Dellingr - a spacecraft that does not exceed the size of the boot. It was created to demonstrate the effective operation of CubeSat technologies. A specific model was released from the ISS on November 20, 2017. In the picture he sails past the station. He was created to extract information in high quality on a small platform.
Initially, CubeSat was created at California State Polytechnic University in 1999, pursuing exclusively educational purposes. But this concept quickly became popular and spread to other universities.
They are not only cheap in terms of manufacturing, but also endowed with high potential for exploring the Earth and the entire system. They can be sent in groups and study objects from different points, which will be much cheaper than launching a large device.