The primary scientific goal of the Atmospheric Chemistry Experiment (ACE) is to measure and understand the chemical and dynamical processes that control the distribution of ozone in the upper troposphere and stratosphere.

A high inclination (74 degrees), low Earth orbit 650 km (400 mi) will provide ACE coverage of tropical, mid-latitudes and polar regions.

The instrument also includes a Suntracker mechanism providing fine pointing toward the radiometric center of the Sun with stability better than 3 μrad.

[6] SCISAT passes through the Earth's shadow 15 times per day, profiting from the occultation of the Sun to make a spectrographic analysis of the structure and chemistry of those parts of the upper atmosphere that are too high to be reached by balloons and airplanes and too low to be visited by orbiting satellites.

SCISAT was placed in low Earth orbit, or LEO, by a Pegasus rocket launched from a NASA Lockheed L-1011 carrier aircraft on August 12, 2003 from Vandenberg Air Force Base.