Surrey Satellite Technology Ltd (SSTL) and Oxford Space Systems (OSS) have confirmed a partnership to build and launch an OSS Wrapped Rib antenna mounted to an SSTL CarbSAR satellite. The In Orbit Demonstration mission advances both companies’ abilities, with OSS gaining space heritage, and SSTL building its ability to integrate capability from new suppliers. The work has been jointly funded by OSS, SSTL, Airbus Defence and Space, the National Security Strategic Investment Fund (NSSIF, HM Government’s corporate venturing arm for national security and defence technologies, www.nssif.co.uk ) and the MoD, and is proving a ground breaking Synthetic Aperture Radar concept which may be of significant interest to UK defence ISR strategies in the near to medium term future.
Surveillance, change detection and “big data” analytics applications are driving interest in spaceborne SAR data, to support day/night and all-weather imaging at a rate faster than can be achieved with any individual satellite. This drives demand for much smaller radar satellites that can be launched within a limited launch volume in groups, however it is still desirable to retain a large antenna for better quality imagery. Having a large, scalable, stowable and lightweight, reflector antenna provides a number of benefits in designing small radar satellites for particular applications. A reflector antenna can also significantly simplify the radar electronics, making it ideal for implementing radar on much smaller spacecraft such as SSTL’s CarbSAR platform.
The Oxford Space Systems Wrapped Rib Antenna for Synthetic Aperture Radar (SAR) enables high resolution imaging from small satellite earth observation missions, irrespective of weather conditions or daylight. These antennas deploy carbon-fibre ribs from a central hub to form a 3m diameter parabolic dish supporting a high performing metal mesh reflector surface. This UK developed antenna technology has a uniquely compact stowed configuration and achieves a highly cost-efficient performance when deployed in orbit. The antenna has successfully completed an extensive ground based test programme, including a Radio Frequency (RF) test campaign and is now ready to demonstrate its performance in orbit.
Carbonite is the latest in a long range of 100kg class smallsat platforms SSTL has been building in Guildford since the early 1980’s. Carbonite-1 launched in 2015 was an innovative development mission based on a commercially available optical telescope. The range was always designed to be multi-sensor and has evolved to feature a standard set of core platform avionics available now with either a high resolution optical, medium resolution multi-spectral, mid-wave infra-red or SAR payload. CarbSAR - delivering high-resolution X-band SAR imagery – sees the SAR electronics embedded with the standard Carbonite satellite core avionics in an elegant combination with the stowable OSS antenna.