Nimbus-6 carried a refined Earth radiation budget instrument and, more unusually, a data collection and location system that could receive transmissions from small beacons on the surface and determine their positions from the Doppler shift.
That capability was used to track drifting ocean buoys, weather balloons and, in an early experiment, wild animals fitted with transmitters. It was among the first demonstrations of satellite-based location and environmental data relay, a service now provided worldwide.
Its radiation budget measurements refined the global energy balance record, and its temperature and humidity sounders continued the atmospheric profiling that had become the mission series' most operationally valuable contribution.
It also carried an instrument measuring the limb of the atmosphere, observing sideways through the edge rather than downwards, which gives far better vertical resolution for the stratosphere and mesosphere.
The spacecraft operated for several years and fed a research programme that increasingly focused on the atmosphere as a coupled system rather than on weather alone — a shift that culminated in the instrumentation flown on its successor.