NASA’s Mars Odyssey orbiter, already the longest-working spacecraft ever sent to Mars, will switch to some fresh, redundant equipment next week that has not been used since before launch in 2001.
Like many spacecraft, this orbiter carries a pair of redundant main computers, so that a backup is available if one fails. Odyssey’s “A-side” computer and “B-side” computer each have several other redundant subsystems linked to just that computer. The Odyssey team has decided to switch to the B-side computer to begin using the B-side’s inertial measurement unit. This gyroscope-containing mechanism senses changes in the spacecraft’s orientation, providing important information for control of pointing the antenna, solar arrays and instruments.