A set of
spacecraft twins destined to stare at the Sun is alternately baking and
freezing in a preflight test.
Built to
snap three-dimensional (3D) images of the Sun's most powerful eruptions for
NASA's STEREO
mission, the two probes are undergoing endurance checks in a vacuum chamber
where temperatures can reach up to 122 Fahrenheit (50 degrees Celsius) and drop
down to -13 degrees Fahrenheit (-25 degrees Celsius), NASA officials said.
"The
satellites are very nearly done," Jim Adams, STEREO deputy project manager at
NASA's Goddard Space Flight Center (GSFC), told reporters Monday at the 2006 meeting of American Meteorological Society in Atlanta,
Georgia. "We're taking the best instruments from NASA's fleet of solar observing
satellites over the years and putting them into STEREO."
Dubbed
STEREO A and B by their handlers, the two spacecraft carry five telescopes each,
as well as a suite of instruments to monitor the Sun for coronal
mass ejections (CMEs) - massive explosions that hurl clouds of charged particles
across the Solar System. The particles can interfere with the regular operations
of satellites
and power grids, as well as pose a danger to astronauts in Earth orbit and
outside the planet's protective magnetic field.
"Because
we have a flat view of the sky, we can't tell when they're coming towards us or
[moving] away from us," said Alex Young, a STEREO scientist at GSFC, of CMEs. "These
solar storms actually create currents that cause the magnetosphere of Earth to
ring like a bell."
In
1989, a strong solar storm knocked out power in Quebec, Canada, while a severe
storm slammed
into the Earth in 1859, shorting out telegraph lines in the U.S. and United
Kingdom and starting fires.
"It has a
strong effect on our daily lives," Young said of space weather. "Today's
society is extremely dependent on technology affected by them...we need to
understand when these things are occurring, and when they are coming towards
us."
The
STEREO mission - short
for Solar TErrestrial RElations Observatory - will place one satellite in an
orbit ahead of Earth while its counterpart trails the planet, NASA officials said.
Both satellites are designed to watch the Sun simultaneously, giving
researchers a 3D view once the data is integrated on Earth, they added.
The $500
million mission is set to launch on June 24 atop a Boeing-built Delta 2 rocket,
NASA officials said. Once thermal vacuum chamber tests are complete, both
STEREO probes will be weighed, and then tested to ensure that their individual
electronic components do not interfere with each other, they added.
advertisement
