Science Channel has found its host for its coverage of the Great American Eclipse. It has tapped former NASA astronaut Mike Massimino for duties on the network’s The Great American Eclipse, which will air August 21 at 9 PM at part of the network’s coverage of the rare total solar eclipse that day, which will span the continental U.S. from Oregon to South Carolina. The eclipse is the first of its kind in 99 years.

Science Channel will feature live coverage starting at noon ET from Madras, OR and continue throughout the day from other locations along the eclipse’s path. Massimino will anchor the network’s coverage from Charleston, SC, one of the last land-based sites to see the eclipse. It will also air an eclipse preview special August 20 at 9 PM.

Massimino, who did two missions to the Hubble Space Telescope and four space walks to help repair it, has also been tapped to host Science Channel’s The Planets, eight hourlong episodes that will take an in-depth look at Venus, Mars, the newly discovered Planet 9, exoplanets and more. It premieres August 22 at 10 PM ET/PT.

“Mike Massimino is a true hero of space exploration having risked his life to fix the Hubble Space Telescope,” said Marc Etkind, Science Channel’s GM. “His dedication to furthering our understanding of the universe make him the perfect guide to take our viewers through the once-in-a-lifetime Great American Eclipse and to the farthest reaches of the galaxy in The Planets.”