Saturn 1B flight data recorder, measuring 7.5˝ x 3.25˝ x 9˝, with a Ralph M. Parsons Company labels applied to the front and top panels: "Model: AIR-940, Part No. 930800-6, Serial No. 1095, Customer Spec. A50C60016 Rev. 0, Contract No. NAS8-4016." Included in this contract was flight dynamics analysis of AS-204/LM-1 which involved much telemetry of flight parameters. To provide a record of the telemetry for transmission when receiving stations were in range, the Saturn 1B had several tape recorders for telemetry (as described in the 'Consolidated Instrumentation Plan for AS-204/LM-01,' a modern printout of which is included).
This flight data recorder is marked "Engr. Test Hdw." in several places, and it has a few areas where the paint was removed for the placement of thermocouples to monitor the temperature of the recorder as it was being tested. For magnetic tape recorders, maintaining the correct tension on the tape is important for consistent recording. Earth-based recorders usually use tension arms; this method adds to the complexity (and so the weight) of the recorder. For many satellite and flight data recorders, as in this example, the tension of the tape is managed by a spring system in the hubs of the tape reels. In order to reduce its size, this recorder uses a coaxial tape reel mechanism in which the reels are on top of each other.
