Wake vacuum measurement and analysis for the wake shield facility free flying platform

• Published in: Vacuum 2001-11, Vol.64 (2), p.119-144
• Main Authors: Strozier, J.A, Sterling, M, Schultz, J.A, Ignatiev, A
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Physics; Vacuum apparatus and techniques
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/S0042-207X(01)00383-9

We report here the temperature and pressure measurements recorded on the Wake Shield Facility (WSF) during the two flights in which it was a free flyer in low earth orbit. The WSF is a disk-shaped platform on which are attached, on the wake side, apparatus necessary for the epitaxial growth of thin film materials. Previous calculations suggest that the pressure on the wake side could be decreased by some 6 orders of magnitude over the ambient pressure in low earth orbit (from 10 −8 to 10 −14 Torr). Analysis of the pressure and temperature data gathered from the two flights and presented here concludes that the decrease was some 2 orders of magnitude or 4 orders of magnitude less than expected. Reasons for this discrepancy are proposed and it is suggested that the original pressure values could be reached if, prior to growth, the WSF was sufficiently outgassed.