Habitable planet finder
A notional space telescope configuration is presented that addresses issues of angular resolution, spectral bandwidth and
rejection of host star glare by means of a double dispersion architecture. The telescope resolves angle by wavelength. In
an earlier embodiment for surveys, a primary objective grating telescope architecture was shown to acquire millions of
objects in one observation cycle, one wave length at a time. The proposed HPF can detect exquisite spectral signatures
out of millions of wavelengths in albedos - one exoplanetary system at a time. Like its predecessor, the new HPF
telescope has a ribbon-shaped flat gossamer membrane primary objective that lends itself to space deployment, but the
preferred embodiment uses a holographic optical element rather than a plane grating. The HOE provides an
improvement in efficiency at select wavelength bands. The considerable length of the membrane can be in the 100 meter
class providing angular resolution sufficient to resolve planets in the habitable zone and also spectral resolution
sufficient to earmark habitability. A novel interferometric secondary spectrograph rejects host star glare. However, the
architecture cannot disambiguate multiple stellar sources and may require unprecedented focal lengths in the primary
objective to isolate one system at a time.