Since humans first looked up into the night sky and wondered about the nature of the objects they saw, space exploration has fascinated us. With the development of rockets that can overcome Earth’s gravity to achieve orbital velocities in the 20th century, it became possible to send machines and then humans above the planet’s atmosphere.
In the early years of space exploration, many nations and companies competed with one another to be the first to reach landmark milestones such as putting a person in space, landing on other celestial bodies or orbiting them. The goal was to gain prestige for their country by demonstrating its technological prowess. After Yuri Gagarin’s orbital flight in 1961, U.S. President Dwight Eisenhower wrote that dramatic achievements in space “symbolize the technological power and organizing capacity of a nation.”
Today, our main focus is on joint human-robotic missions, near-Earth asteroids, Mars and destinations beyond the Solar System. Among the many scientific accomplishments of these missions, we’ve found water on the Moon, discovered Earth-sized exoplanets, mapped the cosmic dust in the Milky Way and studied the origins of galaxies and stars with observatories such as the Hubble Space Telescope.
We’ve learned much about the challenges of sending and sustaining people in outer space with the International Space Station, but establishing a permanent station or colony on other planets or moons will be even more challenging. It will require an understanding of the physical environment, the risks from cosmic radiation, a variety of physiological and psychological effects that may occur during extended forays into space and the design of living quarters that allow occupants to feel comfortable in cramped conditions. Space colonies will need facilities for science research, mining and production, as well as telescopes to take advantage of the clear view of distant stars.