Design and performance of stratospheric balloon-borne platforms for infrared astrophysical observations

The design of a stabilization system for astronomical observations from balloons requires very specific solutions. Technologies used in ground based telescopes or satellite experiments are not directly usable. The frequency and the amplitude of external perturbations are at least one order of magnitude higher in a balloon environment. High gain closed-loop servos are not stable on light balloon gondolas, with low resonance frequencies. The attitude control systems should not excite the high-Q resonance of the flight chain (torsion mode) and the compound pendulum motion of the gondola around its center of gravity. This paper presents solutions to these problems.