Virgin Orbit, the company planning to launch satellites from Cornwall, is to partner with the Royal Air Force to provide a rapid-response launch services.
Following the agreement, the launch services could begin as early as next year.
The news follows defence secretary Penny Mordaunt revealing that the Ministry of Defence was committing £30m to fast-track the launch of a small satellite demonstrator within a year.
The minister also announced that an RAF test pilot would be assigned to Virgin Orbit.
Virgin Orbit will work in partnership with the RAF to provide satellite launch services using its Boing 747-400 carrier aircraft and LauncherOne rocket. The system carries the rocket under the wing of the aircraft before dropping it at altitude for onward travel into space.
Glenn Caplin, chief executive of the Cornwall & Isles of Scilly Local Enterprise Partnership, which is investing £500,000 in Spaceport Cornwall, said: "This is a huge vote of confidence in Virgin Orbit’s capabilities and means we could see the launch of small satellites from Newquay to support the RAF, in addition to the commercial satellite launches that Virgin Orbit expect to attract.
"This announcement should accelerate Virgin Orbit’s plans to set up their European hub in Cornwall.”
Geoff Brown, cabinet member for transport at Cornwall Council, said: "This is very significant because it means that Virgin Orbit will have the UK government as one of its first paying customers for the horizontal launch of satellites into space.
"And given that Cornwall has been chosen as its only location in the UK, there is every possibility that Spaceport Cornwall will be a base for this activity.”
Spaceport Cornwall could create 150 jobs and £200m for Cornwall’s economy in its first five years.
Miles Carden, Spaceport Cornwall director, said: "The RAF is partnering with Virgin Orbit because it requires a flexible launch system that can provide reactive satellite launches in a matter of days or even hours, should the need arise, rather than months or years from traditional procurement routes."