Five NASA
probes blasted into space Saturday, kicking off a two-year mission to hunt down
the source of some of Earth's most
colorful auroral displays.
After two
delayed attempts, a United Launch Alliance Delta 2 rocket successfully hauled
the five THEMIS
probes into orbit for NASA from Pad 17B at Florida's Cape Canaveral
Air Force Station at 6:01 p.m. EST (2301 GMT) [image].
"It was a very smooth count and it was a very
good payout after yesterday's tough one," NASA launch director Chuck
Dovale said after the space shot [VIDEO
animation].
Poor weather prevented preparations for a Thursday THEMIS launch, only to be followed by high upper
level winds that thwarted a Friday
launch attempt just minutes before the mission's planned liftoff. But wind concerns did
not afflict today's spaceflight.
"Upper air
winds were not an issue," Dovale said. "The count was very quiet."
THEMIS,
short for Time History of Events and Macroscale Interactions During Substorms, marks
the most spacecraft ever launched at one time for the space agency, NASA
officials said.
The mission's first probe - dubbed Probe A - popped free of its carriage about
73 minutes after launch as planned, with its four counterparts deploying like flower petals about three seconds later [image].
Each about
the size of a dishwasher, the five 282-pound (128-kilogram) THEMIS probes [image]
are nearly identical and designed to track the origin of powerful geomagnetic substorms
within the Earth's
magnetic field [VIDEO
mission overview].
Substorms occur
when charged particles belched from the Sun
crash into the Earth's magnetic field, where they are funneled along magnetic
field lines to the Earth's North Pole to spur undulating ribbons of
multi-colored hues in the aurora
borealis, also known as the Northern Lights. Without substorms, auroras
would appear as a static sheet of greenish illumination, researchers said.
By
pinpointing substorms, researchers hope to develop a better understanding of
space weather - such as the high-energy particles produced by the Sun in solar flares - which can
interfere with satellite
communications and even endanger
astronauts flying in Earth orbit. But researchers are still unclear on
where substorms originate.
"By
tracking those energy releases from one satellite to the other, [THEMIS] will
be able to detect for the first time where those releases emanate," Vassilis Angelopoulos, the mission's principal investigator
at the University of California, Berkeley's
Space Sciences Laboratory overseeing the mission for NASA, said before today's launch.
"Really it's an analogous system to what meteorologists use on the ground."
Angelopoulos added that he hopes the THEMIS
mission will shed new light on predicting space weather in the future. THEMIS draws
its name from the Greek goddess of justice and wisdom.
The $200
million THEMIS mission stems from a partnership between UC Berkeley and
NASA's Goddard Space Flight Center in Greenbelt,
Maryland.
Built by UC
Berkeley and Swales Aerospace, the five THEMIS probes are designed to take up
stations in ever-higher orbits ranging between one-sixth and half the distance
between the Earth and Moon [image].
Every four days, the probes are expected to align with one another and ground
stations on Earth to provide a curtain
of sensors to scan for substorm activity for at least two years [image].
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