Design, fabrication, assembly and test of the Florida Turbine Technologies, Inc. (FTT) concept for a submersible, superconducting electric boost pump during Phase II will transition the pairing of superconducting motor and high performance pump technology for use in liquid hydrogen (LH2) from TRL 3 to TRL 6. This innovative solution offers significant performance and operability benefits to future nuclear thermal and conventional chemical propulsion powered cryogenic in-space and upper stage systems. FTT's submersible superconducting electric motor driven liquid hydrogen (LH2) boost pump combines a high performance hydrogen pump inducer along with an electric motor drive using active speed modulation to maintain constant discharge pressure with up to 55% vapor at the inlet. The LH2 environment enables an energy dense superconducting motor that is precisely controlled. This approach substantially reduces the risk of cavitation in the main pump and enables the downstream high speed turbopump to be operated at optimum efficiency with much reduced pressures in the propellant tank. Utilization of the low-cost, near-zero NPSHr electric boost pump permits considerable tank weight savings (as much as 40% for the NTP Mars Mission). The concept also offers significant operability and vehicle performance advantages for new cryogenic upperstage vehicles using conventional chemical propulsion engines.