ESA Venus Express Status: Payload Check-out Activities
Report for Period 17 February to 23 February 2006
After the successful calibration test of the Main Engine flight activities have focused on payloads check-out activities. The ground segment and industrial teams are busy with the processing of the data acquired during the Main Engine test and are preparing the trim manoeuvre that shall put the spacecraft on the final trajectory to the target point.
According to a first analysis of the data the burn of the Main Engine was nominal with a slight overperformance all recorded during the Liquid Settling Phase. Preliminary estimation of the disturbance torques show that this is within the expected limits and gives a good control margin.
The table below shows a chronology of the main activities in the reporting period:
MET (Day) | Date | DOY | Main Activity |
101 | 17/02/06 | 048 | SC Monitoring |
102 | 18/02/06 | 049 | SC Monitoring |
103 | 19/02/06 | 050 | SC Monitoring |
104 | 20/02/06 | 051 | VIRTIS Check-out |
105 | 21/02/06 | 052 | SPICAV Check-out |
106 | 22/02/06 | 053 | SC Monitoring |
107 | 23/02/06 | 054 | SC Monitoring |
At the end of the last Cebreros pass in the reporting period (DOY 054, 13:00) Venus Express was 54 million km from the Earth, 110 million km from the Sun, and 15.7 million km from Venus. The one-way signal travel time was 180 seconds.
Spacecraft Status
AOCS Preliminary data analysis of Main Engine calibration test shows the following:
- 14% over-performance of the Liquid Settling Phase
- MEBM performance very close to nominal
- Disturbance torques within the expected limits
The manoeuvre size required to fine tune the trajectory is in the order of 20 cm/s and will be executed early morning of 24 February.
Payload Activities
ASPERA The instrument is OFF. Two science acquisitions have been performed on DoY 051 and 054.
MAG The instrument has been switched ON again on DoY 049 and will be kept ON for the next two weeks.
PFS The instrument is off.
SPICAV The instrument is OFF. It has been switched ON on DoY 052 for a check-out activity conducted in real-time. Preliminary analysis of data showed a functioning instrument. The cover has also been actuated twice.
VeRA The USO is kept powered but muted.
VIRTIS The instrument is OFF. It has been switched ON on DoY 051 for a check-out and parameters update activity. .
VMC The instrument is off.
Future Milestones
The spacecraft trajectory will be corrected with a manoeuvre of about 20 cm/s on 24 February and will set the spacecraft on the trajectory to the target point for insertion on 11 April.
Payload activities in the next weeks will include:
- ASPERA calibration
- MAG last science acquisitions
- VMC SW update
- USO Drift test
Additional spacecraft activities will allow characterisation of the Sun sensors and of the outgassing from the –X face in preparation of the VOI phase.
