Spaceflight

Spaceflight is the act of launching and operating spacecraft outside Earth's atmosphere. It includes suborbital flights that briefly reach space and orbital missions that enter stable Earth orbit or travel beyond it, for purposes such as exploration, satellite deployment, science, and technology demonstration.

The modern spaceflight era began with advances in rocketry in the 20th century, culminating in the launch of the first artificial satellite, Sputnik 1, in 1957, and the first human spaceflight by Yuri Gagarin in 1961. The Moon landings of the late 1960s and early 1970s, the Space Shuttle program, and the continual presence of humans on the International Space Station have shaped subsequent developments. Suborbital programs and sounding rockets have also contributed to atmospheric and space research.

Most space launches rely on chemical rockets, using liquid or solid propellants to provide thrust. In space, electric propulsion such as ion engines enables high-efficiency, low-thrust propulsion for long-duration missions. Reusability and advanced propulsion concepts are reducing costs and increasing mission flexibility.

Spaceflight involves launch vehicles, orbital spacecraft, landers, and probes. Missions vary from satellite deployment and Earth observation to crewed exploration and interplanetary science. Orbital missions operate in Earth orbit or transfer to other celestial bodies; suborbital missions briefly enter space but do not complete an orbit.

Spaceflight activity is conducted by space agencies (for example NASA, Roscosmos, ESA, CNSA, ISRO, JAXA) and by commercial companies (e.g., SpaceX, Blue Origin, Rocket Lab). Ground infrastructure, mission control, and international collaboration support safe and coordinated operations.

Spaceflight has enabled telecommunications, weather forecasting, navigation, and Earth science, while enabling human exploration and satellite-based services. Challenges include cost, safety, radiation, debris, and political considerations; ongoing efforts aim to improve reliability, reusability, and access through international cooperation.