[youtube=http://www.youtube.com/watch?v=LKQ-xj5C2m8] Andy Green, the driver behind the wheel of the car that broke both the landspeed record and the speed of sound in 1997 at Black Rock Desert in Nevada described the experience as "the hardest thing [he'd]ever done: like trying to balance the point of a pencil on the end of your finger."
And the car may be fractionally different in shape from one side to the other. It's a hand-built car. We measured it as accurately as we could, but the tiniest difference, the thickness of a few coats of paint, can make the shock waves form earlier on one side. It happens with aircraft when you take them supersonic, but tiny corrections with the controls can fix that. With the car, it's the wheels that have to take the differences in load, and you start to realise the magnitude of the forces involved when a tiny difference can translate to an extra ton of load on one of the front wheels. Once you get well over Mach 1, life gets much easier. It's getting there that's the challenge.
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