Why does Galileo store imaging and other science data onboard prior to sending it back to Earth?
Starting in May of 1996, the spacecraft’s top data rate will be 160 bits per second. Even at that rate, it’s not possible for the spacecraft to send pictures back in “real time” (i.e., no live imaging coverage, although some Fields and Particles data will be returned to Earth as soon as they are acquired). Instead, Galileo will return pictures on a “tape delay” system. During encounter periods (that is, during Jupiter and satellite flybys, and for several days before and after), and at other selected times during “cruise” (the periods between encounters), data will be collected from the instruments, and stored on the spacecraft’s tape recorder for later processing and downlink to Earth.
