A reaction control system (RCS) is a subsystem of a spacecraft whose purpose is attitude control and steering by the use of thrusters. An RCS system is capable of providing small amounts of thrust in any desired direction or combination of directions. An RCS is also capable of providing torque to allow control of rotation (roll, pitch, and yaw). This is in contrast to a spacecraft's main engine, which is only capable of providing thrust in one direction, but is much more powerful.
RCS systems often use combinations of large and smaller (vernier) thrusters, to allow different levels of response from the combination.
Reaction control systems are used:
- for attitude control during re-entry;
- for stationkeeping in orbit;
- for close maneuvering during docking procedures;
- for control of orientation, or 'pointing the nose' of the craft;
- as a backup means of deorbiting;
- for Harrier "jump jet" stabilisation during operations below stall speed.
Because spacecraft only contain a finite amount of fuel and there is little chance to refill them, some alternative reaction control systems have been developed so that fuel can be conserved. For stationkeeping, some spacecraft (particularly those in geosynchronous orbit) use high-specific impulse engines such as arcjets, ion thrusters, or Hall effect thrusters. To control orientation, a few spacecraft use momentum wheels which spin to control rotational rates on the vehicle.
Read more about Reaction Control System: Location of Thrusters On Space Capsules, Location of Thrusters On Spaceplanes
Famous quotes containing the words control system, reaction, control and/or system:
“America is not so much a nightmare as a non-dream. The American non-dream is precisely a move to wipe the dream out of existence. The dream is a spontaneous happening and therefore dangerous to a control system set up by the non-dreamers.”
—William Burroughs (b. 1914)
“More and more, when faced with the world of men, the only reaction is one of individualism. Man alone is an end unto himself. Everything one tries to do for the common good ends in failure.”
—Albert Camus (1913–1960)
“If the technology cannot shoulder the entire burden of strategic change, it nevertheless can set into motion a series of dynamics that present an important challenge to imperative control and the industrial division of labor. The more blurred the distinction between what workers know and what managers know, the more fragile and pointless any traditional relationships of domination and subordination between them will become.”
—Shoshana Zuboff (b. 1951)
“All who wish to hand down to their children that happy republican system bequeathed to them by their revolutionary fathers, must now take their stand against this consolidating, corrupting money power, and put it down, or their children will become hewers of wood and drawers of water to this aristocratic ragocracy.”
—Andrew Jackson (1767–1845)