DARPA MOIRE: First folding space telescope

Instead of using traditional glass mirrors or lenses, MOIRE seeks to diffract light with Fresnel lenses made from a lightweight membrane roughly the thickness of household plastic wrap. 

MOIRE would house the membranes in thin metal “petals” that would launch in a tightly packed configuration. 

Upon reaching its destination orbit, the satellite would then unfold the petals to create the full-size multi-lens optics.

The capability of orbital telescopes to see wide swaths of the earth at a time has made them indispensable for key national security responsibilities such as weather forecasting, reconnaissance and disaster response.

Even as telescope design has advanced, however, one aspect has remained constant since Galileo: using glass for lenses and mirrors, also known as optics.

High-resolution imagery traditionally has required large-diameter glass mirrors, which are thick, heavy, difficult to make and expensive.

As the need for higher-resolution orbital imagery expands, glass mirrors are fast approaching the point where they will be too large, heavy and costly for even the largest of today's rockets to carry to orbit.

DARPA's Membrane Optical Imager for Real-Time Exploitation (MOIRE) program seeks to address these challenges.

MOIRE aims to create technologies that would enable future high-resolution orbital telescopes to provide real-time video and images of the Earth from Geosynchronous Earth Orbit (GEO)—roughly 22,000 miles above the planet's surface.

Size and cost constraints have so far prevented placing large-scale imaging satellites in GEO, so MOIRE is developing technologies that would make orbital telescopes much lighter, more transportable and more cost-effective.

Currently in its second and final phase, the program recently successfully demonstrated a ground-based prototype that incorporated several critical technologies, including new lightweight polymer membrane optics to replace glass mirrors.

Membrane optics traditionally have been too inefficient to use in telescope optics. MOIRE has achieved a technological first for membrane optics by nearly doubling their efficiency, from 30 percent to 55 percent. The improved efficiency enabled MOIRE to take the first images ever with membrane optics.

With a proposed diameter of 20 meters, MOIRE’s membrane optic “lens” would be the largest telescope optics ever made and dwarf the traditional glass mirrors used in the world’s most famous telescopes.

MOIRE technology houses the membranes in thin metal "petals" that would launch in a tightly packed configuration roughly 20 feet in diameter.

Upon reaching its destination orbit, a satellite would then unfold the petals to create the full-size multi-lens optics.

The envisioned diameter of 20 meters (about 68 feet) would be the largest telescope optics ever made and dwarf the glass mirrors contained in the world's most famous telescopes.