The most powerful rocket produced in the UK for some 20 years is due to be ignited in Cornwall later.
It is being tested by the British Bloodhound team, which intends to use the booster in a car capable of running at more than 1,000mph (1,610km/h).
This feat would also smash the current world land speed record of 763mph.
The rocket will be bolted to the ground in Newquay so that it cannot move, but the firing should make a spectacular noise along the north Cornwall coast.
It is being conducted at the Aerohub, Newquay Cornwall Airport, inside a shelter previously used to house Tornado fighter bombers.
Rocket chamber The 18-inch rocket must go through a series of performance and safety tests
Invited guests will watch the 10-second burn from inside another shelter via a video link.
Bloodhound is essentially the same team that claimed the existing land speed record for Britain in 1997. It includes the driver, RAF Pilot Andy Green, project director Richard Noble and chief aero engineer Ron Ayres.
But whereas their previous vehicle, known as Thrust SSC, used two jet engines to break the sound barrier, the new car, to be called Bloodhound SSC, will incorporate a jet engine and a rocket.