Orbit determination of HAYABUSA from the launch to the asteroid arrival

Paper number

IAC-05-C1.7.03

Author

Dr. Makoto Yoshikawa, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Takaji Kato, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Tsutomu Ichikawa, Japan Aerospace Exploration Agency (JAXA)/ISAS, Japan

Coauthor

Dr. Hiroshi Yamakawa, Kyoto University, Japan

Coauthor

Dr. Junichiro Kawaguchi, Japan Aerospace Exploration Agency (JAXA)/ISAS, Japan

Coauthor

Mr. Takafumi Ohnishi, Japan

Coauthor

Dr. Shiro Ishibashi, Japan

Year

2005

Abstract

The asteroid sample return mission HAYABUSA, which was launched from Uchinoura Space Center (USC) by M-V rocket on May 9, 2003, is in progress favorably. It will arrive at the destination, Asteroid Itokawa, at the end of August 2005. In this paper, we summarize the status of orbit determination of HAYABUSA from the launch to the asteroid arrival.

    The new problem for the orbit determination of HAYABUSA is the orbit determination under the continuous low acceleration by the ion engine system (IES). Before the launch, we prepared the software for the orbit determination in which the acceleration of IES is also estimated. As the results, the estimation of IES acceleration can be done at a certain level, and this estimation is useful for the daily operation of the spacecraft. However, the accuracy of the orbit determination is not good enough when IES is working, so we make ballistic period of three passes (two days and a few hours) once in three weeks or so. We carry out accurate orbit determination at the ballistic period, and we propagate the orbit by using the telemetry information of IES with some correction of acceleration by estimating it. Thus we carry out the orbital operation of HAYABUSA. We summarize the status of the estimation of IES acceleration and daily operations of the orbit determination.

    There are several important phases for the orbit, such as the launch, the earth swingby, and the asteroid arrival. The earth swingby was carried out on May 19, 2004, and it was successful. We were able to put the spacecraft into the orbit that approach to Asteroid Itokawa. The orbital operation at the swingby was performed so well that we did not have to carry out the maneuver by the chemical thrusters after the earth swingby. We summarize the results of our orbit determination at the launch and the earth swingby. We compare the results with those by JPL, which determined the orbit of HAYABUSA separately by using the tracking data of DSN. The agreement of our results and those of JPL is quite good. About one month before the asteroid arrival, we will carry out the optical navigation by using the optical camera on board. We will also report some results about this optical navigation.

Abstract document

IAC-05-C1.7.03.pdf

Manuscript document

IAC-05-C1.7.03.pdf (🔒 authorized access only).

To get the manuscript, please contact IAF Secretariat.