12.  Conclusion

The reconquest of the Moon, the conquest of Mars and life in space will all require new space fuels. The replacement of "traditional" ergols from the hydrazine family (hydrazine, methylhydrazine, asymmetrical dimethylhydrazine), which suffer from a number of drawbacks, may be envisaged. Among the possible alternatives, ionic liquids offer numerous advantages. It is shown here that hypergolicity, the main advantage of the traditional MMH/NTO diergolic system, is also achievable with certain ionic liquids. An exhaustive list of systems for which hypergolicity has been observed, at least in a preliminary manner, has been provided. However, further fundamental and applied studies are still needed to further validate the proposed alternatives.