Imagine taking off from any U.S. airport and landing on any other
runway in the world in less than two hours. Or making a quick hop from that
same airport to the International Space Station and back — a trip that
normally takes days or weeks — to drop off science experiments, provisions
and new equipment.

Sound far-fetched?

Not anymore. Technology now being developed by NASA and its
partners could — within two decades — achieve such rapid trip times,
yielding limitless possibilities for international travel, commerce and
access to space.

And this week, they’re going public with the hypersonic shape of
things to come.

Visitors to the 50th annual Experimental Aircraft Association’s
AirVenture Air Show, opening July 23 in Oshkosh, Wis., will be among the
first to see mockups of NASA’s proposed “Hyper-X” series. These technology
demonstrators, intended for flight testing by decade’s end, are expected to
yield a new generation of vehicles that routinely fly about 100,000 feet
above Earth’s surface and reach sustained travel speeds in excess of Mach 5,
or about 3,750 mph — the point at which “supersonic” flight becomes
“hypersonic” flight.

It also may be the point at which traditional air transportation
becomes as outmoded as the covered wagon.

Technologies for 21st century flight

Revolutionizing the way we gain access to space is NASA’s primary
goal for the Hypersonics Investment Area, managed for NASA by the Advanced
Space Transportation Program at NASA’s Marshall Space Flight Center in
Huntsville, Ala.

The Hypersonics Investment Area — which includes leading-edge
partners in industry and academia — will support future-generation reusable
launch vehicles and improved access to space. Over the next 20 years, the
U.S. will develop and test a series of ground and flight demonstrators. The
flight demonstrators — the Hyper-X series — will be powered by
air-breathing rocket- or turbine-based engines and ram/scramjets.

Air-breathing engines for hypersonic applications are known as
“combined cycle” systems because they use a graduating series of propulsion
systems in flight to reach an optimum travel speed, or to leave the
atmosphere altogether. Air-breathing engines achieve their efficiency gains
over rocket systems by getting their oxygen for combustion from the
atmosphere, as opposed to a rocket which must carry its oxygen. These
systems capture air from the atmosphere during flight — an arrangement that
improves efficiency up to 5-10 times greater than that of conventional
chemical rockets.

Once a hypersonic vehicle has accelerated to more than twice the
speed of sound, the turbine or rockets are turned off, and the engine relies
solely on oxygen in the atmosphere to burn fuel. When the vehicle has
accelerated to more than 10 to 15 times the speed of sound, the engine
converts to a conventional rocket-powered system to propel the craft into
orbit or sustain its top suborbital flight speed.

Despite the astounding paradigm shift it promises for suborbital and
orbital flight, the concept of hypersonic flight is not a new one. NASA’s
hypersonics program is built on research dating back to the 1950s.
But the new effort — leveraging technology resources and manufacturing
capabilities unavailable 30 years ago — is intended to yield practical
results before mid-century: a future fleet of government and commercial
hypersonic vehicles, traveling between dozens or even hundreds of “skyports”
around the world. And beyond it.

The Hyper-X series

NASA’s series of hypersonic flight demonstrators includes three
air-breathing vehicles: the X-43A, X-43B and X-43C.

The X-43A, an unpiloted research craft mounted atop a modified
Pegasus booster rocket, was first flown in June 2001. During the flight, an
in-flight incident forced the mission to be aborted. NASA has planned three
X-43A flights; two more X-43A flight demonstrators, built in early 2002, are
being prepared for flight testing at NASA’s Dryden Flight Research Center in
Edwards, Calif. Fueled by hydrogen, the X-43A is intended to achieve Mach 7
and possibly Mach 10, or speeds of approximately 5,000 and 7,500 mph,

The X-43C demonstrator, powered by a scramjet engine developed by
the U.S. Air Force, is now in development. The X-43C is expected to
accelerate from Mach 5 to Mach 7, reaching a maximum potential speed of
about 5,000 mph. NASA will begin flight-testing the X-43C in 2008.

The largest of the Hyper-X test vehicles, the X-43B, could be
developed — and would fly — later this decade. Successful ground- and
flight-testing of various engine configurations aboard the X-43A and X-43C
will determine whether a rocket- or turbine-based combined-cycle engine
powers the X-43B.

All three X-43 flight demonstrator projects are managed by NASA’s
Langley Research Center in Hampton, Va.

Next-generation flight solutions

NASA expects to spend about $700 million on hypersonics research and
development over the next five years, according to Steve Cook, deputy
manager of Marshall’s Advanced Space Transportation Program. Cook
anticipates the investment will yield unprecedented results, opening up new
commercial markets for industry, furthering human and robotic exploration of
the solar system and significantly improving national security.

“Testing conducted over the last four years proves that
air-breathing propulsion is the most promising technology we’ve seen to date
for accomplishing NASA’s third-generation space transportation goals,” Cook

Those goals — focusing on radically safer, more reliable and less
expensive access to space — permeate not just the Hypersonics Technology
Program, but all NASA’s space transportation and propulsion systems

NASA’s Space Launch Initiative, managed by the Marshall Center, is
working to develop the technology for a second-generation vehicle that could
lead to a replacement for the first-generation Space Shuttle by 2012 —
providing a vastly safer, more cost efficient and more reliable fleet of
vehicles. The third-generation program seeks, by the year 2025, to develop
advanced reusable launch vehicles and associated flight and transportation
technologies that will allow for even more significant reductions in payload
costs, and even greater improvements in safety and reliability.

More about NASA’s Hypersonics Team

NASA is leading national research into hypersonics systems
development, analysis and integration. Spearheaded by the Marshall Center,
the program includes researchers at Ames Research Center in Moffett Field,
Calif.; Dryden Flight Research Center in Edwards, Calif.; Glenn Research
Center in Cleveland, Ohio; Kennedy Space Center, Fla.; Langley Research
Center in Hampton, Va.; and the Air Force Research Laboratory, which
encompasses research and development facilities at nine U.S. Air Force
bases. NASA is also partnering with leading academic institutions and
industry partners around the nation.