Robust diffraction-limited near-infrared-to-near-ultraviolet wide-field imaging from stratospheric balloon-borne platforms—Super-pressure Balloon-borne Imaging Telescope performance
Jauzac, Mathilde; Tam, Sut-Ieng; Benton, Steven J.; Clark, Paul; Lagattuta, David; Romualdez, L. Javier; Brown, Anthony M.; Damaren, Christopher J.; Eifler, Tim; Fraisse, Aurelien A.; Galloway, Mathew N.; Gill, Ajay; Hartley, John W.; Holder, Bradley; Huff, Eric M.; Jones, William C.; Leung, Jason S. -Y.; Li, Lun; Luu, Thuy Vy T.; Massey, Richard J.; McCleary, Jacqueline; Mullaney, James; Nagy, Johanna M.; Netterfield, C. Barth; Redmond, Susan; Rhodes, Jason D.; Schmoll, Jürgen; Shaaban, Mohamed M.; Sirks, Ellen
United States, United Kingdom, Canada, Norway
Abstract
At a fraction of the total cost of an equivalent orbital mission, scientific balloon-borne platforms, operating above 99.7% of the Earth's atmosphere, offer attractive, competitive, and effective observational capabilities—namely, space-like seeing, transmission, and backgrounds—which are well suited for modern astronomy and cosmology. The Super-pressure Balloon-borne Imaging Telescope (SUPERBIT) is a diffraction-limited, wide-field, 0.5 m telescope capable of exploiting these observing conditions in order to provide exquisite imaging throughout the near-infrared to near-ultraviolet. It utilizes a robust active stabilization system that has consistently demonstrated a 48 mas 1σ sky-fixed pointing stability over multiple 1 h observations at float. This is achieved by actively tracking compound pendulations via a three-axis gimballed platform, which provides sky-fixed telescope stability at < 500 mas and corrects for field rotation, while employing high-bandwidth tip/tilt optics to remove residual disturbances across the science imaging focal plane. SUPERBIT's performance during the 2019 commissioning flight benefited from a customized high-fidelity science-capable telescope designed with an exceptional thermo- and opto-mechanical stability as well as a tightly constrained static and dynamic coupling between high-rate sensors and telescope optics. At the currently demonstrated level of flight performance, SUPERBIT capabilities now surpass the science requirements for a wide variety of experiments in cosmology, astrophysics, and stellar dynamics.