Accession Number:

ADA175409

Title:

Development of a Monte Carlo Shuttle Contamination Model.

Descriptive Note:

Rept. for Sep 85-Sep 86,

Corporate Author:

SPECTRAL SCIENCES INC BURLINGTON MA

Personal Author(s):

Report Date:

1986-09-30

Pagination or Media Count:

21.0

Abstract:

This is the first yearly scientific report on a three year effort to develop a Monte Carlo model of contamination for the space shuttle orbiter. Contamination of instruments on the space shuttle orbiter is an issue of major concern. The shuttle gives off matter through surface outgassing, via various thrusters and from flash evaporators. At altitudes where the atmospheric mean free path is comparable to or less than shuttle dimensions, the deposition back onto shuttle-borne instruments will be largely determined by the multiple collision environment surrounding the shuttle. Even at higher altitudes, this may be the dominant source of contaminants for some portions of the shuttle. In addition to physical contamination of shuttle surfaces, radiation contamination, is also a potential problem as gases surrounding the shuttle collide at high speed with atmospheric molecules. These energetic collisions can lead to vibrational excitation and subsequent radiative decay. A similar issue of some concern is the presence of ions in the vicinity of the shuttle which can possibly be produced via the critical ionization velocity effect. Ions in the shuttle environment may remain there for some time due to electric field forces, and radiative recombination is another potential source of radiation contamination.

Subject Categories:

  • Astronautics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE