control attitude because the control surfaces don't work in hovering or slow flight. High altitude aircraft that travel in very thin atmosphere, such as the X-15 or NF-104 would also use RCS systems to maintain control.

[AlexinTokyo]

RCS use during landing is seemingly fairly common in KSP, either to fine tune out horizontal velocity or for last-minute terrain avoidance.

I don't know if it is/has been used for landing of spacecraft in RL, but I suspect someone will be along to tell us fairly soon.

[Galacticruler]

I don't know if it is/has been used for landing of spacecraft in RL, but I suspect someone will be along to tell us fairly soon.

Not from my moderate knowledge of landings.

I know that it actually makes sense for them to use RCS thrusters to stabilize a ship the size of the one in Prometheus, It didn't look too well balanced before the engines went into landing leg mode.