"Logic Design Pathology and Space Flight Electronics"

Richard B. Katz
NASA Goddard Space Flight Center

Dr. Rod L. Barto
Spacecraft Digital Electronics

Ken Erickson
Jet Propulsion Laboratory

Short Abstract
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This paper will first discuss the technologies used for implementing logic designs
in space-flight electronics.  An overview of this technology along with some
samples will given.  This will begin with the development of the Apollo flight
computer and continue through Voyager, Viking, Galileo, Magellan, and Cassini to 
give a historical perspective.  Following this, modern technology which is used 
on-board more modern spacecraft such as the Small Explorers, HST upgrades, Deep 
Space 1 will be discussed.

An in-depth discussion will be given about the types of logic design errors that
have been observed in real space flight missions and the final stages of ground
test.  An examination of the technologies will be discussed giving insight to
the root cause of the failures.  These technologies will range from discrete
integrated circuit based systems, systems of programmable logic, and the CAE
systems used to designs today's microelectronics.

The conclusion will show faults varying from large expensive programs to 
"smaller, faster, cheaper" missions and explore the fundamental reasons for
logic design problems.