THE European Space Agency has settled on the six big science projects it will
undertake over the next 15 years. The two most ambitious are an uncrewed mission
to Mercury and a star-mapping study which could also warn of approaching
near-Earth objects like asteroids. But worries are already mounting over
ESA鈥檚 ability to stick to its ambitious timetable.
ESA advisers warned in September that the planned projects won鈥檛 meet their
schedules, given current budgets. The Next Generation Space Telescope (NGST) and
the LISA gravity-wave detector, being planned jointly with NASA, may also face
delays. Their schedules depend on NASA鈥檚 reassessed timetables following last
year鈥檚 failure of two Mars probes. ESA has even approved a quick project that
can be drafted in if others are delayed beyond 2013.
A craft called Bepi Colombo will release three probes to find out why Mercury
is so dense, whether it has ice at its poles, and what is in its atmosphere. The
launch is scheduled for 2009. But even if it makes its deadline, some say the
mission will only duplicate NASA鈥檚 second Mercury mission, Messenger, which is
set for three years earlier. 鈥淣o one remembers the third person to cross the
Atlantic,鈥� comments Gerry Gilmore of the University of Cambridge.
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In 2012, the GAIA satellite will create a precise, 3D map of the billion
brightest objects in the sky, along with their velocities and information on the
type of light they emit. It could also provide advance warning of near-Earth
objects, so Gilmore believes it should be launched before Bepi Colombo.
The NASA-led NGST, the successor to Hubble, will be built by 2010
(see 鈥淒on鈥檛 look now鈥�).
This all-purpose observatory will look at the faint radiation left over from the
big bang. LISA, the Laser Interferometer Space Antenna, will also be built with
NASA, by 2008. Its three satellites will orbit the Sun in a vast triangle,
firing lasers at each other to measure their relative distances. Small
fluctuations should reveal the elusive gravitational waves predicted by
Einstein.
Meanwhile, ESA鈥檚 Solar Orbiter will circle the Sun well inside the orbit of
Mercury sometime after 2009. It will send back stable images of the solar
surface, as well as measuring the solar wind. Eddington, ESA鈥檚 potential
stop-gap mission, will take a 1-metre telescope far from Earth and look for
small oscillations in the brightness of stars, caused by orbiting planets
passing in front of them.
