Cassini Close To Resuming Nominal Operations Engineers at NASA’s
Jet Propulsion Laboratory, Pasadena, Calif., expect the Cassini
spacecraft will resume normal operations on Nov. 24. They have
traced the steps taken by an onboard computer before Cassini put
itself in precautionary “safe mode” last week. Mission managers
determined that the spacecraft went into safe mode because of a
flip of a bit in the command and data system computer. The bit
flip prevented the computer from registering an important
instruction, and the spacecraft, as programmed, went into the
standby mode. Engineers are still working to understand why the
bit flipped. Since the spacecraft went into safe mode on Nov. 2,
the onboard computer with the bit flip has been reset and one of
the science instruments has been turned back on to keep it warm.
Over the next week or so, engineers will bring the rest of the
science instruments back online. Playback from the computer’s
memory is enabling engineers to extract science data collected
before th