European Space Agency
Press Release No. 12-2006
Paris, France
March 31, 2006

Venus within ESA probe reach

After its five-month, 400-million-kilometre journey inside our Solar System following its lift-off on November 9, 2005, ESA's Venus Express spacecraft will finally arrive on April 11, at its
destination: planet Venus.

Venus Express mission controllers at the ESA Space Operations Centre (ESOC) in Darmstadt, Germany, are making intensive preparations for orbit insertion.

This comprises a series of telecommands, engine burns and manoeuvres designed to slow the spacecraft down from a velocity of 29000 km per hour relative to Venus, just before the first burn, to an entry velocity some 15% slower, allowing the spacecraft to be captured
into orbit around the planet.

The spacecraft will have to ignite its main engine for 50 minutes in order to achieve deceleration and place itself into a highly elliptical orbit around the planet. Most of its 570 kg of onboard propellant will be used for this manoeuvre. The spacecraft's solar arrays will be positioned so as to reduce the possibility of excessive mechanical load during engine ignition.

Over the subsequent days, a series of additional burns will be done to lower the orbit apocentre and to control the pericentre. The aim is to end up in a 24-hour orbit around Venus early in May.

The Venus Orbit Injection operations can be followed live at ESA establishments, with ESOC acting as focal point of interest (see attached programme). In all establishments, ESA specialists will be on hand for interviews.

ESA TV will cover this event live from ESOC in Darmstadt. The live transmission will be carried free-to-air. For broadcasters, complete details of the various satellite feeds are listed at
ESA Television.

The event will be covered on the web at venus.esa.int. The website will feature regular updates, including video coverage of the press conference and podcast from the control room at ESA's Space Operations Centre.

Media representatives wishing to follow the event at one of the ESA establishments listed below are requested to fill in the attached registration form and fax it back to the place of their choice.

For further information, please contact:

ESA Media Relations Division
Tel : +33(0)1.53.69.7155
Fax: +33(0)1.53.69.7690

Venus Express Orbit Insertion - Tuesday April 11, 2006
ESA/ESOC
Robert Bosch Strasse, 5
Darmstadt (Germany)

PROGRAMME  
7:30 Doors open
8:45 Start of local event, welcome addresses
9:10 ESA TV live from Mission Control Room (MCR) starts
9:17 Engine burn sequence starts
9:45 Occultation of spacecraft by Venus starts
9:55 Occultation ends
10:07 Main engine burn ends
10:20 Address by Jean-Jacques Dordain, ESA's Director General,
and other officials
Break and buffet
Interview opportunities
 
11:30 Press Conference
12:15 Jean-Jacques Dordain, Director General, ESA
Prof. David Southwood, Director of Science, ESA
Gaele Winters, Director of Operations and Infrastructure,
ESA
Manfred Warhaut, Flight Operations Director, ESA
Håkan Svedhem, Venus Express Project Scientist, ESA
Don McCoy, Venus Express Project Manager, ESA
1:15 End of event at ESOC

Venus Orbit Insertion Timeline
European Space Agency
March 31 , 2006

Timeline of events during the Venus Orbit Insertion (VOI) manoeuvre, marking arrival of ESA's Venus Express spacecraft at its destination on April 11.

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.

Time Event
(CEST)
 
9:17 VEX main engine burn starts
Venus Express's main engine is due to fire for approximately 51 minutes.
9:45
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.
09:55 Occultation ends
Controllers will closely watch for reacquisition of radio contact once
the occultation ends.
10:07 VEX main engine burn ends
10:10 Announcement by Flight Operations Director
11.07 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.
11:12
Telemetry received
11:30-12:15 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.