Pioneer 10 carries 11 instruments, only 5 of which are still in use. Pioneer 11 carries 12 instruments, only 3 of which were still in use when communications ended in late 1995. Propellants are liquid oxygen and RP1. The Centaur second stage has two engines having a total thrust of 13,273 kilograms. This engine carries insulation panels which are jettisoned just before the vehicle leaves the Earth's atmosphere and are used to prevent heat or air friction from causing boil-off of liquid hydrogen during flight through the atmosphere.
Propellant is liquid hydrogen and liquid oxygen.
This stage also spins the spacecraft up to 60 rpm. The Pioneer 11 instruments are the same as the Pioneer 10 instruments, except that a Flux-Gate Magnetometer was added. Instruments on the spacecraft were gradually turned off as power levels declined. The spacecraft is no longer in communication with Earth. On the plaque a man and woman stand before an outline of the spacecraft.