Evaluation of Space Enviroment
and Effects on Materials
(MIS) Archive System

Micro-Particle Impact Detector Experiment On MightySat I

Patrick J. Serna^*, Gary H. Liechty^*, Craig L.Neslen^*, Renzo Del Frate⁺, and Edwin Draper^+
*Air Force Research Laboratory, VSSE, Kirtland AFB, NM 87111
⁺Science Applications International Corp., Albuquerque, NM 87106

ABSTRACT

This experiment is manifested on an Air Force Research Laboratory spacecraft called MightySat I scheduled for launch in July 1998.

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 seconds. The primary element in this experiment consists of two Metal-Oxide-Semiconductor (MOS) discharge capacitor detectors that discharge upon hypervelocity particle impact. The detectors were developed by Prof. J.J. Wortman from North Carolina State University. Each MOS particle detector is 3 in x 1-1/2 in 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 Spacecraft. The detector assembly and associated electronics weigh less than 0.4 lb and have a total impact detection area of 3.7 in2. 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, developed largely by CTA Space Systems in McLean, VA, designed for ejection from the Space Shuttle 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. The MightySat I spacecraft is scheduled for orbit injection using a standard hitchhiker ejection system from space shuttle flight STS-88. Because this experiment has not yet flown, particle impact data is unavailable at this time. However, a follow-on report will present the resulting particle impact data.

EXPERIMENT CONFIGURATION

This experiment configuration consists of two distinct parts: the electronic board and the micro-particle detector assembly. The electronic board consists of a dc-dc converter section, detector bias section, and output conditioning section. The detector assembly consists of the micro-particle detector and an aluminum mount frame.

The electronic board was fastened to the side of the spacecraft power switching unit which is mounted to the bottom, inside surface of the spacecraft. Figure 1 shows the mounted electronic board with respect to the spacecraft coordinate system. The electronic board is not encapsulated in a separate enclosure but open to the local spacecraft environment. The detector assembly was mounted to the bottom, outside surface of the spacecraft so that the impact detecting surface is in the -Z direction. Figure 2 shows a plan view of the locations of the two micro-particle detector assemblies.

The spacecraft will be spin stabilized and will rotate about the Y axis.

1. Davis, R.J., Monahan, J.F., Itchkawich T.J., Mighty Sat I: Technology In Space For About A Nickel ($M), American Institute of Aeronautics and Astronautics, Tenth Annual AIAA/USU Conference on Small Satellites, 16-19 Sep 96, Logan, Utah
2. Santiago, J.G., A Thermal Analysis Of The Micro-Particle Impact Detector (MPID), Aerospace Technical Memorandum, ATM Number 97 (1212-02)-1, The Aerospace Corporation, P.O. Box 92957, Los Angeles, CA 90009-2957, 310-336-6707
3. Wortman J.J., Kassel P.C., Metal-Oxide-Silicon Capacitor Detectors for Measuring Micrometeoroid and Space Debris Flux, Journal of Spacecraft and Rockets, 1994, Electrical and Computer Engineering Department, North Carolina State University, Raleigh, NC 27695
4. Kassel P.C., Characteristics of Capacitor-Type Micrometeoroid Flux Detectors When Impacted With Simulated Micrometeoroids, Langley Research Center, National Aeronautics and Space Administration, Hampton, VA 23665, NASA TN D-7359
5. Neslen C.L., MPID Qualification Electronic Board Thermal Cycle Test Report, 29-30 Oct 96, Phillips Laboratory/SXE, Aerospace Engineering Facility, 3550 Aberdeen, Ave, SE, Kirtland AFB, NM 87117, Document Number 96-009-290-003
6. Neslen C.L., MPID Flight Electronic Board Thermal Cycle Test Report, 29-30 Oct 96, Phillips Laboratory/SXE, Aerospace Engineering Facility, 3550 Aberdeen, Ave, SE,Kirtland AFB, NM 87117, Document Number 96-009-290-002
7. 1992 Goddard SFC Hitchhiker CARS, Document Number HHG-730-1503-06, Goddard Space Flight Center,Greenbelt, MD 20771
8. Neslen C.L., MPID Flight Electronic Board Vibration Test Report, 13 Nov 96, Phillips Laboratory/SXE, Aerospace Engineering Facility, 3550 Aberdeen, Ave, SE,Kirtland AFB, NM 87117, Document Number 96-009-290-004
9. Neslen C.L., MPID Qualification Electronic Board Vibration Test Report, 12 Nov 96, Phillips Laboratory/SXE, Aerospace Engineering Facility, 3550 Aberdeen, Ave, SE,Kirtland AFB, NM 87117, Document Number 96-009-290-005
10. Neslen C.L., MPID Program Detector Vibration Test, 8 Jan 97, Phillips Laboratory/SXE,Aerospace Engineering Facility, 3550 Aberdeen, Ave, SE, Kirtland AFB, NM87117, Document Number 96-009-290-007
11. Serna P.J., et al, Micro-Particle Detector Experiment on MightySat I, Phillips Laboratory Technical Report, PL-TR-97-1071, 3550 Aberdeen SE, Kirtland AFB, NM 87117

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