NASA's Exploration Systems Progress Report - May 18, 2006

May 18, 2006

Dolores Beasley
Headquarters, Washington
(202) 358-1753

Kim Newton
Marshall Space Flight Center, Huntsville, Ala.
(256) 544-0034

RELEASE: 06-226

NASA'S EXPLORATION SYSTEMS PROGRESS REPORT

NASA has chosen the RS-68 engine to power the core stage of the
agency's heavy lift cargo launch vehicle intended to carry large
payloads to the moon.

The announcement supersedes NASA's initial decision to use a
derivative of the space shuttle main engine as the core stage engine
for the heavy lift launch vehicle.

The cargo launch vehicle will serve as NASA's primary vessel for safe,
reliable delivery of resources to space. It will carry large-scale
hardware and materials for establishing a permanent moon base, as
well as food, fresh water and other staples needed to extend a human
presence beyond Earth orbit.

Recent studies examining life-cycle cost showed the RS-68 is best
suited for NASA's heavy-lift cargo requirements. The decision to
change the core stage engine required an increase in the size of the
core propulsion stage tank, from a 27.5-foot diameter tank to 33-foot
diameter tank, to provide additional propellant required by the five
RS-68 engines.

The RS-68 is the most powerful liquid oxygen/liquid hydrogen booster
in existence, capable of producing 650,000 pounds of thrust at sea
level. In contrast, the space shuttle main engine is capable of
producing 420,000 pounds of thrust at sea level. The RS-68, upgraded
to meet NASA's requirements, will cost roughly $20 million per
engine, a dramatic cost savings over the shuttle main engine.

The prime contractor for the RS-68 engine is Pratt & Whitney
Rocketdyne of Canoga Park, Calif. Pratt & Whitney Rocketdyne is
the same company that manufactures the shuttle main engine.

The RS-68 is used in the Delta IV launcher, the largest of the Delta
rocket family developed in the 1990s by the U.S. Air Force for its
evolved expendable launch vehicle program and commercial launch
applications.

The cargo launch vehicle effort includes multiple project element
teams at NASA centers and contract organizations around the nation
and is led by the Exploration Launch Office at NASA's Marshall Space
Flight Center in Huntsville, Ala.

The project office is part of the Constellation Program led by NASA's
Johnson Space Center in Houston. Constellation is a key program of
NASA's Exploration Systems Mission Directorate in Washington.

For information about NASA's exploration efforts, visit:

http://www.nasa.gov/exploration

For information about NASA and agency programs, visit:

http://www.nasa.gov/home

-end-