Development of a prototype active optics system for future space telescopes

Abstract

It is envisaged that future large space telescopes will be lightweight and employ active optics to maintain optical quality throughout the mission lifetime. We have proposed a 4 m, two-mirror space telescope with an active optics system based on reimaging the telescope primary mirror onto a small active mirror (110 mm optical pupil). Using Zemax, we demonstrate the feasibility of using this mirror to correct low-order Zernike aberrations and show that the aberration is well corrected across the 2.5 arcmin field of the telescope, operating at 0.55 μm. We describe the modeling carried out to develop the active mirror design. Using end-to-end modeling, a 25-actuator mirror with polar actuator geometry, and a ratio of mechanical to optical pupil diameter of 2 has been chosen. A single-actuator prototype has been manufactured and used to test stroke, linearity, and hysteresis. Finally, we describe the design of a laboratory breadboard that will image phase screens onto an exact replica of the space active mirror and show the results of measuring the phase screen accuracy.

Opto-thermo-mechanical phenomena in satellite free-space optical communications: survey and challenges

“…On one hand, adaptive optics systems in space to correct perturbations due to opto-thermo-mechanical phenomena 158 have been studied in depth for their application in astronomical telescopes 159 – 162 On the other hand, adaptive optics have been widely used in the ground segment of FSOC systems during the last decades for correcting atmospheric distortions 163 . However, little research has been done on the use of adaptive optics systems onboard FSOC satellite terminals, 140 to compensate for WFE generated by both atmospheric and opto-thermo-mechanical phenomena.…”

Dynamic stabilization of thin aperture light collector space telescope using active rods

“…This will mainly be used to correct manufacturing defects and/or thermal effects on the shape of the mirrors. 21 The present study focuses on the third type of active control system, which also aims at damping the vibration response of the TALC. The system consists of the active rods linking the segmented mirrors on the external ring (see Figs.…”

An in-orbit correction method based on CNN for the figure errors and component misalignments of TMA telescope

“…When the TMA telescope works on orbit, due to its own errors of design, manufacturing and alignment and the influences of external environment such as temperature change and gravity effect, the image quality of the perturbed system will deteriorate caused by both the figure errors of the primary mirror (PM) and the misalignments of the secondary mirror (SM) and tertiary mirror (TM). To solve the problem, the optimal strategy is to compensate for system aberrations of the perturbed TMA telescope by adjusting the smaller mirror such as the SM [1][2][3] . Two kinds of traditional methods have been used to realize the system aberration compensation.…”