Shadows cast across Mimas' defining feature, Herschel Crater, provide an indication of the size of the crater's towering walls and central peak.
Named after the icy moon's discoverer, astronomer William Herschel, the crater stretches 86 miles (139 kilometers) wide -- almost one-third of the diameter of Mimas (246 miles or 396 kilometers) itself.
The spacecraft, rockets and associated systems in development for NASA's Commercial Crew Program are critical links in the agency's chain to send astronauts safely to and from the Red Planet in the future, even though the commercial vehicles won’t venture to Mars themselves. The key is reliable access to the International Space Station as a test bed.
NASA is assigning veteran astronaut Andrew Feustel and first-flight astronaut Jeanette Epps to missions aboard the International Space Station in 2018.
Feustel will launch in March 2018 for his first long-duration mission, serving as a flight engineer on Expedition 55, and later as commander of Expedition 56. Epps will become the first African American space station crew member when she launches on her first spaceflight in May 2018. She’ll join Feustel as a flight engineer on Expedition 56, and remain on board for Expedition 57.
When astronauts set foot on Mars, they may stay for months rather than days as they did during Apollo missions to the moon. The surface of Mars has extreme temperatures and the atmosphere does not provide adequate protection from high-energy radiation. These explorers will need shelters to effectively protect them from the harsh Martian environment and provide a safe place to call home.