Venus Express electrical tests complete
With less than 50 days to go until the scheduled launch of Venus Express, the successful completion of main electrical functional testing means another milestone has been reached.
The System Validation Test 2 (SVT2) was conducted from 29 August until 2 September 2005. The objective of the test was to verify the chain of communications from the Mission Operations Centre (MOC) at ESOC in Darmstadt, Germany, to the spacecraft located at the Baikonur Cosmodrome in Kazakhstan.
The first day of test was a full simulation of the Low Earth Orbit Phase (LEOP) - an important step in validating the readiness of both the MOC and the spacecraft for launch. For this test, the local team in Baikonur configured the spacecraft in exactly the same way as it will be for launch.
This was followed by a simulated separation of the spacecraft from the launcher. The spacecraft was ‘tricked’ in to thinking it had left an imaginary ‘launcher’ by the opening of a number of electrical connections in its umbilical cables which simulated the launch vehicle adaptor.
It correctly sensed the situation and automatically started an on-board sequence (the Separation Sequence Application Programme, SSAP), bringing the spacecraft to life. This sequence included, among other things, priming the propulsion system and deploying the solar array ‘wings’ (which were not actually installed on the spacecraft for this test).
At the end of this automatic sequence, the flight operations team at ESOC took control of the spacecraft and performed, as they will after the real launch, a sequence of manoeuvres required to safely get the spacecraft on its way to Venus. This was the last time that ESOC had the opportunity to directly command the spacecraft before the launch in October - the next time it will be for real!
