No. 194 - Earth Occultation Season #7
05 Aug 2009 11:08
Report for Period 26 July to 1 August 2009
The Venus Express spacecraft and instruments performed nominally during this week. The seventh Earth occultation season is ongoing, with three observations performed in this reporting period. An orbit control manoeuvre (OCM) was carried out in the night of 25-26 July between 23:06 and 02:07 UT. This manoeuvre constitutes a phase correction to keep the phasing of Venus Express in its orbit in sync with mission operations from ground.
VeRa Earth occultation season #7
The occultation measurements are part of the Venus Express Radio Science Investigations (RSI) performed under the Venus Radio Science experiment (VeRa). For these investigations the VeRa team makes use of the radio links of the spacecraft's communications system. The spacecraft's High Gain Antenna is pointed toward the Earth before the approach to occultation and a dual signal is sent in the S-band and X-band. Just before and after the occultation, the transmitted radio signal passes through the ionosphere and atmosphere of Venus. The effect that this has on the received signal gives valuable information on the composition and characteristics of the atmosphere as a function of altitude.
The 35m ESA deep space antenna at New Norcia (NNO), Australia, was used for receiving the spacecraft's radio signals on ground.
The table below shows a chronology of the main activities:
At the end of the last Cebreros pass in the reporting period (DOY 213) Venus Express was orbiting Venus at 169.9 million km from the Earth. The one-way signal travel time was 566 seconds.