Taiwan and Japan are working out, as quietly as possible, a sharing arrangement so Taiwan can make use of Japanese spy satellites until Taiwan can launch its new Formosat 5. The Formosat 5 was supposed to go up in mid-2015 but the American launcher failed a test and had to reschedule. That launch will take place in late 2016 and Taiwan needs some help because the Taiwanese surveillance satellite it was relying on (Formosat 2) is old and showing signs of failing. Taiwan has worked closely with American satellite manufacturers to develop Taiwanese manufactured satellites. But American firms launch Taiwanese satellites.
Taiwan has been quietly building and launching its own space satellite since the late 1990s. To avoid a major Chinese effort to derail this program Taiwan made sure all its satellites had scientific purposes. But by 2004 Taiwan was putting up dual (scientific/military) purpose satellites like their photo and remote sensing satellites. Japan has one of the most advanced space programs in the region and because Taiwan and Japan both fear China, it made sense for Taiwan to quietly seek Japanese assistance.
Japan launched its first space satellite in 1970 and became the fourth nation (after Russia, America and France) to do so. For decades Japan mainly launched scientific satellites. In the late 1990s Japan, alarmed at the threat of attack by North Korea, began developing and launching military satellites. The first two were launched in 2003, the third in 2006 and the fourth in 2007. Japan continues to build and launch photo and radar satellites. While Japan buys some launcher and satellite tech from foreign nations (mainly the U.S.) Japan has become quite proficient in both areas.
By 201o the cameras on board Japanese photo satellites could make out objects as small as one meter (39 inches) in diameter. By 2013 a new Japanese photo satellite could detect objects .6 meters (two feet) in size. The best U.S. spy satellites can make out much smaller objects, but for Japan's needs .6-1 meters is adequate. The radar satellites provide all weather coverage.
Technically, the satellites are in violation of a 1969 Japanese law, which mandated Japan only use space for non-military purposes. To get around this these satellites are technically non-military and are not controlled by the military. Japan had long refrained from launching military satellites but this changed when North Korea fired a ballistic missile over Japan in 1998. Japan promptly set out to get eight surveillance satellites in orbit by 2006, in order to keep an eye on North Korean nuclear weapons and ballistic missile efforts. This proved impossible to do. While two Japanese satellites were launched in early 2003, another two were destroyed during late 2003, when the rocket malfunctioned.
Japan has long relied on commercial photo satellites and whatever they could get from the Americans. But for high resolution shots, on demand, of North Korea, and electronic eavesdropping from space, they need their own spy satellites. It is believed that the Japanese spy satellites are also being used to watch military developments in China and Russia.
The Japanese program has cost over three billion dollars. Much of this was spent to develop rockets large and reliable enough for satellite work. The latest launch was the 16th consecutive successful use of the locally designed and manufactured H-2A rocket. These rockets operate from a launch complex in southern Japan.
The Japanese optical satellites weigh about a ton, while the radar one weighs about a third more. The United States provided a lot of technical assistance on the design and construction of the satellites and Japan now builds its own rockets to launch them. Like most spy satellite users, Japan does not report on how effective they are. It is known that Japan could get more detailed photos from commercial satellites. But those are not controlled by the Japanese government.