- Detectors for both cosmic rays and low-energy particles. These instruments will look at the intense radiation fields around the outer planets and at radiation levels between them.
- Magnetometers to analyze the magnetic fields of Jupiter, Saturn, and perhaps Uranus and Neptune. The intensity of the fields and their interaction with moons will tell scientists much about conditions deep within each planet.
- A combined spectrometer and radiometer. Among the measurements they will take are energy balance at each planet, atmosphere temperature and dynamics, and cloud characteristics. The device also will let the scientists determine elemental composition of planet and moon atmospheres, surfaces, and rings.
- A photopolarimeter that, among other things, will measure methane, hydrogen, and ammonia in the upper atmospheres of the planets and moons.
- A radio-astronomy package, with two 33-foot whip antennas, to monitor the intense radio bursts from Jupiter and radio emissions from Saturn, the sun, and other sources.
- A plasma experiment to measure interplanetary solar-wind conditions and the wind's interaction with planetary magnetic fields.