Engineers from NASA's Ames Research Center in Moffett Field, Calif.,
have successfully completed launch preparation activities for NASA's
Lunar Atmosphere and Dust Environment Explorer (LADEE) observatory,
which has been encapsulated into the nose-cone of the Minotaur V rocket
at NASA's Wallops Flight Facility in Virginia. LADEE now is ready to
launch when the window opens on Sept. 6, 2013.
After safely arriving at NASA Wallops in June, the LADEE observatory
went through final preparations and close-outs, which included checking
the spacecraft's alignment after its cross-country shipment, checking
the propulsion system for leaks, inspecting and repairing solar panels,
and final electrical tests. After all of the activities were completed,
it was time to start some of the scarier more challenging portions of
the launch preparations: spin testing and fueling.
To make sure that the spacecraft is perfectly balanced for flight,
engineers mount it onto a spin table and rotate it at high speeds,
approximately one revolution per second. The team measures any offsets
during the spinning, and then adds small weights to the spacecraft to
balance it. Once the spacecraft was balanced dry, we then loaded the
propulsion tanks with fuel, oxidizer, and pressurant. The spin testing
was performed again "wet," or with fuel, in order to see if the balance
changed with the full fuel tanks. The final wet spin balance went very
well.
The next step was to lift the LADEE spacecraft onto the fifth stage –
or the top – of the rocket, and then spin that whole stack in order to
balance it for when the fifth stage burns during the ascent. Before and
after this spin balancing, various explosive charges were installed onto
the spacecraft and fifth stage, which will be used during flight to
enable the propulsion system and remove the cover of one of the science
instruments. The combination of propellents, explosives, and spinning
made all of this activity pretty challenging.
After all of that was accomplished, engineers mounted the LADEE
observatory onto the fifth stage rocket motor and encapsulated it in the
nose-cone – or fairing – of the United States Air Force's Minotaur V
launch vehicle, operated by Orbital Sciences Corp., Dulles, Va. It was
then hooked up to an environmental control system that will keep clean,
dry, cool gas flowing into the fairing. After everything was ready, the
combined LADEE and fifth stage motor in the fairing was moved from the
clean room it had lived in all summer, out to the launch pad, and lifted
on top of the rocket stack, with the first through fourth stages
already in place.
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