Determination of SPEAR-1 rocket body potential during high-voltage experiments
By: Thurston Van Horn
Contributors: Naval Postgraduate School (U.S.)
Publisher: Naval Postgraduate School
Published: 1990
Place of publication: Monterey, California
Language: eng
Number of pages: 160
Subjects: Space vehicles; Electrostatic charging
Description: The Space Power Experiment Aboard Rockets (SPEAR) 1 payload was launched on December 13, 1987. It had a primary objective of providing guidelines in designing high-voltage (HV) systems for use in Low-Earth Orbit (LEO). The experiment consisted of 24 HV bias operations using two 20 cm diameter spheres attached to the rocket by booms. The SPEAR-1 rocket charged to substantial negative potentials during the flight when the spheres were biased positive with respect to the rocket. This thesis uses the electrostatic analyzer ion data to determine the charging response of the rocket body. The peak potential was reached during a 45 kV sphere bias sequence resulting in a 17.4 kV rocket body potential at 361 km altitude. The rocket body potential varied between 7 an 38 percent of sphere potential. Geomagnetic orientation, vice altitude, had greater effect on rocket body potential. The flight data also indicated that neutral gas emissions from the rocket attitude control system (ACS) triggered transient discharge currents that effectively grounded the rocket body potential. ACS firings resulted in an order of magnitude change in the rocket body potential. Keywords: Spacecraft charging, Altitude effects, Geomagnetic orientation effects, Electrostatic analyzer, Attitude control system gas emissions. Theses. (RH)
Notes: Thesis Advisor(s): Olsen, R.C. ; Second Reader: Gnanahngham, S.

"June 1990."

Author(s) subject terms: SPEAR-1, Spacecraft Charging, Altitude Effects, Geomagnetic Orientation Effects, Electrostatic Analyzer, Altitude Control System Gas Emissions.

Description based on title screen as viewed on October 15, 2009.

DTIC Identifier(s): SPEAR(Space Power Experiment Aboard Rockets)

Thesis (M.S. in Physics)--Naval Postgraduate School, June 1990.

Includes bibliographical references (p. 153-155)

"Approved for public release, distribution unlimited"--Cover.

Also available in print.

Mode of access: World Wide Web.

System requirements: Adobe Acrobat Reader.

US Army (USA) author.

rb/rb original 10/20/09.