02 Dec 2009 12:08

The table below shows a chronology of the main activities:

At the end of the last Cebreros pass in the reporting period (DOY 332) Venus Express was orbiting Venus at 249.7 million km from the Earth. The one-way signal travel time was 833.1 seconds.

Spacecraft

Attitude and Orbit Control System (AOCS)
The AOCS is in its nominal configuration and performing nominally. Operations continue with all four reaction wheels.

The friction level on reaction wheel 1 (RW1) remained stable up to DOY 329, when new ASPERA scanner operations were introduced. During these scanner operations there are more pointings, requiring more frequent spacecraft slews. The net effect was a slightly raised friction level on RW1 due to higher wheel speeds. The friction level, however, is still within set limits and has had no negative effect on the spacecraft attitude control.

The new scanner operations also resulted in several spikes being observed in RW2's friction level on DOY 329. RW2 in addition continues to show spikes in its friction level, mainly during the Earth pointing communication periods. The latter behaviour has been correlated to higher bearing temperatures. Both types of spikes are small, but their influence on the spacecraft's attitude is being closely monitored.

Payload Activities

ASPERA
The instrument was regularly operated as part of the routine plan.

MAG
The instrument was regularly operated as part of the routine plan.

PFS
The instrument was not operated during the reporting period.

SPICAV
The instrument was regularly operated as part of the routine plan.

VeRA
No radio science observations were made during the reporting period.

VIRTIS
VIRTIS-M was operated in the visual channels only.

VMC
The instrument was regularly operated as part of the routine plan.

Future Milestones

• Pre-solar conjunction test with the Cebreros ground station on 9 December 2009
• Venus at superior conjunction on 11 January 2010. Venus Express superior conjunction operations: 29 December 2009 to 22 January 2010

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Legal disclaimer
This report is based on the ESOC mission operations report, MOR #211. Please see the copyright section of the legal disclaimer (bottom of this page) for terms of use.