Nimbus 4 was launched on April 8, 1970, by a Thor-Agena rocket from Vandenberg Air Force Base in Lompoc, California, United States.

The polar-orbiting spacecraft consisted of three major structures: a torus-shaped sensor mount, solar paddles, and the control system housing.

The solar paddles and the control system were connected to the sensor mount by a truss structure, giving the satellite the appearance of an ocean buoy.

The torus-shaped sensor mount, which formed the satellite base, housed the electronics equipment and battery modules.

An H-frame structure mounted within the center of the torus provided support for the larger experiments and tape recorders.