Measurement of Optical Radiations in Spacecraft Environments
Abstract
Three topics in remote sensing of the gaseous and particulate environment of spacecraft are reported and several further optical contamination and induced-glow phenomenology issues now under consideration are briefly reviewed. The transmission to ground stations of the near-ultraviolet radiation from OH* excited when high-kinetic energy water molecules in thruster rocket exhaust react with the ambient oxygen atoms is calculated from band and atmosphere models, and the measurement signal/noise is shown to depend on the concentrations of both (UV-absorbing) ozone molecules and (UV sky background- producing) O atoms along the view path as well as on the spatial distribution of radiance from the exoatmospheric collision volume. Vacuum-ultraviolet photolysis of water vapor off spacecraft with radiometry of the resulting electronically- excited, microsecond lifetime hydroxyl radicals is shown to be a feasible means for determining its rates of offgassing, and preliminary designs for such active probes are presented. An initial review of the potential for identification of spaceborne particulates from their chemical composition-dependent scattering and emission of visible and infrared quanta indicates these synthetic (instrument response-convolved) spectra of candidate contaminant particles are need to evaluate the concept. Keywords: Rocket exhaust gases; Volume; Space shuttle; Spacecraft rams; Atmospheric limb; Video images; Infrared images; Spacecraft dumping; Water dumping; Spacecraft contamination; Optical glows; Radiometry.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 15, 1989
- Accession Number
- ADA213814
Entities
People
- C. A. Trowbridge
- I. L. Kofsky
- M. A. Maris
- Nghi H. Tran