What was the Perijove Raise Maneuver?
The Jupiter Orbit Insertion (JOI) maneuver placed Galileo into orbit around Jupiter. Much like shaping a ball of putty, however, more than a single ‘action’ or ‘effort’ is required to get the shape we want. The Perijove Raise (PJR) maneuver was successfully performed on March 14 1996 and was designed to change the shape of the spacecraft’s orbit around Jupiter. Another term for ‘closest approach to Jupiter’ is “perijove” (from the Latin). Hence, a perijove raise maneuver is a maneuver designed to increase the closest approach distance to Jupiter, or in other words, “raise” perijove – from 4 Rj to 11 Rj (Jupiter radii) – an altitude just above that of Europas orbit. This action will prolong the life of the spacecraft by moving it out of the high radiation belts surrounding Jupiter. Galileos electronic parts were designed and shielded to withstand 150 krad during its lifetime, a lethal dose for humans. On arrival, the orbiter was subjected to about one-third of its lifetime allowance, fl
