Green Advanced Space Propulsion

Space activities and applications play an important role in strengthening the competitiveness of Europe by scientific progress and by providing strategic influence and security. Major successful space missions under European leadership have placed ESA and its Member States in the European science community at the forefront in this field of activity. To continue this path, Europe must have independent and competitive access to space. With the ITAR (International Traffic in Arms Regulations) continuing to impede the acquisition of US components, Europe must develop an assured, independent source of propulsion components. Currently, spacecraft propulsion relies heavily on toxic and carcinogenic hydrazines as propellants. Hydrazine itself is widely used as a monopropellant and its derivates, mono-methyl hydrazine (MMH) and unsymmetrical di-methyl hydrazine (UDMH), are used as bipropellant fuels. These propellants are a threat to people and the environment, and handling these toxic propellants involves complex and costly safety measures. As concerns about the continued use of such propellants have grown in recent years, there has been a renewed impetus to search for alternative propellants that are less toxic and harmful to the environment. These are generally referred to as 'green propellants'. As new ideas and new technologies have emerged, these green propellants have begun to show potential improvements with respect to performance and cost. The goal of this project is to select the most promising green liquid propellant candidate/s and to push the associated propulsion technology to the level needed to prove that green propellant technology is both feasible and competitive. To date, research and development on green propellants in Europe has been geographically fragmented and insufficiently funded. With the present consortium, the key-players in the Green Propellant technology in Europe will harmonize their capabilities to meet this demanding goal. The GRASP (GReen Advanced Space Propellants) proposal aims to provide the European industry with alternative propellants to replace the currently used highly toxic and carcinogenic propellants (e.g. hydrazine, MMH, UDMH). These alternative so-called green propellants will reduce the potential harm to human operators and the environment and thereby significantly reduce the associated handling costs. At similar, or even improved, performance capabilities, these propellants will allow European industry to keep and even strengthen its capability in space propulsion. GRASP is therefore driven by four essential industrial needs: - Reduction of costs - Reduction in exposure to carcinogens - Performance improvements - Ensuring the competitiveness of the European industry in a challenging and continuously changing environment Laboratory-scale evaluations conducted across the world have shown that several green propellant candidates can indeed provide a performance comparable or even better than those of presently used propellants. Furthermore, studies have shown that the use of green propellants can provide long-term financial benefits. However, to date green propellants are not widely used. The main reasons for this reluctance are, amongst others, the extensive experience the space community has collected with the presently used propellants; the satisfactory performance of those; and the existing infrastructure for those propellants, which is not readily usable for alternative propellants. 3 Part B: Description of Work Proposal acronym: GRASP Furthermore, to convince the space community/industry to switch to green propellants, the following issues must be demonstrated: - Similar or better performance than those propellants used currently - System advantages - Detailed investigation of the storage and handling properties - Compatibility with existing hardware - Likelihood of reduced costs in the long-term The goal of the GRASP project is not to provide incremental progress but to conduct a systematic down-selection to identify the most promising Green Propellant candidate(s) and implement those candidates in demonstrator propulsion systems. The final propulsion systems developed in the framework of this project are envisaged to have a TRL between 2 and 5, mainly depending on the maturity of the propellant and catalyst development already present prior to the initiation of the project. For example, in case of a hydrogen peroxide based system a TRL of 5 is envisioned, while for an ionic liquid based system (e.g. ADN, HAN) and for future propellants a TRL between 3 and 5 and a TRL of 2, respectively, can be expected.