TO-DATE SPACECRAFT APPLICATIONS AND DEMONSTRATION TESTING RESULTS, AND FUTURE PRODUCT DEVELOPMENT FOR NEW MOLECULAR ADSORBER TECHNOLOGIES

摘要

The use of molecular adsorbers to aid in reducing spacecraft contamination levels has recently been implemented for a number of National Aeronautics and Space Administration (NASA) missions. Molecular adsorbers are a family of inorganic materials/minerals characterized by extremely large surface area, molecularly porous substructure, and possessing charged sites capable of retaining molecular contaminant species upon contact. Adsorbent materials of this type have many non-aerospace uses, including, for example, charcoal filters to absorb smoke contaminants in room environments. This same concept has now been applied to the field of spacecraft contamination engineering. Molecular adsorbers for spacecraft applications are fabricated by combining carefully selected adsorbent material with a substrate that is both capable of bonding with the adsorbent and suitable for the desired spacecraft application/environment. Once the completed "unit" (adsorbent and substrate) has been fabricated, it is then placed in specific spacecraft locations. It has been demonstrated that the placement of molecular adsorbing materials in high-outgassing spacecraft compartments or along vent paths serves to "trap and hold" outgassed molecules, thereby eliminating them as contamination threats to other spacecraft locations. The development and qualification of this type of contamination control technique has been and is continuing to be fully explored at the NASA/Goddard Space Flight Center (GSFC) along with Swales Aerospace (SA). This technique has already been employed on two Hubble Space Telescope (HST) servicing missions, as well as for the Tropical Rainfall Measuring Mission (TRMM). The use of molecular adsorbers is being planned for future NASA spacecraft missions. In the future, the incorporation of molecular adsorbers may well be a basic element of contamination control for all spacecraft designs. The use of molecular adsorbers carries the potential for a low cost, easy to fabricate, easy to integrate, highly reliable means of reducing the overall contamination level around spacecraft. This contamination control technique can also be applied during ground testing activities.