In-Space Demonstration of High Performance Green Propulsion and its Impact on Small Satellites

This paper summarizes the pre-launch activities and the results from the in-space demonstration of a novel propulsion system on the PRISMA main satellite, using a “Green” monopropellant. This propellant is a storable ADN-based monopropellant blend (i.e. LMP-103S). The basic mission for the High Performance Green Propulsion System (HPGP) has been successfully completed and all primary objectives of TRL 7 have been met. The HPGP technology is now flight proven and ready for implementation on future missions. The HPGP thruster specific impulse measured in-space is coherent with the measurements performed on ground in the near vacuum test stand. The in-space back-to-back performance measurements between the HPGP and hydrazine propulsion systems shows the Specific Impulse (Isp) improvement for the LMP-103S propellant is higher than expected compared to hydrazine. The specific impulse measurements were performed by means of onboard accelerometers, GPS and precision propellant gauging. The methodology and results from the HPGP performance measurements are discussed in the paper as well as the comparison between the HPGP and hydrazine systems performance. The demonstrations performed on PRISMA take this technology a significant step forward towards its use in future space applications. It is concluded that after more than 10 years of R&D, the HPGP technology has emerged as an enabling technology for improved performance, enhanced volumetric efficiency, reduction of propellant handling hazards and significantly shorter launch preparation operations. The progress of the development has been presented in several papers since 2000. The HPGP technology has already been selected as the propulsion baseline for several new small European and U.S. missions where improved density impulse is of major importance. After one year in orbit the PRISMA basic mission has been successfully completed. The extended mission is ongoing and the in-space demonstration of the HPGP propulsion system will continue to provide ∆V to new experiments.