Double Star Status Report - February 2006
15 February 2006 14:42Mission Status
The two spacecraft and the instruments are operating nominally. The drift of the spin axis is continuing as predicted, TC-1 spin axis is about 3.5 from the ecliptic pole and TC-2 around 16°. It should not cause problems before July 2006 for TC-2 and December 2006 for TC1. TC-1 has entered the eclipse season that will last 7 months and payload operations will be reduced during eclipses longer than one hour.
Operations and Archiving
The European Payload Operation System (EPOS) co-ordinates the operations for the seven European instruments on TC-1 and TC-2 and is running smoothly. The new contract for the extension of EPOS, starting 1 January 2006, is being signed by RAL. ESOC acquired on average about 3 hours of data per day using the VILSPA 2 ground station and covered around 80% of the passes. The rest of the passes were acquired by the Chinese stations in Shanghai and Beijing.
On 27 December 2004, radiation from the biggest starquake on a neutron star ever recorded reached Earth. Unique data obtained by Double Star TC-2 and Cluster satellites have shown the first observational evidence of cracks in the neutron star crust, during the initial phase of the starquake. The intensity of this major peak was hundreds of times stronger than any other observed so far (only two other giant flares have been recorded in the past 35 years). For the first 200 ms it saturated almost all instruments on satellites equipped to observe γ-rays. Although designed to study the Earth's magnetosphere, the PEACE instruments onboard Double star TC-2 and Cluster satellites performed unsaturated observations of this initial flare rise and decay. This result, published in the Astrophysical Journal, will help to discriminate between current theories on the physical origin of such massive starquakes.