Tim Furniss/LONDON
US intelligence officials admit they were caught unawares when North Korea launched a three-stage satellite booster on 31 August. The attempt failed, but it exposed the USA's lack of knowledge about the country's ability to develop a three-stage rocket.
The booster was a two-stage Taepo Dong 1 ballistic missile, a 1,500-2,200km (930-1,370 miles)-range rocket based on the Soviet Scud, equipped with a solid-propellant third stage. The launcher was probably a prototype of the 4,000-6,000km-range Taepo Dong 2 intercontinental ballistic missile which North Korea plans to develop.
The three-stage booster demonstrated a range of 5,950km, says the US Department of Defense. The Taepo Dong 2, development of which was not expected until 2000-4, would therefore be able to reach the western seaboard of the USA and even eastern Europe.
The USA and Japan, concerned about North Korea's ballistic missile developments, agreed on 21 September to study the possible development of a missile defence system. Japan, meanwhile, is studying the development of a 1m-resolution reconnaissance satellite with which to monitor North Korea's missile development activities.
MISSILE OR LAUNCHER ?
Initial Western reaction was that the August launch was of a missile and the North Korean claim that it was a satellite launch was being used to deflect negative reaction to the test.
The US Department of State toned down its initial negative reaction to North Korea's claim to have launched a satellite using the Taepo Dong 1 missile, by admitting that the flight was "-actually an unsuccessful attempt to launch a satellite", rather than a missile test.
North Korea says that its booster was launched on an azimuth of 86í from Musudan-ri and placed the Kwangmyongsong 1 ("Little Star") satellite into orbit in 4min 53s. The first stage separated at T+95s, and fell into the sea 253km downrange; the payload fairing was jettisoned at T+144s; the second stage flew over Japan and separated at T+266s, landing 1,646km downrange: and the third stage placed the satellite into orbit 27s later.
North Korea says the satellite, which must have weighed less than 50kg, had completed 100 orbits by 14 September. On 21 September North Korea reported that the satellite "...had ceased transmitting patriotic hymns".
Details of the satellite's orbital inclination were never released. Phillip Clark, of the London-based Molniya Space Consultancy, says that the launch azimuth implies an orbital inclination of about 41°.
The satellite was reported to be in a 219 x 6,978km orbit, with a period of 165min 6s, transmitting in the 27MHz frequency range. The USA, however, says no satellite was found in the orbit described by North Korea and no new satellite transmissions were tracked.
Although the launch occurred on 31 August, North Korea's formal announcement that it had launched a satellite was not made until 4 September. Although an informal announcement was placed on an Internet web site on 31 August, it appears that the official launch announcement, planned to be made on 4 September to coincide with the nation's 50th anniversary, went ahead either for propaganda purposes or by mistake.
"This caused confusion, since nothing had been tracked on orbit by the US Space Command [Spacecom] since the launch of Astra 2A on 29 August, but, as a result of computer problems, the NASA Goddard Spaceflight Center could not issue the Spacecom data at the time," says Clark.
Because Goddard did not issue details, it was assumed that the USA was waiting to see whether the satellite was in orbit. But Goddard did not release any satellite data at all during this period because the web page providing the data was being relocated and because the 7 September announcement came during the long Labor Day weekend.
On 4 September, Russia had confused matters by reporting that "the Russian service for monitoring space objects has confirmed that North Korea successfully launched its satellite".
NASA Goddard caught up with all of the data on 8 September and simply reported that Spacecom "-had not been able to confirm North Korean assertions that it launched a small satellite". No object had been found in the orbit described by North Korea nor had any new object or objects been found elsewhere. Russia also retracted its first statement by adding that the "-satellite had not been detected in orbit - so far".
Source: Flight International
