SNOE was equipped with three scientific instruments:
An Ultraviolet Spectrometer, which performs a vertical profile of the concentration of nitric oxide.
A two-channel Auroral Photometer, which performs measurements of auroral emissions beneath the satellite.
A five-channel Solar X-ray Photometer, which measures the soft X-ray emissions by the Sun.
The satellite features a GPS receiver to accurately determine its orbit and orientation.
Overview
SNOE was the 72nd mission of the Explorer program by NASA dedicated to the scientific investigation of the space environment of the Earth. SNOE was the first of three projects developed within the university satellite program whose objective is to reach students in the development of satellites with limited means in the context of the strategy of "faster, better, cheaper" promoted by then-NASA administrator Daniel Goldin. The program was funded by NASA and managed by the Universities Space Research Association. The mission, developed by the University of Colorado Boulder in 1994, was selected among 66 proposals to be one of the six pre-selected satellites of the program. In February 1995 the satellite was selected along with TERRIERS of Boston University and CATSAT of the University of Leicester in the United Kingdom. SNOE was built and operated entirely by the Laboratory for Atmospheric and Space Physics of the university. The objective of the mission was the detailed study of variations in the concentration of nitrogen monoxide in the thermosphere. Nitric oxide, though a minor component of this region of space, has a significant impact on the composition of ions in the ionosphere and in the heat of the thermosphere. The detailed objectives are:
Detailing how the variations of X-ray radiation from the sun affects the density of nitric oxide in the lower layer of the thermosphere.
How auroral activity increases the amount of nitric oxide in the polar regions.
The limb-scanning Ultraviolet Spectrometer on SNOE observed polar mesospheric clouds, finding that PMCs occur more frequently in the northern latitudes than in the southern, but that they otherwise conform well to the standard model of cloud formation. SNOE also helped to map the effect of global X-rays on the atmosphere. Enhanced fluxes of solar soft X-rays were detected by SNOE. Solar soft X-ray irradiance was measured by the spacecraft's Solar X-ray Photometer between 2 and 20 nm, and covered irradiance levels outside of solar minimum and maximum conditions. In the 2 to 7 nm interval the irradiance levels ranged from, while in the 6 to 19 nm interval the range was observed to be. These values were a factor of four times higher than those predicted by the Hinteregger, et al. empirical model.
