James Webb is currently undergoing a cryogenci vacuum test in a very large chamber
called Chamber A at NASA Johnson Space Center
and the purpose of this test to make sure that all the components of the telescope
are going to function in the cold vacuum environment of space
Title: Nithin Abraham, NASA Coatings engineer. Abraham: I'm a coatings engineer and I'm working very closely
with the James WEbb Contamination Control team. Before we start the
cryogenic test, the contamination control team works to clean the inside of the chamber so
Webb can stay as contamination free as possible. It's not possible
for anyone to access the chamber during the test so, we have to
do all our contamination mitigation before the test starts.
and my job specifically involves the development and testing of
a new NASA coatings technology that can help mitigate
molecular contamination concerns. So, the plenum is an area at the
bottom of Chamber A, its the space directly below where Webb sits
ready for testing. To get tot he plenum, we have to carefully walk
in the space between the helium shroud, which is surrounding Webb,
and the outer wall of Chamber A. There's no lights so we have to
wear headlamps. The plenum is considered a confined space becuase
there's only one way in, and only one way out. We have to wear oxygen
sensors to make sure that it's safe to be down there. We have to
take a ladder down to the plenum, that's the lowest level at the bottom of the chamber.
And the floor, is actually the curved bottom of Chamber A.
So there are molecular contaminants that exist in the plenum
for example you have your hydrocarbons and your silcones and
these are sometimes very difficult to remove almost completely,
and the contamination team has done an amazing job of reducing the
existing levels down to a very minimal amount and it's
this residual contaminants that can essentially out-gas during
vacuum testing, spread throughout the chamber, and perhaps even deposit on a
very cold. sensitive surface such as James Webb. Graphic: Molecular Adsorber Coating is a highly pourous material that can be sprayed onto surfaces
to passively capture molecular contaminants. Abraham: to tackle the problem at the source and
that's why we placed the MAC samples in the plenum area.
We do a thorough analysis on the types of contaminants that
were collected and how much, the data is very useful and shows that
we are protecting James Webb from molecular contamination
I've devoted a lot of my early career developing and testing
this coating, and I'm really happy to see it being used on a lot of flight projects.
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