Mini Mission RainCube is Sent into Earth Orbit

RainCube was deployed into low-Earth orbit from the International Space Station in July, 2018, where it has been measuring rain and snowfall from space. The size of the tiny weather satellite can be seen in comparison to the Space Station. RainCube is a prototype for a possible fleet of small satellites that could one day help monitor severe storms, lead to improving the accuracy of weather forecasts and track climate change over time.

A closer look at these images reveals there are two CubeSats very close together -- RainCube is the bottom CubeSat closer to Earth, while the one above it is HaloSat, used to map the distribution of hot gas in the Milky Way.

https://photojournal.jpl.nasa.gov/catalog/PIA22653