- The Washington Times - Sunday, November 14, 2004

NASA will attempt to set the world speed record for an air-intake engine tomorrow.

The X-43A Hyper-X is a supersonic ramjet that may lead to more efficient launch vehicles and missiles in the future.

“We are about to fly at Mach 10 — 7,000 mph — a small aircraft inflight with a supersonic ramjet which has never flown at these speeds before; it will be another world record,” said project manager Vince Rauch.

Mach 1 is the speed of sound, and anything above Mach 5 is considered hypersonic flight. A previous X-43A flight on March 27 reached Mach 6.83, and set the speed record for an air-intake engine.

The only way to get into space is with rockets, and they are extremely inefficient because they have to carry both fuel and oxygen. A supersonic ramjet, or “scramjet,” uses the air from the atmosphere and can travel up to fifteen times the speed of sound. That isn’t fast enough to put a satellite into orbit, but could be used as an intermediate stage for a launch vehicle.

A scramjet has no moving parts inside and just uses its hourglass-shape to compress the incoming air. The challenge is to keep it burning at supersonic speeds and avoid blowing out like a candle.

A wind tunnel could be used to simulate the previous flights, but the Mach 10 flight is unknown territory — engineers could only used theoretical computer predictions for how the craft will behave.

“The data we’re going out there to get is something that at this time cannot be obtained any other way other than through flight,” said chief engineer Laurie Marshall.

A B-52 will carry the X-43A to a test area over the Pacific Ocean northwest of Los Angeles. At an altitude of 40,000 feet the B-52 will drop the X-43A with its booster rocket. The rocket will accelerate the X-43A to Mach 10 at an altitude of 110,000 feet and separate.

Then the X-43A is on its own and will ignite its engine and attempt to sustain level flight at Mach 10.

The X-43A program cost taxpayers $230 million for three vehicles. The first flight ended in failure when its booster rocket made a sharp turn and had to be destroyed. The second flight set the Mach 6.83 speed record.

Although tomorrow’s flight will mark the completion of the X-43A project, engineers said they are hopeful that a follow-on program will be approved to improve performance.