They are two long, narrow doors in the belly of the shuttle that open to allow the crew do move whatever is in the cargo bay out into space. Best example: The fabulous Hubble Space Telescope was unloaded out of the shuttle through the payload bay doors.
Payload is carried in the Space Shuttle's Payload Bay. The payload bay is situated behind the crew cabin, in the middle of the orbiter. It is 60 ft long and 15 ft wide. The payload bay has two large doors that open once the shuttle reaches orbit. On the inner side of these doors are radiators which help cool the shuttle. Inside the payload bay, there are latches to hold satellites, space station components, experiments, and other objects in place. The payload bay also holds the space shuttle's remote manipulating system (RMS), KU-band antenna, and several cameras and lights. The space shuttle is capable of carrying about 65,000 pounds of cargo in the payload bay.
Skylab. It was not in the payload bay for every mission, though.
Enough to carry a bus in it's payload bay.
To allow cooling of the Shuttle: The interior side of the two cargo bay doors are covered with radiators. Those radiators are connected to the overall cooling system of the Shuttle. These radiators have to be exposed to space (i.e. the doors have to be opened) to reject their heat and avoid overheating of the Shuttle subsystems. This is why the cargo bay doors are opened as soon as the Shuttle reaches its orbit, and are closed only shortly before re-entry.
A payload bay is an enclosed section on a spacecraft where equipment, experiments, or other cargo can be stored and transported. It is usually designed to protect the payload from the harsh conditions of space, such as temperature fluctuations and microgravity. Payload bays are common on spacecraft like the Space Shuttle and the International Space Station.
The shuttle has a large payload and it is reusable.
The Shuttle can also carry a 65,000 payload.
The space shuttle uses its payload bay to carry and deploy satellites into space. Once the shuttle reaches the desired orbit, the robotic arm or astronauts inside the shuttle release the satellite into space.
A payload bay is where cargo is stored, like on a space mission to the ISS.
Cargo.
The payload of a space shuttle typically refers to the cargo or instruments it carries into space, such as satellites, scientific experiments, or supplies for the International Space Station. Payload capacity can vary depending on the specific mission and configuration of the shuttle.