Venus Express Status Report: Main Engine Calibration Test
Main Engine Calibration Test
17 Feb 2006 13:41
Report for Period 10 February to 16 February 2006
The reporting period has been dedicated to the Main Engine calibration activity, which was successfully conducted in the night between the 16 and 17 February. According to the first telemetry data the burn (3 seconds duration) was nominal and detailed calibration data will now be analysed by the engineers to assess the exact performance of the main engine.
Main Engine calibration burn has shown a working Main Engine thus giving the green light for the last mandatory sub-system to be used for the Venus Orbit Insertion. By coincidence the Main Engine calibration burn took place on mission day 100.
During the reporting period operations have been moved back to the Cebreros station and this will be used as prime station from now onwards.
The table below shows a chronology of the main activities in the reporting period:
|
MET (Day) |
Date |
DOY |
Main Activity |
|
94 |
10/02/06 |
041 |
SC Monitoring |
|
95 |
11/02/06 |
042 |
S-band U/L check |
|
96 |
12/02/06 |
043 |
Skipped |
|
97 |
13/02/06 |
044 |
TCS Configuration for Main Engine Calibration |
|
98 |
14/02/06 |
045 |
SC Monitoring |
|
99 |
15/02/06 |
046 |
Main Engine Pressurisation |
|
100 |
16/02/06 |
047 |
Main Engine Calibration |
At the end of the last New Norcia pass in the reporting period (DOY 048, 05:00) Venus Express was 46.6 million km from the Earth, 112.2 million km from the Sun, and 16.45 million km from Venus. The one-way signal travel time was 155 seconds.
Spacecraft Status
AOCS
The Main Engine calibration burn took place starting on DoY 048 (17 February 2006) at 00:17 with the Boost Initialisation Phase and then the Liquid Settling Phase. The Main Engine fired for circa 3 seconds between 00:27:08 and 00:27:11; the AOCS measured a delta-V of 2.838 m/s versus an expected value of 2.6. Telemetry and radiometric data will now be analysed by the mission teams to give a detailed assessment of the performance. At the exit of this mode the AOCS also successfully went through the first Sun re-acquisition since separation from the launch vehicle.
Payload Activities
ASPERA
The instrument is off.
MAG
The instrument was on producing science and it has been switched off on DoY 44. It will be switched on again after the end of main engine calibration activities.
PFS
The instrument is off.
SPICAV
The instrument is off.
VeRA
The USO is kept powered but muted.
VIRTIS
The instrument is off.
VMC
The instrument is off.
Future Milestones
Activities in the next weeks will be focused to put the spacecraft on its final trajectory to the target point for the Venus Orbit Insertion and to complete outstanding PL check-out and SW update activities. These will include:
- VIRTIS EEPROM parameters update
- SPICAV check-out
- ASPERA calibration
- MAG last science acquisitions
- VMC SW update
Additional spacecraft activities will allow characterisation of the Sun sensors and of the outgassing from the –X face in preparation of the VOI phase.
