Cheryl D. Alexander

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 Imaging X-ray Polarimetry Explorer (IXPE) as mentioned in this paper is a NASA Astrophysics Small Explorer mission with significant contributions from the Italian space agency (ASI) with three identical x-ray telescopes, each comprised of a 4m-focal-length mirror module assembly.

TL;DR: The Imaging X-ray Polarimetry Explorer (IXPE) as discussed by the authors is a NASA Small Explorer mission in collaboration with the Italian Space Agency (ASI), which will open a new window of investigation by imaging x-ray polarimetry.