Grey Hautaluoma/Stephanie Schierholz
Headquarters, Washington
202-358-0668/4997
grey.hautaluoma-1@nasa.gov
stephanie.schierholz@nasa.gov

June Malone
Marshall Space Flight Center, Huntsville, Ala.
256-544-0034
june.e.malone@nasa.gov


RELEASE: 08-208

NASA ENGINEERS COMPLETE ENGINE TEST SERIES FOR ARES I ROCKET

HUNTSVILLE, Ala. -- Engineers at NASA's Marshall Space Flight Center
in Huntsville, Ala., have completed a series of tests on a key
component of the J-2X engine. The J-2X powers the upper stage of the
Ares I rocket, which will launch human explorers to the International
Space Station and to the moon.

The test on Aug. 15 was the last of 20 in this series, concluding the
second of four planned sets of tests on the J-2X's workhorse gas
generator, the driver for the turbopumps which start the engine.

The gas generator test program is designed to demonstrate the
component's performance, durability and combustion environment, and
to reduce risk in the design, fabrication and operation of flight
hardware. The third phase of testing will begin in July 2009. The
J-2X's workhorse gas generator is fabricated by Pratt and Whitney
Rocketdyne of Canoga Park, Calif.

The primary objectives achieved in this series of tests were to
regulate ignition timing and address stability issues in the gas
chamber. During engine start, a pressurized helium system begins to
turn the turbopumps, which draw liquid hydrogen and liquid oxygen
propellants into the system. The propellants flow into the
generator's combustion chamber, where they are sparked into life by
pyrotechnic igniters installed in the side of the main combustion
chamber.

Once combustion is initiated, hot gases flow into the turbine. The
combustion gas provided by the generator drives the turbomachinery,
which delivers high pressure propellants to the main injector during
the J-2X burn. This testing allows engineers to address stability
issues that can arise during operation of the combustion chamber and
will allow engineers to develop a clean design for the J-2X engine.

Beginning in 2015, the Ares I rocket will carry the Orion crew capsule
and as many as six astronauts and small payloads to the International
Space Station. During the first two-and-a-half minutes of flight, the
first stage booster will power the vehicle to an altitude of about
189,000 feet, or 36 miles, at a speed of Mach 4.8. After its
propellant is spent, the reusable booster will separate, and the
upper stage's J-2X engine will ignite -- powering the Orion to low
Earth orbit at an altitude of about 425,328 feet, or roughly 80
miles.

The workhorse gas generator test series is an essential step in
development of the J-2X engine. More than 50 tests have been
performed on the generator to date. This generator was manufactured
to be more durable than the generators that will be used in the J-2X
engine, allowing it to withstand numerous tests.

NASA's Johnson Space Center in Houston manages NASA's Constellation
Program, which includes development of the Ares I rocket, the Ares V
heavy launch vehicle for cargo launcher, the Orion crew capsule, and
the Altair lunar lander. Marshall manages Ares projects for the
agency.

For an image of the workhorse gas generator testing, visit:



http://www.nasa.gov/ares


For information about NASA's Constellation Program, visit:





David Cottle

UBB Owner & Administrator