CASSIOPE - Swarm Echo as a Fourth Element of the Swarm Constellation: Scientific Synergies and the Next Chapter

The Enhanced Polar Outflow Probe (e-POP) was launched as part of the Canadian CASSIOPE small satellite into an elliptic polar orbit in September 2013. It then joined the ESA Swarm mision under ESA's Third Party Mission Programme in 2018, as a Fourth Element of the Swarm constellation of satellites, to take advantage of the highly complementary and synergistic instrumentation and orbital coverage between CASSIOPE/e-POP and the three Swarm satellites. This scientific synergy has made possible a new, high-resolution multipoint data set of magnetic field, GPS, and related optical, radio wave, and plasma composition observations, as an addition to the Swarm mission data system and the basis for a number of new scientific investigations. We will review examples of 'scientific success stories' from such investigations. We will also present examples of new investigations in the next chapter of Swarm Echo: these investigations were not planned previously but have become feasible after the recent partial failure of the spacecraft attitude control system, which necessitated a change to a new spacecraft attitude configuration that will serendipitously provide the necessary observing geometry for such innovative investigations