3, 2, 1 blast off in Newquay, for the rocket that could drive the world's first supersonic car.
The Bloodhound is hoping to travel at 1000mph. That would smash the current world land speed record, which stands at 763mph.
Now engineers are at the Aerohub at Newquay Airport to test its Falcon Hybrid power system, complete with Formula One engine. That is made by Cosworth and will pump hydrogen peroxide fuel to the rocket at a rate of 75 pints per second.
It has been bolted to the ground in a reinforced hangar, which was once used by Tornado fighters. The test of the most powerful rocket to be built in the UK for some twenty years is expected to last about ten seconds.
Spokesman Pio Szyjanowicz said it has got its work cut out: "It's certainly the largest that's been tested in the UK for a fairly long time so it's going to be a pretty impressive feat. We're looking at a tonne of fuel, shipped from its container through to that rocket to be burnt in around about twenty seconds.
"When you get that into the rocket you're having to provide it at a pretty colossal rate to provide all of the thrust that the rocket is pumping out. We'll see today something that we really hope is going to be a very impressive end result but even if it isn't, the whole point of having a test is to learn.
"You should see from the pictures a pretty big plume of rocket fire exhaust coming out of there. These shelters themselves are designed to exhaust out all of the gas that's produced outside, so you might even be able to see some of the smoke and steam and all the rest of it, coming out of the back."
The rocket test will take place in the reinforced shelter at 1pm.
You can watch it live here.
If it all goes well it will clear the way for the world record attempt to take place in South Africa by the end of next year.