Micro-Particle Impact Detector Experiment on MightySat I

This is a AIR FORCE RESEARCH LAB KIRTLAND AFB NMSPACE VEHICLES DIRECTORATE report procured by the Pentagon and made available for public release. It has been reproduced in the best form available to the Pentagon. It is not spiral-bound, but rather assembled with Velobinding in a soft, white linen cover. The Storming Media report number is A690143. The abstract provided by the Pentagon follows: The purpose of this paper is to present an engineering design of a spaceborne Micro Particle Impact Detector (MPID) experiment. This experiment is manifested on an Air Force Research Laboratory spacecraft called MightySat I scheduled for launch in July 1998. A follow on report will present the resulting particle impact data. The objective of this experiment is to measure direction and time of impact of spaceborne micron size particles with time of impact resolution of 0.1 s. The primary element in this experiment consists of two Metal Oxide Semiconductor (MOS) discharge capacitor detectors that discharge upon hypervelocity particle impact. These detectors were developed by Prof. J.J. Wortman from North Carolina State University. Each MOS particle detector is 3 in x 11/2 inches and approximately 0.013 in thick. Each particle detector is bonded to a detector assembly that is in turn mechanically fastened to the external bottom plate of the MightySat I spacecraft. The detector assembly and associated electronics weigh less than 0.4 lb and have a total impact sensing area of 3.7 in 2. Each particle impact causes an impact event record to be stored in the spacecraft control unit for later downlink. Each impact event record will store time of impact and output from two coarse sun sensors. Data from the coarse sun sensors is used to help determine attitude of the spacecraft. The Air Force Research Laboratory MightySat I spacecraft is a 6-sided composite structure, 20. 5 in (height) by 19.0 in (diameter), 150 lb., and spin stabilized with 5 degree attitude knowledge.