Balloon borne telescopes can achieve much of the promise of satellite borne experiments, at a fraction of the cost, while providing important tests for upcoming satellite missions. Two tonne telescopes can be launched above ~99.5% of the atmosphere for flights up to several weeks.
I will discuss results from the BLAST sub-mm telescope which has made extensive maps looking at galactic and extragalactic star formation, and at upcoming missions, including Spider mission, which will measure the polarization of the cosmic microwave background in order to constrain models of cosmological inflation in the early universe.