Rosetta
European Space Agency

Third Lander Commissioning Slot

May 24, 2004

Report for week 14 to 21 May

The main activities in the reporting period were the touch-up deep-space manoeuvre, the second Comet Linear observation and the completion of the Lander commissioning slot 3.

The touch-up deep-space manoeuvre was executed on 16 May and very successfully completed the trajectory targeting activities that were planned around perihelion. Spacecraft performance for this short burn (less than 17 minutes, for a delta-V of 4.989 ms-1) was again very good, with an error of the order of 5 mms-1.

The spacecraft +Z axis was pointed to Comet Linear on 17 May for several hours, to allow scientific observations by ALICE and MIRO. Reports on the results of this observation have not been finalised by the Principal Investigators yet, however all instrument telecommands were successfully executed.

The Lander commissioning slot 3 has also been carried out very successfully, with achievement of all the objectives for this slot. The next Lander activation is currently planned for the last commissioning period in Autumn 2004.

ROSINA RTOF and DFMS instrument covers were opened on 18 May in preparation for the last commissioning slot scheduled to begin next week.

On the subsystems side the thermal environment is stable as the spacecraft is now very close to perihelion, which will be reached on 24 May at 17:00. The temperature of the fuel and oxidizer tanks were controlled via manual heater switching to remain around 20 ?C in view of the isolation planned for next week.

The table below shows a chronology of the main activities in the reporting period:

Mission
Day Date DOY Main Activity
74 14/15.05.04 135/136 Lander commissioning slot 3 pass 2
75 15/16.05.04 136/137 Lander commissioning slot 3 pass 3
76 16/17.05.04 137/138 DSM-1 Touch-up Manoeuvre;
Lander commissioning slot 3 pass 4
77 17/18.05.04 138/139 Lander commissioning slot 3 pass 5
78 18/19.05.04 139/140 Lander commissioning slot 3 pass 6
79 19/20.05.04 140/141 Lander commissioning slot 3 pass 7
80 20/21.05.04 141/142 Lander commissioning slot 3 pass 8

At the end of the last New Norcia pass in the reporting period (DOY 142, 02:00) Rosetta was at 35.9 million km from the Earth. The one-way signal travel time was exactly 2 minutes.

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