The feedback hardware includes three independent tachometers that close the feedback loop through a failure tolerant voting circuit with independently set able speed limits. The room speed can also be controlled by a 0 to 10 volt external speed reference. The external reference, when used, usually comes from an onboard computer, which provides the speed reference signal through slip rings. This is necessary when one computer must control both the onboard experiment and the speed of the room, or when the speed of the room must be contingent on the subject's responses. The dedicated computer usually controls room speed through previously programed speed profiles.
Feedback control ensures a constant room speed while people or objects are moving within the room.
The room can also be sinusoidally oscillated over a wide range of frequencies. The computer control of the slow rotation room is monitored by a trained operator in the control room, who also monitors the onboard experiments through onboard video cameras and microphones. The floor of the room is laid out with a 20 inch grid for securing apparatus. The grid pattern and screw thread are compatible with that of NASA's KC-135, reduced gravity test aircraft so that consoles can be interchanged between the test facilities. The floor layout of the room is illustrated in Figures 1 and 2.