Summary: In 1972, the two expected principal users of the Space Transportation System, the National Aeronautics and Space Administration (NASA) and the Department of Defense (DOD), agreed that the program would require two launch sites, Kennedy Space Center (KSC) in Florida and Vandenberg Air Force Base in California. NASA budget requests include additonal orbiters which would bring the total to five. The cost to construct and operate the Vandenberg complex to serve DOD activities during 1983 through 1992 would be $3.8 billion. The needs for the second launch site and for five orbiters were questioned. Polar orbits from KSC are not practicable because launches from KSC involve unacceptable land overflight and could cause an adverse reaction from the Soviet Union. If the Shuttle is as reliable as expected, the overflight objections do not justify the need for the Vandenberg facilities. The concern over Soviet reaction is difficult to assess and further inquiry may be needed, but a 1971 United States-Soviet agreement could preclude problems in this area. The request for five orbiters is based on NASA models which project up to 65 flights per year. These models have been questioned. Congress should not fund Vandenberg modifications to accommodate the Shuttle unless compelling reasons present themselves. Three orbiters (102, 103, and the upgraded structural test orbiter) can accommodate a substantial increase in space activity during the next decade and, if a more significant increase is anticipated, orbiter 101 could be upgraded to operational capability.