Space Laser Project Heats
Up Source: Space.com November 28, 2000
WASHINGTON -- The pace of work is not quite light-speed.
But the end product may be just that -- an orbiting laser that churns
out a high-power beam to destroy a ballistic missile in flight by
2013.
Industry and government teams are now shaping the
Space-Based Laser (SBL) concept. The idea is seen as next-generation
directed-energy weaponry, whereby dozens of space platforms would be
interlinked to create an Earth-orbiting global missile defense system.
In early November, the Air Force awarded a $97 million
contract to three companies: TRW Space & Electronics Group, Lockheed
Martin Missiles & Space Operations and Boeing Space & Communications
Group.
Those monies are earmarked to continue work on an
Integrated Flight Experiment (IFX) to be lofted into orbit in 2012.
The experimental show-and-tell technology would be ready for target
practice on a U.S.-launched ballistic missile the following year.
Team SBL-IFX, a joint venture comprising TRW, Lockheed
Martin and Boeing, demands a host of new advancements. Here, an
aluminum ring is under development. More than 100 of these rings will
be stacked to form the laser's primary combustion chamber.
To date, Team SBL-IFX -- the working moniker for this
trio of companies since early 1999 -- has been awarded some $240
million to design, build and test a satellite capable of toting a
high-energy laser, as well as blueprinting how best to demonstrate the
hardware while in flight.
Souped-up chemical laser
The effort to create a space-based missile defense
system is under the rubric of the U.S. Air Force and the Pentagon's
Ballistic Missile Defense Organization. $3.5 billion is budgeted to
complete the SBL-IFX program.
"This is an ambitious project. Everybody should
understand that," said Colonel Neil McCasland, director of the Air
Force's SBL-IFX project in Los Angeles, California. "But this is a
reach that is in the domain of the possible for American industry. The
implications are commensurate with the ambition," he told SPACE.com.
McCasland said that the SBL-IFX is not an operational
weapon. "It's a path to that operational weapon, if the country so
chooses," he said.
A souped-up cylindrical, hydrogen-fluoride chemical
laser is at the heart of the SBL-IFX test satellite.
Once in orbit, the laser is to be put through a series
of tests prior to its first firing, said Major Arnie Streland, chief
of acquisition management and planning, at the U.S. Air Force Space &
Missile Systems Center in Los Angeles, California.
"We'll basically prove out all the systems, including
lighting off the high-energy laser before we actually go after a
target," Streland said.
Less than a dozen firings of the laser are expected over
the equipment's three-year lifetime, McCasland said. Studies are
underway for designing the laser for on-orbit refueling, he said.
Boost phase blast
Directed energy beamed from a spacecraft travels at the
speed of light, a blistering 186,000 miles (300,000 kilometers) per
second. That's about 43,000 times faster than the most capable
ground-based interceptors.
The Space-Based Laser is designed to kill hostile
rockets in their boost phase -- the period of time shortly after a
rocket leaves the ground. It is within that boost phase that military
planners see an aggressor's missile as most vulnerable.
Why? First, thanks to a rocket's burning engines, the
missile produces a large infrared plume, ideal for tracking by
spaceborne sensors. Secondly, the missile is slowly arcing through the
sky, making it easier to track. Thirdly, at this point of flight, the
rocket body is relatively fragile and under great stress.
"This is an ambitious project. Everybody should
understand that. But this is a reach that is in the domain of the
possible for American industry. The implications are commensurate with
the ambition." Moreover, because the rocket has yet to toss its warhead
toward an intended target, there is a large "lethal-hit area" when
trying to down a missile via laser beam. The heat from a laser beam
weakens the missile's skin, leading to the vehicle's destruction.
For the SBL-IFX project, McCasland said the plan is to
construct a target rocket stage, propelled by a Minuteman missile.
This target stage is to be specially instrumented to collect data
about the laser beam's knock-out punch.
Priceless testing
The orbiting laser idea is the only ballistic missile,
boost-phase intercept system being pursued by the U.S. Department of
Defense to provide global defense coverage to counter intercontinental
ballistic missile attacks against America or its allies.
But trying to build an affordable, compact and
less-weighty Space-Based Laser is no small task. One key step was
recently taken using results of a TRW-built Alpha chemical laser
firing last month.
That six-second test shot of the megawatt-class Alpha
demonstrated ways to tailor the laser's chemical efficiency and output
power, as well as the shape of the light beam. That data is a bonus
for the megawatt-class SBL-IFX laser, McCasland said.
"Ground tests are priceless in helping us reduce risks
for the space demonstration. What you can't do on the ground, however,
is completely emulate the space environment. So the proof is in the
flight," McCasland said.
Tug of war
Other hardware elements for a spaceborne laser are
coming together.
For example, a new, self-cooling laser nozzle that feeds
chemical reactants into a special cavity has been developed. Faster
and more reliable fabrication techniques to form the primary
combustion chamber for the SBL-IFX laser have proven successful.
Also achieved are manufacturing processes to crank out
and coat uncooled, single-crystal silicon optics needed to form
special mirrors for the SBL-IFX laser.
The use of uncooled optics means a weight-savings and
use of less-complex "plumbing" inside a chemical laser payload.
Ultimately, the issue at hand is the laser's ability to
pump out ample power in a small enough spot, McCasland said. It's a
tug-of-war, he said, between combustion forces that breed laser energy
and a need for rock-steady optics, all while precisely tracking and
pointing a lethal laser beam at a fast-moving missile stage.
Major decision
While a hardware liftoff in 2012 might seem light-years
away, a major decision is forthcoming for the project.
A new laser test facility is to be constructed and three
locations are now being eyed, Streland said.
The candidate sites are: NASA's John C. Stennis Space
Center in Mississippi; the Army's Redstone Arsenal adjacent to the
space agency's Marshall Space Flight Center in Huntsville, Alabama and
Cape Canaveral, near NASA's Kennedy Space Center in Florida.
"We want to get started in 2001," McCasland said. "The
test facility will allow us to run the flight configuration laser long
enough to convince us that we're ready to take it to the launch pad,"
he said.
Show-stoppers?
It seems the most troublesome aspect for the laser
project is more political than technical.
The "technology demonstration" by the SBL-IFX is to be
conducted in full compliance with all relevant international treaties,
officials of the project said, including the 1972 Antiballistic
Missile (ABM) Treaty.
"The experiment will comply with the treaty," McCasland
said. "This is not an operational weapon. It's only one satellite.
We're not fielding something with the operational intent to shoot down
ballistic missiles," he said.
Data gleaned from flight testing the SBL-IFX in 2013
will be used by Department of Defense policymakers to wrestle with a
go/no-go decision to construct and deploy in orbit a full-scale laser
missile defense system.
If given the green light, an operational fleet of lasers
could be placed in space around 2020.
by Leonard David
Senior Space Writer
http://www.space.com/businesstechnology/technology/space_laser_001127.
html
- Colonel Neil McCasland, Los Angeles Director of the USAF's SBL-IFX
project