The OICETS (Optical Inter-orbit Communications Engineering Test) satellite, scheduled to be launched this coming summer, is being modified to match a change of inclination (from 35 to 98 degrees), due to a change of its launch vehicle.
Final satellite verification began in February, with all operations at the manufacturer’s plant complete.
The satellite is now in its flight configuration stage. Since the start of April, OICETS has been tested using facilities at the Tsukuba Space Center and the DRTS (the data relay satellite “Kodama”) to assess its overall performance. On April 8, an acoustic test was carried out.
OICETS enables communications between satellites via optical links.
OICETS will enable optical inter-orbit communications tests between satellites that are tens of thousands of kilometers apart.
An optical inter-orbit communications system will bring various advantages: more stable communications with less interference; lighter, more compact communications equipment; and higher data transmission rates.
These tests are expected to lead to new technologies that will improve global data reception from Earth Observation satellites and continuous communication links with manned space stations.
OICETS is to be launched into a low Earth orbit in the fiscal year 2005, for the purpose of conducting demonstrations with ARTEMIS, the latest geostationary satellite belonging to the European Space Agency.
Communications Engineering Tests
The distance between ARTEMIS, a stationary satellite, and OICETS, positioned in a low Earth orbit, will be around 45,000km at its maximum point.
As a result, optical inter-orbit communications tests require elements like high-gain optical antennas, a high-power semiconductor laser, and highly sensitive signal detectors.
Using these devices, JAXA will be able to test beam acquisition operations: to take in an incoming laser beam; beam tracking, to detect and control the angle of an incoming laser; and beam pointing, to accurately transmit a laser beam in the right direction, taking into consideration the relative motion between the two satellites.
Important issues to be tackled, still, include the need for technologies to establish a stabilized, high-capacity attitude-control system, and to build ground stations to evaluate the performance of the optical inter-orbit communications equipment.
