Modification of a Commercial NLV Booster Concept for Use as a Low-Cost Upper Stage for the XS-1

The opportunity exists to significantly advance the introduction of a low-cost upper stage for DARPAs Experimental Spaceplane (XS-1) by leveraging our teams on-going nanosat launch vehicle (NLV) development program.The Phase I effort has resulted in an upper stage concept that is ready to enter final design, followed by assembly, integration, checkout and static fire testing of an initial engineering unit.This final upper stage design reflects multiple trades that addressed the original Phase I objectives .The most significant design driver was the mitigation of technical risk by selection of a dual-stage configuration for the XS-1 upper stage(s), for which the stage presented here serves as the final (Stage 3) element of the launch system.We determined that the impact on marginal operating costs was offset by the reduction in risk and costs during development and qualification for a single upper stage configuration which would require adoption of extremely challenging design targets and advanced technologies.Moreover, the current design provides sufficient flexibility for use across a variety of XS-1 configurations and can be employed on its own for early development flights.It also retains a high degree of traceability to our commercial NLV.