Galileo Probe
    The Probe in the Lab/ NASA SP-479

    Galileo Probe

    Mission Objectives or Goals
    • Determine the chemical composition of the Jovian atmosphere;
    • Characterize the structure of the atmosphere to a depth of at least 10 bars;
    • Investigate the nature of cloud particles and the location and structure of cloud layers;
    • Examine the Jovian radiative heat balance;
    • Study the nature of Jovian lightning activity; and,
    • Measure the flux of energetic charged particles down to the top of the atmosphere.

    Mission Events
    Galileo Launch: Oct. 18, 1989
    Probe release: July 12, 1995
    Entry and relay: Dec. 7, 1995

    Mission Summary
    The probe returned data until it reached a depth corresponding to an atmospheric pressure of ~24 bars. The probe and all scientific instruments functioned successfully, and accumulated data on composition, clouds, thermal structure, winds, energy balance, lightning, and inner radiation belts. Wind speeds in excess of 600 kilometers per hour (> 400 mph) were detected along with less water than estimated from earlier Voyager observations and from models of the Comet Shoemaker-Levy 9 impact. There was less lightning activity than anticipated; however, individual lightning events were about ten times stronger on Jupiter than the Earth. The helium abundance was similar to solar abundance (24% compared to 25%).

    Access to the Galileo Probe Data Volume

    References Helpful in Scoping the Mission

    The Instrument ensemble was composed of:
    The Atmospheric Structure Instrument (ASI)
    The Energetic Particle Instrument (EPI)
    The Helium Abundance Detector (HAD)
    The Lightning and Radio Emission Detector (LRD)
    The Nephelometer (NEP)
    The Net Flux Radiometer (NFR)
    The Neutral Mass Spectrometer (NMS)
    The Doppler Wind Experiment (DWE) – The analysis
    of the radio signal to determine atmospheric winds.