Scramjets: High-speed global bomber in the works

R. A. Hettinga rah at shipwright.com
Sun Nov 30 16:38:47 PST 2003


<http://www2.ocregister.com/ocrweb/ocr/article.do?id=69113&section=NEWS&subsection=FOCUS&year=2003&month=11&day=29>

The Orange County Register
Saturday
Nov. 29, 2003

Saturday, November 29, 2003

High-speed global bomber in the works
 Plan calls for weapons system that could strike anywhere on Earth in two
hours, cutting the need for foreign bases.

By ANDREW BRIDGES
The Associated Press


LOS ANGELES - It is the latest in the U.S. military's quest for faster,
more lethal, remotely operated weaponry - an aircraft that could bomb
targets anywhere on Earth within a scant two hours of taking off from the
United States.

The robotic bomber would streak eight times the speed of sound and have a
20,000-mile range, putting the entire globe within its deadly reach.

The Department of Defense and the Air Force are jointly sponsoring the
program, known as Force Application and Launch from the Continental United
States - or FALCON.

"The bottom line is, what we want to be able to do is have the capability
to strike anywhere on the globe in less than two hours," said Jan Walker, a
spokeswoman for the Defense Advanced Research Projects Agency in Arlington,
Va.

DARPA and the Air Force recently selected the program's first contractors,
a 10-company list that includes Northrop Grumman Corp., Lockheed Martin
Corp. and Orbital Sciences Corp.

The earliest such a reusable hypersonic aircraft would enter operation is
2025. However, simpler versions of the vehicles, including one designed to
carry small satellites to orbit, could be flying within the decade,
officials said.

"What we're talking about is decades of drawings and prototypes," said
Richard Aboulafia, an aerospace industry analyst at the Teal Group in
Fairfax, Va.

Huge technological hurdles remain, including the development of the exotic
materials needed to protect the airplanes from the tremendous heat
generated during hypersonic flight. How to propel, steer and communicate
with the aircraft also will have to be worked out.

"They are going to be a stretch from a technology standpoint, but there is
no reason why they can't develop and deploy them. There is no 'unobtainium'
in them," said Dennis Poulos, Northrop's FALCON program manager in El
Segundo.

Key to the project is the development of an air-breathing engine called a
scramjet. DARPA and the National Aeronautics and Space Administration are
working on the exotic engines.

Scramjets, or supersonic combustion ramjets, scoop oxygen from the
atmosphere to combust fuel carried aboard. They can fly as fast as rockets
but are lighter, since they don't have to carry both fuel and an oxidant to
burn it, as do rockets.

However, scramjets must be traveling at about five times the speed of sound
to work. That requires the use of a rocket to initially get them up to
speed.

In June 2001, a NASA demonstration flight of a scramjet vehicle failed when
the rocket used to accelerate it began to fall apart and veer off course.

NASA hopes to test its second scramjet-propelled X-43A next year, perhaps
as early as February, agency spokeswoman Leslie Williams said.

Days after the first NASA jet failed, DARPA successfully launched a 4-inch
diameter titanium mockup of a missile powered by a scramjet, in what it
said was the first-ever free flight using the technology. The projectile
covered 260 feet in just over 30 milli seconds. DARPA later repeated the
feat.

Scaling up the technology to the size needed to move an aircraft at
hypersonic speeds will be challenging.

Before building a hypersonic bomber, the Pentagon seeks to develop a
smaller, unpowered glider that could still fly at mind-numbing speeds. A
modified version could ferry small satellites to space.

"That's more doable in the near term," Walker said.

The tactical version of the steerable glider would be accelerated using a
rocket, perhaps in combination with a scramjet, and then released to
plummet back to Earth on a one-way trip to its target. Its range would
allow it to hit targets around the world.

The disposable glider, and the 1,000 pounds of munitions it conceivably
would carry, would hit targets at Mach 25, far faster than the more
advanced hypersonic bomber. Mach 25 is as fast as the space shuttle travels
when it first enters Earth's atmosphere on return from orbit.

Pentagon officials envision the more advanced bomber version carrying up to
12,000 pounds of munitions, including cruise missiles or other conventional
weapons.

That capability, coupled with the plane's unparalleled speed, would free
the military from having to rely on overseas air bases to station bombers
capable of "promptly and decisively" striking enemies, according to DARPA.

The Pentagon can already dispatch B-2 bombers from U.S. soil to strike
anywhere on Earth, but the missions can take a day and a half to complete.
B-2s made 37-hour roundtrip flights from Whiteman Air Force Base in
Missouri to strike targets in Iraq this year.

Theoretically, a hypersonic bomber could be quickly scrambled and complete
a similar mission over the course of an afternoon.

"It's a new capability," Poulos said. "It would be considered
transformational in nature."

-- 
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R. A. Hettinga <mailto: rah at ibuc.com>
The Internet Bearer Underwriting Corporation <http://www.ibuc.com/>
44 Farquhar Street, Boston, MA 02131 USA
"... however it may deserve respect for its usefulness and antiquity,
[predicting the end of the world] has not been found agreeable to
experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'


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