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Right now, we are at the Johnson Space Center in Houston, Texas, standing
inside the space environment simulation laboratory in front of Chamber A
Chamber A actually the largest thermal vacuum chamber in the world
It has a 40 foot diameter door which weighs 40 tons
The door is Hydraulically operated and it's 3 tons
and it's perfectly balanced, it's so balanced that 2 people can push against the door
and move it. Chamber A is currently undergoing
upgrades so that it can house the largest satellite, the James Webb Space Telelscope
and its testing for the space environment
So for the last 3 years we've been rebuilding, remodeling the interior
of the chamber so that it's acceptable for the cleanliness and the temperature that
James Webb needs. Some of the things we've done, is we've upgraded
our helium system, we've upgraded our liquid nitrogen system.
As well as updating our air flow management system.
With all these upgrades put together, we can now reach temperatures that no one has ever
really been able to reach before.
We're actually going to 11 Kelvin, which is 11 degrees Celsius essencially
above Absolute Zero, so the absolute coldest we can get to.
That's possible, not even really possible.
What we get out of a thermal vacuum chamber test
is that we can evaluate whether or not the spacecraft
all its systems perform like they're supposed to perform once they're out
in space. All the air
inside the chamber right now at ambient temperature weighs about as much as 12
and a half Volkswagen Beatles, so about 25 tons
so by tie you remove all the air and all the molecules out, all the mass inside the chamber is equivalent of about half
a staple. That's very rough, but you
kind of put it in perspective of what we are doing.
[sound of door closing]
Chamber a was originally built as a simulation
for the Apollo missions to test the Apollo capsule
Back for Apollo, the chamber had to be ready to have
people put into the chamber inside their vehicle, so it was
man-rated. It still is man-rated, but we obviously
don't need to put people on the telescope, so that's not much of a concern for us anymore
what is a concern is that the telescope has have a very clean environment
because it's an optical telescope. Actually, right where I'm standing right now,
several feet back and all the way to the chamber and all the way to both sides of the highbay
we're going to be installing a very large clean room that will allow
engineers and technicians to work on the satellite as they are prepping it to go into
the chamber.
During the final flight test of James Webb
it will be in the chamber for, we're anticipating 90 days
The first, roughly 30 of those days
we will not be doing anything more than cooling it down
because its got to radiate all its heat out to those cold shroud
walls, it will take a long time for it to drift down to its eventual
operating temperature. Then for the next period of weeks they will be running
tests on the instrumentation systems and at the end
it will take us about another two and a half, three weeks to warm it back up so we bring it back out
into the Houston humidity
Chamber is
now the most capable thermal vacuum chamber on the planet
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