The Particle Physics and Astronomy Research Council is responsible for organising the design, construction and commissioning of the VISTA telescope through its UK Astronomy Technology Centre (UKATC) in Edinburgh, Scotland. VISTA, the Visible and Infrared Survey Telescope for Astronomy, is a 4.1m diameter, wide field survey telescope being which is located at the Cerro Paranal Observatory and operated as part of the European Southern Observatory (ESO) in Chile.

Observatory Sciences is designing, developing and implementing the software to adjust the position and shape of the VISTA telescope’s primary (M1) mirror. The mirror control system hardware consists of a set of 84 supports which carry a share of the external forces during changing conditions. These include different telescope positions and variable wind gusts as well as gravity. As the telescope changes position, so the loads on the primary mirror alter. At a rate of 50 times a second, the software will calculate the forces to be applied by the active supports to compensate for the ongoing changes and ensure that the mirror maintains optimal shape for best possible image quality at all times. Client comment (2003) “Observatory Sciences is experienced in designing and producing software used to control large telescopes. For example, the company was responsible for several telescope and instrument control systems software projects for the Gemini 8m telescope. This was an important factor in our selection of Observatory Sciences as the winner of the competitive tender for this part of VISTA.” Malcolm Stewart, head of software, UK ATC. Technical Control system: VME-based hardware, Wind River VxWorks / Power PC processor; higher level software: ESO VLT Common Software running on a Hewlett Packard Unix (HP-UX) workstation; communications: via CANbus (Control Area Network bus).