Summary of the CTS Transient Event Counter Data after One Year of Operation

A spacecraft electrical system transient detector has been operating on the joint Canadian-American Communications Technology Satellite (CTS), now called Hermes, since January 31, 1976. This detector, called the transient event counter (TEC), senses and counts transients having a minimum amplitude o...

Full description

Saved in:
Bibliographic Details
Published in:IEEE transactions on nuclear science 1977-12, Vol.24 (6), p.2270-2275
Main Authors: Stevens, N. John, Klinect, Vernon W., Gore, J. Victor
Format: Article
Language:English
Subjects:
Aircraft manufacture
Communications technology
Counting circuits
Detectors
Electromagnetic coupling
Satellites
Space vehicles
Surface charging
Surface discharges
Wiring
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A spacecraft electrical system transient detector has been operating on the joint Canadian-American Communications Technology Satellite (CTS), now called Hermes, since January 31, 1976. This detector, called the transient event counter (TEC), senses and counts transients having a minimum amplitude of 5 volts and a rise time of less than 0.3 μsec. The transients in three separate wiring harnesses are counted: the attitude control harness, the solar array instrumentation harness and the solar array power harness. Recently, anomalous behavior of geosynchronous satellites has been attributed to the electrostatic charging of spacecraft surfaces by the environment during geomagnetic substorms. Insulating surface materials subjected to high electrical stress by such charging can discharge through electrical arcing. It is believed that the electromagnetic pulses from such discharges can couple into the spacecraft wiring harnesses and result in uncommanded switching of logic circuits, which in turn is responsible for the observed anomalies. The function of the TEC is to count such transients. This report describes the TEC and presents the flight data for a year of operation. A large number of transients have occurred but these have not caused any anomalous electronic switching events in the satellite systems. The character of the transients seems to imply that additional sensors are required to understand the discharge phenomenon on large satellites. The results of this experiment indicate that satellite system immunity to discharge-related electronic switching anomalies can be obtained by filtering out the harness transients.
ISSN:0018-9499
1558-1578
DOI:10.1109/TNS.1977.4329205