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Reconfigurable Modular Computer Networks for Spacecraft On- Board Processing

IP.com Disclosure Number: IPCOM000131331D
Original Publication Date: 1978-Jul-01
Included in the Prior Art Database: 2005-Nov-10
Document File: 14 page(s) / 52K

Publishing Venue

Software Patent Institute

Related People

David A. Rennels: AUTHOR [+3]

Abstract

[Figure containing following caption omitted: Standardized fault-tolerant microcomputers in a reconfigurable distributed network promise to meet spacecraft reliability requirements at low cost.] Over the last 20 years, a number of unmanned spacecraft have been sent to investigate the moon, Mars, Venus, and Mercury and have returned more information about these bodies than had been collected in all of previous human history.' Each of these spacecraft, as well as those in the planning stages for future missions, consists of two major parts: a science payload and a set of engineering subsystems which supply power, control, and communications with the science instruments. The science payload scans the electromagnetic spectrum and the environment in the vicinity of the spacecraft. Typical experiments employ television cameras, ultraviolet and infrared scanning devices, charged particle detectors, magnetometers. and radio astronomy instruments. The core engineering subsystem -- the one that must control and collect data from these experiments, as well as point the spacecraft, control the other engineering subsystems, and handle any serious anomalies which may occur on the flight -- is the computer.

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THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

This record contains textual material that is copyright ©; 1978 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Contact the IEEE Computer Society http://www.computer.org/ (714-821-8380) for copies of the complete work that was the source of this textual material and for all use beyond that as a record from the SPI Database.

Reconfigurable Modular Computer Networks for Spacecraft On- Board Processing

David A. Rennels

Jet Propulsion Laboratory

(Image Omitted: Standardized fault-tolerant microcomputers in a reconfigurable distributed network promise to meet spacecraft reliability requirements at low cost.)

Over the last 20 years, a number of unmanned spacecraft have been sent to investigate the moon, Mars, Venus, and Mercury and have returned more information about these bodies than had been collected in all of previous human history.' Each of these spacecraft, as well as those in the planning stages for future missions, consists of two major parts: a science payload and a set of engineering subsystems which supply power, control, and communications with the science instruments. The science payload scans the electromagnetic spectrum and the environment in the vicinity of the spacecraft. Typical experiments employ television cameras, ultraviolet and infrared scanning devices, charged particle detectors, magnetometers. and radio astronomy instruments. The core engineering subsystem -- the one that must control and collect data from these experiments, as well as point the spacecraft, control the other engineering subsystems, and handle any serious anomalies which may occur on the flight -- is the computer.

Distributed computers.

The core electronics subsystems on these spacecraft have progressed through an evolution from simple fixed controllers and analog computers in the 1960's to generalpurpose digital computers in current designs. This evolution is now moving in the direction of distributed computer networks. Current Voyager spacecraft already use three on-board computers. One is used to store commands and provide overall spacecraft management. Another is used for instrument control and telemetry collection, and the third computer is used for attitude control and scientific instrument pointing. The scientific instruments are also candidates for dedicated computers. These instruments vary in complexity, but they all contain command interfaces and internal logic sequencers which generate control signals to operate electronic mechanisms and to collect data. Instrument cycles vary in periodicity from a few seconds to a minute. An examination of the control logic in these instruments shows that, for many, it is cost- effective to replace the sequencing logic with a microcomputer -- either to save chips or to establish standardization in instrument logic designs.

An additional factor in favor of multiple computers is a potential simplifica...