Space Shuttle

The space shuttle, America's only manned launched vehicle, is one of NASA's largest programs, consuming more than one-quarter of the agency's total budget. This report examines (1) factors associated with achieving planned flight rates, (2) processes to ensure that safety is not compromised by increasing flight rates, (3) the impact of variations in flight rate estimates on procuring subsystems and spare parts, and (4) planned use of expendable launch vehicles for payloads not requiring the shuttle. GAO recommends that NASA reduce advanced solid rocket motor manufacturing equipment to be consistent with current shuttle flight rate estimates and determine how much could be saved by reducing the size of motor manufacturing facilities.

GAO found that: (1) although NASA has reduced its maximum annual shuttle flight rate projection to 10 flights a year, it will not be able to achieve that rate before late in the decade; (2) NASA may be unable to achieve 10 flights a year, especially if it fails to reduce shuttle ground processing time or loses or severely damages another orbiter; (3) no evidence existed suggesting that NASA might compromise safety to increase its flight rate; (4) since the Challenger accident, NASA has delayed shuttle launches over reasonable questions about safety concerns, and has implemented adequate controls to ensure that safety is considered during shuttle processing modification or elimination decisions; (5) although optimistic flight rate projections have not resulted in excess procurement of spare parts, adjustments in delivery schedules for shuttle subsystems made necessary when NASA did not achieve projected flight rates have created inefficiencies; (6) NASA is moving from a policy that exclusively relies on shuttles to launch its payloads to one using shuttles only when necessary; (7) 89 percent of the payloads on the shuttle's current manifest require either human interaction or some unique shuttle capability to be launched, and the remaining payloads are on the shuttle manifest for national security reasons or because expendable launch vehicles are unavailable to meet launch schedules; (8) NASA is designing most of its new payloads to fly on expendable launch vehicles; and (9) NASA has contracted to build advanced solid rocket motor production facilities in excess of current requirements.

Recommendations

Our recommendations from this work are listed below with a Contact for more information. Status will change from "In process" to "Open," "Closed - implemented," or "Closed - not implemented" based on our follow up work.

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