SUMMARY

Due to the high mass requirement of bringing fuel to Mars, in situ resource utilization (ISRU) systems provide propellants that are a vital step in the dream of a manned mission to the red planet. Oxygenated fuels, such as alcohols and diols, can be manufactured using algal biosynthesis on Mars utilizing the natural water found near the poles and high concentrations of CO2 in the atmosphere of the planet. However, no such fuel has ever been used in a rocket engine, let alone one that would have to experience the harsh climates of Mars for extended periods of time. Bio-propellants differ greatly from conventional RP-1 due to bio-propellants having far higher viscosity as well as heat of vaporization. These properties would cause noticeable variations in the spray behavior. Thus, this thesis aims to evaluate the characteristics of these novel fuels in comparison to a conventional liquid rocket propellant at typical combustion chamber as well as at cold startup conditions anticipated on Mars. Using Diffuse Back-Illumination (DBI) imaging, the propellant injection, atomization and vaporization processes are characterized and, based on the behavior from Kerosene, a surrogate of RP-1, an estimate on the behavior of the novel fuels in actual combustion chambers is made.