New Concept in High Reliability Tape Recorders for Spaceborne Data Storage

Abstract

The need for large bit capacity in on-board data storage for deep-space probes, spacecraft, satellites, and aircraft, has created a requirement for a tape recorder of ultra-high reliability. In an ideal recorder, the conventional capstan would be eliminated and the reels would be driven such that the linear velocity and the tension of the tape between reels would be constant from the beginning to the end of the reel. The heads would also be the only elements in contact with the tape. Reliability would be enhanced by driving the reels, rather than the tape, through a reduction in the number of moving parts. Reducing the number of elements in contact with the tape would also increase tape life. The Iso-Elastic Drive, closely approaches the ideal recorder drive system. The reels are driven by a seamless polyester belt which is in direct contact with the periphery of the tape reel. The belt is driven at constant linear velocity (resulting in low flutter) and in such a manner that it generates a constant tension in the tape connecting the two reels and passing across the heads. Constant tape tension in a high-reliability recorder is necessary in order to optimize 1) tape tracking and guidance, 2) effective bias level on the tape during direct-type recording, 3) playback level, 4) head wear, and 5) drop-outs. The Iso-Elastic Drive reduces the number of moving parts by approximately 30% as compared with conventional recorders. The tape drive has the additional desirable characteristic of operation equally well in either direction.