FIRST — Far Infrared and Submillimetre Space Telescope

The present status of the ESA cornerstone mission FIRST is presented. A recent industrial study has generated a spacecraft concept employing a 4.5 m passively cooled telescope with focal plane instrument cooling provided by a superfluid helium cryostat. The model payload complement includes two direct detection instruments as well as two heterodyne instruments. After a shared launch by Ariane 5 into GTO, FIRST propels itself into the 24-hour highly eccentric operational orbit, where observations can be conducted up to 17 hours per day with an expected approximate mission duration of 3 years. An additional complementary study of a non-cryostat spacecraft option will also be performed.