Reader's advisory: Wired News has been unable to confirm some sources for a number of stories written by this author. If you have any information about sources cited in this article, please send an e-mail to sourceinfo[AT]wired.com.
NEW YORK -- At first glance, it looks like an illustration from a particularly creepy kid's book, a scene depicting an accident in which a gigantic fairy somehow lost one of its wings.
But the developers of the 47-foot silvery object that's now suspended 10 stories above the crowds in New York's Rockefeller Center hope their project doesn't turn out to be the stuff of fantasy.
That "wing" is actually a replica of one of the eight blades from the Cosmos 1 solar sail spacecraft, scheduled to launch in September.
The solar sail exhibit is part of Rockefeller Center's new Centennial of Flight show, which traces technological advances made in aviation during the last century.
If all goes well, Cosmos will prove that solar sails are the future of space flight, a viable technology that can allow humans to glide gracefully through space relying primarily on naturally produced propulsion instead of jet engines and fuel.
But some scientists say solar sailing is an impossible dream that defies the unbreakable laws of physics. Others insist that those very same laws of physics indicate that solar sailing is quite feasible.
"Personally, I have no idea if it'll work," said airline pilot Sam Crenshen, who was visiting the exhibit when it opened Tuesday morning. "But I figure the best technology always rides real close to the edge of rationality.
"A hundred years ago everyone thought the Wright brothers were totally wacky for insisting humans could make flying machines."
Rockefeller Center's Centennial of Flight show is one of the many events being held nationwide over the next few months to mark the upcoming December anniversary of the Wright brothers' first flight in 1903.
On exhibit at the show are full-scale replicas of historic aircraft including the Wright Flyer, the F-16 Fighting Falcon and the Mercury-Redstone rocket from Project Mercury, part of the first U.S. manned space program.
The possible future of flight is represented with exhibits from NASA, General Electric, the U.S Air Force and that blade from the Cosmos 1 solar sail spacecraft.
Cosmos 1 is a privately funded project of the Planetary Society, a worldwide group of people interested in space travel, and the late astronomer Carl Sagan's Cosmos Studios.
In theory, solar sailing would enable space travel without fuel. Reflected light pressure pushing on the craft's eight giant sails would propel it between the planets from Mercury out to Jupiter. Beyond Jupiter the craft would rely on laser propulsion against the sails, but the lasers would be powered by solar energy, explained Louis Friedman, the project's director.
But in a recent paper, Thomas Gold, professor emeritus of astronomy at Cornell University in New York, said solar sailing defies the laws of physics.
Some scientists agree with Gold; others dispute his conclusions.
"Gold has done some extraordinary work, but I believe in this particular paper he is wrong," said Hungarian physicist Laszlo Karoly, who attended the Tuesday opening of the Centennial of Flight show.
"Solar sailing is firmly based on the laws of physics, it does not defy them," Karoly said. "The theories at work here are fully in accordance with the way the universe works. It may take some time to sort the details out, but I see no reason why we shouldn't be sailing across the solar system within the next few decades."
In the meantime, humans will rely on engines for both outer space exploration and travels nearer to home.
General Electric documents the inner workings of jet engines in the Imagine the Power exhibit, a two-block-long tunnel containing a computer simulation that provides an up-close look at how engines allow airplanes to take off, cruise and land.
Technology now under development at GE includes "intelligent engines" that can identify mechanical problems and compensate for them, and a turbine-powered space shuttle that flies like an airplane, but at speeds up to Mach 5, before the shuttle's rockets take over the launch sequence.
Also on display is the mother of all jet engines, GE's 13-by-25-foot, 20,000-pound GE90-115B, the most powerful commercial jet engine ever built. The engine, capable of conjuring up 115,000 pounds of thrust, can toss two-ton boulders about as if they were pebbles.
But despite all the dazzling new technology on display, the most popular exhibits appear to be the historical ones.
A scale model of the Kitty Hawk, North Carolina, sand dunes that mark the location of the Wright brothers' first flight experiments is drawing crowds. And on Tuesday morning a carefully restored World War II P-51 Mustang aircraft was surrounded by a group of veterans who talked about the 32-foot, crimson-tailed plane as if it was an old sweetheart.
"Just look at her," said George Tarken, a World War II vet. "She's saved lives, saved democracy and she still looks like a lady. But in reality she's a tough old broad."
The vets were planning to be present Aug. 5 to watch kids at Floyd Bennett Field in Brooklyn get pelted with sweets from the sky when pilot Gail Halvorsen, the Berlin "Candy Bomber," re-enacts his historic flights during the Berlin Airlift of 1948-49.
After World War II, Halvorsen released small parachutes packed with candy over Berlin, a predecessor to today's humanitarian airlift efforts.
Other planned events include astronaut appearances, a workshop on "World's Longest Duration Paper Flying Airplanes" and a performance by the U.S. Air Force Academy Falcon Team.
Centennial of Flight will be on display at Rockefeller Center through Aug. 18.
