Galileo Survives Antenna Failure Through Ground-and-Software Rescue

When Galileo’s large high-gain antenna failed to deploy in 1991, NASA and the ground team rewrote onboard and ground software, upgraded the Deep Space Network, and compressed data to squeeze its flagship science through a low-gain antenna. The workaround let Galileo return substantial science from Jupiter (arriving in 1995 and operating until 2003), including studies of its atmosphere, Io’s volcanism, and evidence supporting a subsurface ocean on Europa, albeit at data rates far lower than originally planned.