HIREX
Off-Axis Mirror Mount
Design overview:
The off-axis mirror mount design consists of several key components:
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Primary Mirror,
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Mirror Bezel,
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Flexures,
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Launch Locks
The Primary mirror substrate in the off-axis design is cylindrical. It
has no detail on the back surface, and there is no central hole. As such
the TRACE mounting arrangement is unusable. Instead we have selected an
approach that was used on the AXAF spacecraft and all the optics in the
refitted MMT instruments, tangential flexures. The flexures allow the primary
mirror to be held in place without transmitting figure distorting force
to it as the temperature varies from that of assembly. Unfortunately the
flexures are so weak that they would not survive application of the mirror
weight in earth's gravity, let alone launch. Therefore, in order for the
assembly to survive from assembly to launch, the launch locks will be engaged
at all times that the mirror is not actively off-loaded. Once in zero gravity,
the launch locks will be retracted.
An
analysis of this design appears here.
Questions, comments pcheimets@cfa.harvard.edu