Overview
The Swarm constellation consists of three satellites to be placed in three different polar orbits, two flying side by side at an altitude of 450 km (280 mi) and a third at an altitude of 530 km (330 mi). The launch has been delayed and rescheduled to October 2013. ESA contracted Astrium to develop and build the three orbiters, while Eurockot will provide the launch services.
Read more about this topic: Swarm (spacecraft)