A spacecraft is a vehicle designed to operate in a controlled flight pattern above Earth’s lower atmosphere, with or without a crew. It is the only means of travel to the planets and their moons and other solar system bodies, such as asteroids, comets, and even the far reaches of the universe. Spacecraft are usually launched into orbit with a rocket and then released into space. Some are reusable and can be flown again after undergoing some repairs.
A mystery Chinese spacecraft returned to Earth on Monday after staying in orbit for 276 days, completing a landmark mission to test the country’s reusable space technologies.
According to state media, the uncrewed spacecraft returned to the Jiuquan launch center in northwest China on Monday as scheduled. However, no details were given on the spacecraft, what technologies were tested, how high it flew, or whether it landed in the ocean or a desert.
Chinese officials hailed the secretive mission as an essential breakthrough in their research into reusable spacecraft technology. In addition, it is expected to make future space missions cheaper and more convenient for the country.
China has ambitious plans to establish a permanent space station and send astronauts to the moon by the end of this decade. But its military has also long wanted to gain the ability to launch satellites and other spacecraft from domestic factories, allowing it to operate a sophisticated space surveillance network with its independent capability to monitor activities in outer space.
One of the main reasons that spacecraft must land is to avoid a collision with other satellites and debris, known as space junk. Most such objects are in low Earth orbit, but they pose a risk to satellites and other spacecraft that need to maintain an accurate position in space. As a result, several satellites and other spacecraft regularly perform collision avoidance maneuvers to reduce the risk.
These are often highly precise and require the spacecraft to be at a specific point in its orbit, called periapsis. The opposite point of an orbit is called apoapsis. The distance between periapsis and apoapsis is the orbit’s radius, which can be calculated from the spacecraft’s velocity and direction of motion.
On Monday, the spacecraft that returned to Earth performed its apoapsis maneuver by undocking from the International Space Station, deploying its two drogues and four main parachutes. It then performed a series of departure burns to move away from the orbiting lab before entering Earth’s atmosphere.
The Dragon cargo ship then separated from the ISS and performed a series of deorbit burns to slow down as it entered the atmosphere. Once it was clear of the ISS, it deployed its drogue and main parachutes for a soft water landing. The Dragon was carrying a load of supplies for the astronauts living aboard the ISS. It has spent 167 days in space, the most extended duration for a U.S. spacecraft since the final Skylab mission in 1974. The retrieved items include food, supplies for science experiments, and the ISS’s next generation of power systems.