  LISA is a proposed low resolution (R~15-30) imaging spectrometer for SOFIA,
the American-German Stratospheric Observatory for Far Infrared Astronomy.
Covering the wavelength range from 40micron to 220micron with three channels,
LISA provides diffraction limited spectroscopy for each pixel within a
rectangular field of view (FOV). The FOV sizes for the channels are 18x11
arcsec for 40 to 70micron, 32x19arcsec for 70-120 micron, and 22x22arcsec for
120-220micron, each channel upgradable to about twice the linear size. LISA
will be able to address a variety of astrophysical topic, in particular on
faint targets. Spatially resolved temperature distribution of dust emission
will be studied in the environments of young and evolved stars, star forming
regions, as well as in nuclear regions of nearby galaxies. Spectral energy
distributions (SEDs) of distant galaxies will be determined in search for cold
gas components. LISA's spectral resolution will be high enough to search for
broad spectral features (e.g. PAHs, ices). The optical design, the mechanical
layout, the estimated sensitivity, and the scientific potential of such an
instrument is briefly discussed.
