Description
The groundbreaking success of the James Webb Space Telescope (JWST) has been a cornerstone in space science and engineering. By using a pioneering deployable mirror architecture, JWST demonstrated how complex optical systems can be compactly packaged for launch, precisely deployed and aligned in space. Through deployment, it is possible to launch at cheaper cost and find a wider availability of launch service (crucially overcoming the launcher fairing size limitation), achieving performance levels previously unattainable.
With applications such as free space optical communications (FSOC) and Earth Observation (EO), the design of deployable telescopes can vary and adapt to specific requirements. For instance, EO deployable optics need to be optimised for a high modulation transfer function and a corresponding nominal point spread function (PSF) to optimally image all spatial frequencies within the observed scene. A larger aperture benefits the satellite by improving the ground sampling distance, providing diffraction-limited performance, and enabling high-resolution imaging. For FSOC applications, a larger deployed aperture can significantly improve the communications link budget, and the performance of the system maybe be less sensitive to degradation of optical quality.
Alignment of deployable segments within nanometre precision is required to achieve the necessary optical quality. In a simple segmented aperture telescope model, each segment needs optimisation across three degrees of freedom: piston, tip, and tilt (PTT). This presentation will explore how the design of deployable segments directly impacts the performance of the system, and will review the work carried out to develop machine learning models to align them.
