Esa Bulletin November 1998 [antikvár]

Ariane-5 Completes Flawless Third Test FlightA launch-readiness review conducted on Friday 16 and Monday 19 October had given the go-ahead for the final countdown for a launch just two days later within a 90-minute launch window between 13:00 to 14:30 Kourou time. The launcher's roll-out from the Final Assembly Building to the Launch Zone was therefore scheduled for Tuesday 20 October at 09:30 Kourou time.On 21 October, Europe reconfirmed its lead in providing space transportation systems for the 21st Century. Ariane-5, on its third qualification flight, left no doubts as to its ability to deliver payloads reliably and accurately to Geostationary Transfer Orbit (GTO). The new heavy-lift launcher lifted off in glorious sunshine from the Guiana Space Centre, Europe's spaceport in Kourou, French Guiana, at 13:37:21 local time (16:37:21 UT).This third Ariane-5 test flight was intended primarily to qualify Europe's new launcher for satellite injection into GTO, but also carried the Atmospheric Reentry Demonstrator (ARD) capsule, packed with the most advanced equipment to test and qualify new European technologies and flight-control capabilities for atmospheric reentry and landing. Flight 503 was the final qualification flight carried out under ESA responsibility prior to the launcher entering commercial service with Arianespace.The launch, delayed twice from 13:00 by minor problems, was flawless. The solid-propellant boosters separated as planned at an altitude of about 62 km, 2 min 16 sec into the flight. The fairing was jettisoned after 3 min 6 sec, followed by separation of the cryogenic main stage after 9 min 52 sec at an altitude of 168 km. The Atmospheric Reentry Demonstrator was released approximately 2 min later, at an altitude of 216 km, and 3 min 14 sec thereafter the storable-propellant upper stage began to propel the stage assembly and Maqsat-3, built by Kayser-Threde, Germany, as a representative mock-up of a commercial satellite, towards its injection point. Almost exactly 33 min after lift-off, the upper-stageengine shut down and Maqsat-3 was successfully injected into GTO. The orbital parameters at that point were:Perigee: 1027 km, compared with the1028 3 km predicted Apogee: 35 863 km, compared with the 35 898 200 km predicted Inclination: 6.999 deg, compared with the 6.998 0.05 deg predicted.Speaking in Kourou immediately after the flight, Fredrik Engstrom, ESA's Director of Launchers and the Ariane-503 Flight Director, confirmed that: "The third Ariane-5 flight has been a complete success. It qualifies Europe's new heavy-lift launcher and vindicates the technological options chosen by the European Space Agency. "ESA's Director General, Antonio Rodota, speaking at the European Press Centre at Evry near Paris, drew the media's attention to the fact that : "The European Space Agency is already working to meet the challenges of the 21st Century with increasingly powerful and versatile launchers designed to handle the widest possible range of space missions."This sentiment was echoed by Alain Bensoussan, Chairman of CNES (to which ESA has delegated prime contractor responsibility for the new launcher), who commented that: "France is proud to have helped make this ambitious European programme a success. The Ariane programme, consolidating as it does Europe's standing in the world space community, is an outstanding illustration of Europe's capacity to pool its best scientific and industrial teams in pursuit of a common goal."With the highly successful release, reentry and subsequent recovery of the automatic Atmospheric Reentry Demonstrator capsule (built for ESA by the French company Aérospatiale), Europe has moved a step closer to flying its own complete space missions. Engineers analysing real-time telemetry data