Swales Aerospace has delivered the last of five microsatellite platforms and the dispenser probe carrier for NASA‘s Time History of Events and Macroscale Interactions during Substorms (Themis) mission, the company announced June 13.

The mission, which consists of five identical spacecraft carrying a suite of electric, magnetic and particle instruments, is designed to study what factors lead to the creation of the northern lights. The mission is scheduled to be launched in October.