Maximizing MESSENGER's Science Return with Technologies and Innovation

The great success of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission was possible only through a series of technological advances and a number of innovative uses of existing technologies. A Mercury orbital mission had been studied for 30 years before MESSENGER and was believed to require a multi-billion-dollar effort. However, the innovations developed by the MESSENGER team enabled the mission to be accomplished within NASA's low-cost planetary program, known as Discovery. Not only were key enabling developments put into practice before launch, but also a number of innovations were implemented after launch, and in-depth planning for critical events greatly enhanced the scientific return from the mission. These postlaunch improvements also simplified mission operations and saved enough propellant to permit extending the mission beyond the originally planned 1 Earth year at Mercury. The communications practices were optimized to ensure that even more science data could be returned to Earth, and the orbital period was lowered to give 50% more low-altitude coverage. When part of the Gamma-Ray Spectrometer had exceeded its useful life, the rest of the instrument was repurposed to give new insight into the rapidly varying magnetosphere.