NASA Explores Ways To Quiet Passage To Supersonic Flight
Remember the sonic
booms of the 1960s? I do.
Windows shook and sometimes broke. Children were absolutely
terrified at the massive claps of thunder that rocked the
neighborhood. The sound was like a wall, knocking people and
Grandma's favorite glass figurines on their collective butts. It
was dizzying. And boy, was Grandma mad.
Now, NASA is working on ways to quiet the sonic storm. Over the
very same desert where Chuck Yeager first broke the sound barrier
in 1947, the space agency is investigating ways to make supersonic
flight kinder and gentler.
But the question is how? Last week, NASA proved a long-held
theory that says, changing the shape of the aircraft changes the
shape and impact of its passage through the sound barrier.
Even though the sound barrier was broken more than five decades
ago, no aircraft has gone quietly into that cold fast place. But by
flattening the nose and changing the characteristics of the skin,
NASA changed the sound of a Navy F-5E breaking into supersonic
flight. Instead of the sharp crack of God's own firecracker, NASA
engineers produced a duller boom, something just a bit less
So What Good Is It?
There are a couple of applications that are immediately
enticing. For instance, softening the sonic boom can improve a
Then there's the possibility that blunting the sonic boom of a
passing aircraft could lead to a resurgence in supersonic passenger
flight. That's a niche currently unserved. Boeing, of course,
dropped plans for its Sonic Cruiser. Next month, the Concorde, the
world's only supersonic passenger aircraft, will go the way of the
dodo after being retired by both Air France and British
How They Did It
NASA engineers put a specially shaped "glove" on the nose of the
F-5E, then applied a composite compound to the jet's belly. They
compared the sonic boom created by the modified aircraft with that
of another. "We were all blown away by the clarity of what we
measured," said Peter Coen, of NASA's Langley Research Center in
Hampton (VA). Cost of the test? A mere $7 million.