ESRO 2 (European Space Research Organisation), Iris (International Radiation Investigation Satellite) was a 75 kg spin-stabilized spacecraft. On the launch of ESRO 2A, the third stage vehicle failed and the spacecraft did not achieve orbit.

The Scout family of rockets were were American launch vehicles designed to place small satellites into orbit around the Earth. The Scout multistage rocket was the first orbital launch vehicle to be entirely composed of solid fuel stages.

The European Space Research Organisation (ESRO) was an international organisation founded by 10 European nations with the intention of jointly pursuing scientific research in space. It was founded in 1964. As an organisation ESRO was based on a previously existing international scientific institution, CERN. The ESRO convention, the organisations founding document outlines it as an entity exclusively devoted to scientific pursuits. This was the case for most of its lifetime but in the final years before the formation of ESA, the European Space Agency, ESRO began a programme in the field of telecommunications.