INTEGRATED ION AND ELECTRON SPECTROMETER
Plasma Experiment for Planetary Exploration (PEPE)
The Plasma Experiment for Planetary Exploration (PEPE) combines multiple instruments into one compact package. At 5.6 kg and 9.6 W, PEPE is less than 25% of the mass and consumes less than 50% of the power of a comparably performing (but more expensive) instrument on Cassini.
PEPE played three roles on DS1. It validated the design for a suite of plasma physics instruments in one small package; it assisted in determining the effects of the IPS on the local plasma environment, including interactions with the solar wind and photoelectrons; and it made scientifically interesting measurements during the cruise and the encounters. This device measured charged particles in space, both electrons and charged atoms, or ions, and made detailed measurements of solar wind.
The validation of PEPE on DS1 has been a step in preparing NASA for its future of smaller, less expensive missions to explore the solar system.