MILESTONE REVIEW BRINGS NASA ONE STEP CLOSER TO NEW LAUNCH 
VEHICLE

     NASA is another step closer to defining the next-
generation reusable space transportation system and successor 
to the Space Shuttle.

The Space Launch Initiative (SLI), a NASA-wide effort 
defining the future of human space flight, has completed its 
first milestone review -- resulting in a narrower field of 
potential candidates for the nation's second-generation 
reusable space transportation system.

"To use the resources afforded by space, it's critical to 
increase reliability and safety while at the same time 
reducing the cost of space transportation," said Art 
Stephenson, director of NASA's Marshall Space Flight Center, 
Huntsville, Ala., which manages the SLI for the Office of 
Aerospace Technology. "The Space Launch Initiative is doing 
the groundwork to accomplish these goals and create a second-
generation launch system." 

"We're not just designing a launch vehicle," added Dennis 
Smith, also of Marshall, program manager of the Space Launch 
Initiative. "We're designing the complete system." 

The recent review, called the Initial Architecture Technology 
Review, analyzed and evaluated competing second-generation 
reusable space transportation architectures and technologies 
against NASA and commercial mission requirements, as well as 
safety and cost goals.  

Architecture refers to the complete transportation system 
design -- that is, the vehicles and their components that fly 
into space, as well as the ground operations needed for 
launch. The transportation system design includes an Earth-
to-orbit reusable launch vehicle (the Space Shuttle is the 
first-generation reusable launch vehicle); on-orbit transfer 
vehicles and upper stages to put satellites into orbits; 
mission planning; ground and flight operations; and support 
infrastructure, both on orbit and on the ground. 

Three contractor architecture teams -- The Boeing Company of 
Seal Beach, Calif.; Lockheed Martin Corp. of Denver; and a 
team including Orbital Sciences Corp. of Dulles, Va., and 
Northrop Grumman of El Segundo, Calif. -- presented dozens of 
potential architectures for review. Following the review, 
each retained a handful of possible candidates for the 
nation's next-generation reusable space launch system.  

The review allows the Space Launch Initiative to target 
investments and support what the program manager called the 
"up-front, homework part of the program" -- furthering 
technologies to aid in the development of a second-generation 
reusable launch vehicle. Another review will be held in 
November to further narrow potential space transportation 
architectures to two or three choices.  

"We're going to seek the final and best ideas from industry, 
academia and government," said Smith. With the final 
selection of an architecture, full-scale development of a 
reusable launch vehicle could begin around the middle of this 
decade. 

Since propulsion systems require a long lead-time to design, 
develop, test and evaluate, it isn't surprising that 
propulsion analysis was a chief driver through the recently 
completed review activity.  

"We spent a lot of time analyzing propulsion technologies," 
said Smith. "Among the outcomes is a focus on kerosene-fueled 
main engines." This focus is based on studies, conducted by 
the architecture contractors, that examine performance of 
competing technologies in safety, reliability, cost and 
operability. Studies indicated that kerosene main engines 
have excellent potential to meet government and commercial 
needs. The second-generation vehicle will have a two-stage-
to-orbit propulsion system based on engines fueled by all 
kerosene, all hydrogen or a combination of kerosene and 
hydrogen.

Dependable, long-life engines, along with crew escape and 
survival systems, and long-life, lightweight integrated 
airframes are among the Space Launch Initiative's highest 
priorities. Each greatly impacts the program's bottom line of 
increased safety, reliability and cost effectiveness.

All NASA's field centers and the Air Force Research 
Laboratory are actively participating in the Space Launch 
Initiative. Additional information on NASA's Space Launch 
Initiative, including a list of the selected contractors, is 
available on the Internet at:

http://www.slinews.com
http://www.spacetransportation.com