eitb24.com offers an infographics giving complete info of the mission as well as a photo gallery. As the European Space Agency reports, the Venus Express will start orbit insertion at 09:17 CEST.
After a flawless journey across nearly 400 million kilometres of space, the European Space Agency's Venus Express probe is close to its final destination. But the greatest challenge still lies ahead: at 09:17 CEST on April 11th, the spacecraft will need to use its main engine for nearly one full hour to slow down and enter an orbit around Venus. For this critical manoeuvre, precise timing will be crucial.
The spacecraft will have to slow down 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.
Venus Express needed 155 days travelling through space to reach the planet where it will be captured into an orbit by firing the main engine. This process will last for 51 minutes and during the burn sequence, spacecraft controllers at the European Science Operations Centre (ESOC) in Darmstadt, Germany, cannot send commands to the spacecraft, because of its relative position to the Earth during the burn.
At 09:45 occultation starts. Venus Express travels behind Venus so the libe of sight to Earth is blocked and it loses radio contact for almost 10 minutes. During the journey to Venus, communication has been in X-band, via the high-gain antenna HGA2. During VOI, neither of the two high-gain antennas can be used because of the spacecraft orientation. Only the low gain antenna (S-band) can carry a feeble signal to Earth to tell about the spacecraft velocity.
Occultation ends at 09:55. Twelve minutes later, the VEX main engine burn ends. At 11:07 the X-band transmitter of the high-gain antenna HGA1 will be switched on for the first time in the mission, and will start sending Earth information about the health status of the spacecraft. Telemetry will be received from 11:12.