Measurement apparatus for operating load of fast steering mirror unit for large telescopic system and large telescopic system having the same

The present invention relates to an apparatus of measuring an operation load of a fast steering mirror unit for a large-aperture telescope that can simultaneously measure loads of three-axis directions applied to a tip-tilting system when the fast steering mirror unit of the large-aperture telescope is tip-tilted, and can utilize the loads to generate a track for the minimized reaction, and that can verify the correct assembled state of the fast steering mirror unit and the stabilization of its driving characteristic, and to a large-aperture telescope having the same. The apparatus of measuring the operation load of the fast steering mirror unit of the large-aperture telescope includes a support member having a lateral support for connecting a mirror cell housing and a secondary mirror provided in the large-aperture telescope to measure the loads of three-axis directions applied to the secondary mirror, with one end of the lateral support being fixed to a fastening adaptor of the mirror cell housing; a three-axis force sensor fixed to the other end of the support member; and a flexure elastic member for elastically supporting the three-axis force sensor.