Preliminary investigations into UHCRE thermal control materials
Erste Untersuchungen an UHCRE-thermischen Schutzmaterialien
This paper presents an overview of the initial work which has been done in the ESTEC Materials and Processes Division to evaluate the effect of space environment on the thermal blankets of the Ultra- Heavy Cosmic Ray Nuclei Experiment (UHCRE): 1. Preliminary survey of the perforations of the two- thirds of the thermal blanket returned to ESTEC. 2. Thermo-optical properties and thickness recessions of three samples cut from each of the third centre parts of the 16 thermal blankets were measured and effects of environments, i.e.: sun illumination and atomic oxygen fluences, evaluated. 3.Contamination has been analysed on trays, external blanket and internal aluminized Kapton foil by IR technique and SEM/EDX examination. 4. The pattern of contamination on the Al Kapton foils has been observed, sketched and related to atomic oxygen flow. 5. LDEF yaw angle misorientation has been evaluated from the contaminated areas visible on some of the trays. In addition, impacts of micrometeoroids and space debris have been experimentally simulated on spare flight thermal blankets by means of the plasma acceleration facility of the TU München and the EMI light gas gun acceleration facilities. Glass, steel and aluminium projectiles with sizes between about 50 Mym and 1 mm have been accelerated in a velocity range between 2 km/s and 10 km/s. Circular shock- induced delamination zones surrounding impact locations in the foil have been obtained.