Telescope with optical alignment system

The telescope of any preceding claim further comprising:

• a set of one or more actuators;
• and
• an actuator control system coupled to the metrology system and to the set of actuators;
• wherein each of one or more of the mirror segments has a respective actuator to move the mirror segment;
• wherein the metrology system is configured to capture an image of the received light from the light source after reflection by each of the mirror facets;
• and
• wherein the actuator control system is configured to control the set of actuators dependent upon the captured image to move the one or more mirror segments to align the reflections from the mirror facets of the mirror segments.

The telescope of any preceding claim wherein one or more of the mirror segments has a diffraction grating on the segment surface, the light source includes a monochromatic source, and further comprising:

• a diffracted light metrology system;
• wherein the light source and the a diffracted light metrology system are located at conjugate optical positions defined by the diffraction grating;
• and
• the diffracted light metrology system is configured to characterize the diffracted light from the monochromatic light source for determining a degree of optical alignment of the telescope.

A method of aligning a telescope, the telescope comprising:

• a segmented primary mirror, the segmented primary mirror having a plurality of mirror segments, each mirror segment having a segment surface defining part of an imaging surface of the primary mirror;
• each mirror segment having a mirror facet, wherein a direction of light reflected from the mirror facet defines an orientation of the segment surface of the mirror segment, and wherein the mirror facet is configured to reflect light in a different direction to light reflected from the segment surface of the mirror segment;
• the method comprising:
• using a light source to illuminate the mirror facet of each mirror segment;
• moving one or more of the mirror segments to align a reflection from the mirror facet of each mirror segment.