Britain is about to launch its first ever dedicated military spy satellite.
Called Tyche, the washing machine-sized spacecraft will have sufficient resolution to identify battlefield troop positions and vehicles.
A successful launch will mean that the UK will no longer be the onlyG8 nation without a sovereign satellite imaging capability.
The satellite is a demonstrator model that should be followed by a network of satellites this decade using a variety of sensors.
Some of these future spacecraft will be able to see through cloud and even eavesdrop on radio transmissions.
Tyche’s ride to orbit is booked on a SpaceX Falcon rocket flying out of California. Lift-off is scheduled for 11:20 local time (19:20 BST).
The British mission will be ejected at an altitude of roughly 500km to begin what’s expected to be a minimum of five years of operations.
UK forces have long benefited from the use of their own, state-of-the-art satellite communications system, called Skynet, but getting access to surveillance and reconnaissance imagery from space has largely required a friendly request to allies, particularly the United States.
While the Ministry of Defence (MoD) has contributed funds in the past to projects in the UK commercial sector, Tyche will be its first wholly owned imaging capability.
Commissioned by UK Space Command and built by Surrey Satellite Technology Ltd (SSTL) in Guildford, the 160kg satellite will collect its imagery at optical wavelengths – in the same light we sense with our eyes.
It’s designed to capture 5km-wide spot scenes on the ground and have a best resolution of 90cm.
The imagery is by no means the best performance possible (some classified US satellites are reported to see features as small as 10cm across), but it fits with the British military’s generalised needs.
Tyche was born out of a 2021 Space Command Paper and a 2022 Space Defence Strategy which committed the last government to spend £970m over 10 years on a programme called Intelligence, Surveillance, Target Acquisition, and Reconnaissance, or ISTAR.
The strategy set out a number of initial R&D efforts with the eventual goal of launching a sovereign constellation of military and national security satellites to orbit.
These spacecraft are intended to carry a range of technologies, among them radar sensors that can see the Earth’s surface in all weathers and at night – a capability Ukraine has found invaluable in tracking invading Russian forces.
“This is the start of a journey,” said Maj Gen Paul Tedman, commander of UK Space Command. “The space defence strategy lays out how we’re going to become a meaningful space power by 2030.
“We’re hoping to see many more launches of satellites in the coming months and years. Tyche is absolutely the beginning of that.”

SSTL has been working closely with UK Space Command on ISTARI and hopes to win further defence contracts, at home and abroad.
“Many other countries are setting up space commands,” said Darren Jones, the manufacturer’s head of defence business.
“There’s lots of appetite around the world for space capabilities for defence purposes. What this Tyche contract shows for us is that we’ve got confidence from the MoD to deliver these types of missions, which can only help us in future with other nations around the globe.”
Tyche is based on the company’s Carbonite model, which can be assembled rapidly and at relatively low cost (the Tyche contract is worth £22m).
One interesting feature is its propulsion system which manoeuvres the satellite using water.
“The water goes through a thruster that heats it up to make superheated steam. That’s how we get thrust and do station-keeping,” explained chief technology officer Andrew Haslehurst.
“Tyche carries 10 litres. It’s enough to get five-to seven years of in-orbit life.”
Shortly after the Defence Space Strategy was published, the then Commons Defence Select Committee criticised the UK for being, “at best, a third-rank space power”.
The committee raised specific concern for ISTARI’s future prospects, given the MoD’s “woeful track record in delivering major projects on time and to budget”.
A new government was elected in July, of course, and immediately initiated a root and branch review of UK defence needs and spending.
With other countries highlighting the growing importance of the space domain in future conflicts, it seems unlikely the latest UK defence assessment will tack a different course to the last one. But policy experts would be watching closely, said Julia Balm, research associate at the Freeman Air and Space Institute, King’s College London.
“I think if there’s anything negative on ISTARI or there are any cutbacks when it comes to things that have already been committed in strategies, then that’s just indicative of the UK’s inability to deliver any sort of long-term or large-scale project. And it also doesn’t really hold a good message about the UK being committed to growing as a space power,” she told BBC News.