CASSIOPE is a hybrid satellite project of the Canadian Space Agency. Planned for launch in an elliptical polar orbit in 2007, it will carry a commercial communications system called Cascade and a scientific experiment package called ePOP (enhanced Polar Outflow Probe). This combination gives rise to the acronym CASSIOPE: CAScade, Smallsat and IOnospheric Polar Explorer.

The University of Calgary's Institute for Space Research will lead the project. The satellite instruments will gather data on Solar storms in the upper atmosphere. These storms give rise to the Polar aurora or "northern lights" seen in the skies in northern latitudes. While these wavy monsters may offer a thrilling night time spectacle, they can have interfere with radio communications, GPS navigation, and other space-based systems. The eight scientific instruments aboard CASSIOPE will help scientists understand "solar weather" and eventually plan for measures to mitigate its deleterious effects.

The commercial payload will provide a secure digital store-and-forward file delivery service, exploiting the fact that CASSIOPE passes over much of the globe 15 times per day. It is often described as a courier service, with the customers using a small parabolic antenna of one or two meters (three or six feet) to upload or download files at a rate of 1.2 gigabits per second. The storage capacity will be between 50 and 500 gigabytes and the "delivery" time will be about 90 minutes, depending on the pickup and deposit points on the globe.

The two missions will also serve as a test for the bus or platform for this kind of small satellite. The same design would be reused for subsequent missions, after any required enhancements.

The main contractor will be Bristol Aerospace of Winnipeg, Manitoba and two of the eight scientific instruments aboard will be supplied by international partners, NASA and NASDA.

At this stage designers estimate that CASSIOPE will weigh approximately 375 kg. (about 800 pounds). It will have an hexagonal shape with dimensions of 1.6m (about 5 feet) at its narrowest and 1.8m (about 6 feet) at its widest. This might change as the project advances.