2月15日,陆地卫星-4专题制图仪X波段发射机失灵,这是专题制图仪X波段的备分发射机,在这以前,其主发射机早已停止使用,由于两台发射机都已停止工作,因而目前专题制图仪不能再向地面站发射数据。陆地卫星-4上的S波段和Ku波段发射机仍可工作。 X波段发射机发生故障的原因尚不清楚,NASA官员说还要再用一周时间才能得出结果。目前NASA和通用电气公司正在与X波段发射机承包商TRW公司一起研究发生故障的原因。 On February 15, the X-band transmitter for the Landsat-4 thematic plotter failed, which was a stand-alone transmitter for the X-band of the thematic plotter, and until then its main transmitter had ceased to be operational, as both transmitters had been Stop working, so the current thematic plotter can no longer transmit data to the ground station. S-band and Ku-band transmitters on land satellite-4 are still operational. The reason for the failure of the X-band transmitters is unclear, and NASA officials said it will take another week to get results. NASA and General Electric are now working with X-band transmitter contractor TRW to investigate the cause of the crash.