1996-F03
The four Cluster satellites, part of ESA's Cornerstone 1 (CS1) project, were lost in the launch failure of the first Ariane 5.
Cluster F1 was paired with Cluster F2 above the Speltra structure on Ariane 501. The Dornier built satellite had a mass of 1200 kg at launch. 650 kg of this is N2O2/MMH fuel. DDS (Dornier Satellitensysteme) is a unit of Daimler-Benz Aerospace (DASA). The propulsion system was built by Matra Marconi Space/Bristol (formerly British Aerospace) using a DASA 400N/8 x10N thruster system.
The plan was for the Ariane 5 EPS to leave the four spacecraft in a 280 x 36000 km x 10 deg orbit. Cluster F1 and F2 separate from Speltra and then from each other. Five burns with the 400N engine on each satellite leaves them in a 25000 x 140000 km polar orbit. The four spacecraft are maintained in a tetrahedral cluster with 200 to 18000 km separations. The satellite has four 50-m booms with 100m span, and is 2.9m diameter and 1.3m tall. There are also two 5-m booms with magnetometers. Science goals include study of the bow shock, the polar cusp, and the magnetotail. The mission is commanded from ESOC with a science center at RAL.
The Ariane 5 took off from ELA3 at Kourou, but half a minute into the flight, travelling at an altitude of 3500 m, the on-board computer incorrectly read the vehicle's attitude and ordered the vehicle to turn sharply, causing structural failure. The vehicle automatically self destructed when the solid boosters and core stage broke apart.
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| Cluster F1/Ariane 501 |
| |
|
| Date | Time | Event | Orbit |
|---|
|
| 1996 Jun 4 | 1233:59 | EPC Vulcain ignition (H0) |
| | 1234:06 | EAP ignition |
| | 1234:06 | Launch by Ariane 5 (501) | CSG ELA3 |
| | 1234:36 | Altitude 3.5 km |
| | 1234:36 | EAP nozzles hard over |
| | 1234:37? | Vulcain nozzle hard over |
| | 1234:37 | L0+31.3s: EPS N2O4 tank rupture? |
| | 1234:38.5 | L0+32.5s: 90 deg angle of attack |
| | 1234:38 | L0+32.8s? EPC structural breakup |
| | 1234:39 | Vehicle destroyed |
Payload:
- ASPOC Active SC Potential Control
- CIS Cluster Ion Spectrometry
- DWP Digital Wave Processor
- EFW Electric Fields and Waves
- EDI Electron Drift Instrument
- FGM Fluxgate Magnetometer
- PEACE Plasma Electron and Current Analyser
- RAPID Research with Adaptive Particle Imaging Detectors
