Tags: Artificialsatellite, Satellite.
SDS-4 (Small Demonstration Satellite 4) is a small satellite (50 cm cube with mass of 50 kg) developed by JAXA and to be launched as a secondary payload on the Shizuku mission in mid-2012.There are four rather specialised systems on the satellite: SPAISE (SPace-based Automatic Identification SystEm) – test on-orbit a receiver for picking up signals from Automatic Identification System transmitters on ships well out to sea and determine how space-based reception is affected by interference between nearby transmitters and by environmental conditions.