Flight performance of radiant coolers onboard FengYun-2 satellites

•FY-2E and F satellites operate at 93 K during summer solstice.•Flight performance of the four radiant coolers are presented and tabulated.•The major technologies are discussed.

The IR detectors of optical instruments onboard FengYun-2 (FY-2) meteorological satellites are cooled by passive radiant coolers (RC). The operation principles, characteristics and flight performance of the radiant coolers installed on four FengYun-2 satellites (FY-2C/D/E/F) are presented. The orbiting data from the four satellites (FY-2C/D/E/F) are tabulated and compared. It is concluded that the radiant coolers (FY-2E/F) can operate stably at 93 K in the sunshine and have a long service lifetime. The major technologies of FY-2 radiant coolers are mainly discussed in terms of thin-walled structure design and optical coating of the sun shield. The problem of contamination control in orbit is solved.