NASP vehicle interactions and signatures above 100 kilometers
Abstract
As hypersonic space vehicles (such as the NASP X-30 Research Vehicle) traverse the 80-300 km altitude range, a variety of phenomena will arise from the interaction of the spacecraft with the residual atmosphere. Across this altitude regime, the flow surrounding the vehicle makes a transition from continuum to free molecular. A simple modeling effort is presented to quantify the variety of processes likely to occur. For example, communications will be severely hampered by the enhanced plasma cloud created at lower altitudes. Optical emissions will be generated in the high-velocity collisions of the atmospheric O, N2, and O2 with the vehicle surfaces and with outgassed molecules, transpired coolant, exhausts, and reflected atmospheric species. We have developed elementary gas kinetic descriptions of the flowfield and interaction lengths surrounding the lifting body vehicle. This information and assumed radiative efficiencies permitted predictions of relative radiance as a function of altitude. Quantitative predictions of the emissions from the ultraviolet through infrared spectral regions will occur and will result in decreased visibility of remote emission features. The local interaction radiances are sufficiently bright to obscure emission from the upper atmosphere and will even substantially obscure the hard Earth in certain bands.
- Publication:
-
Journal of Spacecraft and Rockets
- Pub Date:
- March 1994
- DOI:
- 10.2514/3.26427
- Bibcode:
- 1994JSpRo..31..231G
- Keywords:
-
- Aerospace Planes;
- National Aerospace Plane Program;
- Spectral Bands;
- Spectral Signatures;
- Radiance;
- Upper Atmosphere;
- Visibility;
- Spacecraft Design, Testing and Performance