Payloads

Payload is a term used across several fields to designate the portion of a system’s output that is intended to be consumed or delivered to a target, distinct from the system’s structure, control signals, or propulsion. The concept centers on usable content or cargo.

In aerospace and spaceflight, the payload is the cargo carried by a rocket, satellite, or spacecraft. It includes satellites, scientific instruments, landers, or resupply cargo. The vehicle’s propulsion and frame are separate from the payload, and payload mass influences launch costs, performance, and mission design.

In data communications and cybersecurity, the payload is the actual data carried within a frame, packet, or message, excluding headers and metadata. In security contexts, the term also denotes the component of an exploit or malware designed to perform its intended effect, such as system compromise or data exfiltration, distinct from the delivery mechanism or exploit code.

In software development and web services, a payload refers to the body of a request or response, for example the JSON or XML data sent to or from an API. The payload contains the substantive information a client wants the server to process or return.

In transport and robotics, payload capacity is the maximum weight or volume a vehicle or device can safely carry, excluding its own weight. This concept is used to estimate load limits for air, land, sea, and space vehicles and for designing equipment such as drones, trucks, and cargo ships.