Wegrich, R. D. | Search NASA

NASA NTRS1992

Space Station Freedom thermal control and life support system design

The Space Station Freedom thermal control system (TCS) and environmental control and life support system (ECLSS) are reviewed. Differences in the TCS and ECLSS are discussed between the early man-tended configuration (MTC) compared to the eventual evolutions to the permanently manned configuration (PMC). Concurrent analytical and developmental testing programs are included in the systems discussions as well as a description of an early 1993 flight test program on elements of the PMC water recovery system. Recent TCS design changes to the air cooling of rack mounted equipment are discussed. An overview of all TCS and ECLSS subsystems is included.

Wegrich, R. D.↗

NASA NTRS1983

Precise thermal control test demonstration on simulated space telescope main ring

A simulated section of the main ring of the Space Telescope, (ST) the part that holds the primary mirror, was manufactured and tested for thermal stability characteristics in a complex structural assembly. The other telescope subassemblies are also mounted on the main ring, which is constructed of a titanium alloy. The entire ring is wrapped in heater elements around the outside diameter to reduce the external temperature gradient effects by two orders of magnitude. A thermal vacuum test was performed using a stainless steel alloy tailored to represent the titanium ring's thermal characteristics. The tests examined the thermal performance and controllability of the test ring, the effects of a 24-hr slew manuever that produced worst-case environment changes, hot and cold simulation of predicted ST orbital thermal environments, and the effects of heater failure. Pointing and thermal control features were verified, but a heater failure on the 'on' side was found to quickly lead to exceeding the thermal design limits.

Bettini, R. G.↗