The European Mars Express spaceprobe has been placed successfully in
a trajectory that will take it beyond the terrestrial environment
and on the way to Mars – getting there in late December. This first
European Space Agency probe to head for another planet will enter an
orbit around Mars, from where it will perform detailed studies of
the planet’s surface, its subsurface structures and its atmosphere.
It will also deploy Beagle 2, a small autonomous station which will
land on the planet, studying its surface and looking for possible
signs of life, past or present.
The probe, weighing in at 1 120 kg, was built on ESA’s behalf by a
European team led by Astrium. It set out on its journey to Mars
aboard a Soyuz-Fregat launcher, under Starsem operational
management. The launcher lifted off from Baikonur in Kazakhstan on 2
June at 23.45 local time (17:45 GMT). An interim orbit around the
Earth was reached following a first firing of the Fregat upper
stage. One hour and thirty-two minutes later the probe was injected
into its interplanetary orbit.
“Europe is on its way to Mars to stake its claim in the most
detailed and complete exploration ever done of the Red Planet. We
can be very proud of this and of the speed with which have achieved
this goal”, said David Southwood, ESA’s Director of Science
witnessing the launch from Baikonur. Contact with Mars Express has
been established by ESOC, ESA’s satellite control centre, located in
Darmstadt, Germany. The probe is pointing correctly towards the Sun
and has deployed its solar panels. All on-board systems are
operating faultlessly. Two days from now, the probe will perform a
corrective maneuvre that will place it in a Mars-bound trajectory,
while the Fregat stage, trailing behind, will vanish into space –
there will be no risk of it crashing into and contaminating the Red
Planet.
Mars Express will then travel away from Earth at a speed exceeding
30 km/s (3 km/s in relation to the Earth), on a six-month and 400
million kilometre journey through the solar system. Once all payload
operations have been checked out, the probe will be largely
deactivated. During this period, the spacecraft will contact Earth
only once a day. Mid-journey correction of its trajectory is
scheduled for September.
There in time for Christmas
Following reactivation of its systems at the end of November, Mars
Express will get ready to release Beagle 2. The 60 kg capsule
containing the tiny lander does not incorporate its own propulsion
and steering system and will be released into a collision trajectory
with Mars, on 20 December. It will enter the Martian atmosphere on
Christmas day, after five days ballistic flight. As it descends,
the lander will be protected in the first instance by a heat-shield;
two parachutes will then open to provide further deceleration. With
its weight down to 30 kg at most, it will land in an equatorial
region known as Isidis Planitia. Three airbags will soften the final
impact. This crucial phase in the mission will last just ten
minutes, from entry into the atmosphere to landing.
Meanwhile, the Mars Express probe proper will have performed a
series of maneuvres through to a capture orbit. At this point its
main motor will fire, providing the deceleration needed to acquire a
highly elliptical transition orbit. Attaining the final operational
orbit will call for four more firings. This 7.5 hour quasi-polar
orbit will take the probe to within 250 km of the planet.
Getting to know Mars – inside and out
Having landed on Mars, Beagle 2 – named after HMS Beagle, on which
Charles Darwin voyaged round the world, developing his evolutionary
theory – will deploy its solar panels and the payload adjustable
workbench, a set of instruments (two cameras, a microscope and two
spectrometers) mounted on the end of a robot arm. It will proceed to
explore its new environment, gathering geological and mineralogical
data that should, for the first time, allow rock samples to be dated
with absolute accuracy. Using a grinder and corer, and the “mole”, a
wire-guided mini-robot able to borrow its way under rocks and dig
the ground to a depth of 2 m, samples will be collected and then
examined in the GAP automated mini-laboratory, equipped with 12
furnaces and a mass spectrometer. The spectrometer will have the job
of detecting possible signs of life and dating rock samples.
The Mars Express orbiter will carry out a detailed investigation of
the planet, pointing its instruments at Mars for between
half-an-hour and an hour per orbit and then, for the remainder of
the time, at Earth to relay the information collected in this way
and the data transmitted by Beagle 2.
The orbiter’s seven on-board instruments are expected to provide
considerable information about the structure and evolution of Mars.
A very high resolution stereo camera, the HRSC, will perform
comprehensive mapping of the planet at 10 m resolution and will even
be capable of photographing some areas to a precision of barely 2 m.
The OMEGA spectrometer will draw up the first mineralogical map of
the planet to 100 m precision. This mineralogical study will be
taken further by the PFS spectrometer – which will also chart the
composition of the Martian atmosphere, a prerequisite for
investigation of atmospheric dynamics. The MARSIS radar instrument,
with its 40 m antenna, will sound the surface to a depth of 2 km,
exploring its structure and above all searching for pockets of
water. Another instrument, ASPERA, will be tasked with investigating
interaction between the upper atmosphere and the interplanetary
medium. The focus here will be on determining how and at what rate
the solar wind, in the absence of a magnetic field capable of
deflecting it, scattered the bulk of the Martian atmosphere into
space. Atmospheric investigation will also be performed by the
SPICAM spectrometer and the MaRS experiment, with special emphasis
on stellar occultation and radio signal propagation phenomena.
The orbiter mission should last at least one Martian year (687
days), while Beagle 2 is expected to operate on the planet’s surface
for 180 days.
Only a start to exploration
This first European mission to Mars incorporates some of the
objectives of the Euro-Russian Mars 96 mission, which came to grief
when the Proton launcher failed. And indeed a Russian partner is
cooperating on each of the orbiter’s instruments. Mars Express forms
part of an international Mars exploration programme, featuring also
the US probes Mars Surveyor and Mars Odyssey, the two Mars
Exploration Rovers and the Japanese probe Nozomi. Mars Express may
perhaps, within this partnership, relay data from the NASA rovers
while Mars Odyssey may, if required, relay data from Beagle 2.
The mission’s scientific goals are of outstanding importance. Mars
Express will, it is hoped, supply answers to the many questions
raised by earlier missions – questions concerning the planet’s
evolution, the history of its internal activity, the presence of
water below its surface, the possibility that Mars may at one time
have been covered by oceans and thus have offered an environment
conducive to the emergence of some form of life, and even the
possibility that life may still be present, somewhere in putative
subterranean aquifers. In addition the lander doing direct analysis
of the soil and the environment comprises a truly unique mission.
Mars Express, drawing heavily on elements of the Rosetta spacecraft
awaiting to be launched to a comet next year, paves the way for
other ESA-led planetary missions, with Venus Express planned for
2005 and the BepiColombo mission to Mercury at the end of the
decade. It is a precursor too for continuing Mars mission activity
under Aurora, the programme of exploration of our solar system.
For further information, please contact:
ESA Media Relations Service
Tel:+33.(0)1.5369.7155
Fax:+33.(0)1.5369.7690
Further information:
ESA, Media Relations Service
Tel: +33.(0)1.5369.7155
Fax: +33.(0)1.5369.7690