NASA’s space shuttle system operated in low Earth orbit for 30 years before its retirement in 2011. However, the U.S. space agency’s replacement for these vehicles, the Orion spacecraft, returned to the conical capsule design familiar from Mercury, Gemini and Apollo missions. This was because NASA intended that this newer craft be used for exploring targets beyond low Earth orbit.
In recent years, however, there’s been a return of the spaceplane design. Since 2010, the U.S. Space Force (and formerly the U.S. Air Force) has been launching a robotic spaceplane called the X-37B into low Earth orbit on classified missions. The Chinese Communist Party has its own military spaceplane called Shenlong.
A test flight of the company Sierra Space’s Dream Chaser — the first commercial spaceplane capable of orbital flight — is planned for 2025. If successful, the vehicle could be used to resupply the International Space Station with cargo and, eventually, crew.
Spaceplanes can fly or glide in the Earth’s atmosphere and land on runways rather than using parachutes to land in water or flat ground like capsules. They’re also more maneuverable as the spacecraft reenters the atmosphere, increasing the area of the Earth’s surface where landing is possible from a specific reentry point.
There has been interest in spaceplanes from the earliest days of human spaceflight. A military spaceplane project called Dyna-Soar was started in the U.S. in 1957, then canceled just after construction started. The vehicle was sophisticated for its time, built using a metal alloy that could withstand high temperatures and featuring a heat shield on the front that could be detached after it returned from space, so that the pilot could see clearly during landing.
The space shuttle, which entered service in 1981, was the first operational spaceplane. It was supposed to launch more often than it did and have greater reusability, but it turned out that extensive refurbishment was required between launches.
Other space agencies invested in the 1980s and 1990s, in Europe with the Hermes spaceplane, and Japan with the HOPE vehicle. Both programs were canceled in large part because of cost. The Soviet Union developed its own shuttle-like vehicle called Buran, which successfully flew to space once in 1988. The program was canceled after the collapse of the Soviet Union.
For the foreseeable future, spaceplanes look promising for the following reasons: new design techniques, improved materials for thermal protection systems, advanced computer modeling and simulation tools that optimize different aspects of design and flight parameters, and continual improvements in propulsion systems. Reuters