The FORCAST mid-infrared facility instrument and in-flight performance on SOFIA

FORCAST has completed 16 engineering and science flights as the “First Light” U. S. science instrument aboard SOFIA and will be commissioned as a SOFIA facility instrument in 2013. FORCAST offers dual channel imaging (diffractionlimited at wavelengths < 15 microns) using a 256 x 256 pixel Si:As blocked impurity band (BIB) detector at 5 - 28 microns and a 256 x 256 pixel Si:Sb BIB detector at 28 - 40 microns. FORCAST images a 3.4 arcmin × 3.2 arcmin fieldof- view on SOFIA with a rectified plate scale of 0.768 arcsec/pixel. In addition to imaging capability, FORCAST offers a facility mode for grism spectroscopy that will commence during SOFIA Cycle 1. The grism suite enables spectroscopy over nearly the entire FORCAST wavelength range at low resolution (~140 - 300). Optional cross-dispersers boost the spectroscopic resolution to ~1200 at 5 - 8 microns and ~800 at 9.8 – 13.7 microns. Here we describe the FORCAST instrument including observing modes for SOFIA Cycle 1. We also summarize in-flight results, including detector and optical performance, sensitivity performance, and calibration.