Hydroxylammonium nitrate

Hydroxylammonium nitrate or hydroxylamine nitrate (HAN) is an inorganic compound with the chemical formula NH3OHNO3. It is a salt derived from hydroxylamine and nitric acid. In its pure form, it is a colourless hygroscopic solid. It has potential to be used as a rocket propellant either as a solution in monopropellants or bipropellants. Hydroxylammonium nitrate (HAN) based propellants are viable and effective solution for future green propellant based missions, as it offers 50% higher performance for a given propellant tank compared to commercially used hydrazine. Hydroxylammonium nitrate or hydroxylamine nitrate (HAN) is an inorganic compound with the chemical formula NH3OHNO3. It is a salt derived from hydroxylamine and nitric acid. In its pure form, it is a colourless hygroscopic solid. It has potential to be used as a rocket propellant either as a solution in monopropellants or bipropellants. Hydroxylammonium nitrate (HAN) based propellants are viable and effective solution for future green propellant based missions, as it offers 50% higher performance for a given propellant tank compared to commercially used hydrazine. The compound is a salt with separated hydroxyammonium and nitrate ions. Hydroxylammonium nitrate is unstable because it contains both a reducing agent (hydroxylammonium cation) and an oxidizer (nitrate), the situation being analogous to ammonium nitrate. It is usually handled as an aqueous solution. The solution is corrosive and toxic, and may be carcinogenic. Solid HAN is unstable, particularly in the presence of trace amounts of metal salts. HAN is a potential rocket propellant, both in the solid form as a solid propellant oxidizer, and in the aqueous solution in monopropellant rockets, including the Network Centric Airborne Defense Element boost-phase interceptor being developed by Raytheon. It is typically bonded with glycidyl azide polymer (GAP), hydroxyl-terminated polybutadiene (HTPB), or carboxy-terminated polybutadiene (CTPB) and requires preheating to 200-300 °C to decompose. The catalyst is a noble metal, similar to the other monopropellants that use silver or palladium. HAN also enabled the development of solid propellants that could be controlled electrically and switched on and off. Developed by DSSP for special effects and microthrusters, these were the first HAN based propellants in space; and aboard the Naval Research Laboratory SpinSat, launched in 2014. It will be used in a fuel/oxidizer blend known as 'AF-M315E' in the high thrust engines of the Green Propellant Infusion Mission, which was initially expected to be launched in 2015, and as of March 2019 planned to be launched in 2019. The specific impulse of AF-M315E is 257 s.The aqueous solution of HAN can be added with fuel components such as methanol, glycine, TEAN (tri-ethanol-ammonium nitrate) and amines to form best high performance monopropellants for space propulsion systems. Japanese technology demonstration satellite Innovative Satellite Technology Demonstration-1, launched in January 2019, contains a demonstration thruster using HAN and operated successfully in orbit. HAN is sometimes used in nuclear reprocessing as a reducing agent for plutonium ions.