Michel Lyszyk

Development status of the PPS 1350 plasma thruster

A new SPT thruster is jointly developed and qualified by FAKEL and SEP. It is intended to be flown on STENTOR experimental spacecraft in year 2000. The technical design has been frozen two years ago. It has been validated by a 3500 h test on a Development Model. Now the program is entering in two qualification phase. A first model -MIwill undergo a 7000 h test and a second one -QMthe environmental qualification. The qualification program includes also the cycling test of several cathode. The test facilities LI-A and LI-B have been updated to perform the endurance test and the thermal vacuum test. INTRODUCTION The PPS 1350 specifications reflect the need to increase the total impulse delivered by the thruster, itself linked to the mass increase of geostationary spacecrafts and to the increase of AV requirements (NSSK plus orbit injection). The vibrations resistance is also improved in order to accommodate higher vibrations levels induced by new spacecraft design. The formal qualification needs new or updated facilities especially to perform thermal vacuum test on an operating thruster. THRUSTER CHARACTERISTICS The thruster specifications have been established by an integrated team (CNES, AEROSPATIALE, MMS and SEP). The thruster specifications are summarized in table 1 below. Table 1 PPS 1350 functional specifications Reference thrust Discharge voltage Propellant flowrate Discharge power Specific impulse Specific power Total efficiency Total impulse Operating cycles Divergence angle 88 mN 350V 5,2 mg/s 1500W 1720s 17 W/mN 51% 1.44MN.S 5200 42° PPS 1350 environmental specifications Temperature: Operating Qualification Random vibrations: Acceptance Qualification Sinus vibrations : Acceptance 5-21 Hz 21-100 Hz Qualification 5-21 Hz 21 -100 Hz Shock: Acoustic noise: -43, +205°C -48,+210°C