138:
1364:
146:
33:
100:
satellites. The high apogee meant that the polar regions were visible for long amounts of time, and only two satellites were required in order to achieve constant communications ability. In addition, two geostationary satellites appear to be part of the system. The SDS satellites were constructed by
149:
The SDS 3-4 satellite (USA 179, 2004-034A) created a tiny trail perpendicular to the star trails in this 10 second exposure with a Zeiss Sonnar MC 2.8/180mm lens made by amateur satellite observer Marco
204:
downlink. Two dishes are 4.5 m (15 ft) in diameter, while the third is 2 m (6 ft 7 in) in diameter. The solar arrays generate 1238 watts of power. It is believed that the
1275:
1179:
1567:
788:
720:
660:
72:. The first generation was named simply 'SDS', the second generation was named 'Quasar' and the third generation each had their own designations.
1330:
1228:
1130:
1079:
829:
1477:
200:
The SDS-2 is significantly more massive at 2,335 kg (5,148 lb), with three separate communication dishes, including one for a
1931:
1326:
1224:
1175:
1126:
1075:
1022:
974:
926:
875:
825:
1421:
591:
547:
503:
460:
413:
366:
319:
1936:
1272:
1026:
978:
930:
879:
1532:
1762:
1515:
1577:
1941:
1560:
1702:
1492:
1651:
587:
543:
499:
456:
409:
362:
315:
246:
241:
114:
1656:
1553:
768:
102:
81:
701:
641:
1307:
1253:
1206:
1157:
1109:
1057:
1005:
957:
909:
858:
808:
749:
683:
623:
570:
526:
482:
439:
392:
345:
298:
1905:
205:
175:
1817:
1789:
1716:
1697:
1347:
1335:
1293:
784:
716:
656:
261:
182:
179:
155:
122:
1822:
1781:
1741:
1545:
732:
167:
1799:
1794:
1736:
1731:
1605:
1369:
736:
118:
53:
779:
711:
651:
1845:
1757:
1692:
1672:
1417:
434:
387:
340:
293:
93:
1895:
1301:
1247:
1201:
1152:
1000:
952:
904:
853:
803:
1809:
744:
678:
618:
565:
171:
521:
477:
68:
from 1998 to the present. It is believed that these satellites were known by the code name
1832:
1536:
1519:
1436:
224:
97:
1925:
1625:
1529:
1512:
1097:
1044:
897:
763:
696:
636:
201:
188:
It has been speculated that the early satellites served as data relays for the first
126:
37:
1635:
1630:
1615:
189:
137:
17:
1620:
1449:
1610:
1414:
The
Wizards of Langley. Inside the CIA's Directorate of Science and Technology
1359:
582:
538:
494:
451:
404:
357:
310:
113:
The primary purpose of the SDS satellites is to relay imagery from low-flying
1397:
145:
174:. The SDS-1 had a mass of 630 kg (1,390 lb) and was launched on
1121:
1017:
969:
921:
870:
820:
221:
159:
1910:
1900:
1840:
1320:
1266:
1218:
1169:
1104:
1069:
1052:
266:
32:
1478:"NROL-61 satellite launched Thursday spotted in space by sky-watchers"
1874:
1383:
775:
707:
647:
271:
217:
213:
209:
178:
rockets. The SDS-1 satellites had similar orbits to the Air Force's
1462:
1772:
144:
136:
89:
85:
31:
1528:
Vick, Berman, Lindborg, Fellow, Pike, Aftergood (March 19, 1997)
1196:, geosynchronous satellite at 144° West, replacement for USA-162
208:
has been used to launch several satellites, possibly on missions
1890:
163:
1549:
125:
radar reconnaissance satellites to ground stations in the
1437:
1147:, geosynchronous satellite at 10° West, replaced USA-155
36:
The current SDS-3 constellation, consisting of three
162:
in shape, roughly 25 ft (7.6 m) long. 980
1883:
1862:
1831:
1808:
1780:
1771:
1750:
1724:
1715:
1685:
1665:
1644:
1598:
1591:
1584:
154:Each SDS-1 satellite had 12 channels available for
141:
Releasable
Picture of NRO satellite, possible SDS-1
1511:Vick, Berman, Lindborg, Fellow (March 19, 1997)
27:American military satellite communication system
731:Geosynchronous satellite, deployed along with
56:. At least three generations have been used:
1561:
8:
1450:"Shadow dancing: the Satellite Data System"
1777:
1721:
1595:
1588:
1568:
1554:
1546:
995:, geosynchronous satellite at 144° West
234:
166:of electrical power were available from
1530:SDS-2 Military Communications Satellite
1513:SDS-1 Military Communications Satellite
1493:"Atlas V finally launches with NROL-52"
1376:
947:, geosynchronous satellite at 10° West
92:in order to allow communications with
1416:. Boulder, Colorado: Westview Press.
84:, going from about 300 kilometers at
40:type and two geostationary satellites
7:
1491:Graham, William (15 October 2017).
1448:Day, Dwayne A. (26 February 2018).
54:military communications satellites
25:
1540:Federation of American Scientists
1523:Federation of American Scientists
735:and initially misidentified as a
1480:. Spaceflight Now. 30 July 2016.
1362:
220:. Other launches have used the
158:(UHF) communication. They were
52:) is a system of United States
1578:National Reconnaissance Office
1:
1296:, might be a new generation
96:stations that cannot contact
88:to roughly 39,000 km at
192:reconnaissance satellites.
121:optical reconnaissance and
1958:
1465:List of satellite launches
843:
608:
283:
1932:Communications satellites
1535:20 September 2016 at the
1463:Jonathan's Space Report:
1398:Jonathan's Space Report:
1384:Jonathan's Space Report:
1242:Geosynchronous satellite
664:
115:reconnaissance satellites
1412:Richelson, J.T. (2001).
1047:, final Atlas II launch
1937:Hughes Aircraft Company
1542:Accessed April 24, 2004
1525:Accessed April 24, 2004
103:Hughes Aircraft Company
82:highly elliptical orbit
76:Orbital characteristics
1518:28 August 2016 at the
151:
142:
80:SDS satellites have a
41:
1495:. NASASpaceFlight.com
148:
140:
46:Satellite Data System
35:
1348:Geosynchronous orbit
1294:Geosynchronous orbit
156:Ultra high frequency
1942:Military satellites
1452:. The Space Review.
1400:Satellite Catalogue
1386:NRO Satellite Names
64:from 1989 to 1996;
60:from 1976 to 1987;
1576:Satellites of the
1370:Spaceflight portal
739:SIGINT spacecraft
262:Launch designation
152:
143:
42:
18:Quasar (satellite)
1919:
1918:
1858:
1857:
1854:
1853:
1790:Rhyolite/Aquacade
1711:
1710:
1681:
1680:
1353:
1352:
1314:
1260:
1212:
1163:
1115:
1066:10 December 2007
1063:
1011:
963:
915:
864:
814:
755:
692:15 November 1990
689:
629:
611:Second generation
579:15 February 1987
576:
532:
488:
448:13 December 1980
445:
398:
351:
304:
249:
16:(Redirected from
1949:
1778:
1722:
1596:
1589:
1570:
1563:
1556:
1547:
1505:
1504:
1502:
1500:
1488:
1482:
1481:
1474:
1468:
1460:
1454:
1453:
1445:
1439:
1434:
1428:
1427:
1409:
1403:
1395:
1389:
1381:
1372:
1367:
1366:
1365:
1317:15 October 2017
1312:
1310:
1258:
1256:
1210:
1161:
1122:Delta IV-M+(4,2)
1113:
1061:
1009:
966:11 October 2001
961:
918:6 December 2000
913:
867:29 January 1998
862:
846:Third generation
812:
773:
766:
758:2 December 1992
753:
699:
687:
639:
627:
574:
535:8 February 1985
530:
486:
443:
396:
349:
302:
286:First generation
245:
235:
21:
1957:
1956:
1952:
1951:
1950:
1948:
1947:
1946:
1922:
1921:
1920:
1915:
1879:
1850:
1827:
1804:
1767:
1746:
1707:
1677:
1661:
1640:
1580:
1574:
1537:Wayback Machine
1520:Wayback Machine
1508:
1498:
1496:
1490:
1489:
1485:
1476:
1475:
1471:
1461:
1457:
1447:
1446:
1442:
1435:
1431:
1424:
1411:
1410:
1406:
1396:
1392:
1382:
1378:
1368:
1363:
1361:
1358:
1311:
1306:
1257:
1252:
1209:
1160:
1112:
1060:
1014:31 August 2004
1008:
960:
912:
861:
848:
811:
774:
762:
761:
752:
706:
695:
686:
646:
635:
626:
613:
573:
529:
491:28 August 1984
485:
442:
395:
348:
301:
288:
255:Launch vehicle
244:
233:
198:
135:
111:
78:
28:
23:
22:
15:
12:
11:
5:
1955:
1953:
1945:
1944:
1939:
1934:
1924:
1923:
1917:
1916:
1914:
1913:
1908:
1903:
1898:
1893:
1887:
1885:
1881:
1880:
1878:
1877:
1872:
1866:
1864:
1860:
1859:
1856:
1855:
1852:
1851:
1849:
1848:
1843:
1837:
1835:
1829:
1828:
1826:
1825:
1820:
1814:
1812:
1806:
1805:
1803:
1802:
1797:
1792:
1786:
1784:
1775:
1769:
1768:
1766:
1765:
1760:
1754:
1752:
1748:
1747:
1745:
1744:
1739:
1734:
1728:
1726:
1725:Radar location
1719:
1713:
1712:
1709:
1708:
1706:
1705:
1700:
1695:
1689:
1687:
1683:
1682:
1679:
1678:
1676:
1675:
1669:
1667:
1663:
1662:
1660:
1659:
1654:
1648:
1646:
1642:
1641:
1639:
1638:
1636:Kennen/Crystal
1633:
1628:
1623:
1618:
1613:
1608:
1602:
1600:
1593:
1586:
1582:
1581:
1575:
1573:
1572:
1565:
1558:
1550:
1544:
1543:
1526:
1507:
1506:
1483:
1469:
1455:
1440:
1429:
1422:
1404:
1390:
1375:
1374:
1373:
1357:
1354:
1351:
1350:
1344:
1342:
1340:
1338:
1333:
1324:
1318:
1315:
1304:
1298:
1297:
1287:
1285:
1283:
1281:
1278:
1270:
1264:
1261:
1250:
1244:
1243:
1240:
1238:
1236:
1234:
1231:
1222:
1216:
1213:
1204:
1198:
1197:
1191:
1189:
1187:
1185:
1182:
1173:
1167:
1164:
1155:
1149:
1148:
1142:
1140:
1138:
1136:
1133:
1124:
1119:
1118:11 March 2011
1116:
1107:
1101:
1100:
1091:
1089:
1087:
1085:
1082:
1073:
1067:
1064:
1055:
1049:
1048:
1038:
1036:
1034:
1032:
1029:
1020:
1015:
1012:
1003:
997:
996:
990:
988:
986:
984:
981:
972:
967:
964:
955:
949:
948:
942:
940:
938:
936:
933:
924:
919:
916:
907:
901:
900:
891:
889:
887:
885:
882:
873:
868:
865:
856:
850:
849:
847:
844:
841:
840:
838:
836:
834:
832:
823:
821:Titan IV(405)A
818:
815:
806:
800:
799:
797:
795:
793:
791:
782:
759:
756:
747:
741:
740:
729:
727:
725:
723:
714:
693:
690:
681:
675:
674:
672:
670:
668:
666:
663:
654:
633:
630:
621:
615:
614:
612:
609:
606:
605:
603:
601:
599:
597:
594:
585:
583:Titan III(34)B
580:
577:
568:
562:
561:
559:
557:
555:
553:
550:
541:
539:Titan III(34)B
536:
533:
524:
518:
517:
515:
513:
511:
509:
506:
497:
495:Titan III(34)B
492:
489:
480:
474:
473:
471:
469:
467:
465:
463:
454:
452:Titan III(34)B
449:
446:
437:
431:
430:
428:
425:
422:
419:
416:
407:
405:Titan III(34)B
402:
401:5 August 1978
399:
390:
384:
383:
381:
378:
375:
372:
369:
360:
358:Titan III(34)B
355:
354:6 August 1976
352:
343:
337:
336:
334:
331:
328:
325:
322:
313:
311:Titan III(34)B
308:
305:
296:
290:
289:
287:
284:
281:
280:
277:
274:
269:
264:
259:
256:
253:
250:
239:
232:
229:
225:launch vehicle
197:
194:
134:
131:
117:, notably the
110:
107:
98:geosynchronous
77:
74:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
1954:
1943:
1940:
1938:
1935:
1933:
1930:
1929:
1927:
1912:
1909:
1907:
1904:
1902:
1899:
1897:
1894:
1892:
1889:
1888:
1886:
1882:
1876:
1873:
1871:
1868:
1867:
1865:
1863:Communication
1861:
1847:
1844:
1842:
1839:
1838:
1836:
1834:
1830:
1824:
1821:
1819:
1816:
1815:
1813:
1811:
1807:
1801:
1798:
1796:
1793:
1791:
1788:
1787:
1785:
1783:
1779:
1776:
1774:
1770:
1764:
1761:
1759:
1756:
1755:
1753:
1751:Ship location
1749:
1743:
1740:
1738:
1737:Chalet/Vortex
1735:
1733:
1730:
1729:
1727:
1723:
1720:
1718:
1714:
1704:
1701:
1699:
1698:Lacrosse/Onyx
1696:
1694:
1691:
1690:
1688:
1684:
1674:
1671:
1670:
1668:
1664:
1658:
1655:
1653:
1650:
1649:
1647:
1643:
1637:
1634:
1632:
1629:
1627:
1624:
1622:
1619:
1617:
1614:
1612:
1609:
1607:
1604:
1603:
1601:
1597:
1594:
1590:
1587:
1583:
1579:
1571:
1566:
1564:
1559:
1557:
1552:
1551:
1548:
1541:
1538:
1534:
1531:
1527:
1524:
1521:
1517:
1514:
1510:
1509:
1494:
1487:
1484:
1479:
1473:
1470:
1467:
1466:
1459:
1456:
1451:
1444:
1441:
1438:
1433:
1430:
1425:
1423:9780813340593
1419:
1415:
1408:
1405:
1402:
1401:
1394:
1391:
1388:
1387:
1380:
1377:
1371:
1360:
1355:
1349:
1345:
1343:
1341:
1339:
1337:
1334:
1332:
1328:
1325:
1322:
1319:
1316:
1309:
1305:
1303:
1300:
1299:
1295:
1291:
1288:
1286:
1284:
1282:
1279:
1277:
1274:
1271:
1268:
1265:
1263:28 July 2016
1262:
1255:
1251:
1249:
1246:
1245:
1241:
1239:
1237:
1235:
1232:
1230:
1226:
1223:
1220:
1217:
1214:
1208:
1205:
1203:
1200:
1199:
1195:
1192:
1190:
1188:
1186:
1183:
1181:
1177:
1174:
1171:
1168:
1166:20 June 2012
1165:
1159:
1156:
1154:
1151:
1150:
1146:
1143:
1141:
1139:
1137:
1134:
1132:
1128:
1125:
1123:
1120:
1117:
1111:
1108:
1106:
1103:
1102:
1099:
1098:Molniya orbit
1095:
1092:
1090:
1088:
1086:
1083:
1081:
1077:
1074:
1071:
1068:
1065:
1059:
1056:
1054:
1051:
1050:
1046:
1045:Molniya orbit
1042:
1039:
1037:
1035:
1033:
1030:
1028:
1024:
1021:
1019:
1016:
1013:
1007:
1004:
1002:
999:
998:
994:
991:
989:
987:
985:
982:
980:
976:
973:
971:
968:
965:
959:
956:
954:
951:
950:
946:
943:
941:
939:
937:
934:
932:
928:
925:
923:
920:
917:
911:
908:
906:
903:
902:
899:
898:Molniya orbit
895:
892:
890:
888:
886:
883:
881:
877:
874:
872:
869:
866:
860:
857:
855:
852:
851:
845:
842:
839:
837:
835:
833:
831:
827:
824:
822:
819:
816:
810:
807:
805:
802:
801:
798:
796:
794:
792:
790:
786:
783:
781:
777:
772:
771:
765:
764:Space Shuttle
760:
757:
751:
748:
746:
743:
742:
738:
734:
730:
728:
726:
724:
722:
718:
715:
713:
709:
705:
704:
698:
697:Space Shuttle
694:
691:
685:
682:
680:
677:
676:
673:
671:
669:
667:
662:
658:
655:
653:
649:
645:
644:
638:
637:Space Shuttle
634:
631:
625:
622:
620:
617:
616:
610:
607:
604:
602:
600:
598:
595:
593:
589:
586:
584:
581:
578:
572:
569:
567:
564:
563:
560:
558:
556:
554:
551:
549:
545:
542:
540:
537:
534:
528:
525:
523:
520:
519:
516:
514:
512:
510:
507:
505:
501:
498:
496:
493:
490:
484:
481:
479:
476:
475:
472:
470:
468:
466:
464:
462:
458:
455:
453:
450:
447:
441:
438:
436:
433:
432:
429:
426:
423:
420:
417:
415:
411:
408:
406:
403:
400:
394:
391:
389:
386:
385:
382:
379:
376:
373:
370:
368:
364:
361:
359:
356:
353:
347:
344:
342:
339:
338:
335:
332:
329:
326:
323:
321:
317:
314:
312:
309:
306:
300:
297:
295:
292:
291:
285:
282:
278:
275:
273:
270:
268:
265:
263:
260:
257:
254:
251:
248:
243:
240:
237:
236:
230:
228:
226:
223:
219:
215:
211:
207:
206:Space Shuttle
203:
195:
193:
191:
186:
184:
181:
177:
173:
169:
165:
161:
157:
147:
139:
132:
130:
128:
127:United States
124:
123:Lacrosse/Onyx
120:
116:
108:
106:
104:
99:
95:
91:
87:
83:
75:
73:
71:
67:
63:
59:
55:
51:
47:
39:
38:Molniya orbit
34:
30:
19:
1869:
1795:Magnum/Orion
1539:
1522:
1497:. Retrieved
1486:
1472:
1464:
1458:
1443:
1432:
1413:
1407:
1399:
1393:
1385:
1379:
1289:
1215:22 May 2014
1193:
1144:
1093:
1040:
992:
944:
893:
817:3 July 1996
769:
702:
642:
632:2 June 1989
307:2 June 1976
276:Inclination
258:Launch site
252:Launch date
199:
190:KH-11 Kennen
187:
185:satellites.
168:solar panels
153:
112:
79:
69:
65:
61:
57:
49:
45:
43:
29:
160:cylindrical
1926:Categories
1884:Technology
1499:15 October
1356:References
1018:Atlas IIAS
970:Atlas IIAS
945:Great Bear
922:Atlas IIAS
231:Satellites
150:Langbroek.
1308:2017-066A
1254:2016-047A
1207:2014-027A
1158:2012-033A
1110:2011-011A
1058:2007-060A
1006:2004-034A
958:2001-046A
910:2000-080A
894:Capricorn
871:Atlas IIA
859:1998-005A
809:1996-038A
780:Orbus-21S
770:Discovery
750:1992-086B
712:Orbus-21S
684:1990-097B
652:Orbus-21S
624:1989-061B
571:1987-015A
508:SDS F-5A
483:1984-091A
440:1980-100A
427:63.3 deg
424:39315 km
393:1978-075A
380:63.3 deg
377:39315 km
346:1976-080A
333:63.3 deg
330:39315 km
299:1976-050A
242:COSPAR ID
172:batteries
1818:Jumpseat
1626:Gambit 3
1621:Gambit 1
1533:Archived
1516:Archived
1280:NROL-61
1233:NROL-33
1184:NROL-38
1135:NROL-27
1094:Scorpius
1084:NROL-24
983:NROL-12
935:NROL-10
703:Atlantis
643:Columbia
596:SDS F-6
527:195-014A
435:OPS 5805
418:SDS F-3
388:OPS 7310
371:SDS F-2
341:OPS 7940
324:SDS F-1
294:OPS 7837
279:Remarks
247:SATCAT №
222:Titan IV
180:Jumpseat
176:Titan-3B
1901:USA-193
1896:GeoLITE
1841:Samos-F
1823:Trumpet
1742:Mercury
1631:Hexagon
1616:Lanyard
1599:Keyhole
1592:Optical
1585:Imaging
1346:Likely
1336:NROL-52
1321:Atlas V
1302:USA-279
1267:Atlas V
1248:USA-269
1219:Atlas V
1202:USA-252
1170:Atlas V
1153:USA-236
1145:Gryphon
1131:SLC-37B
1105:USA-227
1070:Atlas V
1053:USA-198
1041:Nemesis
1031:NROL-1
1027:SLC-36A
1001:USA-179
993:Aquilla
979:SLC-36B
953:USA-162
931:SLC-36A
905:USA-155
884:NROL-5
880:SLC-36A
854:USA-137
804:USA-125
733:Prowler
421:380 km
374:380 km
327:380 km
267:Perigee
119:Keyhole
109:Mission
86:perigee
1906:Colony
1875:SLDCOM
1800:Mentor
1732:Canyon
1717:SIGINT
1606:Corona
1420:
1331:SLC-41
1276:SLC-41
1229:SLC-41
1180:SLC-41
1080:SLC-41
789:LC-39A
776:STS-53
745:USA-89
737:Magnum
721:LC-39A
708:STS-38
679:USA-67
661:LC-39B
648:STS-28
619:USA-40
592:SLC-4W
566:USA-21
552:USA-9
548:SLC-4W
504:SLC-4W
461:SLC-4W
414:SLC-4W
367:SLC-4W
320:SLC-4W
272:Apogee
218:STS-53
216:, and
214:STS-38
210:STS-28
202:K-band
90:apogee
70:Quasar
1846:Poppy
1773:ELINT
1758:Poppy
1703:FIA-R
1693:Quill
1686:Radar
1673:Samos
1666:Other
1652:Misty
1645:Misty
1611:Argon
1327:CCAFS
1313:42973
1290:Spike
1273:CCAFS
1259:41724
1225:CCAFS
1211:39751
1194:Drake
1176:CCAFS
1162:38466
1127:CCAFS
1114:37377
1076:CCAFS
1062:32378
1023:CCAFS
1010:28384
975:CCAFS
962:26948
927:CCAFS
914:26635
876:CCAFS
863:25148
830:LC-40
826:CCAFS
813:23945
767:
754:22518
700:
688:20963
640:
628:20167
575:17506
531:15546
522:USA-9
487:15226
478:USA-4
444:12093
397:10993
350:09270
303:08871
238:Name
196:SDS-2
183:ELINT
164:watts
133:SDS-1
94:polar
66:SDS-3
62:SDS-2
58:SDS-1
1891:STEX
1763:NOSS
1501:2017
1418:ISBN
1323:421
1269:421
1221:401
1172:401
1072:401
665:N/A
588:VAFB
544:VAFB
500:VAFB
457:VAFB
410:VAFB
363:VAFB
316:VAFB
170:and
44:The
1911:RPP
1870:SDS
1833:LEO
1810:HEO
1782:GEO
1657:EIS
785:KSC
717:KSC
657:KSC
50:SDS
1928::
1329:,
1292:,
1227:,
1178:,
1129:,
1096:,
1078:,
1043:,
1025:,
977:,
929:,
896:,
878:,
828:,
787:,
719:,
659:,
590:,
546:,
502:,
459:,
412:,
365:,
318:,
227:.
212:,
129:.
105:.
1569:e
1562:t
1555:v
1503:.
1426:.
778:/
710:/
650:/
48:(
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
