Tim Furniss/LONDON
The Hughes-built AsiaSat 3 communications satellite was left drifting in a useless orbit after the the failure of the fourth stage of the Russian Proton K booster which launched it from Baikonur on 24 December.
It was the first failure suffered by the US/Russian ILS International Launch Services consortium, which markets the Proton and Atlas vehicles (Flight International, 17-23 December, 1997).
The launch was the final in a sequence of six flights undertaken between 20 and 24 December by European, Russian and US vehicles carrying 17 satellites.
The $70 million Khrunichev Proton launch from Pad 23 at Baikonur was also the first in the vehicle's history to be delayed - by two days - because of high winds at altitude. The launch went well up to the first burn of the Proton's Energia DM stage, which placed the Asiasat 3 and the DM stage into geostationary-transfer orbit.
The second DM stage burn to circularise the orbit to a geostationary position over the equator cut out only 1s into the planned 110s firing, because of a suspected turbopump malfunction. The satellite, which separated from the DM stage, was stranded in a 26,008 x 203km orbit at 51.37¹ inclination. It was the third DM failure since May 1996.
There is not enough propellant on the 2,534kg satellite to raise it to the required orbit and it will be written off as an insured loss. A replacement satellite will be ordered by Hong Kong-based AsiaSat and could be delivered in 15 months' time.
The nine planned ILS Proton launches scheduled for 1998 will be delayed pending an investigation. A new Breeze M upper stage is scheduled to replace the DM stage in about 1999.
Also on 24 December, a Start 1 booster - a modified SS-25 missile - launched from the Svobodny Cosmodrome in Russia's Far East, successfully placed the US Early Bird commercial remote-sensing satellite into 473km Sun-synchronous orbit.
The Early Bird's 3m-resolution images will be marketed by Earthwatch of Colorado. A 1m-resolution satellite, the Quick Bird, is planned for 1999.
An Orbital Sciences (OSC) Pegasus XL booster placed eight Orbcomm data-communications satellites into an 810km, 45¹-inclination orbit, after an air launch from a Lockheed L-1011 carrier aircraft off the east coast of the USA on 23 December.
It was the fifth consecutive successful XL mission of 1997. Ten of a planned 28 satellites for OSC-subsidiary Orbcomm have been launched and these are due to be joined by a further ten by the end of 1998.
The launch was delayed when the US Office of Commercial Space Transportation temporarily revoked a launch licence, pending investigations into OSC's work to ensure that the hypergolic upper stage of the Pegasus XL is safe. In 1995, a similar spent stage exploded in orbit, creating more than 700 pieces of trackable space debris.
Russia launched the Progress M37 tanker on a Soyuz booster from Baikonur on 22 December, to dock successfully with the Mir space station.
On the same day, Arianespace lofted the Intelsat 804 communications satellite into orbit on flight V104/42L - the eleventh Ariane 4 flight of 1997, and 19 days after the previous Ariane launch. Arianespace's next launch will be the V105/44LP, carrying the Brasilsat B3 and Inmarsat 3F5 satellites, and is scheduled for 27 January.
Five Motorola Iridium satellites were placed in orbit by a Delta 2 launched from Vandenberg AFB, California, on 20 December. Forty-six Iridium satellites have been launched in eight months, with 26 more planned this year to provide worldwide mobile-telephone services by September.
Source: Flight International
