Proposal of Smart Lander for Investigating Moon

Paper number

IAC-09.A3.2INT.18

Author

Dr. Tetsuo Yoshimitsu, ISAS/JAXA, Japan

Coauthor

Dr. Shujiro Sawai, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Takahide Mizuno, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Seisuke Fukuda, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Nobutaka Bando, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Mr. Shin-ichiro Sakai, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Ken Higuchi, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Tatsuaki Okada, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Takashi Kubota, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Daisuke Kobayashi, Japan

Coauthor

Dr. Ryoichiro Yasumitsu, Japan

Coauthor

Mr. Makoto Kunugi, Japan

Coauthor

Mr. Shoji Yoshikawa, Mitsubishi Electric Corporation, Japan

Coauthor

Mr. Katsumi Furukawa, Mitsubishi Heavy Industries, Ltd., Japan

Coauthor

Mr. Tetsuya Matsuo, Japan

Year

2009

Abstract

\section{Introduction}

After the success of remotely-sensed global observation by SELENE orbiter, Japan has been focusing on the in-situ exploration of the Moon.

To know more about the Moon, numerous missions have to be launched to the Moon for surveying different interesting places. Naturally the cost of single mission must be reduced.

Japan has been considering the landing mission ``SELENE-2'' for about ten years. This has a few tons of weight and costs three or four million dollars including the cost of the launch vehicle because it also features the future manned mission. Obviously, SELENE-2 is not suitable for scientific in-situ exploration, which must be conducted repeatedly.

The authors have been studying a small lander on the Moon or the planets in order to enable the multiple in-situ explorations cheaply. With the technologies developed in our studies, the mission named SLIM (Smart Lander for Investigating Moon) has been proposed to demonstrate an autonomous, accurate and soft landing on the specified place of the Moon. SLIM is also helpful to increase the success probability of the large landing mission such as SELENE-2 when it is conduced as a precursor.

This paper describes the proposed SLIM mission.


\section{SLIM framework}

Institute of Space and Astronautical Science (ISAS) of JAXA has been developing a framework of small scientific spacecraft, which enables the space science mission in low cost and manageable by non-agency people such as university professors. The spacecraft is assembled with the combination of the prepared components and the mission-specific instrument. The prepared components include the data processing unit, the attitude controller, the thermal controller and so on. The mission manager can concentrate on the development of observation sensor, which is installed on the prepared spacecraft bus. With this framework, ISAS would like to launch three small spacecraft in five years.

ISAS has also been developing a new solid rocket to put the above small spacecraft into space. The rocket is the successor of M-V solid rocket which is not in use since 2007. The new rocket will have a capability to put the payload of about 400[kg] into an interplanetary orbit.

The first launch of the small spacecraft and the new rocket will be conducted simultaneously in 2012. The selected payload is TOPS which is a space telescope observing the planets in our solar system.

SLIM is fabricated by using as many prepared components as possible to reduce the cost. The authors have proposed our spacecraft to the public offer of the small science spacecraft in 2008.


\section{SLIM mission}
SLIM is a spacecraft with a weight of 428[kg] including fuel of 330[kg]. The dry mass is 98[kg].

SLIM will demonstrate the autonomous, pin-pointed and soft landing to the designated place of the Moon. These techniques are essential for the future landing mission to investigate the specified location of the target body.

The spacecraft is once inserted into the Earth orbit after the launch in order to adjust the departure time to the Moon. Then the spacecraft heads for the Moon by firing the thrusters, followed by the deceleration into the Moon orbit. The altitude from the Moon is gradually decreased to 100[km]. The final descent starts by canceling the gravity with the thrusters.

During the descent, the image-based navigation is used. The spacecraft shoots the surface image periodically to extract the craters, which are matched to the prepared onboard crater map to calculate the current position. After the spacecraft gets to the surface of less than 3.5[km], the radar measures the distance from the surface and the relative speed to the surface so as to control the spacecraft as vertical as possible. At the height of 10[m], the thrusters are cut and free fall descent to the surface will be conducted, softening the collision by the deformable legs. The option rover of 1[kg] will appear to start the surface exploration.

Abstract document

IAC-09.A3.2INT.18.pdf

Manuscript document

IAC-09.A3.2INT.18.pdf (🔒 authorized access only).

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