Building the World's Largest by Scott Milligan, Springfield
Telescope Makers Page 5 of 7 The First System Test An auto
collimation test of such a large optical system posed the
practical difficulty of finding a vibration-isolated test bench
large enough to host the test. Fortunately, such a bench existed
at OSTI, and with proper planning, we figured that our setup
could be built, evaluated, and torn down in a matter of a day,
or at most, two. The bench was an old cast iron lathe bed that
had a 12' long x 4' wide 1" thick aluminum plate fastened on top
of the ways. This arrangement was far from ideal from a
vibration isolation standpoint, but it was the only available
test space large enough to do the job. I quickly constructed
makeshift plywood test stands to hold the optical elements that
were mounted in their cells. The convex surface of the L2
corrector was given a temporary silver coating, and the lens
elements were loaded into their cells. When the alignment of the
first system test had been optimized, a