By Jonathan AmosScience correspondent, BBC NewsBloodhound's driver, Wing Commander Andy Green, shows how the car's three engines are expected to work together
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.
The Health and Safety Executive will be on hand to ensure everything runs smoothly.
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.
The jet is the well-established EJ200 power unit used in the Eurofighter-Typhoon, but the rocket is bespoke and must be put through a test programme to prove its performance and to certify it is safe for use in a manned machine.
Wednesday's firing is the first of 15 planned to take place over the next year or so.
Developed by Daniel Jubb of Falcon Project Ltd in Manchester, the rocket is what is termed a hybrid. That is, it burns a combination of a solid fuel (hydroxyl-terminated polybutadiene, or HTPB) and a liquid oxidiser (high-test peroxide, or HTP) to provide thrust.
Hybrids are not as simple to operate as all-solid motors, but they have the advantage of all-liquid rockets in that by closing valves they can be shut down rapidly - critically important if Andy Green experiences problems on his high speed runs.
The rocket test rig is enclosed in a shelter built to protect Tornado aircraft from attack
Getting the fuel grain to burn smoothly and evenly is the big challenge for Mr Jubb and his colleagues. Hybrids are prone to disrupting oscillations. The team will be poring over the data to assess the 18in by 12ft (45cm by 3.6m) chamber's burn characteristics.
"We should get a pretty good indication as to whether or not it was smooth just by looking at the video feed," Mr Jubb told BBC News. "And if we've got a significant combustion instability issue, we may even be able to hear it."
Wednesday's test will see the rocket motor fed HTP at a pressure of 600psi (2.7MPa). This should deliver an average thrust of 12,000-14,000lbf (50-60kN) with a peak somewhat over that. This would be insufficient to get Bloodhound SSC up to 1,000mph, however. For that, the pressure will need to be almost doubled, to produce an average thrust of 25,000lbf, or 111kN, for 20 seconds; and a peak of 27,500lbf (122kN).
Perhaps the most remarkable aspect of the Bloodhound rocket system's design is its use of a Cosworth Formula 1 engine. This racing technology will have no role in driving the wheels of the car. Rather, its function will be to drive the HTP pump.
An F1 engine by itself makes a big noise - about 120 decibels. Add in the 180 decibels expected from the hybrid rocket in full voice and there should be quite a roar drifting over Newquay in the coming months.
Computer animation showing how the hybrid rocket system will work
If all goes to plan, Bloodhound should be conducting "slow speed" runway tests in the UK in the first half of next year, with an assault on Thrust's land speed record taking place on a specially prepared track in South Africa by the end of 2013. It will be 2014 before the car tries to go beyond 1,000mph.
"Firing the whole end-to-end rocket system - which is the hybrid rocket with the Formula 1 engine, the pump and the HTP tank - as a unit, for the first time, is really exciting," said Bloodhound driver Andy Green.
"And by the end of 2012, we will have test-fired the rocket, we will have the car going on to its wheels and we will be turning this into a running vehicle for 2013.
"We've done good ideas, we've done detailed design - this is now transition to reality. This is actually happening and we are going to have a car next year."
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