Pioneer P-31 - On-board Equipment

On-board Equipment

The scientific instruments consisted of an ion chamber and Geiger-Müller tube to measure total radiation flux, a proportional radiation counter telescope to measure high energy radiation, a scintillation counter to monitor low-energy radiation, a scintillation spectrometer to study the Earth's (and possible lunar) radiation belts, a VLF receiver for natural radio waves, a transponder to study electron density, and part of the flux-gate and search coil magnetometers mounted on the instrument platform. A plasma probe was mounted on the sphere to measure energy and momentum distribution of protons above a few kilovolts to study the radiation effect of solar flares. The micrometeorite detector and sun scanner were mounted on the sphere as well. The only difference between Pioneer P-31 and the earlier Pioneer P-30 was the addition of a solid state detector sensitive to low energy protons on the satellite and an STL-designed rubidium frequency standard experiment placed on a pod attached to the booster. The total mass of the science package including electronics and power supply was roughly 60 kg. Total cost of the mission was estimated at 9 - 10 million dollars.