ETS 5 (Kiku 5) (original) (raw)
ETS 5 [NASDA]
ETS 5 (Engineering Test Satellite), renamed Kiku 5 in orbit, was launched to confirm H-1 UM-129A launch vehicle performance, as well as to establish basic geostationary three-axis bus system technology for future satellite applications, amass independent technology required for next-generation satellite development and carry out experiments for mobile communications satellite.
Kiku-5 finished its 1.5 year programmed opration on March 31,1989, while AMEX (Aerouautical Mobile Experimeutal Trausponder) still keeps gathering data and carring out experments.
Mobile Satellite Communications Experiment
Means of communications with mobile bodies such as ships, air-planes and automobiles, etc. are solely depend on radio-wave.
But the conventional communications to the mobile bodies have limited application and are not necessarily satisfactory in terms of quality and amount of information.
Especially, small ships and airplanes, Iocated on or over the open sea far from land cannot help depending on inefficient microwave communications as they did before.
The development of satellite communications system for ships and airplanes facilitates not only outstanding improvement of navigation safety but also rendering new services such as remote medical services. Furthermore, the introduction of the system to the communications equipment easily carried by vehicles and men moving on the ground is very beneficial for the communication at mountaneous or isolated areas or at the time of disaster and emergency.
NASDA developed a mobile communications experiment equipment called AMEX (aeronautical maritime experimental transponder) in coorporation with the Communication Research Laboratory of the Ministry of Posts and Telecommunications and the Electronic Navigation Research Institute of the Ministry of Transportation.
Synthetic experiments on mobile satellite communications covering land, ocean and sky are presently conducted by the above mentioned two organizations utilizing Engineering Test Satellite-V (Kiku-5)
Mobile Satellite Communications System
This experimental system uses radio wave of L - band (1.6 GHz for uplink and 1.5 GHz for downlink) between mobile bodies and satellite. and C - band (6 GHz for uplink and 5 GHz for downlink) between satellite and coast/aerial earth stations.
L-band antenna posseses two-beam structure consisting of N-beam to irradiate northern parts of Pacific Ocean Region including whole Japan and S - beam to irradiate southern parts of Pacific Ocean Region. Basic communication circuits undergoing experiments are C/ L, L/C circuits between coast/aerial earth stations and mobile bodies, but experiments on mutual L/L circuits between mobile bodies and C/ C circuit for ranging satellite are also carried out.
The mobile satellite communications using two - beam antenna is the first try in Japan, and it is expected that the experiments with AMEX will lead to the application in various fields of communication.