SAGE III and Hexapod installed on the International Space Station.
NASA’s Stratospheric Aerosol and Gas Experiment, or SAGE III, monitors aerosols, ozone and other gases in Earth’s high atmosphere by looking at the sunlight and moonlight as they pass through. Astronauts on the Space Station often remark at how thin the atmosphere appears when seen from the side.
SAGE is improving our understanding of ozone and climate change in the upper atmosphere by looking at the Sun and Moon as they skim the horizon – and this where ESA’s Hexapod comes in.
Hexapod’s six legs work together to track the Sun and Moon precisely in the few seconds of their setting and rising dozens of times each day.
Hexapod tracks the Sun until it disappears behind the horizon and then returns to a starting position to repeat the process with the Moon, for years on end.