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Information Gathering Satellites
Imagery Intelligence

In 1994 Japan began serious consideration of redefining its long-held policy prohibiting the use of space for military purposes. The Japanese Defense Agency, Japan's Space Activities Commission, and the non-governmental Defense Research Center all issued findings that non-lethal, particularly photographic reconnaissance, military space missions were a logical extension of Japan's space and national defense activities. Japan's 1969 space law prohibits Japan participating in any militiary space activities. Should national policy be modified to allow military photographic reconnaissance systems, Japanese officials would decide whether to develop domestic spacecraft, procure a foreign space system, or merely purchase high resolution imagery products from commercial vendors.

Mitsubishi is the Japanense partner in the Lockheed-Martin SpaceImaging Corporation IKONOS 1-meter resolution commercial satellite imagery system. The Mitsubishi Group proposed detailed plans for a series of four "information-gathering satellites". Two of the satellites would have optical sensors with 1-meter resolution, and the other two would have imaging radar capabilities. The proposed satellites would orbit at an altitude of 500 km, using a large satellite bus based on a standard commercial bus built by Mitsubishi. The potential role of US sub-contractors was unclear, given the potential for technology tranfer to Japanese prime contractors.

The system was characterized as a "multi-purpose information-gathering satellite" that could also monitor weather, natural disasters, smuggling and illegal immigration. These euphemisms were adopted to avoid provoking other countries in the region, and to avoid violating the 1969 parliamentary resolution on space policy. This re-interpretation of this vague space law would enable the program to proceed with ministeral authorization, rather than requiring a change in the law by the parliament.

The Japanese Defense Agency (JDA) released its 1999 white paper on 27 July 1999. The paper said that the Government was working vigorously toward the introduction of Information Gathering Satellites. This satellite will orbit the Earth at an altitude of 400-600km and gather information on the Earth's surface. The launch of four satellites of two types—two with optical sensors and two with synthetic aperture radar (SAR)—is planned. A frequency of more than one observation of any given location by each type of satellite each day will be possible. The proposed system would cost $1.3 billion.

The optical sensors work like cameras in that they collect light from an observed object in a lens and gather information on the object's shape and other features. The Government intends to introduce optical sensors with resolution of 1m. (This is an indicator of sensor performance. In simple terms, a resolution of 1m means that objects of a size of 1m and larger can be recognized.) The SAR hits the Earth's surface with microwaves from the satellite. By observing the reflection, the device obtains information on the shape of the object reflecting the microwaves. This radar can make observations unaffected by the weather or nighttime darkness. The Government intends to introduce SAR with a resolution of 1-3m.

By using imagery data with a resolution of 1m, the Government believes it will be able to detect ballistic missile sites and to distinguish major maritime and air military assets such as warships and fighting aircraft from commercial ships and aircraft. If, at the time when such a satellite starts being utilized, its functions are deemed to be used commonly, then it will not be considered to be in violation of the aim of the Resolution on the Peaceful Use of Space, even if the SDF also uses it. Therefore, the Defense Agency believes that imagery data from the Information Gathering Satellites will be useful for assuring the security of Japan and looks forward to its commencement with great anticipation.

The budget for Japan's reconnaissance satellite may be as great as high as 260 billion yen (around US$2.6 billion, including expenses on R&D, launch, land requisition and construction). The research and development is undertaken by Japan's space development work group, with some technologies provided by the United States. The satellites will be LEO birds at orbits of 500 Km, and will make use of large satellite buses that could be partly based on a standard commercial bus or be used as a test bed for Mitsubishi's first commercial bus. After April 2002, H-2A rockets carrying information-gathering satellites and others will be launched, weighing in at 1.5 metric tons are expected to be launched by early 2003.