尽管日本是第一个向每个家庭用户直接提供彩色电视转播服务的先进国,但其广播卫星的发射和在轨工作情况却使NASDA、通信广播卫星机构和日本广播协会(NHK)、日本卫星广播公司大伤脑筋。实际上自1990年8月以来,各方面都采取了“保BS-3b”的紧急行动,同时,围绕着BS-3b的“继承人”问题开展了繁忙的工作,为BS-4制定方案。一、困境 BS-3b发射前,日本国内广播卫星转发 Although Japan is the first advanced country to provide color television broadcasting directly to each home user, the launch and in-orbit of its broadcasting satellites have enabled NASDA, the Communications Broadcasting Satellite Service and the NHK, Japan Satellite Broadcasters have big headache. In fact, since August 1990, “BS-3b” emergency actions have been taken on all fronts. At the same time, we have been busy working on the “heirs” of BS-3b and have formulated a plan for BS-4. First, the dilemma BS-3b before the launch, Japan’s domestic broadcasting satellite forwarding