All Pages © MMSSI 1953

The Mount McCaber Space Science Institute

The Earl Clancarty Telescope - the Jewel in a Highland Crown

The largest optical telescope in the British Isles, the Earl Clancarty Telescope, or ECT,  was commissioned at the time of the MMSSI’s founding in 1953. In fact the whole of the MMSSI facility was designed around the telescope and its dome which are absolutely vital to the Institute’s important Government work.

First Light through the ECT took place at midnight on the Winter Solstice of 1953, a mere six months after Parliament had ordered its construction. This remarkably fast deployment was, in part, achieved by innovative re-purposing of components from the scrapped battleship, HMS Thunderer, whose construction was, coincidentally, cancelled just after Mid-Summer of 1953 when the inaugural meeting of a secret Parliamentary sub-committee concluded that its planned capabilities were “no longer adequate” for the future defence needs of the UK. Although a huge blow to the Clyde ship-building industry this decision proved strangely fortuitous for the nascent MMSSI as the half-finished battleship was towed to the Pacific for use during the UK’s early – and still classified – atomic bomb testing programme before being returned to the UK and sold for scrap, much of which found a home at Mt McCaber.

The ECT is of an unusual Cassegrain-Schmidt design, giving it a wide Field of View, coupled with high sensitivity, and yet a fairly short “tube-length”. This compact nature makes the telescope surprisingly nimble and so it can be easily and rapidly manoeuvred within its dome. The ECT was also the first fully computer-controlled telescope in the world, with its – for the time – enormously advanced Celestial Object Stabilisation Tracking Array for Large Optical Telescopes being re-purposed from the analogue computer-based Fast Air Target Attack And Suppression System originally developed for controlling the air defence guns of the ill-fated HMS Thunderer. In passing it is of interest to note that the conversion of the computers to their new role was allegedly overseen by computer pioneer Alan Turing, shortly before his mysterious death the year after the Institute opened. This combination of compact, nimble hardware and high-speed analogue computer control makes the ECT ideally suited for tracking fast moving celestial objects such as meteors or other similar bodies moving rapidly through the Earth’s outer atmosphere.

The ECT is maintained and operated by the Institute’s Chief Engineer, Ron Preston, who directly oversees and controls all ECT-related activities.

Please note that the ECT dome is not open to the General Public or to anyone else for that matter.

Curiously, there are no images of the ECT in the public record