On Monday, a small capsule launched off its test stand at the White Sands Missile Range in New Mexico, reaching speeds of more than 600 mph in just seconds. The spacecraft was Boeing’s Starliner crew capsule, which will begin carrying NASA astronauts to the International Space Station next year. Later this week, SpaceX will also perform a test of its Crew Dragon capsule, a second try after a catastrophic explosion ended a similar trial run earlier this year.