Measurement of long-term outgassing from the materials used on the MSX spacecraft

Mark T. Boies; B. David Green; Gary E. Galica; O. Manuel Uy; Richard C. Benson; David M. Silver; Bob E. Wood; Jeffrey C. Lesho; David F. Hall; James S. Dyer

doi:10.1117/12.400834

20 September 2000 Measurement of long-term outgassing from the materials used on the MSX spacecraft

Mark T. Boies, B. David Green, Gary E. Galica, O. Manuel Uy, Richard C. Benson, David M. Silver, Bob E. Wood, Jeffrey C. Lesho, David F. Hall, James S. Dyer

Author Affiliations +

Proceedings Volume 4096, Optical Systems Contamination and Degradation II: Effects, Measurements, and Control; (2000) https://doi.org/10.1117/12.400834
Event: International Symposium on Optical Science and Technology, 2000, San Diego, CA, United States

Abstract

The Midcourse Space Experiment (MSX) spacecraft was specifically designed and processed to minimize contamination. This spacecraft represents a best case scenario of spacecraft induced environment. The contamination instrument suite consisted of 10 sensors for monitoring the gaseous and particulate environment. The Total Pressure Sensor (TPS) has continuously measured the ambient local pressure surrounding MSX since its launch on April 24, 1996. The sensor's primary goal was to monitor the early mission (less than one week) ambient pressure surrounding the spacecraft's optical telescopes and to indicate when environmental conditions were acceptable for opening the protective covers. However, the instrument has illustrated that it is quite robust and has successfully measured the long-term decay of the pressure environment. The primary constituent of the atmosphere is water outgassed from the thermal blankets of the spacecraft. The water-induced environment was expected to rapidly decay over the first few months to levels more closely approaching the natural environment. The data generally shows decay toward this level, however, the pressure is quite variable with time and can be influenced by discrete illumination and spacecraft orbital events. Several experiments conducted yearly indicate that the thermal blankets retain significant quantities of water. The local pressure due to water vapor is shown to increase by a factor of 100 from direct solar illumination. Moreover, the multi-layer construction of the blankets causes them to form a deep reservoir that continues to be a source of water vapor 3+ years into the mission. We will present pressure data from several experiments, each separated by one orbital year, that exhibit these water vapor induced pressure busts. The decay and longevity of these bursts will also be discussed.

Citation Download Citation

Mark T. Boies, B. David Green, Gary E. Galica, O. Manuel Uy, Richard C. Benson, David M. Silver, Bob E. Wood, Jeffrey C. Lesho, David F. Hall, and James S. Dyer "Measurement of long-term outgassing from the materials used on the MSX spacecraft", Proc. SPIE 4096, Optical Systems Contamination and Degradation II: Effects, Measurements, and Control, (20 September 2000); https://doi.org/10.1117/12.400834

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available