Information Gathering Satellite

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An Information Gathering Satellite (IGS) is a satellite in a Japanese spy satellite program. It was started as a response to the 1998 North Korean missile test over Japan. The satellite program's main mission is to provide early warning of impending hostile launches in the neighborhood. This program is under direct control of the cabinet. However it should be noted, that Earth observation is a rather new field for Japan. The first Japanese mission in this field MOS-1 was launched only in 1987. For this reason Japan still lacks some technology in this field with a resolution of one meter.

The first pair of satellites, IGS 1A and IGS 1B, was launched on March 28, 2003 aboard an H-2A rocket. The radar satellite of the pair stopped working in March 2007. The program suffered a big setback when Japan lost the second pair of satellites because of an H-2A launch failure on November 29, 2003.

Another pair of Japanese military reconnaissance satellites, IGS 4A and IGS 4B (Information Gathering Satellites 4A and 4B) were launched by an H-2 rocket from Tanegashima Space Center at 04:41 UT on February 24, 2007.

Japan plans to launch optical satellite IGS 5 with an improved resolution of 60 cm in FY 2009.

[edit] Timetable

Date (UTC)	Satellite	Launch Vehicle	Comment	Orbit
March 28, 2003	IGS 1A and 1B	H-IIA	Radar satellite until March 2007	?
November 29, 2003	IGS 2A and 2B	H-IIA	Lost through launch failure	?
September 11, 2006	IGS 3	H-IIA	Optical Satellite	?
February 24, 2007	IGS 4A and 4B	H-IIA	Radar Satellite and Optical Test Satellite	period 94.4 min, apogee 494 km, perigee 481 km, and inclination 97.2°.^[1]

On 28 March 2003, presumably partly in response to North Korea's launch of a Taepodong rocket over Japan in 1998, and partly to provide a source of satellite images other than through cooperation with the US, where the US charged roughly $10,000US dollars for each satellite image, Japan launched a radar and an optical spy satellite, officially known as Information Gathering Satellites (情報収集衛星, Information Gathering Satellites^?) IGS-1A and IGS-1B.

These satellites follow one another at 37-minute separation in a 492km orbit, which passes over Pyongyang at 11:22am each day, according to observations collected on the seesat-L mailing list.

A second pair of satellites were lost in an H-IIA launch accident in November 2003.

An optical surveillance satellite IGS-2A was launched on 11 September 2006; a radar satellite and an unexpected third optical satellite suspected to be of a more advanced type were launched on 24 February 2007.