Accession Number : ADA321639

Title :   Optical Contamination and Signatures in the Near-Space Environment.

Descriptive Note : Final rept. 18 Jun 91-18 Jun 96,

Corporate Author : PHOTOMETRICS INC WOBURN MA

Personal Author(s) : Gardner, J. A. ; Rall, D. L. ; Kofsky, I. L.

PDF Url : ADA321639

Report Date : 30 SEP 1996

Pagination or Media Count : 113

Abstract : Research supporting the USAF Phillips Laboratory Spacecraft Interactions Branch (WSAI) mission to characterize the environment of spacecraft and the interactions of their effluents with the atmosphere is reported. The principal issues investigated are optical emissions associated with spaceborne and powered suborbital vehicles; excitative reactions between neutral and ionized aeronomic and thruster associated species; and ultraviolet airglow, which besides providing critical information about thermospheric composition and transport degrades performance of surveillance systems. The work, done in collaboration with WSAI scientists between June 1991 and June 1996, is further documented in six earlier interim reports. The principal optically active gaseous effluents from Shuttle Orbiter are combustion products of its liquid bipropellant attitude and orbit controlling rocket motors (which DoD vehicles also use), and H2O evaporated from its surfaces and/or released in bulk in connection with housekeeping. The emissions, which as scene foregrounds hinder and as targets assist surveillance, include electronic and vibrational bands of these species and chemiluminescence from their reactions with the low-density atmosphere; in addition the nearby gases attenuate atmospheric and astronomical radiations. Data on these glows were obtained from both onboard and a mountaintop station (the Air Force Maui Optical Site) by the 'GLO' multichannel imaging spectrograph, several electronic array-detector cameras, and an infrared scanning spectrometer. GLO also surveyed the ^80-400 km altitude Earth limb between ^1200 and 11000A, during several-10's-hr segments of four shuttle missions that provided a range of latitude and local time distributions at these tangent intercepts.

Descriptors :   *SPACECRAFT, *OPTICAL SIGNATURES, *EXHAUST GASES, ULTRAVIOLET RADIATION, SPACE SHUTTLES, CONTAMINATION, THRUSTERS, AIRGLOW, SPECTROGRAPHS, BIPROPELLANTS, ULTRAVIOLET SPECTRA, CHEMILUMINESCENCE, COMBUSTION PRODUCTS, VERNIER ROCKET ENGINES.

Subject Categories : Optical Detection and Detectors
      Astronautics

Distribution Statement : APPROVED FOR PUBLIC RELEASE