Reflective Occultation Mask for Evaluation of Occulter Designs for Planet Finding
- Created: Thursday, 01 December 2011
Advanced formation flying occulter designs utilize a large occulter mask flying in formation with an imaging telescope to block and null starlight to allow imaging of faint planets in exosolar systems. A paper describes the utilization of subscale reflective occultation masks to evaluate formation flying occulter designs. The use of a reflective mask allows mounting of the occulter by conventional means and simplifies the test configuration.
The innovation alters the test set-up to allow mounting of
the mask using standard techniques to eliminate the problems
associated with a standard configuration. The modified configuration
uses a reflective set-up whereby the star simulator
reflects off of a reflective occulting mask and into an evaluation
telescope. Since the mask is sized to capture all rays required
for the imaging test, it can be mounted directly to a supporting
fixture without interfering with the beam.
Functionally, the reflective occultation mask reflects light from the star simulator instead of transmitting it, with a highly absorptive carbon nanotube layer simulating the occulter blocking mask. A subscale telescope images the star source and companion dim source that represents a planet. The primary advantage of this is that the occulter can be mounted conventionally instead of using diffractive wires or magnetic levitation.
This work was done by John Hagopian, Richard Lyon, Shahram Shiri, and Patrick Roman of Goddard Space Flight Center. GSC-15943-1