The European Space Agency (ESA) has confirmed that its next ‘large’ (L-class) mission, dubbed L2, will be an X-ray telescope investigating the “hot and energetic Universe”.
At a meeting in Paris yesterday, the agency’s Science Programme Committee selected the theme on the basis of the recommendation of ESA’s director of science and robotic exploration, Alvaro Giménez, reported in Nature earlier this month.
Scheduled for launch in 2028, the L2 project will investigate how gas evolves into galaxy clusters and how black holes grow and shape the Universe. The exact mission will be selected through a call next year, with the Advanced Telescope for High-energy Astrophysics (Athena+), the mission outlined alongside the theme, a clear forerunner.
At the same meeting the committee confirmed “the gravitational Universe” as the theme for the following L-class mission, L3, in 2034, meaning advocates for space-based gravitational wave astronomy, a field never before attempted in space, will have to wait another two decades for their observatory.
Its associated mission, the evolved Laser Interferometer Space Antenna (eLISA), would detect the gravitational waves that are thought to stretch the fabric of space-time, opening a new window on the Universe outside the electromagnetic spectrum. A pathfinder mission to test the necessary technology for the observatory — which would eventually hope to detect signals from colliding supermassive black holes and the early Universe — is set to fly in 2015 after several years of delays.
The L2 and L3 science themes were chosen from 32 proposals that the European science community had put forward since March. Total costs for the two selected will be in the order of €2 billion (US$2.7 billion).
ESA’s first L-class mission of its current programme, the Jupiter Icy Moons Explorer (JUICE), was approved last year and is set for launch in 2022.
(Additional reporting by Quirin Schiermeier)