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The Galileo Energetic Particles Detector


Galileo EPD Handbook




Appendix A. EDR File Structure (continued)


3. EPD Subsystem Telemetry (continued)

Source: GLL-3-280, Rev. B, Appendix A, March 15, 1985




The contents of the CMS PHA/LEMMS PHA Data section can be either CMS PHA data or LEMMS PHA data. The timing of when the data is CMS PHA or LEMMS PHA is shown in Table 3.


Table 3. SI vs. CMS PHA/LEMMS PHA section contents


MOD 91 Contents
2 LEMMS PHA data
9 LEMMS PHA data
16 LEMMS PHA data
23 LEMMS PHA data
30 LEMMS PHA data
37 LEMMS PHA data
44 LEMMS PHA data
51 LEMMS PHA data
58 LEMMS PHA data
65 LEMMS PHA data
72 LEMMS PHA data
79 LEMMS PHA data
86 LEMMS PHA data
All others CMS PHA data


The CMS PHA data section contains information on Composition Measurement System (CMS) Pulse Height Analyzer (PHA) data. LEMMS PHA data contains information on Low Energy Magnetospheric Measurement System (LEMMS) PHA spectrum data.  When this section contains CMS PHA data, the contents are described in Table 4, which refers to one event.


Thirteen times throughout one major frame (i.e., when the MOD 91 counter registers 2, 9, 16, 23, 30, 37, 44, 51, 58, 65, 72, 79, and 86) the 12 bytes (96 bits) of CMS PHA data will be replaced by LEMMS PHA data. The 12 bytes, in addition to the 35 bytes of LEMMS PHA found in bits 169 to 208 of each of the 7 packets of EPD telemetry, form one complete 47 byte LEMMS PHA spectrum. The 47 byte LEMMS PHA spectrum will be sorted into energy bins (or bin numbers), which are given in Table 6.


Table 4. CMS PHA Data (bit 1 is MSB)




Next: LEMMS PHA Data


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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.