Venus Express set for launch to the cryptic planet (Forwarded)

European Space Agency
Press Information Note No. 01-2005
Paris, France 21 October 2005

Venus Express set for launch to the cryptic planet

A dense curtain of mysteries surrounding Venus, the hot and hazy sister
planet to Earth, awaits to be opened after the launch of Venus Express,
the next planetary probe of the European Space Agency.

On Wednesday, 26 October 2005, the sky over the Baikonur Cosmodrome,
Kazakhstan, will be illuminated by the blast from a Soyuz-Fregat rocket
carrying this precious spacecraft aloft.

The celestial motion of the planets in our Solar System has given Venus
Express the window to travel to Venus on the best route. In fact, every
nineteen months Venus reaches the point where a voyage from Earth is the
most fuel-efficient. To take advantage of this opportunity, ESA has
opted to launch Venus Express within the next 'launch window', opening
on 26 October this year and closing about one month later, on 24 November.

Again, due to the relative motion of Earth and Venus, plus Earth's daily
rotation, there is only one short period per day when it is possible to
launch, lasting only a few seconds. The first launch opportunity is on
26 October at 06:43 Central European Summer Time (CEST) (10:43 in
Baikonur, 04:43 GMT).

Venus Express will take only 163 days, a little more than five months,
to reach Venus. Then, in April 2006, the adventure of exploration will
begin with Venus finally welcoming a spacecraft, a fully European one,
more than ten years after humankind paid the last visit.

The journey starts at launch

One of the most reliable launchers in the world, the Soyuz-Fregat
rocket, will set Venus Express on course for its target. Soyuz, procured
by the European/Russian Starsem company, consists of three main stages
with an additional upper stage, Fregat, atop. Venus Express is attached
to this upper stage.

The injection of Venus Express into the interplanetary trajectory which
will bring it to Venus consists of three phases. In the first nine
minutes after launch, Soyuz will perform the first phase, that is an
almost vertical ascent trajectory, in which it is boosted to about 190
kilometres altitude by its three stages, separating in sequence.

In the second phase, the Fregat-Venus Express 'block', now free from the
Soyuz, is injected into a circular parking orbit around Earth heading
east. This injection is done by the first burn of the Fregat engine, due
to take place at 06:52 CEST (04:52 GMT).

At 08:03 CEST, about one hour and twenty minutes after lift-off and
after an almost full circle around Earth, the third phase starts. While
flying over Africa, Fregat will ignite for a second time to escape Earth
orbit and head into the hyperbolic trajectory that will bring the
spacecraft to Venus.

After this burn, Fregat will gently release Venus Express, by firing a
separation mechanism. With this last step, the launcher will have
concluded its task.

Plenty of ground activities for a successful trip

Once separated from Fregat at 08:21 CEST, Venus Express will be awoken
from its dormant status by a series of automatic on-board commands, such
as the activation of its propulsion and thermal control systems, the
deployment of solar arrays and manoeuvres to 'orient' itself in space.

From this moment the spacecraft comes under the control of ESA's
European Space Operations Centre (ESOC) for the full duration of the
mission. The flight control team co-ordinate and manage a network of ESA
ground stations and antennas around the globe, to regularly communicate
with the spacecraft.

The New Norcia station in Australia and the Kourou station in French
Guiana will in turn communicate with Venus Express in the initial phase
of the mission. The first opportunity to receive a signal and confirm
that the spacecraft is in good health will be the privilege of the New
Norcia station about two hours after launch.

In this early phase of the mission, once ESOC has taken full control of
the satellite, the spacecraft will be fully activated. Operations will
also include two burns of the Venus Express thrusters, to correct any
possible error in the trajectory after separation from Fregat.

On 28 October, the newly inaugurated Cebreros station in Spain, with its
35-metre antenna, will start to take an active part in ground network
operations to relay information between ESOC and the spacecraft. During
the cruise phase and once the spacecraft has arrived at Venus, Cebreros
will be the main information relay point between ESOC and Venus Express.

Reaching for Venus

During its 163 day journey to Venus, Venus Express will cover about 400
million kilometres at an average speed of some 28 kilometres per second
with respect to the Sun. After an initial commissioning period, the
spacecraft will cruise peacefully with no specific operations planned,
besides routine checks of its subsystems and scientific instruments, and
minor trajectory corrections if needed.

The thrills will start again on 6 April 2006, at the end of the cruise,
when the spacecraft will have to perform a delicate manoeuvre to brake
and be captured into orbit around Venus. The energy required for Venus
Orbit Insertion (VOI) is very high, and will need the main engine to
fire (burn) for approximately 51 minutes.

This manoeuvre will place the spacecraft in a highly elliptical
'capture' orbit around the planet, with a pericentre (closest point to
the Venusian surface) of 250 kilometres near the north pole, and an
apocentre (furthest distance from the surface) at 350 000 kilometres
roughly at the south pole.

At the end of this initial 10-day 'capture' orbit, Venus Express will
ignite its main engine again. About six days later, after a series of
other minor orbit adjustments, the spacecraft will have been positioned
in its final operational orbit. This will be an elliptical polar orbit,
lying between 250 and 66 000 kilometres above Venus, and will last 24 hours.

The capture orbit could already provide the first opportunity for
scientific observations, but the nominal science phase will start on 4
July 2006, after the spacecraft and instruments commissioning phase has
been concluded.

The set of seven instruments on board Venus Express represents an
unprecedented diagnostic package to study the thick and enigmatic
atmosphere of Venus -- an atmosphere so dense and so intimately coupled
with the planet's surface, that studying it will help provide clues
about the features, status and evolution of the entire planet.

Note to editors

Venus Express is an almost identical twin spacecraft to Mars Express,
but adapted to operate in the hot and harsh environment around Venus. It
was built by EADS Astrium, Toulouse (France), leading a group of
industrial partners throughout Europe. Completing the spacecraft took
less than four years from concept to launch, making it the fastest-built
ESA scientific satellite ever.

Besides the spacecraft manufacturing and testing, industry will still be
involved during the mission on a collaboration and consultancy basis for
the ESA Venus Express Project team, led by the Project Manager, and for
the Venus Express ground control team, led by the Spacecraft Operations
Manager.

On 4 July 2006, when the nominal science phase begins, the Venus Express
Project Manager will hand over responsibility for the mission to an ESA
Venus Express Mission Manager, leading the Venus Express Science
Operations Centre (VSOC) in ESA's European Space Research and Technology
Centre (ESTEC) in the Netherlands. The VSOC performs the routine
planning for scientific observations, in co-ordination with the Project
Scientist and the instrument Principal Investigators.

ESA's investment in Venus Express amounts to about 220 million Euros,
covering development of the spacecraft, launch and operations. This
figure also includes 15 million Euros for instrument development,
including support to several research institutes (Principal
Investigators) for building the instruments. Venus Express is one of a
family of missions in which costs are shared, the others being Rosetta
and Mars Express.

For more information:

ESA Media Relations Division
Tel: +33 (0) 1 53 69 71 55
Fax: +33 (0) 1 53 69 76 90

Don McCoy, ESA Venus Express Project Manager
E-mail: Don.McCoy @ esa.int

Hakan Svedhem, ESA Venus Express Project Scientist
E-mail: Hakan.Svedhem @ esa.int

More about...

* Looking at Venus
http://www.esa.int/SPECIALS/Venus_Express/index.html
* Venus Express factsheet
http://www.esa.int/esaSC/SEM2EE1A6BD_index_0.html
* Venus Express in-depth
http://sci.esa.int/venusexpress
* Status reports
http://sci.esa.int/science-e/www/obj...objectid=31574
&farchive_objecttypeid=31 &farchive_objectid=30928

Related articles

* Venus Express ready for lift-off
http://www.esa.int/esaCP/SEM5M76Y3EE_index_0.html
* Postcards from Venus: enter the Planetary Society Art Contest
http://www.esa.int/esaCP/SEMGR66Y3EE_index_0.html
* Venus Express mated with upper-stage
http://www.esa.int/esaCP/SEMTYW5Y3EE_index_0.html
* Venus Express Flight Control Team preps for launch
http://www.esa.int/esaCP/SEM9TY5Y3EE_index_0.html
* Venus Express ready for 'mating' with upper-stage
http://www.esa.int/SPECIALS/Venus_Ex...XB5Y3EE_0.html
* Venus Express propellant loading completed
http://www.esa.int/SPECIALS/Venus_Ex...1A5Y3EE_0.html
* Venus Express gets wings
http://www.esa.int/SPECIALS/Venus_Ex...MW7X9DE_0.html
* Venus Express electrical tests complete
http://www.esa.int/esaSC/SEM31B7X9DE_index_0.html
* No shortage of mysteries on Venus
http://www.esa.int/esaCP/ESAHRH7708D_index_0.html

[NOTE: Images supporting this release are available at
http://www.esa.int/esaCP/SEM0U7R01FE_index_1.html ]

"Andrew Yee" wrote in message
...
European Space Agency
Press Information Note No. 01-2005
Paris, France 21 October 2005

Venus Express set for launch to the cryptic planet

A dense curtain of mysteries surrounding Venus, the hot and hazy sister
planet to Earth, awaits to be opened after the launch of Venus Express,
the next planetary probe of the European Space Agency.

On Wednesday, 26 October 2005, the sky over the Baikonur Cosmodrome,
Kazakhstan, will be illuminated by the blast from a Soyuz-Fregat rocket
carrying this precious spacecraft aloft.

Provided they don't lose this one like the last two. I wish them good
luck. I know it is an exciting mission.