WASHINGTON-- The U.S. Department of Defense has signed off on NASA's plan to use majorspace shuttle components as the basis for separate vehicles that will launch theagency's new crew transport and 100-ton loads of Moon-bound cargo.
The U.S.Space Transportation Policy issued by the White House in January requires NASAto coordinate its future launch vehicle plans with the Pentagon and submit ajoint recommendation to the president on the nation's next heavy-lift rocket.
NASAAdministrator Mike Griffin and U.S. Air Force Undersecretary Ronald Sega, thePentagon's top space official, sent the White House a letter Aug. 5 outlining ajoint strategy for the use and development of national launch systems. Theletter, a copy of which was obtained by Space News, was addressed to JohnMarburger, director of the White House Office of Science and Technology Policy.Senior U.S. government officials copied on the letter include National SecurityCouncil Director Steve Hadley, Deputy Defense Secretary Gordon England, andWhite House Office of Management and Budget Director Josh Bolten.
Thetwo-page letter says "NASA will initiate development of a Crew Launch Vehiclederived from Space Shuttle solid rocket boosters with a new upper-stage forhuman spaceflight missions in the 25-30 metric-ton-class following retirementof the Space Shuttle in 2010. NASA then plans to develop a new 100metric-ton-class launch vehicle derived from existing capabilities with theSpace Shuttle external tanks and solid rocket boosters for future missions tothe Moon."
The letteralso says NASA and the Pentagon will use the Atlas 5 and Delta 4 rocketsdeveloped under the U.S. Air Force's Evolved Expendable Launch Vehicle (EELV)program "for all intermediate and larger payloads for national security, civil,science, and International Space Station cargo re-supply missions in the 5-20metric-ton-class to the maximum extent possible."
The letterfurther noted that new commercially developed launchers, should they becomeavailable, will be allowed to compete for such missions.
NASA andthe Pentagon, according to the letter, have agreed to complete a joint costbenefit analysis in the coming months of phasing out Boeing's Delta 2 rocket infavor of the EELV. Although the Air Force has largely moved on to the EELV, thesmaller Delta 2 remains NASA's workhorse for launching medium-sized sciencesatellites and interplanetary probes.
Alsoaccording to the letter, the Pentagon will consider using NASA's proposedheavy-lift launcher for any future military missions that might require such apowerful rocket. But it is unlikely, the letter says, that the Pentagon wouldendorse a shuttle-derived vehicle as an EELV back-up "due to the significantrisk, reliability, and cost of modifications required to [Defense Department]satellites and infrastructure."