Ground-based astronomical instrument for planetary protection

Abstract

Planetary protection consists of the measurement and characterization of near-earth objects including earth threatening asteroids and earth orbiting debris. The Lockheed Martin STAR Labs in Palo Alto California is developing new astronomical instruments for use in planetary protection. The observation of asteroids is standard for astronomical facilities and there are available instruments designed with this specific science mission in mind. Orbital debris observation and characterization has a somewhat different set of requirements and includes large fields of view with simultaneous spectro-polarimetric data on multiple closely spaced objects. Orbital debris is comprised of spent rocket bodies, rocket fairing covers, paint chips, various satellite components, debris from satellite collisions and explosions and nonoperational satellites. The debris is present in all orbital planes from Low Earth orbit out to the geosynchronous graveyard orbit. We concentrate our effort on the geosynchronous and nearby orbits. This is because typical groundbased astronomical telescopes are built to track at sidereal rates and not at the 1 degree per second rates that are required to track low earth orbiting objects. The orbital debris materials include aluminum, mylar, solar cell materials, composite matrix material and other materials that are used in the fabrication of satellites and launch vehicles. These materials typically have spectral features in different wavebands than asteroids which are mostly composed of materials with molecular absorption bands such as in H2O. This will drive an orbital debris material identification instrument to wavebands and resolutions that are typically not used in asteroid observations.