The Technology Reference Studies (TRS) were introduced before the Cosmic Vision call for proposals to focus the early development of strategically important technologies of likely relevance to future science missions. This has been accomplished through the study of several technologically demanding and scientifically interesting missions, which are not part of the ESA science programme. The TRS have been selected to cover a wide range of different scientific topics ranging from astrophysics, through fundamental physics to planetary exploration, with an even wider range of strategically important technologies.

Most science missions are in many respects technologically very challenging. It is very important to define and prepare critical technologies far in advance to ensure that they are developed in a timely manner and that the associated cost, risk and feasibility of potential future mission concepts can be estimated properly. Technology Reference Studies (TRS) are set up to provide a set of realistic requirements for these technology developments far before specific science missions are proposed by the scientific community.

Each TRS had a clear scientific goal or set of scientific goals, none of which are easily attainable using current spacecraft technologies and/or methodologies. Associated with each TRS is a coherent set of clearly identified technological challenges, which must be addressed if the TRS mission profile was to be implemented. Envisaged technologies were assumed to have a technology readiness level compatible with a launch in the 2010-2020 timeframe to ensure that only realistic mission scenarios are studied and that the technology requirements can be properly defined.