Space science for Europe 2015–2025

Cosmic Vision 2015–2025 is the current cycle of ESA's long-term planning for space science missions. It is the latest in a series of mechanisms through which ESA's science missions are implemented and provides the stability needed for activities which typically take over two decades to go from initial concept to the production of scientific results.

Intended as an introduction to Cosmic Vision, this article explains the reasons for its existence, the way it works, the current status of its missions and the involvement of the scientific community.

The need for a long-term plan

Early in 2005, ESA's Huygens probe made its memorable descent through the atmosphere of one of Saturn's moons, Titan, and landed on the surface of the most distant body ever physically visited by a scientific probe. During the descent and for several hours after landing, Huygens returned a wealth of science data to Earth via its 'mother ship', the NASA planetary orbiter Cassini.

Illustration depicting Huygens' landing on Titan. Credit: ESA

Conceiving and executing the Huygens mission took more than 20 years, from the proposal in 1982 through approval in 1988, launch in 1997 and arrival in 2005. The success of this scientific and technological tour-de force was due to the interest and perseverance of the proposing scientists and to the highly creative and ingenious solutions worked out by industry to build a device that pushed the frontiers of space exploration to new limits. None of this – a development time of 17 years, preceded by a long preparatory effort – would have been possible if ESA had not had a long-term space science plan.

Continuation of a successful strategy

Scientists, technologists, national funding agencies, space industry and international partners all relied very heavily on the existence of ESA's long-term plan to build confidence in the success of a project that took two decades to develop. Huygens is by no means an exception in the length of development for a space science mission, which typically take decades to return their final science. The Horizon 2000 plan, which included the Cassini-Huygens mission, was prepared in 1984. Horizon 2000 Plus was drawn up in 1994-1995. Cosmic Vision 2015-2025, created in 2005, is the logical continuation into the next decade of the ESA science planning cycle. Horizon 2000 replaced the previous a la carte style of mission selection by an appetising table d’hôte. At its inception, there was judicious provision for updating the programme with missions still to be chosen. The promise of Horizon 2000 was fulfilled when the astronomy missions Herschel and Planck set off into space in 2009. The second step in this decadal series is Horizon 2000 Plus, which includes the missions Gaia, BepiColombo and the European contribution to the James Webb Space Telescope.