|A step closer to an
economical entry platform to space travel? Well, a step forward it most
definitely is, but overcoming 'melting' airframes and maintaining precise
controls will test the designers mental dexterity. One would not want to
suddenly veer a tad left or right at these speeds. Unlike 'Star Trek' the
technology to 'avoid' inertia and G Force doesn't seem to be on the drawing
boards as yet!
The flight of
NASA's X-43A at seven times the speed of sound got a lift from Boeing (NYSE:BA)
research expertise with hypersonic vehicles and spacecraft.
On Saturday, a NASA Dryden Flight Research Center B-52 aircraft flown from
Edwards Air Force Base, Calif., carried the X-43A off the California coast,
where it was launched just before 2 p.m. PST over the Pacific Ocean mounted
on a booster rocket.
The booster took the X-43A up to its test altitude of about 95,000 ft.,
where the X-43A separated and flew freely for several minutes. During the
free flight, the scramjet engine operated for about 10 seconds and the X-43A
successfully achieved its test speed of Mach 7.
"This successful flight is an important step toward validating the use of
advanced air-breathing propulsion technology for achieving more rapid global
travel and routine, affordable access to space," said Bob Krieger, president
of Phantom Works, Boeing's advanced R&D unit. "Applied to civil, military
and space systems, this technology has the potential to open new frontiers
Boeing Phantom Works is teamed with prime contractor ATK GASL to develop and
build the X-43A or Hyper-X for NASA. Boeing designed the vehicle, the
airframe thermal protection systems and flight control and navigation
systems. ATK GASL was responsible for vehicle fabrication, assembly, systems
integration and testing in addition to providing the scramjet engine. The
booster is a modified Pegasus rocket built by Orbital Sciences Corp.
The 12.3-foot-long X-43A is powered by a scramjet, or supersonic combustion
ramjet engine. As air-breathing engines, scramjets have significantly fewer
moving parts than traditional turbojet engines, and do not require oxidizer
to be carried onboard for combustion like conventional rocket engines do.
Scramjets allow for the design of smaller, simpler, more affordable reusable
vehicles for potential space, military and civil applications.
Hypersonic flight, defined as flying at least five times the speed of sound,
remains a mostly unexplored region. At those speeds, metals can melt or
vaporize almost instantly, and aerodynamic control must be extremely
precise. Additionally, strong shockwaves are created that can cause
exceptionally high temperatures and forces on various parts of the airframe.
To meet these challenges, the X-43A employs a tile-based thermal protection
system, carbon-carbon composites, and high temperature-resistant metals; a
control system designed to deal with the rapid changes in forces and motions
expected at Mach 7; and a special control technique to sense and prevent
disruption of the supersonic airflow through the inlet, which would
dramatically reduce engine thrust.
Boeing has explored the challenges of hypersonic flight since the 1950s,
beginning with the X-15 to the space shuttle to the X-43A.
Phantom Works is currently teamed with Pratt & Whitney on the Scramjet
Engine Demonstrator - WaveRider program for the Air Force. Additional
Phantom Works projects include the FALCON Hypersonic Cruise Vehicle program
for DARPA and the HyFly hypersonic missile demonstrator program for DARPA
and the Navy.
"Many challenges remain to be overcome, particularly in developing efficient
and high-performing engines for sustained hypersonic flight," said Tom
Harsha, Boeing Phantom Works X-43A program manager. "But we'll learn
important lessons from the X-43A about the technology we'll need to make
hypersonic flight practical."
NASA's Langley Research Center in Hampton, Va., and Dryden Flight Research
Centre near Edwards, Calif., jointly conduct the Hyper-X program.
Boeing Phantom Works is the advanced research and development unit and a
catalyst of innovation for The Boeing Company. It provides advanced
solutions and innovative, breakthrough technologies that reduce cycle time
and cost while improving the quality and performance of aerospace products