Advanced Technologies Applied to "HAYABUSA" Asteroid Explorer
- Paper number
IAC-05-A3.5.A.02
- Author
Mr. Yasuo Horiuchi, NEC TOSHIBA Space Systems (NTS), Japan
- Coauthor
Mr. Shinji Hagino, NEC TOSHIBA Space Systems (NTS), Japan
- Coauthor
Mr. Takeshi Oshima, NEC TOSHIBA Space Systems (NTS), Japan
- Coauthor
Mr. Masashi Uo, NEC TOSHIBA Space Systems (NTS), Japan
- Coauthor
Dr. Hitoshi Kuninaka, Japan Aerospace Exploration Agency (JAXA)/ISAS, Japan
- Coauthor
Dr. Junichiro Kawaguchi, Japan Aerospace Exploration Agency (JAXA)/ISAS, Japan
- Year
2005
- Abstract
The asteroid explorer HAYABUSA was launched into the deep space by the M-V rocket on May 9th 2003 from Uchinoura Space Center, and has been executing a round trip space mission between Earth and the asteroid ITOKAWA. It takes an aim at the first sample and return from a near Earth asteroid. The primary objective of the program is to demonstrate four (4) key technologies which are all requisite for the future scientific missions; 1) Use of ion engines as a primary propulsion in the interplanetary space, 2) Highly autonomous satellite control especially guidance and navigation based on the optical measurements during the rendezvous and touchdown operation, 3) Sample collection under low gravity environment and 4) Direct reentry from interplanetary trajectory for sample recovery. In addition to these representative technologies, there are many other new technologies which enable the deep space exploration. This paper will present a detail of advanced technologies which are applied to HAYABUSA, and also report the current mission status and the technical achievements up to now. The explore mission is distinguished between “cruising phase” and “mission phase”. The cruising phase is to execute the round trip between Earth and the asteroid using the combination of the ion engine and the gravity assist. In this phase, distance between the explorer and Sun is varied from 0.86 to 1.7 AU and the distance from Earth increases up to 2.33 AU. The explorer system should adapt to such a wide change of electrical power and thermal environment, and also get over the time delay of communication. In the mission phase, the explorer makes a rendezvous with the asteroid and touchdown to collect samples. All these operations should be performed autonomously because distance from Earth becomes greater than 2.0 AU and the communication delay reaches nearly 40 minutes. In order to fulfill these tough requirements under the limitation of satellite mass and electrical power, the following technologies are developed and applied; 1) X-band high-sensitive and wide range bit-rate variable communication, 2) Autonomous satellite bus control by the Data Handling Unit (DHU) using satellite condition monitor and multiple types of macro command, 3) High efficiency electrical power system consists of multi-junction GaInP2/Ga/Ge solar cell, lithium ion battery and series switching regulator (SSR) -power supply, 4) Intelligent heater control electronics (HCE) for peak power suppression, 5) Precise and dynamic control of electrical power distribution between HCE and the Ion Engine System (IES) by DHU, 6) Smart Radiation Device (SRD) which varied the emissivity depending on temperature for thermal control, 7) High specific impulse (Isp) bi-propellant small thruster, 8) Microwave discharge ion engine which has the merit of long duration and wide throttle range, 9) Reaction wheel (RW) unloading via ion engine, and so on. These technologies are “packed in” only 510 kg (including 133 kg of fuel and 33 kg of scientific mission payload) of small satellite body for the ambitious mission. HAYABUSA has been accelerating toward the asteroid steadily, and the amount of the IES operational time exceeded 22,000 hour-unit. The explorer has already passed both the nearest (0.86AU) and farthest (1.7AU) point from Sun, and successfully demonstrates its design performance. It will arrive at the asteroid on this September, and come back to Earth again in 2007.
- Abstract document
- Manuscript document
IAC-05-A3.5.A.02.pdf (🔒 authorized access only).
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