SuperBIT

SuperBIT (for Super-pressure Balloon-borne Imaging Telescope) is a 0.5-meter optical reflector telescope aimed at surveys with a 0.5 degree field of view. It makes use of a super-pressure balloon (SPB) to observe at an altitude of 40 km which essentially eliminates atmospheric absorption. The telescope mounting is designed to stabilize its aim so as to be compatible with its angular resolution. I believe so far it is only equipped for imaging. During its development, it underwent four test flights, in 2015, 2016, 2018, and 2019 (the first two under the name Balloon-borne Imaging Test-bed, BIT). A 2023 fifth flight of 39 days completed four circuits around Antarctica, launching on April 16 in New Zealand and finishing the flight in the planned manner (so as to preserve the telescope) on May 25 in Argentina.

A future plan is a 1.5-meter follow-on named GigaBIT.