Challenges in the development of large-scale hybrid rockets

Abstract

Advanced hybrid rockets, which combine fast burning fuels, composite motor construction, and innovative internal ballistic design, have the capability to deliver high performance while retaining the cost, environmental, and simplicity advantages of the classical hybrids. This makes hybrid rocket propulsion a tipping point technology in the sense that a small, short-term investment could have game-changing consequences in the development of green, safe, affordable, and high-performance systems needed for future space missions. In order to demonstrate the advantages of hybrids most effectively, the effort should be concentrated on improving the technology readiness level of the technology for a carefully selected class of missions. That being said, some serious challenges still exist in the development of operational motors, even for applications highly suitable for hybrid propulsion. These challenges, some perceived whereas others are very real, are carefully outlined in this paper. The real-life importance of each challenge is also discussed, along with potential methods to mitigate these issues. The ultimate strategy in the elimination of any practical challenge is that the solution should not compromise the simplicity, cost, and safety advantages of classical hybrid rockets. The solution methodology should be an iterative process that involves a well-balanced combination of theoretical modeling, numerical simulations, and actual motor testing.