October 1981:space activities report

ANOTHER ANTI-SATELLITE TEST?

One of the earliest Soviet flights of 1981 involved a test of a satellite interception vehicle. On 2 February, Cosmos 1243 passed within a few kilometres of its target. Cosmos 1241,which had been in orbit for just under two weeks.

Cosmos 1241 was placed into a 976 x 1010 km orbit, with a period of 104.98 minutes and an inclination of 65.82 degrees to the equator. The launching vehicle was a C-1 and it came out of the Plesetsk cosmodrome on January 21.

On 2 February, at approximately 0221 GMT. Cosmos 1243 was launched from Tyuratam by an F-1 vehicle. It attained an orbit of 296 x 1015 km,97.85 minutes,inclination of 65.82 degrees, leaving an intermediate stage behind in a 59 x 306 km, 88.16 minute orbit which decayed after less than one revolution. The chosen orbit was such that it passed within 15 km of Cosmos 1241 at 0539 GMT as it approached apogee at the end of its second orbit. The height was 1010 km, and the two craft were at latitude 59 degrees north, longitude 32 degrees east, near Leningrad. At about this time. Cosmos 1243 manoeuvred, so the miss distance may well have been less than that quoted above. The manoeuvre put the interceptor into a trajectory which caused it to re-enter the Earth’s atmosphere; NORAD issued a decay note for the same day.

The interception was similar to that of Cosmos 967 by Cosmos 1009 in May 1978. On that occasion, too, the interception came at the end of the second orbit and the interceptor re-entered immediately. The interception of Cosmos 1171 by Cosmos 1174 during April 1980 started off in a similar way but on that occasion, the interceptor got no closer than about 60 km. However, later manoeuvres produced two more close passes, the second was to within 20 km.

The Cosmos 1174/1171 interception apparently involved also the microthruster-controlled Cosmos 1167. At the time of the first two close passes, it was within 5000 km, and on the occasion of the third interception of 1174 by 1171, it was directly below the event, presumably as an observer. There is no evidence to suggest that any other satellites were involved in the latest test, although Cosmos 1167 was still in orbit along with its later companion Cosmos 1220. During the 1980 test,Cosmos 1167’s orbit was in the same plane as the target and interceptor. On this occasion its (and Cosmos 1220's) orbit was nearly 180 degrees away in longitude.

US press reports at the time of Cosmos 1174 indicated that it and Cosmos 1009 represented a version of the USSR's interceptor which uses optical-thermal detection of the target rather than radar. They were also said to carry (possibly) a laser as the method of disabling the target. The flight of Cosmos 1174 was reported as being a failure because the close interception did not take place on the second orbit, but the interaction between it and Cosmos 1167 suggests this may not necessarily be true.

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SHUTTLE MAIN ENGINES

Following the successful launch of the Columbia in April,emphasis at Rocketdyne, the builders, is on full power level (FPL) development of the engine.

The Orbiter's three main engines were certified in January 1981 for the STS-1 launch and other early Shuttle flights. Full power level, 109 percent of the engine’s nominal operation, is planned for later missions.

A two-year programme of testing is planned to certify the engine for 10,000 seconds, (the equivalent of approximately nine Shuttle missions) at full power operation by early 1983. Three engines will initially be used in the programme to demonstrate operating capability at the higher power level.

Single engine test stands A-1 and A-2 at NASA's National Space Technology Laboratories in Mississippi,.will be used for testing of Engine's 2108 and 0204 respectively. Engine 2108,after re-assembly following incorporation of design modifications to extend its FPL life capability, was installed in Test Stand A-1 in late April. Engine 0204 began FPL testing on Test Stand A-2 in early April. Engine 0110 is undergoing tests on Stand A-3 at Rocketdyne Division's test site in the Santa Susana Mountains in California.

With the 23 March completion of its 109 per cent mission test series,Engine 0008 was designated as a rated power level stand-by engine. During four tests conducted in March, the engine was operated at 107 percent of rated power for 360 seconds during each of two tests and at 109 percent of rated power for 360 seconds during each of the other two tests.

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HIPPARCOS PROPOSALS

ESA has asked for observing proposals for its Hipparcos astrometric satellite to be submitted by October 1982 at the latest. The satellite, due for launch in 1986, will measure the positions, parallaxes and proper motions of some 100,000 stars and star-like objects over its mission life of 2 years.