Japanese Infrared Astronomical Missions in Space: Infrared Imaging Surveyor (IRIS) and the HII/L2 Mission

We present a Grief description of an on-going Japanese infrared astronomical telescope mission in space: Infrared Imaging Surveyor (IRIS), as well as that of a future mission, a 3m class cooled telescope to be put into a halo orbit around the Sun-Earth L2 point by the Japanese H-IIA rocket(the HII/L2 mission). The IRIS is a 70cm cooled telescope dedicated to an infrared sky survey at 2 - 200 mu m. The HII/L2 mission is an ideal observatory-type platform to make follow-up observations to the IRIS survey mission. The mission is optimized for mid-infrared and far-infrared deep imaging and spectroscopic observations, thus will be complementary with NGST and FIRST. The target launch year is 2010.