FIREBall (the Faint Intergalactic Redshifted Emission Balloon, Tuttle et al., 2010) is a balloon-borne UV multi-object spectrograph attempting to image the CGM in emission via specific spectral lines redshifted to 205nm. This emission is extremely faint and so places stringent requirements on many of the telescope's components. FIREBall is a collaboration between Caltech, Columbia, JPL, and CNES/LAM. FIREBall-1 launched in 2007 and 2009 using a GALEX flight spare NUV micro-channel plate (MCP) and a fiber bundle IFU (Milliard et al., 2010). Since then, the spectrograph has been redesigned to incorporate the high efficiency detectors our team has developed (see Hamden et al., 2011 and Nikzad et al., 2012) and to utilize a slit mask; both improvements will increase overall transmission.
Below is an image from the first launch of FIREBall-1 in 2007. FIREBall-1 was relaunched in 2009.