NASA THEMIS Probes Launch and Deployment: 5 for the price of 1

NASA's Time History of Events and Macroscale Interactions during Substorms (THEMIS) resolved one of the oldest mysteries in space physics, how magnetic reconnection in near-Earth space drives substorms, the violent eruptions of the aurora that occur in the Earth's magnetosphere. The THEMIS mission impartially distinguished, as implied by the Greek goddess' namesake, between two disparate phenomenological and plasma-physical models of substorm onset in order to solve the tantalizing mystery: Where and when do substorms start in the Earth's magnetosphere? This question had been the subject of scientific contention for over thirty years.

THEMIS is the first mission ever to launch 5 identical probes in one rocket payload, effectively getting the most bang for the taxapayer's buck. Launched in 2007, the THEMIS probes are still operating flawlessly and making new discoveries every day. Further, by diverting two of the five probes to conduct heliophysics and planetary science investigations at the Moon, the ARTEMIS mission was created without incurring the significant cost of new probes and another launch. Thus, THEMIS and ARTEMIS are two of the most economical missions ever undertaken, on a per satellite cost basis.

CREDIT: NASA/GSFC SVS