Second, the RBS business case does not address the impacts of single-source providers. So, while the business case assumes that RBS captures the complete Air Force launch manifest and is developed with a single-source provider, the cost risks associated with using a single source are not adequately addressed. Put another way, the cost benefits associated with retaining competition in vehicle development were not included in the business case. Since the commercial launch market is rapidly changing and will be driven by cost considerations, not assessing the role of competition is a weakness of the current RBS business case.

Third, the RBS business case assumed full capture of the Air Force launch manifest, but the Air Force maintains a requirement for independent launch capabilities to assure its mission needs. With this need for development and maintenance of a second launch system capability, the RBS business case model is overly optimistic in assuming it will capture the entire Air Force launch manifest.

The end result of these factors is that the uncertainties associated with the RBS business case are sufficiently large that the business case cannot be considered to be closed at the present time.

Finding 3: Reusability remains an option for achieving significant new full-spectrum launch capabilities at lower cost and greater launch flexibility.

The Air Force Space Command has identified a long-term S&T objective for achieving full-spectrum launch capabilities at significantly reduced costs, and reusability remains an option for realizing this objective. A robust reusable system might have additional benefits beside reduced costs, including replenishment of satellites on demand; deployment of distributed constellations; rapid deployment; robust launch operations from multiple defendable launch sites; and operability by Air Force personnel.

Finding 4: For RBS to significantly impact Air Force launch operations, it would have to be more responsive than current expendable launch systems. However, no requirement for RBS responsiveness has been identified that would drive technology development.

The existing business case for RBS is built on satisfying the current EELV launch manifest with a launch-on-schedule assumption to operations. With this assumption and given the lack of an operability requirement for RBS, the technologies necessary to significantly enhance operability and reduce operating costs will not be given a high priority. It is in the development of design features and technologies and the resulting changes to Air Force operations that the true value of a reusable system lies.

Finding 5: Technology areas have been identified in which continued applied research and advanced development are required before proceeding to large-scale development. These areas include reusable oxygen-rich, staged-combustion hydrocarbon-fueled engines, rocketback return-to-launch-site operation, vehicle health management systems, and adaptive guidance and control capabilities.

Finding 6: Given the uncertainties in the business case and the yet-to-be mitigated technology risks, it is premature for Air Force Space Command to program significant investments associated with the development of a RBS capability.

While the committee found that the RBS business case cannot be closed at this time, and it is premature to begin large-scale RBS development activities, the committee does strongly endorse the continued research and advanced technology development needed for future launch systems. The committee makes the following six recommendations.

Recommendation 1: Launch responsiveness should be a major attribute of any reusable launch system. To address this perceived disconnect, the Air Force should establish specific responsiveness objectives independent of the Evolved Expendable Launch Vehicle launch-on-schedule requirements that can be used to drive technology development.

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