Watching for Scuds from Space

Scud hunting from geostationary orbit has moved a step closer with Ball Aerospace beginning work on a key component for a demonstration telescope under Darpa's Membrane Optic Imager Real-time Exploitation (MOIRE) program.

Concept: DARPA

MOIRE is intended to demonstrate technology for persistent, tactical, full-motion video surveillance from geosynchronous orbit. After delivery to GEO, the satellite would unfurl a micron-thin diffractive-optics membrane, to form a massive segmented lens.

With a target cost of less than $500 million a copy, the objective space telescope would have a 20-meter-dia. lens. It would be able to image an area greater than 100 x 100 km with a video update rate of at least one frame a second, providing a 99% chance of detecting a Scud-class missile launch.

Photo: DARPA

MOIRE is a multi-phase program intended to culminate in a space-based telescope flight demonstrator. Under Phase 2, for which it received a $36.9 million contract in September, Ball Aerospace will build a sub-aperture section of a 5 meter-dia. demonstration telescope.

In Phase 1, which culminated in a late-August preliminary design review, the team created an 80-cm-dia., 32.5-meter focal-length diffracted optical element (below) representative of the sub-aperture. The diffraction pattern was printed and etched onto an 18-micron-thick membrane by Lawrence Livermore National Laboratory.

Photo: LLNL

Other key technologies required for MOIRE to work include large, lightweight structures able to deploy the membrane optics and hold them tight and flat; secondary optical elements able to turn the diffraction-based lens into a wide-bandwidth imaging device; and extremely accurate attitude determination and control for image stabilization and geolocation.

Tags: ar99, MOIRE, Darpa, os99