Engineering topics

Stewart, Alan F.

Publications and source records attributed to Stewart, Alan F..

3 records

NASA NTRS2013

Further Analysis of Materials Exposed on MISSE-6 and-7B

Materials samples were exposed to the low Earth orbit (LEO) environment as part of the MISSE- 6 and -7B flight experiments. Optical properties, thickness/mass loss, surface elemental analysis, visual and microscopic analysis for surface change are some of the techniques employed in this investigation. Effects of molecular contamination are discussed. Where possible, the MISSE-6 and -7B results are compared to analyses from other LEO experiments.

Finckenor, Miria↗

NASA NTRS2012

Post Flight Analysis of Optical Specimens from MISSE7

More than 100 optical specimens were flown on the MISSE7 platform. These included bare substrates in addition to coatings designed to exhibit clearly defined or enhanced sensitivity to the accumulation of contamination. Measurements were performed using spectrophotometers operating from the UV through the IR as well as ellipsometry. Results will be presented in addition to discussion of the best options for design of samples for future exposure experiments.

Stewart, Alan F.↗

NASA NTRS2006

Optical Coatings and Surfaces in Space: MISSE

The space environment presents some unique problems for optics. Components must be designed to survive variations in temperature, exposure to ultraviolet, particle radiation, atomic oxygen and contamination from the immediate environment. To determine the importance of these phenomena, a series of passive exposure experiments have been conducted which included, among others, the Long Duration Exposure Facility (LDEF, 1985- 1990), the Passive Optical Sample Assembly (POSA, 1996- 1997) and most recently, the Materials on the International Space Station Experiment (MISSE, 2001 - 2005). The MISSE program benefited greatly from past experience so that at the conclusion of this 4 year mission, samples which remained intact were in remarkable condition. This study will review data from different aspects of this experiment with emphasis on optical properties and performance.

Stewart, Alan F.↗