Payload is the load that can accommodate a vehicle (airplane, spaceship, car, truck etc.), until the maximum permissible laden mass is reached. It corresponds to the mass of the load that can be transported. In bombers one speaks of ' bombs '.
In space, the payload refers to the weight, which can transport a rocket or a space ship (next to the fuel). Sometimes the load capacity is only 2 % of the starting weight ( see launcher ).
A secondary payload is another load capacity that is carried in addition to the primary payload to best take advantage of the transportation options, such as piggyback satellites such as the CubeSats.
Payload is the maximum load that can transport a ready vehicle without the permissible axle loads and the permissible total mass be exceeded (see Directive to § 42 traffic regulations of 15 August 1983 Transport Gazette 1983, p 464 ). This definition applies to German approval regulations, the manufacturer can be different conceptions based.