Particle detection by optical systems on MSX

Abstract

One of the missions of the Midcourse Space Experiment (MSX) satellite, launched in April 1996, is to acquire databases of earthlimb, terrestrial, and celestial background using state-of-the-art IR, visible, and UV sensor systems. Emissions from particulate contaminants in the primary sensors fields of view can degrade these background measurements. As a result, it is important to future systems that we understand the mechanisms of particulate release and the optical emissions from particulates. Because of its five year mission life and the comprehensive suite of optical and contamination sensors, the MSX satellite offers a unique opportunity to characterize the spaceborne particulate environment. This paper presents particulate data observed in the first few months of the MSX mission. Particulate data associated with discrete events, such as sensor cover deployments and spacecraft maneuvering as well as quiescent times, are presented. Modeling of the spectral and temporal signatures of near-field particles has been performed to permit their detection and identification in the optical sensor data bases. Velocities and elementary trajectory vectors have been extracted from the images. Modeling results indicate that particle composition and trajectory (and thus orbital source of the particulate) can be extracted from the orbital observations. (Author)