Session
Science/Mission Payloads
Location
Salt Palace Convention Center, Salt Lake City, UT
Abstract
SSTL has been developing a deployable telescope with funding from the UK Defence and Security Accelerator (DASA). The aim of the study was to design a telescope that could achieve higher resolutions in the visible spectrum while utilising a smaller launch volume. To achieve a cost-effective launch the deployable system has been sized such that it would fit within a representative SSTL platform in a SpaceX Falcon 9 small satellite launch volume. A monolithic system with equivalent performance would require a larger launch volume and, therefore, it is expected that a deployable telescope can secure an overall mission price advantage. It should be noted that the study did not explore platform design in detail and future work will need to explore these constraints further.
The telescope features a 150cm deployable segmented primary mirror. This was designed to stow within the restricted launch volume, rotate into position then deploy post launch. While the segmentation results in a monolithic equivalent aperture of 75cm, the system can employ advanced post processing and sensor technology to recover the lost performance. Utilising a detector with a 2D staggered array for half pixel shifting, the imager can achieve a Ground Resolution Distance (GRD) of 0.3m at 500km. Time Delay Integration (TDI) further ensures a high Signal-to-Noise Ratio (SNR) of 161:1 despite the fine resolution.
A key innovation in this design is the integration of an Adaptive Optics (AO) fine-tuning unit, which provides real-time correction of distortions caused by dynamic mechanical and thermoelastic effects. The Wavefront Sensor (WFS) of the AO unit is used to capture the imager’s overall optical performance in the form of a wavefront and then used by the post-processing to recover the lost wavefront thereby increasing its optical resolution to produce the GRD of 0.3m.
Future work must address the integration of the imager within a spacecraft platform to ensure the objective of cost-effective launch can be achieved. Key next steps include maturing the petal deployment mechanism; focus mechanisms; and quantification of the AO system's dynamic range to ensure it can fully compensate for platform microvibration.
This paper will explore the design constraints and challenges faced in the development of the telescope, in addition to how they were solved by integrating deployable segmented mirrors with active wavefront correction.
Document Type
Event
A Novel Deployable Telescope for Small Satellites Using Adaptive Optic Technology
Salt Palace Convention Center, Salt Lake City, UT
SSTL has been developing a deployable telescope with funding from the UK Defence and Security Accelerator (DASA). The aim of the study was to design a telescope that could achieve higher resolutions in the visible spectrum while utilising a smaller launch volume. To achieve a cost-effective launch the deployable system has been sized such that it would fit within a representative SSTL platform in a SpaceX Falcon 9 small satellite launch volume. A monolithic system with equivalent performance would require a larger launch volume and, therefore, it is expected that a deployable telescope can secure an overall mission price advantage. It should be noted that the study did not explore platform design in detail and future work will need to explore these constraints further.
The telescope features a 150cm deployable segmented primary mirror. This was designed to stow within the restricted launch volume, rotate into position then deploy post launch. While the segmentation results in a monolithic equivalent aperture of 75cm, the system can employ advanced post processing and sensor technology to recover the lost performance. Utilising a detector with a 2D staggered array for half pixel shifting, the imager can achieve a Ground Resolution Distance (GRD) of 0.3m at 500km. Time Delay Integration (TDI) further ensures a high Signal-to-Noise Ratio (SNR) of 161:1 despite the fine resolution.
A key innovation in this design is the integration of an Adaptive Optics (AO) fine-tuning unit, which provides real-time correction of distortions caused by dynamic mechanical and thermoelastic effects. The Wavefront Sensor (WFS) of the AO unit is used to capture the imager’s overall optical performance in the form of a wavefront and then used by the post-processing to recover the lost wavefront thereby increasing its optical resolution to produce the GRD of 0.3m.
Future work must address the integration of the imager within a spacecraft platform to ensure the objective of cost-effective launch can be achieved. Key next steps include maturing the petal deployment mechanism; focus mechanisms; and quantification of the AO system's dynamic range to ensure it can fully compensate for platform microvibration.
This paper will explore the design constraints and challenges faced in the development of the telescope, in addition to how they were solved by integrating deployable segmented mirrors with active wavefront correction.
