Tim Furniss/LONDON
Arianespace's first Ariane 5 commercial flight placed the European Space Agency's (ESA) X-Ray Multi Mirror (XMM) space telescope into elliptical orbit after launch from Kourou, Guiana, on 10 December.
The success of the fourth Ariane 5 flight buoyed commercial hopes for the booster after a chequered ESA test flight history. The first Ariane 5, carrying four ESA Cluster satellites, failed in June 1996 and the second, carrying demonstration payloads, did not reach its geostationary transfer orbit (GTO) target in October 1997.
A third ESA-funded mission - replacing a commercial mission originally planned by Arianespace - was flown in October 1998, carrying a dummy communications satellite into GTO.
But satellite delays this year and a lack of customer confidence in the launcher meant that the Ariane 504 was left to carry the XMM, Europe's largest payload, placing it not into GTO but into a planned hybrid 827km-113,946km transfer orbit, with an inclination of 40í, 29min after launch. The perigee will be raised by the XMM thrusters to 7,000km.
Arianespace is now ready for up to six Ariane 5 missions in 2000, carrying 12 of the 18 satellites in Arianespace's 40-spacecraft orderbook that are compatible for dual launches on the Ariane 5.
In February, an Ariane 42L launch of the Galaxy X communications satellites will be followed by an Ariane 505 launch of the Insat 3A and AsiaStar satellites.
With an Ariane 44L model scheduled to launch the Galaxy XI communications satellite on 21 December, Arianespace will have completed three launches in just 18 days.
On 3 December, an Ariane 40 launched the Helios 1B reconnaissance satellite and the French military satellite Clementine, built by the UK's Surrey Satellite Technology.
The Ariane 5's single-payload GTO injection capability of 6,300kg (13,875lb) will be increased to 10,500kg by late 2001 and to 12,000kg in 2005 by improvements to the first stage engine and the introduction of new upper stages.
At 3,800kg and 10m (33ft) tall, the XMM telescope is Europe's biggest science satellite. It was built by an industrial consortium of 35 European companies led by DaimlerChrysler Aerospace's Dornier Satellitensysteme.
The XMM, the world's most powerful observatory for X-ray astronomy, will be five times more sensitive than NASA's Chandra X-ray telescope, although the Chandra has a sharper view. The two telescopes will complement each other as they explore the universe for X-rays emitted by supernovae, pulsars and black holes.
Source: Flight International
