A Caltech Library Service

Solar Particle Induced Upsets in the TDRS-1 Attitude Control System RAM During the October 1989 Solar Particle Events

Croley, D. R. and Garrett, H. B. and Murphy, G. B. and Garrard, T. L. (1995) Solar Particle Induced Upsets in the TDRS-1 Attitude Control System RAM During the October 1989 Solar Particle Events. IEEE Transactions on Nuclear Science, 42 (5). pp. 1489-1496. ISSN 0018-9499. doi:10.1109/23.467946.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


The three large solar particle events, beginning on October 19, 1989 and lasting approximately six days, were characterized by high fluences of solar protons and heavy ions at 1 AU. During these events, an abnormally large number of upsets (243) were observed in the random access memory of the attitude control system (ACS) control processing electronics (CPE) on-board the geosynchronous TDRS-1 (Telemetry and Data Relay Satellite). The RAM unit affected was composed of eight Fairchild 93L422 memory chips. The Galileo spacecraft, launched on October 18, 1989 (one day prior to the solar particle events) observed the fluxes of heavy ions experienced by TDRS-1. Two solid-state detector telescopes on-board Galileo designed to measure heavy ion species and energy, were turned on during time periods within each of the three separate events. The heavy ion data have been modeled and the time history of the events reconstructed to estimate heavy ion fluences. These fluences were converted to effective LET spectra after transport through the estimated shielding distribution around the TDRS-1 ACS system. The number of single event upsets (SEU) expected was calculated by integrating the measured cross section for the Fairchild 93L422 memory chip with average effective LET spectrum. The expected number of heavy ion induced SEUs calculated was 176. GOES-7 proton data, observed during the solar particle events, were used to estimate the number of proton-induced SEUs by integrating the proton fluence spectrum incident on the memory chips, with the two-parameter Bendel cross section for proton SEU's. The proton fluence spectrum at the device level was gotten by transporting the protons through the estimated shielding distribution. The number of calculated proton-induced SEU’s was 72, yielding a total of 248 predicted SEU’s, very close to the 243 observed SEU’s. These calculations uniquely demonstrate the roles that solar heavy ions and protons played in the production of SEU’s during the October 1989 solar particle events.

Item Type:Article
Related URLs:
URLURL TypeDescription
Additional Information:© Copyright 1995 IEEE. Manuscript received July 22, 1993; revised August 22, 1994 and March 21, 1995. This work was supported by the Jet Propulsion Laboratory, California Institute of Technology under contract to The National Aeronautics and Space Administration.
Group:Space Radiation Laboratory
Funding AgencyGrant Number
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Space Radiation Laboratory1995-43
Issue or Number:5
Record Number:CaltechAUTHORS:20140624-135742495
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:46479
Deposited By: Deborah Miles
Deposited On:25 Jun 2014 00:52
Last Modified:10 Nov 2021 17:26

Repository Staff Only: item control page