No. 12 - Conclusion of Second Payload Pointing Scenario
After an update of the RF link tool spacecraft performance in terms of RF link can now be predicted in a better way and are within the expected values.
The table below shows a chronology of the main activities in the reporting period:
|
MET (Day) |
Date |
DOY |
Main Activity |
|
73 |
20/01/06 |
020 |
Science data downlink |
|
74 |
21/01/06 |
021 |
Science data downlink |
|
75 |
22/01/06 |
022 |
Spacecraft monitoring |
|
76 |
23/01/06 |
023 |
Start -Y Face exposure |
|
77 |
24/01/06 |
024 |
End -Y face exposure / start cooling |
|
78 |
25/01/06 |
025 |
End cooling / Start +Y face exposure |
|
79 |
26/01/06 |
026 |
End +Y face exposure / Start cooling |
At the end of the last Cebreros pass in the reporting period (DOY 026, 15:00) Venus Express was 26.5 million km from the Earth, 122 million km from the Sun, and 17.7 million km from Venus. The one-way signal travel time was 89 seconds.
Spacecraft Status
Thermal
On DoY 023 at 11.18 the thermal in-flight characterisation has started by exposing the –Y face of the spacecraft to the Sun for 24 hours. After a 24-hours period of cooling also the +Y face has been exposed to the Sun for 24 hours starting on DoY 025 at 11.08. In all the activities conducted so far no anomaly could be observed in the spacecraft behaviour.
Payload Activities
ASPERA
The instrument is off.
MAG
The instrument had been switched ON on DoY 016 and has been switched OFF at the end of the pointing scenario on DoY 021. It will be switched ON again on DoY 032 after the end of the thermal characterisation.
PFS
The instrument is off.
SPICAV
The instrument has been activated on DoY 019 and 020 as part of the payload pointing scenario. Data analysis done by the PI team revealed positive preliminary results.
VeRA
The USO is kept powered but muted.
VIRTIS
The instrument has been activated on DoY 020 as part of the payload pointing scenario. Data analysis is on-going by the PI team.
VMC
The instrument has been activated on DoY 020 as part of the payload pointing scenario. Data analysis is on-going by the PI team.
Future Milestones
The thermal characterisation will finish on DoY 031 when the –Z face will be exposed to the Sun with an aspect angle of 90 degrees for 60 minutes. During this test both STRs will be kept ON in order to try to characterise their behaviour versus straylight.
Further tests will be conducted in the area of TTC to validate the RF link budget tool.
Operations will then be moved again to New Norcia as from DoY 034 as planned to allow the completion of the work to be done in Cebreros. During this period the preparation of the Main Engine calibration will start.