Reaction Control System

The Reaction Control System (RCS ) is used to control a spacecraft outside the dense atmosphere with attitude control thrusters, there are aerodynamic control surfaces, such as those used in aircraft for position control ineffective here. It allows the orientation of the spacecraft along all three axes in space.

Control principle

As for the control in orbit only the inertia of the spacecraft is to be overcome, only small control forces are needed in comparison to atmospheric flight. The control of the orbiter through the RCS by short, shock-like firings, giving the spacecraft a pulse in the opposite direction of the ejected from the RCS gas. Wherein the initiated movement is terminated by a return pulse when it reaches the desired position. This brake ignition has to exercise as the first, but in the opposite direction exactly the same acceleration on the spacecraft. Any change in position so requires at least two firings of the attitude control jets.

Space Shuttle

For complete position control when the Space Shuttle Reaction Control System Orbital Maneuvering nor by the system (OMS ) is added, which allows the change of the orbital altitude. The overall system allows the orientation and movement of the shuttle along all three axes in space.

The Space Shuttle RCS consists of 44 different rocket engines thrust, which are grouped into three groups: below the two OMS engines, there is one block of 14 nozzles and 16 motors are housed in the Orbiternase. 38 in addition to the main units, which have a pushing force of 3.9 kN, there are six smaller nozzles ( two per group RCS ) only 106.8 Newton thrust. These are used for fine control.

History

In early X - programs of the U.S. Air Force similar systems have been tried. The North American X-15 already had a working posture control system because it was designed for a flight to the limit of the atmosphere.