No. 187 - High Gain Antenna Swap
17 June 2009 17:05
Report for Period 7 June to 13 June 2009
The Venus Express spacecraft and instruments performed nominally during this week of quadrature operations. The swap from High Gain Antenna 2 (HGA2) to HGA1 and the associated 180° flip of the spacecraft around its Z-axis were successfully executed prior to the Cebreros ground station pass on 8 June (DOY 159).
The HGA swap and the attitude flip were performed as part of the current quadrature operations: the spacecraft entered an outbound quadrature phase on 29 May, and this phase will last until 3 July 2009. Quadrature phases occur regularly and are defined by the periods in the orbit of the planet Venus during which the Sun-spacecraft-Earth angle is between 75° and 95°.
The HGA1 will be used from now up to the mission's next (inbound) quadrature phase, when the swap back to HGA2 will be performed, in about 14 months time.
The table below shows a chronology of the main activities:
At the end of the last Cebreros pass in the reporting period (DOY 164) Venus Express was orbiting Venus at 114.34 million km from the Earth. The one-way signal travel time was 381 seconds.