NASA, the Air Force and two
prime aerospace contractors have successfully completed testing of
two key rocket engine components -- critical milestones in the
development of innovative engine systems that could, within
decades, power a new generation of American space launch
vehicles.
The tests -- of a new, liquid-hydrogen turbopump and a unique
oxidizer preburner -- are part of a project called the Integrated
Powerhead Demonstrator, or IPD. The project is a joint venture
between NASA's Next Generation Launch Technology program, managed
for the Agency at the Marshall Space Flight Center in Huntsville,
Ala., and the Integrated High Payoff Rocket Propulsion Technologies
program, managed for the Department of Defense by the U.S Air Force
Research Laboratory at Edwards Air Force Base, Calif.
Both tests are part of component-level, risk-reduction studies,
intended to lead to development of a hydrogen-fueled, full-flow,
staged-combustion rocket engine -- the first of its kind. The
engine will employ preburners featuring both oxygen-rich and
hydrogen-rich staged combustion, which help to cool engines during
flight, achieve higher engine efficiency and reduce exhaust
emissions.
"Completion of these tests moves us two steps closer to
full-scale, integrated testing of the entire IPD system," said
Garry Lyles, manager of the Next Generation Launch Technology
program, which manages the IPD project for NASA. "America's future
in space hinges on cutting-edge technology development, and
together with our Air Force and industry partners, we're focused on
creating a more reliable, robust engine system."
"These testing successes wrap up a very exciting year for the
IPD project," said Jeffrey Thornburg, IPD project manager for the
Department of Defense at the Air Force Research Laboratory. "I
can't say enough about how well the NASA, Air Force and industry
team has come together to overcome many technical challenges to
help us complete this testing."
Integrated system testing is scheduled to begin in late 2004 at
NASA's Stennis Space Center near Bay St. Louis, Miss.
The liquid-hydrogen fuel turbopump was developed for NASA and
the Air Force by the Rocketdyne Propulsion and Power division of
the Boeing Company of Canoga Park, Calif. The turbopump test
series, conducted at the Stennis Space Center, was completed Oct.
29.
The turbopump is designed to provide high-pressure hydrogen to
the rocket engine thrust chamber, enabling the combustion process
and generating thrust. The turbopump extracts energy from hot
gases, which are generated by the fuel preburner and flow through
the turbine, causing the turbopump rotor to spin at more than
50,000 rpm. As the rotor spins, an impeller attached to the other
end of the shaft pumps the hydrogen to pressures greater than 6,600
psi. These high pressures are necessary to generate the 3,000 psi
combustion gases in the thrust chamber, which expand through the
chamber and nozzle to produce 250,000 pounds of thrust.
The design and
technologies of the fuel turbopump address key life limitations of
current reusable rocket engines, and is intended to achieve a
lifespan goal of 200 flight missions and 100 flights between
periods of engine refurbishment -- 10 times the current capability
of reusable rocket engines.
"We are very pleased with the results of the turbopump testing,"
said Don McAlister, IPD program manager at Boeing Rocketdyne.
"We've met all our objectives and we've learned valuable lessons
for future rocket engine design and testing. With the turbopumps
well characterized, we can now move confidently into engine system
testing next year."
"With the successful completion of the fuel turbopump component
test series, we have substantially lowered the risks associated
with pursuing the future integrated engine system test series,"
said Harry Ryan, IPD project manager at the Stennis Center.
"Incremental component testing provides a building-block approach
to identify key requirements and reduce risks associated with
integrated engine development."
Testing of the oxidizer preburner was conducted by component
designer Aerojet Corp. at its Sacramento, Calif., facilities. The
test series was completed Oct. 28.
The oxidizer preburner -- which initiates the combustion process
-- is designed to generate oxygen-rich steam for use by the oxygen
turbopump's turbine. The preburner burns a large quantity of liquid
oxygen with a small quantity of hydrogen to produce this steam,
which then mixes with additional hydrogen fuel to be burned in the
main combustion chamber.
The preburner is the first flight-capable, oxygen-rich preburner
developed in the United States for a large-scale engine. The use of
oxygen-rich steam to power the oxygen turbopump is intended to
dramatically increase safety of engine system operation, limiting
seal failure between the pump and the turbine that could leak
extremely hot gases into the turbine and cause them to burn
prematurely.
"We are very excited about the operating characteristics
demonstrated during the preburner testing," said Robert Werling,
project manager for Aerojet. "They provided the thermal
environments required to meet the extended turbine life goals,
while providing the power necessary to realize the performance
goals of the integrated engine system."
The Integrated Powerhead Demonstrator is a cornerstone of NASA's
Next Generation Launch Technology program, which seeks to provide
safe, dependable, cost-cutting technologies for future space launch
systems, increasing engine operability and leading to aircraft-like
flight operations. The project also is part of the Department of
Defense's Integrated High Payoff Rocket Propulsion Technology
program, which seeks to double the performance and capability of
today's state-of-the-art rocket propulsion systems while decreasing
costs associated with military and commercial access to space.