Wide-Field Imager measures extragalactic fluctuations on large angular scales. These angular scales are critical to detect the characteristic first-light galaxy power spectrum.

• Wide 2x2 degree field eliminates mosaicing artifacts
• Two spectral bands discriminate first-light fluctuations from foregrounds.
• Spatial resolution of 7" deeply removes galaxy clustering and shot noise.
• High sensitivity probes significantly deeper than the fluctuations reported by Spitzer and the IRTS.

Narrow-Band Spectrometer measures the absolute intensity of the Zodiacal brightness using the reflected Ca II 854.2 nm Fraunhofer absorption line in order to test Zodiacal dust models.

• Compact imaging spectrometer detects theintegrated Ca II 854.2 nm line strength.
• High sensitivity measures the absolute Zodiacal brightness to < 1 % in 6 fields.
• Control systematic errors associated with the instrument to 3 % in order to compare with DIRBE J-band.

Low-Resolution Spectrometer searches for the Lyman cutoff signature of reionization in the IRB. At the IRB level reported by the IRTS, such a bright feature would be apparent without any foreground subtraction. It will also measure the Zodiacal color.

• Absolute grating spectrometer measures in the spectrally unexplored 0.8 - 2.0 μm range between IRTS and HST.