Kenichi Kajiwara

Electric Propulsion Development Activity at MELCO

MELCO has been developing electric propulsions for about 30 years under some national projects in Japan. The 20mN class xenon ion engine subsystem (IES) has arrived at the practical stage of a satellite NSSK propulsion. The IES is applied for NSSK of the engineering test satellite of JAXA, which will be launched in FY2006. Furthermore, now MELCO is developing 200mN class hall thruster and power processing unit for high power next generation satellite. The target specification is that the thrust level is over 250mN, the specific impulse is over 1,500s under the PPU input power of 5kW, and the lifetime is over 3,000 hours. To date, the development status is engineering model (EM) phase after the evaluation of breadboard model (BBM) and development model (DM). The thruster EM showed 264mN of the thrust level and 1,721s of the specific impulse under the thruster input power of 4.56kW. The PPU EM showed the anode efficiency was over 93% for 250V and 350V at output power between 1.75-4.5kW. We will start the endurance test of the thruster EM from the middle of 2006 after the coupling test between the thruster and PPU EM.

VISUALIZATION FOR A VOIDED CATALYST BED OF HYDRAZINE THRUSTER IN MICROGRAVITY

Meeting Information: 40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit(11-14 July 2004), Fort Lauderdale, Florida

Design of a new discharge power supply for ion engine

JAXA has researched the Super Low Altitude Test Satellite (SLATS) for next generation earth observing satellite. We started research and development of a new IES in order to apply for the SLATS program. In this paper, we describe the preliminary design results of the IES configuration plan for the SLATS, performance requirements of the power processing control unit (PPCU) and the developments results of the bread board of model (BBM) of this discharge power supply.

20mN Class Xenon Ion Engine Operation on Orbit

The Engineering Test Satellite VIII (ETS-VIII) of Japan Aerospace Exploration Agency (JAXA) uses a 20mN class xenon ion engine subsystem (IES) for NorthSouth Station Keeping (NSSK). The IES was modified for larger satellite with longer lifetime on the basis of the former IES. ETS-VIII was launched 18 th Dec. 2006 JST, reached the planned geosynchronous orbit and all bus system was successfully checked out. The IES showed good results and is now under normal operation in progress.

Feasibility testing for high temperatures on SV14 cold gas jet thruster

This paper presents and discusses some fundamental feasibility test results from the Phase-B design activity of the Mercury Magnetospheric Orbiter (MMO) cold-gas thruster, performed in the JAXA Satellite Propulsion Reliability Evaluation Test Stand at the Tsukuba Space Center (TKSC). The tests were dedicated mainly to cycle motion test at the requested temperature, internal leakage, and valve response measurements. The tests apparently complied with the MMO system requirements for the high temperature Mercury orbital environment. As the next step, the MMO project and Marotta UK will develop the MMO Cold Gas thruster systems thruster valve based on SV14 cold thruster design .

The Development of a Japanese 20N Thruster Valve for a Spacecraft Propulsion System

§** †† The Japan Aerospace Exploration Agency (JAXA) is now developing a 20N-class thruster valve for spacecraft propulsion systems. We intend to develop this valve with the high reliability, and a robust and durable design. The suspended armature type was chosen for the base design of the new 20N valve based on the results of a trade-off study. Experiments and analysis were performed for the critical parts and manufacturing process. The results enabled us to manufacture a prototype model with single type 20N thruster valves. Good results were obtained in functional tests. We will now proceed to the next phase and complete the detailed design for series redundancy and prepare for the qualification test. Nomenclature a σ = stress amplitude B σ = tensile yield stress m σ = mean stress max σ = maximum stress min σ = minimum stress w σ = Endurance limit when completely reversed

Research and Development Status of JAXA 35‐cm Ion Thruster Technology

The research and development status of the 150‐mN‐class xenon ion thruster is described. After a couple of redesigns and trial fabrications, the first breadboard thruster achieved a very low ion production cost of 104 W/A. Endurance tests suggest that the grid system will have a lifetime of about 25,000 h. A hollow cathode wear test suggests that it will be over 30,000 h before its orifice plate is completely worn out. A thrust range of 80 to 200 mN without performance degradation has been demonstrated. In the power conditioner development, efficiencies of 87 to 88% have been achieved in the main power supplies. Its compatibility with the thruster was demonstrated.