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UHF Milsats

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Polar Satellites: Satellite Data System and Package D

There are two programs of classified-host satellites that provide support for AFSATCOM payloads: the Satellite Data System (SDS) and Package D.

These satellites provide UHF SATCOM communications for the users in the polar regions where communications using other more equatorial-based satellites are difficult, if not impossible. The SATCOM Management Center receives orbital information for the available polar satellites and then determines appropriate times for the AFSATCOM payloads onboard these satellites to be enabled or disabled.

Satellite Data System: SDS satellites include a payload similar to the 12-channel AFSATCOM 5 kHz system onboard the FLTSATs, with the exception that all 12 channels are regenerative and support only 75 bps customers. EAM functions are the same and channels one through seven can frequency hop. There are no non-regenerative channels, 5, 25, or 500 kHz, available on the SDS satellites.

Package D: The Package D satellites provide a UHF package identical to the SDS satellites, with the exception that the first 10 channels can frequency-hop versus the first seven on the FLTSATCOM and SDS satellites.

In addition, Package D satellites include an SCT payload similar to that onboard the DSCS-III satellites, and allow an SHF uplink. The Package D SCT does not provide an SHF downlink, however, and transmits only at UHF.

Satellite Data System
08871 SDS 02 OPS 7837 1976-050A 197606022056 Inactive 19970221
09270 SDS 03 OPS 7940 1976-080A 197608062221 Inactive 19970221
10688 SDS 04 OPS 6031 1978-021A 197802250600 Inactive 19970221
10993 SDS 05 OPS 7310 1978-075A 197808050500 Inactive 19970221
12093 SDS 06 OPS 5805 1980-100A 198012131401 Inactive 19970221
12418 SDS 07 OPS 7225 1981-038A 198104242132 Inactive 19970221
14237 SDS 08 OPS 7304 1983-078A 198307311541 Active 19970221
15226 SDS 09 USA 004 1984-091A 198408281803 Active 19990404
15546 SDS 10 USA 009 1985-014A 198502080615 Active 19990404
17506 SDS 11 USA 021 1987-015A 198702120630 Active 19990404
05053 SDS A OPS 4788 1971-021A 197103210350 Inactive 19970221
06791 SDS B OPS 7724 1973-056A 197308211605 Inactive 19970221