Cluster status reports from ESOC
16 August 2000Following the completion of the orbital manoeuvres on Spacecraft FM5 (Rumba) and on FM8 (Tango) on Tuesday 15 August and successfully achieving the GO/NO-GO criteria relative to orbit accuracy, the Main engine of all four spacecraft has been declared not needed anymore. From now on, all manoeuvres will be performed using the 10 N thrusters.
On Wednesday 16 August, the covers protecting the delicate instrumentation of the ASPOC and CIS experiments during launch, have been released. For ASPOC the telemetry data have confermed the success of the operation immediately, for CIS the successful result will be confirmed tomorrow, after analysis of the dowloaded telemetry data.
"Another successful step has been achieved today" commented the deputy Project Manager Alberto Gianolio "we will soon be able to start the commissioning of the 44 experiments and to experience the full power of the four cluster spacecraft in formation." The next planned activity will be the release of the radial rigid booms on the four spacecraft, which will take place starting from Thursday 17 August until Monday 21 August.
Following the successful launch of the second pair of ESA's Cluster satellites on Wednesday, 9 August at 13:13 CEST, all major orbit manoeuvres were successfully completed for each spacecraft. The last inclination change manoeuvre and perigee raising was performed yesterday, 13 August at 18:55 and 18:58 CEST over the Perth and Canberra ground stations. Subsequent analysis revealed excellent manoeuvre performance. The spacecraft are now in their final elliptical orbit with 17.200 km perigee and 120.600 km apogee. In order to bring the spacecraft to their required attitude a small slew manoeuvre to 94 degrees is planned for today at 17:15 and 19:15 hrs. local time. CIS and ASPOC experiment cover release is planned for 16 August. Until 26 August a series of orbit trim manoeuvres will be carried out in order to acquire the first tetrahedron constellation.
"Thanks to these manoeuvres skillfully performed by ESOC, our four spacecraft are now truly a cluster! We are very happy to have reached this long-awaited goal," said a delighted Alberto Gianolio, Cluster deputy project manager. A full report will be published after the spin-down manoeuvres this afternoon.
12 August 2000
The third apogee raising manoeuvre was performed today at 01:35 CEST for spacecraft FM5 (Rumba) and at 02:19 CEST for FM8 (Tango)
The manoeuvre took place nominally with very good result. "Again, as for the first couple of spacecraft, the precision achieved by means of careful flight dynamics computations by the ESOC team for this type of manoeuvres is absolutely remarkable" said Alberto Gianolio, Cluster deputy project manager.
11 August 2000
The second apogee raising manoeuvre was performed today, 11 August at 5:40 CEST for spacecraft FM5 (Rumba) and at 6:58 CEST for FM8 (Tango) out of ground station coverage. Subsequent analysis releaved excellent manoeuvre performance. The spacecraft are now in an elliptical orbit with 240 km perigee and 33.997 km apogee. In order to bring the spacecraft to their operational orbit another two apogee raising manoeuvres and an inclination change manoeuvre to the desired 90 degrees inclination are required. The next apogee raising manoeuvre is foreseen for tonight, 12 August at 1:34 and 2:18 local Darmstadt time. The two satellites will join the first pair on 15 August and complete the formation.
10 August 2000
Following the successful launch of the second pair of four ESA Cluster satellites on 9th August at 13:13 CEST, the first signals of both spacecraft have successfully been acquired at 14:45. Operations are proceeding to schedule. Both spacecraft have undergone a spin-up manoeuvre from 5 to 13.7 revolutions per minute and an attitude manoeuvre. The first apogee raising manoeuvre took place out of ground station coverage today, 10 August at 10:53 for FM 8 (Tango) and at 15:59 for FM5 (Rumba). Subsequently both spacecraft were acquired confirming the successful burn and the correct orbit. The spacecraft are now in an orbit with 239 km perigee and 23.199 km apogee. The next apogee raising manoeuvre will take place tomorrow, 11th August at 5:46 and 7:05 local Darmstadt time. In total 4 apogee raising manoeuvres will be performed plus an inclination change manoeuvre to the desired 90 degrees inclination. These shall bring the two spacecraft to the required operational orbit by 15 August.
9 August 2000 23:21
The Cluster Rumba spacecraft has already been observed from the Starkenburg observatory, by the same team that observed the first two Cluster satellites, Salsa and Samba.