The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) is a sub-orbital experiment designed to study the process of star formation in local galaxies (including the Milky Way) and in galaxies at cosmological distances. Using a 2m Cassegrain telescope, BLAST images the sky onto a focal plane, which consists of 270 bolometric detectors split between three arrays, observing simultaneously in 30% wide bands, centered at 250, 350, and 500 μm. The
diffraction-limited optical system provides a resolution of 30" at 250 μm. The pointing system enables raster-like scans with a positional accuracy of ~30", reconstructed to better than
5" rms in postflight analysis. BLAST had two successful flights, from the Arctic in 2005, and from Antarctica in 2006, which provided the first high-resolution and large-area (~0.8−200 deg2) submillimeter surveys at these wavelengths. As a pathfinder for the SPIRE instrument on Herschel, BLAST shares with the ESA satellite similar focal plane technology and scientific motivation. A third flight in 2009 will see the instrument modified to be polarization-sensitive (BLAST-pol). With its unprecedented mapping speed and resolution, BLAST-pol will provide insights into Galactic star-forming nurseries, and give the necessary link between the larger, coarse resolution surveys and the narrow, resolved observations of star-forming structures from space and ground based instruments being commissioned in the next 5 years.
We have developed two redundant daytime star cameras to provide the fine pointing solution for the balloon-borne submillimeter telescope, BLAST. The cameras are capable of providing a reconstructed pointing solution with an absolute accuracy < 5". They are sensitive to stars down to magnitudes ~ 9 in daytime float conditions. Each camera combines a 1 megapixel CCD with a 200mm f/2 lens to image a 2° × 2.5° field of the sky. The instruments are autonomous. An internal computer controls the temperature, adjusts the focus, and determines a real-time pointing solution at 1 Hz. The mechanical details and flight performance of these instruments are presented.
As technological and scientific path-finder towards future observatory missions, a balloon-born hard X-ray imaging observation experiment InFOCμS has been developed. The payload has flown four times since 2000. In its 2004 Fall flight campaign InFOCμS successfully achieved first scientific observations of multiple astronomical objects from galactic compacts to cluster of galaxies. Significant signal has been detected from bright galactic objects while analysis of extragalactic objects is underway. InFOCμS plans additional and upgraded telescope-detector system as early as 2006. High energy telescope for nuclear gamma-ray line observations is under planning.
Advances in bolometric detector technology over the past decade have
allowed submillimeter wavelength measurements to contribute important
data to some of the most challenging questions in observational
cosmology. The availability of large format bolometer arrays will
provide observations with unprecedented image fidelity. The
Balloon-borne Large Aperture Submillimeter Telescope (BLAST) will be
one of the first experiments to make full use of this new capability.
The high altitude (~35$ km) of the balloon platform allows for
high-sensitivity measurements in the 250, 350 and 500 micron bands
with a total of 260 detectors.