launch system for the vast majority of national security payloads for decades. The most optimistic motivation to replace or supplement the RBS would be if the launch rates got sufficiently high that it was worth the investment to build a second system. A new space launch system could be introduced to take advantage of new technologies that could not be introduced as RBS improvements or if the RBS became so expensive that an alternative would be cost effective.
The caveat “if all goes well,” however, is not an insignificant consideration. Experience with aircraft programs suggests that when a fundamental change is desired (such as from fourth- to fifth-generation stealth) it has been beneficial to continue with two options well into the program, including flight test. With aircraft, there is a presumption that eventual production quantities make this continued competition cost-effective in the long run. Whether or not that has turned out to be true, there is little doubt that a better end unit was achieved than if a single contractor had been chosen based on paper designs and some component hardware. If the RBS flyback booster is the highest initial risk, the program should consider demonstrating it with two (or more) designs and take the best qualities determined from both, incorporating them into the demonstrator. This implies, as a minimum, two different Pathfinders with government ownership of all the resulting data. It would be beneficial if the same development and fly-off strategy be applied to the demonstrator vehicles for the same reasons.
In addition to a better technical outcome, a single Pathfinder that crashes, for whatever reason, early in flight test probably kills the program. A single Pathfinder that is unable to demonstrate the rocketback turnaround and RTLS maneuvers almost certainly kills the program, even if there was another approach that would have been successful but was not pursued because it did not appear better on paper.
The apparent program approach of single contractors may appear to be lower cost, especially in development, and therefore an easier “sell” for the initial investment, but it has far more technical and, in most cases, programmatic risk. It would be desirable for the RBS program to maintain competition as long as practicable to obtain and retain the “A-Team” from the contractors, foster innovation as each contractor strives to deliver the better product, sustain a larger industrial base for when reusable systems finally dominate the market, and achieve a lower life cycle cost.