Pointing Sensors for Balloon-borne Telescopes

Natalie Gandilo, Department of Astronomy & Astrophysics, U of T

The best place to put a telescope is to hang it from a giant balloon, 38km above Antarctica. One small challenge of doing this, however, is figuring out which way it is pointing while it is up there. And not being able to get to it when things go wrong. I will discuss the many pointing sensors that can be used in stratospheric balloon experiments, and how I have implemented these systems for two telescopes – BLASTPol and Spider. I will also talk about how well these sensors performed in the 2010 & 2012 BLASTPol flights.