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NASA's Galaxy
Evolution Explorer Successfully Opened Its Telescope Cover on May
6.
The cover deployment
sequence involved the heating of a wax thermal actuator, which melted
a wax pellet. When the wax melted, it pushed a mechanical pin, which
in turn released the cover. This release enabled a spring-loaded
hinge to swing open the cover. The cover is now safely stowed against
the side of the spacecraft, where it will remain for the duration
of the mission. Confirmation of successful cover deployment was
received in real time at the Mission Operations Center at Orbital
Sciences Corporation in Dulles, Virginia.
"The spacecraft
is meeting all our expectations for in-orbit checkout, the team
couldn't be more pleased," said Frank Snow, GALEX mission
manger from NASA Goddard.
On Sat., May
3, engineers began the process of turning on the science instrument.
So far, engineers have powered up both the digital processing unit,
which houses the main computer, and the detector front-end electronics
box, which contains the photon discrimination and processing logic.
The spacecraft computer, mechanisms and heaters are operating properly,
and telemetry and data have been routinely transmitted to Earth.
Next week, the
high voltage power supply will gradually be brought up to operational
voltage. High voltage is essential for the telescope to gather the
ultraviolet photons that will help scientists piece together the
story of how and when stars form inside galaxies.
The two weeks
after launch serve as a decontamination period, when moisture and
other materials absorbed into the spacecraft's paint and thermal
blankets bleed away, or "outgas."
Once the optic
wheel is rotated into position, the telescope will begin gathering
photons, a milestone known as first light. First light will occur
on or about May 19.
The Galaxy Evolution
Explorer mission will image millions of galaxies across 10 billion
years of cosmic history, which is 80-percent of the way back to
the Big Bang. Additional information about Galaxy Evolution Explorer
is available at http://www.galex.caltech.edu.
GALEX was developed under the NASA Explorers Program, which is managed
by Goddard
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