From: ESA Venus Express Mission
Posted: Saturday, April 1, 2006
Timeline of events during the Venus Orbit Insertion (VOI) manoeuvre, marking arrival of ESA's Venus Express spacecraft at its destination on 11 April.
VOI is a series of telecommands, engine burns and manoeuvres designed to slow the spacecraft from a velocity of 29 000 kilometres per hour relative to Venus to an entry velocity some 15 percent slower, allowing it to be captured into orbit around the planet.
VEX main engine burn starts
Venus Express's main engine is due to fire for approximately 51 minutes.
Occultation starts (loss of S-band signal)
An occultation occurs when Venus Express travels behind the planet so that the line of site to Earth is blocked; it will lose radio contact (S-band) for almost 10 minutes. During the journey to Venus, communication has been in X-band, via the high-gain antenna HGA2. During VOI, communications reverted to S-Band.
Controllers will closely watch for reacquisition of radio contact once the occultation ends.
VEX main engine burn ends
Announcement by Flight
X-band transmitter on
S-band provides omnidirectional coverage for both up and downlink over small distances, while X-band provides a high-rate data downlink and a telecommand uplink while in Venus orbit.
Press Conference |
All times above are 'Earth Received' time - i.e. after the actual events have taken place at the spacecraft. During orbit insertion, the spacecraft will be 125 000 000 kilometres from Earth and the round-trip signal time will be 13 minutes and 32 seconds.
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