Open AccessSPEAR 3 flight analysis: Grounding by neutral gas release, and magnetic field effects on current distribution
Author(s) -
Mandell M. J.,
Jongeward G. A.,
Cooke D. L.,
Raitt W. J.
Publication year - 1998
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/97ja02702
Subject(s) - spear , rocket (weapon) , aerospace engineering , ground , physics , current (fluid) , altitude (triangle) , computational physics , environmental science , meteorology , engineering , geometry , mathematics , archaeology , quantum mechanics , history , thermodynamics
The Space Power Experiment Aboard Rockets (SPEAR) 3 experiment was launched on March 15, 1993, to test grounding devices for negative payloads. In this paper we review two aspects of the high‐altitude flight data and compare them with preflight predictions. The SPEAR 3 neutral gas release experiment studied a grounding mechanism observed on previous flights during attitude control system (ACS) firings. Preflight calculations using Paschen law physics generalized to three dimensions predicted that the high rate gas release (about one order of magnitude below normal ACS) would reduce the rocket potential to within 200–300 V of plasma ground. The flight data is well fit by a value of −225 V. Orientation relative to Earth's magnetic field had no effect on the floating potential or grounding operations but had a large effect on the portion of the current collected by the boom. We compare these flight measurements with preflight calculations made with the DynaPAC computer code.