Jeff Apple

TL;DR: HERO as mentioned in this paper is a balloon-borne hard-x-ray telescope that utilizes grazing incidence optics, which can provide unprecented sensitivity in the hard x-ray region and will achieve milliCrab-level sensitivity in a typical 3-hour balloon-flight observation and 50 microCrab sensitivity on ultra-long-duration flights.

TL;DR: In this paper, a star camera was designed, built, and flight-tested for pointing a pointed balloon-borne experiment at altitude around 40 km. The camera and lens are commercially available, off-the-shelf components, but require a custom-built baffle to reduce stray light, especially near the sunlit limb of the balloon.

TL;DR: In this article, the authors developed high-energy grazing-incidence replicated optics for a balloon-borne hard-x-ray telescope, which will have 170 cm2 of effective collecting area at 40 keV and 130 square cm at 60 keV with <= 30 arc seconds half power diameter.

TL;DR: The ProtoEXIST2 CZT detector plane consists of 64 of 5 mm thick 2 cm × 2 cm CZTs with a minimal gap as discussed by the authors, which is a prototype for a next generation hard X-ray imager MlRAX-HXI on board Lattes, a spacecraft from the Agencia Espacial Brasilieira.

TL;DR: The first high-altitude balloon flight of a wide-field hard X-ray coded-aperture telescope ProtoEXIST1, which was launched from the Columbia Scientific Balloon Facility at Ft. Sumner, New Mexico on October 9, 2009, was reported in this paper.