ESA Venus Express Status Report No. 91

15 Aug 2007 17:30 Report for Period 05 August to 11 August 2007

Routine observations took place during this reporting period, occurring as planned. The spacecraft is nearing its closest approach to Earth, and the reduced distance allowed to sustain the highest TM Bit Rate with HGA2 (228 kbps).

Taking advantage of the high bit rate, the second VIRTIS Movie activity started this week (will conclude next week), and due to several causes data overflows occurred in the VIRTIS Packet Store which led to limited data losses.

At the end of the last Cebreros pass in the reporting period (DOY 223, 15:00z) Venus Express was orbiting Venus at 44.1 million km from the Earth. The one-way signal travel time was 147 seconds.

Payload Activities

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

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

PFS
No PFS operations were carried out this week.

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

VeRA
No RSI activities took place this week

VIRTIS
As of DOY 218, the instrument commenced the second VIRTIS Movie activities. This involved taking numerous time-lapse images of the South Pole, over a symmetric apocenter arc, to be later processed into an animation. This activity generates large amounts of data (thus leaving little spare capacity in the science packet store), and it requires the highest bit rate to be used for downlink. This in turn implies that any problems at the ground station, even brief ones, can result in relatively large data volumes not being dumped, and thus the potential for data overflows onboard is greatly increased.

VMC
The instrument is operated as part of the routine plan.

Future Milestones

• VIRTIS Movie #2 scheduled in the second week of August.


• Low PLL bandwidth acquisition tests with LGA and S-band over NNO scheduled for mid-August.