WASHINGTON -- CIA agents hunting a future Saddam Hussein or Osama bin Laden might suddenly pass the word: The fugitive and his cronies just started dinner halfway around the globe.
The Air Force dispatches a warplane from the United States to deliver dessert: some laser-guided bombs.
Another scenario: The International Space Station calls for help, and a rescue crew takes off in minutes -- not in the weeks now necessary to prepare a space shuttle for launch.
Seemingly far-fetched possibilities are inching toward reality as the U. S. military reinvents itself to engage distant enemies with lightning-like speed and as NASA recovers from the space shuttle Columbia disaster. The Pentagon and the space agency have quietly joined forces to fulfill one of the most elusive goals in aviation: a practical hypersonic aircraft.
Ronald Sega, the Defense Department's chief technology officer and a former astronaut, recently told Congress the United States will probably develop within a decade an aircraft that can fly 12 times the speed of sound. That would be 8,000 miles per hour -- one third of the way around the world.
"Technology has progressed to the point where we believe that demonstrations of [an additional] Mach number per year, reaching Mach 12 by 2012, are within reach," Sega testified.
Aviators have dreamed of hypersonic flight since 1947 when test pilot Chuck Yeager first broke the sound barrier in a Bell XS-1 "rocket plane." That was aviation's transition from subsonic to supersonic flight. Supersonic flight becomes "hypersonic" at Mach 5, about 3,750 mph.
U. S. Army researchers first achieved it in 1949 with an unmanned German V-2 rocket. In the 1950s, an X-15 rocket plane snared the world record for piloted flight, Mach 6.72. A spyplane called the SR-71 Blackbird, which can fly at Mach 3, is the world's fastest jet-powered plane.
The Pentagon's interest in hypersonic warplanes eventually took a back seat to its pursuit of radar-evading stealth technology, spy satellites and laser-guided bombs. Only a handful of hypersonic weapons exist, including intercontinental ballistic missiles and tank-busting shells that travel short distances.
NASA's long-standing hypersonics program lost funding year after year to the money-hungry shuttle and International Space Station programs, and it was grounded in 2001 after an X-43 rocket plane crashed during its inaugural flight.
New demands have drawn these two old hypersonics enthusiasts together to build aircraft that could fly anywhere on Earth within a couple hours.
The Pentagon sees hypersonic flight as the key to a smaller, faster, more flexible war machine that is less dependent on overseas air bases in politically volatile places.
"The development of hypersonic technology could reduce vulnerability of future systems, while potentially providing a flexible capability to strike quickly and effectively deny enemy sanctuary anywhere in the world," according to Sega.
NASA sees the project as key to its salvation from the space shuttle Columbia disaster, which exposed NASA's limited ability to rescue astronauts and renewed concerns about the shuttle's inherent safety. Hypersonic vehicles could replace the technologically dated shuttle fleet and be quickly deployed for space rescues.
NASA Administrator Sean O'Keefe believes a new space plane would provide cheaper, more reliable access to earth-orbit and the space station. The plane could be launched much like an aircraft, without the weeks of preparation needed for shuttles.
The Pentagon envisions the hypersonics effort as a latter-day Apollo program, a highly-publicized project that will capture the public's imagination.
Some scientists and engineers think unsolved technical problems put routine hypersonic flight in the pipedream category. The last major review of the technology, done in late in 2000 by the U. S. Air Force Science Advisory board, made this odd comparison:
"Accepting hypersonics as the wave of the future is somewhat like belief in the Second Coming of Christ. One might accept its inevitability, but with little idea when it might actually happen."
Sega counters that some of the basic technology for a "Mach twelve-by-twelve" timetable is available from NASA and other hypersonics research dating to the 1950s. The rest, he believes, can be developed one step at a time.
A 2003 report in the journal Science, partially concurs, noting: "An array of recent developments -- from real-world tests of new engines to improvements in materials and computer simulations -- boosts the chances for success."
A new hypersonic engine capable of Mach 5 speeds already has been ground-tested and is scheduled for flight tests in 2006. That would leave researchers two years to ramp up performance to the Pentagon's Mach 7 goal for 2008.
Piloted hypersonic craft probably will have "combined cycle" engines, which use a graduated series of propulsion systems during different stages of flight.
A rocket engine, for instance, would accelerate the vehicle to about twice the speed of sound. Then the rocket would turn off, and a high-powered jet engine would accelerate to Mach 10 or so. Jet engines use oxygen from the air -- a big advantage over rockets, which must carry their own. The rocket could kick in again after March 10 to propel the craft into orbit or sustain suborbital cruising speed.
Among other technological challenges is the development of a light reliable insulation system to protect the vehicle's outer skin from searing temperatures generated by friction as it zooms through the atmosphere.
The Pentagon is adding an extra $150 million annually to its existing hypersonics program, the exact scope of which has not been revealed.
NASA plans to invest up to $2.4 billion through Fiscal 2007 in a crew rescue vehicle and other hypersonics research, and it plans to resume the X-43 program in a few months. Its goal is Mach 7.
NASA says the program will fly this time around because of new super-strength materials, manufacturing techniques and other capabilities unavailable 30 years ago.
It foresees eventual benefits beyond weapons systems and space rescues, including "a future fleet of government and commercial hypersonic vehicles, traveling between dozens or even hundreds of 'skyports'" around the world -- and beyond."
Michael Woods can be reached at mwoods@nationalpress.com or 1-202-662-7072.
