Short-term scientific missions (STSM) are visits of researchers based in a home institution in a COST participating country to a host institution in another COST participating country or to a formally approved host institution in a non-COST country with the aim of contributing to the scientific objectives of the Action. 

The purpose of these visits is to work on a jointly authored article, to learn or use a new technique or research method not available at the home institution, to work on a joint research proposal or any other activity linked to the objectives of the Action. 

More information, application procedure and eligibility conditions as well as some examples of undertaken STSMs can be found here