Explanation:
Who are these masked men?
Technicians from Ball Aerospace and NASA at
Marshall
Space Flight Center's X-ray and Cryogenic Facility, of course,
testing primary mirror segments
of the
James Webb Space Telescope (JWST).
Scheduled for launch in 2014,
JWST
will be optimized for the
infrared exploration
of the early Universe,
utilizing a primary mirror 21.3 feet across,
composed of 18 hexagonal segments.
Here, a group of JWST mirror segments are being prepared
for tests to assure they meet the exacting mission requirements.
The technicians' suits and masks help prevent contamination of
the mirror surfaces.
At the Marshall X-ray and Cryogenic Facility,
the mirrors
are tested in the large circular chamber after evacuating
the air and cooling the chamber
to -400 degrees
Fahrenheit
(only 60 degrees above absolute zero).
The extremely low pressure and temperature simulate
the JWST
mirror operating environment in space.
JWST mirror segment testing will continue for the next 18 months.
