Sfera (satellite)
Sfera | |
---|---|
Type: | Earth surveying satellite |
Country: | Soviet Union |
Mission dates | |
Dimensions: | 600-880 kg |
Size: | 3.0 m × 2.04 m |
Begin: | First launch: February 20, 1968 |
Starting place: | Plesetsk Cosmodrome |
Launcher: | Cosmos-3M |
Orbit data | |
Track height: | 1200-1400 km |
Orbit inclination : | 74 ° or 83 ° |
Sfera ( Russian Сфера , for sphere , GRAY index : 11F621) is the name for Soviet earth surveying satellites .
history
When planning global nuclear strikes during the Cold War , the Soviet military needed very accurate maps and precise navigational data. Factors that affected geographic accuracy included tiny variations in the shape of the earth and its gravitational field. In 1965, the design office NPO Prikladnoj Mechaniki began developing a specialized satellite based on the KAUR-1 satellite bus for this task, which was named Geoid-Sfera. The payload of the cylindrical satellite consisted of a flashlight that emitted a series of strong flashes of light. By taking photographs of these flashes of light from several points of view and comparing the position of the satellite relative to the stars, its position could be determined with an accuracy of about 3 to 6 arc seconds . Thanks to this data, the positions of points could be determined even at great distances with an accuracy of 25 to 30 meters. In addition, the satellites were also equipped with a special radio transmitter to determine the speed of the satellite with an accuracy of 0.1 meters per second by evaluating the Doppler shift of the signal. The Sfera system significantly improved the positioning of objects on land and sea and contributed to updating the standard model of the earth's geometry and developing a new coordinate system based on it.
The satellites were usually placed in a circular orbit with an inclination of 74 °, initially 1200 kilometers later up to 1400 km high. The orbit height reduced the influence of the atmosphere on the satellite, so that only deviations from the orbit caused by the earth's gravitational field had to be taken into account. The Kosmos 3M rocket , which brought the satellites into orbit from the Plesetsk Cosmodrome , was always used for the launch .
The first satellite was launched on February 20, 1968 under the official name Kosmos-203. Although the first satellite worked for 19 months, significantly longer than the expected six months, the system suffered from significant technical problems until 1972. In 1973 the system was finally declared ready for use and serial production started. A total of 18 Sfera satellites were launched, the last of which was launched on December 26, 1978 and was in operation until May 1, 1980. Of the 18 satellites launched, 17 reached Earth orbit.
Satellites
A total of 18 satellites were launched before the series was replaced by Geo-IK satellites .
number | Surname | Start date | Launch complex | Takeoff weight kg |
COSPAR name | NORAD ID | Orbit inclination | Apogee km |
Perigee km |
---|---|---|---|---|---|---|---|---|---|
1 | Cosmos-203 | 20th February 1968 | LC132 | 600 kg | 1968-011A | 3129 | 74.1 ° | 1201 | 1183 |
- | - | 4th June 1968 | LC132 / 2 | Startup failure | |||||
2 | Cosmos-256 | November 30, 1968 | LC132 / 1 | 600 kg | 1968-106A | 3576 | 74.1 ° | 1223 | 1172 |
3 | Cosmos-272 | 17th March 1969 | LC132 / 1 | 600 kg | 1969-024A | 3818 | 74.0 ° | 1208 | 1178 |
4th | Cosmos-312 | November 24, 1969 | LC132 / 1 | 600 kg | 1969-103A | 4254 | 74.0 ° | 1175 | 1141 |
5 | Cosmos-409 | April 28, 1971 | LC132 / 1 | 600 kg | 1971-038A | 5180 | 74.0 ° | 1218 | 1183 |
6th | Cosmos-457 | 20th November 1971 | LC132 / 2 | 600 kg | 1971-099A | 5614 | 74.0 ° | 1211 | 1176 |
7th | Cosmos-480 | March 25, 1972 | LC132 / 1 | 600 kg | 1972-019A | 5905 | 83.0 ° | 1199 | 1173 |
8th | Cosmos-539 | December 21, 1972 | LC132 / 2 | 600 kg | 1972-102A | 6319 | 74.0 ° | 1379 | 1342 |
9 | Cosmos-585 | September 8, 1973 | LC132 / 2 | 600 kg | 1973-064A | 6825 | 74.0 ° | 1424 | 1364 |
10 | Cosmos-650 | April 29, 1974 | LC132 / 2 | 600 kg | 1974-028A | 7281 | 74.0 ° | 1401 | 1368 |
11 | Cosmos-675 | 29th August 1974 | LC132 / 2 | 600 kg | 1974-069A | 7424 | 74.1 ° | 1424 | 1364 |
12 | Cosmos-708 | February 12, 1975 | LC132 / 1 | 600 kg | 1975-012A | 7663 | 69.2 ° | 1410 | 1368 |
13 | Cosmos-770 | September 24, 1975 | LC132 / 1 | 650 kg | 1975-089A | 8325 | 83.0 ° | 1208 | 1165 |
14th | Cosmos-842 | July 21, 1976 | LC132 / 1 | 650 kg | 1976-070A | 9025 | 83.0 ° | 1006 | 966 |
15th | Cosmos 911 | May 25, 1977 | LC132 / 2 | 700 kg | 1977-039A | 10019 | 83.0 ° | 999 | 965 |
16 | Cosmos-963 | November 24, 1977 | LC132 / 1 | 650 kg | 1977-109A | 10491 | 82.9 ° | 1206 | 1179 |
17th | Cosmos-1067 | December 26, 1978 | LC132 / 2 | 880 kg | 1978-122A | 11168 | 83.0 ° | 1213 | 1156 |
Web links
- Gunter's Spage Page: Sfera (English)
Individual evidence
- ↑ Sfera on the Russian Space Web (English)
- ↑ Sfera in the Encyclopedia Astronautica (English)
- ↑ Cosmos 1067 in the NSSDCA Master Catalog (English)