No. 111 - Routine Operations
02 Jan 2008 12:00Report for Period 23 December to 29 December 2007
It took several days to download the VIRTIS data stored onboard the spacecraft after the problems at Cebreros reported in the previous week.
The Radio Science Dual band ranging in NNO has failed during this week. The reason is the drop in the S-band signal present in the HGA1 antenna. A fine tuning of the configuration is being attempted in order to optimise the setting.
The table below shows a chronology of the main activities in the reporting period:
At the end of the last Cebreros pass in the reporting period (DOY 363, 12:00z) Venus Express was orbiting Venus at 169.6 million km from the Earth. The one-way signal travel time was 565 seconds.
New Norcia support of radio science
The current ranging standard does not permit different integration times for different bands. The problem is the relatively high signal-to-noise ratio in X-band with respect to S-band making it challenging to optimise integration time. This needs to be short enough to avoid saturation in X-band and long enough to allow tone lock in S-band. New configurations setting will be tried in the next reporting period.