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Left to its own devices, NASA’s Deep Space 1 probe would have struck out on
its own last week. The probe had a glitch in its “remote agent”, the computer
program designed to wean the spacecraft off mission control (“You’re on your
own”, 91av, 24 October 1998, p 38). Last Tuesday, a bug in
this software prevented the probe from shutting down its engines as planned.
“The root cause of this is a mistake in the logic that went into the program,”
says Marc Rayman, the project’s chief mission engineer. Ground controllers
overrode the unruly program, and the spacecraft remained on course. The
engineers will continue to test the software, which is intended to give the
probe a high degree of autonomy.