Japan launches the world's lowest orbiting satellite
Japan launched the world's lowest orbiting satellite. If the altitude of the satellite is low, you can see the ground better. The Japanese government said it was a cost of disaster, but analysts said it could be used to reconnaissance North Korea's missile base.
Japan Aerospace Exploration Agency (JAXA) announced that it succeeded in launching the Earth Observation Satellite "Tsubame" on H2A rocket at 10:26 am on the 23rd at the Tanegashima Space Center in Kagoshima.
Tsubame, which means swallowing in Japanese, was developed to test very low altitude satellite technology. Earth observing satellites such as Korea's multi-use satellite (Arirang satellite) usually travel around the earth at an altitude of 600 to 800 km, but Tsubame orbit around 180 to 268 km. Until now, it was the very low record that the GOCE satellite of the European Space Agency (ESA) orbit the altitude of 224 km between 2012 and 2013. The Tsubame plans to enter the 480km orbit first, then lower the altitude to 180km over the next two years.
Very low altitude satellites can more closely observe the surface of the earth. European solid satellites were able to detect even the sound waves from the earthquake. However, there is a high risk of falling if you go to very low altitudes. The closer to the surface, the higher the atmospheric density. Because of this, ultra-low satellites receive 1000 times more air resistance than ordinary satellites. It is very likely to lose speed and crash.
Japanese researchers have overcome the shortcomings of ultra-low satellites with a new engine. Tsubame's ion engine uses xenon gas as fuel. Xenon collides with the electrons emitted from the electrodes and emits their electrons. Then Xenon is (+) energized. At this time, if you apply the opposite electricity from the side of the engine nozzle, Xenon will accelerate to 100,000 km per hour. The satellite goes forward with this force. The electricity required for xenon acceleration is made by solar panels.
Ion engines are 10 times more efficient than conventional satellite engines that use liquid or solid fuels. It is also possible to put less fuel. It was also thanks to Ion Engine that Japan's asteroid probe Hayabusa, who returned to Earth in 2010, was able to fly for seven years.
The Japanese government said it would use Tsubame for scientific research such as investigation of disaster damage area and oxygen concentration measurement. But Japanese media reported that it could be used for military and security purposes. By using the Tsubame, it is possible to efficiently scout North Korea's missile base.