[astroCS] ESA targets missions to study Near Earth Objects

[Marek Husarik]

Zdroj:
http://www.nearearthobjects.co.uk/


Early on the morning of 30 June 1908 an alien object streaks across the
cloudless sky, 8 km above the surface it explodes flattening an area over
2000 square km. Despite the huge detonation, equivalent to a 10 megaton
nuclear warhead, there are few casualties. If this object had exploded over
a major city like London, the devastation and loss would be unthinkable.

Fortunately, objects of this size collide with the Earth only every few
centuries. Objects around one km in size typically collide every few hundred
thousand years, such impacts may cause climate change and even mass
extinctions. This cosmic game of Russian roulette has increased awareness
and pushed efforts to detect, categorise and reduce the threat from NEOs.

In July 2002 the general studies programme of ESA provided funding for
preliminary studies on six space missions that could provide significant
contributions to our knowledge of NEOs.


The six missions under study were:

Don Quijote: The launch of two spacecraft (Hidalgo and Sancho) to
investigate technologies required to deflect an asteroid heading towards
Earth. Hidalgo will be targeted to impact a 500-metre-diameter asteroid. Its
companion, ancho' will deliver sensors to the surface of the asteroid and
observe from a safe distance what happens during and after the high speed
collision.

Earthguard 1: Proposes to mount a "hitchhiker" telescope on a spacecraft en
route to the inner Solar System, e.g. ESA's BepiColombo Mercury orbiter. The
telescope would detect Earth-crossing asteroids larger than about 100
metres, which are very difficult or impossible to detect with ground-based
telescopes.

EUNEOS: A medium-sized telescope mounted on a dedicated spacecraft platform
that would search for the most dangerous NEOs from inside the orbit of
Venus. Its main goal is to detect 80% of the potentially hazardous objects
down to a few hundreds of metres in size.

ISHTAR (Internal Structure High-resolution Tomography by Asteroid
Rendezvous): In addition to measuring the mass, density and surface
properties of an NEO, this spacecraft would probe by using radar tomography
the interior of an NEO in order to study its structure and internal
strength.

SIMONE( Smallsat Intercept Missions to Objects Near Earth): A fleet of five
low-cost micro-satellites that would each fly by and/or rendezvous with a
different type of NEO. Each spacecraft would carry a suite of scientific
instruments that would provide valuable insights into the nature of large
asteroids.

Remote observation from a space-based observatory that would carry out
remote sensing and detect physical and compositional characteristics of
NEOs.

With these mission proposals feasible and affordable, a valuable framework
of studies by industry and academia will be provided for developing future
missions. Each mission will be discussed by ESA and its international
Partners to determine how best to proceed.


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