Two satellites have become the first to exchange information from different orbits using a laser . The feat may lead to super-fast data-relay systems between spacecraft.
The laser link took place on Friday between two satellites designed to test communications technologies.
One, a Japanese mission called Kirari (Optical Inter-orbit Communications Engineering Test Satellite), flies at an altitude of 610 kilometres, in low-Earth orbit. The other, a European satellite called ARTEMIS (Advanced Relay and Technology Mission), soars 36,000 kilometres above Earth in geostationary orbit.
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Pointing and maintaining a laser connection between the two satellites is difficult because they can be as much as 45,000 kilometres apart and are moving at a relative speed of several kilometres per second.
Eye of a needle
The achievement is like 鈥渉itting the eye of a needle placed on top of Mount Fuji from Tokyo Station鈥�, says a statement from Japan鈥檚 Aerospace Exploration Agency (JAXA). Watch a video about Kirari .
Researchers hope to exploit lasers for communication because they operate at higher frequencies than traditional radio transmitters, and can therefore transmit more information in a set time.
JAXA says the test may pave the way for environmental-observation satellites in low-Earth orbit to send data efficiently to a satellite in geostationary orbit that could act as a communications router that is always in contact with its ground station.
Kirari, which carries an instrument to measure how small vibrations on the spacecraft affect the satellite鈥檚 ability to direct its laser, was launched on 24 August 2005. ARTEMIS began taking data in 2003, after its ion propulsion unit boosted it from the incorrect orbit it had been placed in after it launched in 2001.