Sira Electro-Optics' highly successful space instruments prolong active life

Citation

(2001), "Sira Electro-Optics' highly successful space instruments prolong active life", Sensor Review, Vol. 21 No. 2. https://doi.org/10.1108/sr.2001.08721bab.006

Sira Electro-Optics' highly successful space instruments prolong active life

Sira Electro-Optics' highly successful space instruments prolong active life

Keywords: Optics, Aerospace

Sira Electro-Optics' radiation hard electronics capability received a top accolade from the European Space Agency (ESA) recently, following an extended mission on NASA's massive 17-ton Compton Gamma-Ray Observatory (CGRO). Launched in April 1991, the satellite was successfully de-orbited in June this year, burning up during a controlled descent into the Pacific Ocean.

The observatory's purpose was to study a broad range of high-energy phenomena, including Supernova, Black Holes and Quasars. The payload included ESA's COMPTEL (Compton Telescope), one of four instruments on CGRO, each addressing a different aspect of the gamma ray spectrum. COMPTEL was an imaging telescope, producing a sky map from "pictures" of medium energy gamma-ray sources (1-30MeV) and detecting Gamma-Ray Bursts, the most mysterious and energetic events known in the Universe.

The COMPTEL digital electronics was designed and built by UK-based Sira Electro-Optics, a world class space instrument organisation. With a planned duration of just two years, the system survived over nine years in the harsh radiation environment of space and was still fully operational when the satellite mission was completed.

In thanking their contractors, ESA confirmed that "The Sira equipment worked flawlessly throughout the nine-year mission". Sira's radiation expertise has since been put to good use in providing a service to the global space industry, with a full suite of radiation analysis and measurement facilities run by acknowledged world expert, Dr Gordon Hopkinson.

The COMPTEL Digital Electronics was the instrument's control and data handling computer, receiving and implementing all commands from ground controllers and interfacing with the spacecraft telemetry system for the return of science data. Sira's Digital Electronics, comprising 19 PCBs, each 300mm x 220mm, was mission-critical for the instrument and so was designed to be fully redundant.

COMPTEL was a large international collaboration, involving many organisations and subcontractors. The instrument was named after US physicist Arthur Holly Compton (1892-1962), Nobel Prize winner in 1927 for the Compton effect – the way high energy photons interact with matter. This Compton effect was the detection principle of COMPTEL.

Contact: Sira Electro-Optics Limited, South Hill, Chislehurst, Kent BR7 5EH, UK. Tel: +44 (0)20 8467 2636; Fax: +44 (0)20 8467 6515; E-mail: info@siraeo.co.uk; WWW: www.siraeo.co.uk