Is it safer to land on water or on land?
Spacecraft can safely return to Earth in either environment.
During the 1960s and 1970s, NASA’s Mercury, Gemini and Apollo capsules all splashed down in the ocean while Soviet capsules all ended their trips on land. Russia’s current Soyuz capsules continue to make ground landings, as do China’s astronaut-carrying Shenzhou capsules.
The last water landing by NASA astronauts occurred in July 1975 at the end of the Apollo-Soyuz mission, during which an American crew aboard an Apollo module docked in orbit with two Soviet astronauts aboard a Soyuz capsule.
While the crew splashed down safely, a problem with the Apollo spacecraft during re-entry caused fumes from rocket propellant to fill the capsule, causing breathing and eye problems for the astronauts.
When Boeing’s Starliner capsule begins carrying crews to the space station, it will return on land, in New Mexico. SpaceX had originally planned for the Crew Dragon to do ground landings, but decided that water landings, employed for the earlier version of Dragon for taking cargo, simplified the development of the capsule. Elon Musk, the founder of SpaceX, further explained the reasoning on Twitter early on Sunday: