1、Lessons Learned Entry: 1333Lesson Info:a71 Lesson Number: 1333a71 Lesson Date: 2002-11-27a71 Submitting Organization: GRCa71 Submitted by: Michael DohertySubject: Commercial Off The Shelf (COTS) Electronic Hardware Susceptibility to Radiation Description of Driving Event: The Physics of Colloids in
2、Space (PCS) experiment was launched on ISS Flight 6A in April 2001, was activated in EXPRESS Rack 2 on May 31, 2001, and was successfully operated on the International Space Station (ISS) until February 24, 2002. On February 24, 2002, at the onset of a scheduled operational run on ISS, the PCS fligh
3、t system computer (within the PCS Avionics Section) failed to boot up. On-orbit recovery efforts were undertaken but were unsuccessful. The Avionics Section was removed and brought back on ISS Flight UF-2.Lesson(s) Learned: A detailed hardware inspection and troubleshooting process was initiated on
4、the Avionics Section. The Project asserts with a measure of confidence that the on-orbit failure of the PCS experiment was due to a Single Event Effect (radiation event) on the Single Board Computers CMOS (i.e., the battery-backed Random Access Memory). Commercial Off The Shelf (COTS) electronic har
5、dware memory devices deployed on ISS can be highly susceptible to space radiation effects.Recommendation(s): One response to this lesson is, where vulnerabilities have been identified, to deploy radiation hardened solutions. For reflight, PCS will employ a Programmable Read-Only Memory (PROM) device
6、 for storage of Basic Input Output System (BIOS) application and parameters, a technology that is much less susceptible to Single Event Effects than either CMOS or flash memory technologies.Specifically, the solution being pursued by the Project to reduce the vulnerability of the BIOS is to have the
7、 Original Equipment Manufacturer of the original Single Board Computer create a customized BIOS application that will force a boot-up using BIOS parameters stored in Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Programmable Read-Only Memory (PROM)
8、 technology. PROM memory technology is far less susceptible to radiation events than either CMOS or flash memory. The PCS BIOS program and the BIOS parameters themselves will be ”burned” into a One Time Programmable- Programmable Read-Only Memory (OTP-EPROM) device. Storing all BIOS parameters in OT
9、P-EPROM will then effectively bypass CMOS as a storage location for the PCS startup parameters and also provide a far less susceptible storage location than flash memory for the BIOS application itself.Evidence of Recurrence Control Effectiveness: Not yet available.Documents Related to Lesson: N/AMi
10、ssion Directorate(s): a71 Exploration Systemsa71 Aeronautics ResearchAdditional Key Phrase(s): a71 Computersa71 Flight Equipmenta71 Flight Operationsa71 Hardwarea71 Payloadsa71 Safety & Mission Assurancea71 SoftwareAdditional Info: Approval Info: a71 Approval Date: 2003-04-07a71 Approval Name: Jim Cerya71 Approval Organization: GRCa71 Approval Phone Number: 216-433-3002Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
