The likely final mission
will emerge and evolve from concepts that are already
on the table and have been debated for some time.
One is ExoMars - a large
rover that flies with a relay orbiter. An ExoMars-lite
version would use orbiters already at Mars to send home
its data.
And then there is BeagleNet,
a twin lander design with smaller rovers, which delivers
improved versions of the instruments that flew with Beagle
2.
Although the final architecture
of the mission will not become clear for several months,
there are certain "must haves" scientists have
said should be built in to any lander - and these go to
technologies that Europe feels will complement any instrumentation
the American plan to send on their future rovers. The
must haves include:
a drill or "mole",
such as the one designed for Beagle 2, that could go under
the oxidised surface of Mars to find water and help investigate
the subsurface geochemistry
"life-marker" experiments that would analyse
the soil, rocks and gases in the atmosphere for signs
of biological activity. Life traces would have specific
chemical "signatures"
a seismometer to detect Marsquakes and other geological
activity.
No one has got as far as identifying landing sites yet,
but they could include the locations shown by Europe's
Mars Express orbiter to have local "hot spots"
of methane in the atmosphere.
One such location is the
planet's near-equatorial Elysium region, which also appears
to have a huge, frozen sea just beneath the Martian surface.
The site has been proposed
as an excellent place to start looking for life.
As a known by-product of
biochemistry, methane could indicate the presence of microbial
organisms - it could also just be an outcome of volcanism.
You have to eliminate the
possible solutions," said Professor Colin Pillinger,
the chief scientist on the illfated Beagle 2 mission.
"We have seen hints of recent
lava flows, but if you go to Mars and you can't recognise
any geological activity that solution has a problem,"
he told the BBC News website. "If you can't find
a geological signal, don't propose a geological answer."
Aurora envisages not only a roving
mission to Mars in the near future, but a sample-return
mission, too. Scientists want to bring rocks back from
the Red Planet to study in labs on Earth.
But the scale of such a mission,
probably costing billions of euros, means it will almost
certainly be a joint effort with the US, much like the
successful Cassini-Huygens double spacecraft sent to Saturn.
Sample-return means not only getting
to the planet, finding and storing suitable rocks, but
then blasting them off the surface of Mars in a secure
container that can be returned safely to Earth free from
contamination.
"It is such a big undertaking
and in its present concept, it is American-led - the same
as Cassini," said Bruno Gardini, the Esa Aurora programme
manager.
"The question is what can Europe
contribute? This could be a rover that goes to fetch the
samples. This could be the European component and ExoMars
gives us that tremendous possibility."
UK returns
The UK is expected to have a major
input into the new landing mission. British scientists
and industrialists were the lead partners in the Beagle
2 probe.
Although this mission never achieved
its final objectives, scientists and engineers on the
project felt they built up considerable expertise in the
process and would like another go.
The Particle Physics and Astronomy
Research Council (PParc), the major funding body in the
UK for this area of science, plans to put aside considerable
sums of money over the next few years to give British
researchers a leading role in Aurora.
