TL32 ETC, TL32 Datasheet - Page 19

• Manufacturer Part Number: TL32
• Description: Real Time System Testing MIT 16.070 Lecture 32
• Manufacturer: ETC

Who needs 4 computers and a backup? The Space Shuttle
• On ascent and landing/entry the Space Shuttle uses 4 identical
• During rendez-vous and docking, 2 computers are used
• On orbit, only one computer is necessary
• In all cases, the backup computer is always available and runs a
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5/4/01
computers and one backup. Why? A 1/2 second glitch in the
guidance, navigation & control software will cause the shuttle to spin
out of control.
different set of software than the other 4, a technique known as N-
version programming.
Fault Tolerance - Redundant Processors