The quest to study extra-solar planets and search for extra-terrestrial life becomes stronger and stronger as we learn more about our solar system. However, the resolution of any optical instrument is ultimately limited by diffraction at its entrance pupil. Higher spatial resolution in astronomical imaging thus requires telescopes with extremely large apertures. This presents a particularly difficult challenge for space telescopes because rockets for launching these telescopes will always have limited dimensions.

The only solution to deploy a telescope with a mirror of more than 10 m in diameter is to unfold a segmented mirror in space or to assemble a mirror in space from several pieces. However, this will invariably lead to optical aberrations because it will not be practical to achieve a sufficiently accurate surface across the full diameter of a segmented mirror. In addition, temperature gradients have a strong influence on large mirrors and will warp their surface. Correcting the aberrations of the large segmented primary mirror of a space telescope by an adaptive deformable mirror is therefore required. A deformable mirror that can operate in space is thus a prerequisite of any meaningful effort to study large segmented space telescopes.

Deformable mirrors need to be thin in order to be deformable. They are often made out of brittle materials such as glass or ceramics. This makes them susceptible to damage during launch of a space rocket. We are investigating new materials and new designs that will make these mirrors sufficiently robust to survive launch and operation in space.

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