Low-Cost, Scalable, Hybrid Launch Propulsion Technology

Physical Sciences Inc. (PSI), in collaboration Purdue University, proposes to develop a novel launch propulsion technology for rapid insertion of nano/micro satellites (~ 5-100 kg scale) into low earth orbit, with the potential to lower the current state-of-the-art launch stage cost by 2X. The technology employs a propulsion scheme comprising a storable liquid oxidizer and a unique solid fuel with excellent mechanical and thermochemical properties. The proposed application to launch vehicle stages will result in low-cost, mass-efficient launch systems and will reduce technical development risk for NASA. The fuel and oxidizer are commercially available at low cost as an inexpensive engineering material and as an industrial chemical. Both have high density, are green, and the system has a high specific impulse (> 275s; vacuum). The oxidizer storage, handling, transportation, and loading operations are simpler and safer compared to cryogenic/toxic propellants. The foregoing attributes enable the lower cost of the proposed hybrid launch vehicle stage. The performance of current hybrids is limited by their typically low fuel regression rates. In Phase I, we investigated techniques for significantly augmenting the regression rate, demonstrating ~ 3.5X increase in 30 lbf thruster firings. Using this data, we performed design trades for a hybrid stage as the second/upper launch vehicle stage. The enhanced regression rate allowed a more compact, lighter, higher thrust-to-weight stage than would be possible with current hybrids. In Phase II, we will perform detailed experiments to optimize propulsive performance on the same Phase I hybrid thruster, and demonstrate a large scale (~1000 lbf) motor, representative of upper stages of a launch vehicle incorporating the optimized design. Phase II will end with a flight prototype design and a plan for a sub-orbital flight test, or a comprehensive ground test in simulated environment.