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The Galileo Energetic Particles Detector


Galileo EPD Handbook


Chapter 1. Instrument Summary


CMS Subsystem


This section on the CMS subsystem is organized as follows:


CMS Subsystem - Post-Challenger (as flown)


Source: The Galileo Energetic Particles Detector, D. J. Williams et al., Space Science Reviews, 60, 385, 1992 (excerpts).


The CMS is designed to measure the composition of ions in the Jovian environment from energies of ≥10 keV nucl-1 to ≥10 MeV nucl-1. This system contains two types of energetic particle telescopes, shown schematically in Figure 1-11.  A small time-of-flight (TOF) telescope looks in the 0° direction while a pair of DE x E solid state detector telescopes (JK detectors) covering higher energies are oriented in the 180° direction.


The TOF portion of CMS is a replacement of the original EPD TOF telescope built for launch in early 1986. JPL, NASA, and the Bundesministerium fur Forschung und Technologie allowed us the opportunity to take advantage of new technology in order to lower our energy threshold for composition measurements by at least a factor of ten....The new TOF telescope, its high voltage power supply, the new TOF circuitry, and the major modifications to the electronics subsystem were designed, built, tested, and integrated into the EPD in 1987 and 1988.  All instrument and spacecraft tests and calibrations were successful and were indicative of an instrument response that exceeded expectations.


CMS Channel Descriptions: Table 6


Figure 1-12a. Detail of EPD CMS detector head (as flown).



Figure 1-12b. Schematic cross-section of TOF system. Source: Critical Design Review, Dec. 1987.



Figure 1-12c. Detailed cross-section of TOF system. Source: Critical Design Review, Dec. 1987.



High Voltage Output Filter
Source: Critical Design Review, December 1987, MPAe


Part No. Function Type-Value Factory
R50 μ film resistor RNR55 100k Da6
R51 μ film resistor RNR55 3k Da6
R52 μ film resistor 102 Ω RNR55 Da6
R53 μ film resistor 1.2k RNR55 Da6
R54 μ film resistor 1.5k RNR55 Da6
R55 μ film resistor 102 Ω RNR55 Da6
R56 μ film resistor " Da6
R57 μ film resistor " Da6
R58 μ film resistor " Da6
R59 μ film resistor " Da6
R60 μ film resistor " Da6
R61 μ film resistor " Da6
R62 μ film resistor " Da6
R63 μ film resistor " Da6
R64 μ film resistor " Da6
R65 μ film resistor " Da6
R66 μ film resistor " Da6
R67 μ film resistor

100 Ω RNR55



High Voltage Output Filter - schematic and details:




Next: Post-Challenger Revisions: Hardware Changes 


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Updated 8/23/19, Cameron Crane


Manufacturer: The Galileo Spacecraft was manufactured by the Jet Propulsion Laboratory, Messerschmitt-Bölkow-Blohm, General Electric, and the Hughes Aircraft Company.

Mission Duration: Galileo was planned to have a mission duration of around 8 years, but was kept in operation for 13 years, 11 months, and 3 days, until it was destroyed in a controlled impact with Jupiter on September 21, 2003.

Destination: Galileo's destination was Jupiter and its moons, which it orbitted for 7 years, 9 months, and 13 days.