Current backbone for the development of HNF based propellants

In this paper, recent activities on the development of Hydrazinium Nitroformate (HNF) and HNF based propellants are discussed from different perspectives -programmatic, technical, and strategic. From a programmatic point of view, the current programmes on HNF and their goals are discussed in relation to the Milestone Decision Points that have been identified in the Roadmap on HNF and HNF based propellant development. [1]. From a technical point of view, the so-called target specification of HNF is reviewed, indicating where HNF meets this target specification and where extra effort is required. Earlier research has shown that the properties of HNF (like purity, stability, morphology and sensitivity) to a large extent determine the properties of the HNF based propellant (like mechanical, ballistic, processing and sensitivity characteristics). Therefore, one of the main focal points of recent and future development activities is the improvement of the HNF properties. The other main focal point is the preparation for motor tests on 1 kg propellant scale, raising the Technology Readiness Level (TRL) of HNF-based propellants from 4 to 5 [2]. From a strategic point of view, the possibilities of embedding HNF and HNF based propellant advances in the development-frame of future applications are discussed. Particular emphasis is placed on space applications