The proposed addition, intended for the Space Geodesy Facility at Herstmonceux Castle, would support ongoing scientific work at the site.
The application has been made by the Natural Environment Research Council (NERC) and the British Geological Survey (BGS) on behalf of the UK Space Agency.
Herstmonceux Castle is a Grade I listed, 15th-century landmark and a scheduled monument.
Herstmonceux Castle in East Sussex (Image: Nick Macneill)
The site was once the home of the Royal Greenwich Observatory, which operated the facility from 1947 until 1990 and constructed several telescope domes on the grounds.
These include the Solar Dome to the southwest, the Isaac Newton Telescope dome to the southeast, and the Equatorial Group of six domes now run by the Observatory Science Centre.
The Solar Dome building is currently home to the Space Geodesy Facility (SGF), which is operated by NERC and BGS.
The domes of the Observatory Science Centre at Herstmonceux (Image: Science Projects Ltd)
According to the SGF website, the facility uses advanced observational techniques to help create a highly accurate global geodetic reference frame and support satellite missions studying Earth.
The new planning application seeks permission to build an additional 3.5-metre telescope dome at the facility.
The new dome forms part of a global strategy by the UK Space Agency to install optical telescopes at multiple locations worldwide.
How the new telescope would appear (Image: UK Space Agency/Natural Environment Research Council)
Data collected from these telescopes will be used to track both active satellites and orbital debris, helping to prevent potential collisions in space and limit the growth of hazardous debris.
The application explains: “This is a global issue of enormous significance to wider society, given our increasing reliance on space systems for navigation, timing, and weather, amongst other issues.
“This important UK asset will belong to a larger, global effort.”
Existing telescopes at the site (Image: UK Space Agency/Natural Environment Research Council)
The dome would measure 3.5 metres in diameter and 3.39 metres in height. It would sit on a plinth raised 100mm above ground level, bringing the total height to 3.49 metres.
The Royal Greenwich Observatory vacated the site in 1990, after which it was acquired by Queen’s University, Ontario, Canada.
The plans have been submitted to Wealden District Council, and can be viewed using reference number WD/2026/0161/F.