Lewis was one of two missions selected under NASA's SSTI (Small Spacecraft Technology Initiative) program to demonstrate advanced spacecraft technologies (11 July 1994). Lewis' payload consisted of:

- Earth imaging Hyperspectral Imager (HSI) with 384 bands (0.4 - 2.5 µm, 30 m pixels, 7.7 km swath, panchromatic: 0.45 - 0.75 µm, 5 m pixels, 13 km swath)
- Linear Etalon Imaging Spectral Array (LEISA), from NASA GSFC (1.0 - 2.5 µm, 256 channels, 300 m pixels, 77 km swath).
- Ultraviolet Cosmic Background (UCB), from UC Berkely (35 - 85 nm)

After reaching orbit, the satellite spun out of control and was losing power just days after launch because an attitude-control thruster remained in the on position longer than planned, so that Lewis could not manouver to its operational orbit and decayed soon after.