William G. Tanner

Description of the COMRADE experiment

The COMRADE experiment is designed to return minimally degraded particles to Earth along with complete in‐situ information concerning mass, velocity, and trajectory of encountered particles. The objectives of the program are very diverse. A set of flight‐tested active detectors will be combined in an array to identify some of the physical properties of an incident grain, e.g., velocity vector, momentum, mass. The use of passive detectors gives access to the chemical and isotopic properties of the grains in the micron size range. We are also concerned simultaneously with a destructive capture, using metallic collectors, and a nondestructive capture, using a new low density target in which the impacting grains are captured, practically intact.

IMPA:Ct--in-situ monitors of the particulate ambient: circumterrestrial--an international consortium of instrument suppliers

The Industry and University participants listed above have joined together to form the IMPA:Ct consortium, which offers a broad range of flight qualified technologies for real time monitoring of small particles, 0.1 micron to 10 cm, in the space environment. Instruments are available in 12 months or less at costs ranging from 0.5 to 1.5 million dollars (US) for the total program. Detector technologies represented by these groups are: impact-induced capacitor-discharge (MOS, metal-oxide-silicon), cratering or penetration of electroactive thin film (polyvinylidene fluoride), impact-plasma detection, acoustic detection, ccd tracking of optical scatter of sunlight, and photodiode detection of optical scatter of laser light. The operational characteristics, general spacecraft interface and resource requirements (mass/power/telemetry), cost and delivery schedules, and points of contact for 7 different instruments are presented.