Date of Award

Fall 2014

Degree Type


Degree Name

Doctor of Philosophy (PhD)


Aeronautics and Astronautics

First Advisor

Stephen D. Heister

Second Advisor

Steven F. Son

Committee Chair

Stephen D. Heister

Committee Co-Chair

Steven F. Son

Committee Member 1

Sally P. Bane

Committee Member 2

Timothee L. Pourpoint


Hypergolic hybrid rockets have the potential of providing systems that are simple, reliable, have high performance, and allow for energy management. Such a propulsion system can be applied to fields that need a single tactical motor with flexible mission requirements of either high speed to target or extended loitering. They also provide the possibility for alternative fast response dynamic altitude control systems if ignition delays are sufficiently short. ^ Amines are the traditional fuel of choice when selecting a hypergolic combination as these tend to react readily with both nitric acid and dinitrogen tertroxide based oxidizers. It has been found that the addition of a borane adduct to an amine fuel tends to reduce the ignition delay by up to an order of magnitude with white fuming nitric acid (WFNA). The borane addition has resulted in fuels with very short ignition delays between 2-10 ms - the fastest times for an amine based fuel reacting with nitric acid based oxidizers. The incorporation of these amine-boranes, specifically ethylenediamine bisborane (EDBB), into various fuel binders has also been found to result in ignition delays between 3-10 ms - the fastest times again for amine based fuels. ^ It was found that the addition of a borane to an amine increased theoretical performance of the amine resulting in high performance fuels. The amine-borane/fuel binder combinations also produced higher theoretical performance values than previously used hypergolic hybrid rockets. Some of the theoretical values are on par or higher than the current toxic liquid hypergolic fuels, making amine boranes an attractive replacement. The higher performing amine-borane/fuel binder combinations also have higher performance values than the traditional rocket fuels, excluding liquid hydrogen. Thus, amine-borane based fuels have the potential to influence various area in the rocket field. ^ An EDBB/ferrocene/epoxy fuel was tested in a hypergolic hybrid with pure nitric acid as the oxidizer. Hypergolic ignition occurred repeatably and with short combustor pressurization times of under 100 ms. The regression rate of the fuel exhibited never before observed high pressure dependence regression rates. The presence of a foam like layer on the fuel surface provides an adequate explanation for the observed combustion behavior with a calculated regression rate that depends on pressure raised to the 2nd power. Extrapolation of this theory indicates that amine-borane based fuels could produce high regression rate fuels.