EChO - Exoplanet Characterisation Observatory

http://sci.esa.int/science-e/www/area/index.cfm?fareaid=124

A 1 metre class telescope to measure the visible and IR properties of transiting extrasolar planets.

The scientific case for the EChO Mission:

http://www.ias.u-psud.fr/pperso/pborde/publications/tinetti_2012_exa.pdf

A lot of science attainable, the most exciting being the characterization of Super-Earths around bright stars, including Earth-sized objects in the habitable zone around M-dwarfs; additional benefits include atmospheric studies of Hot Jupiters orbiting around stars as faint as V=15, exoplanets phase variations and search for exo-moons down to 1/3 Earth radii.

EChO Open Science Workshop being organized next July:

http://www.echo2013.net/

On the potential of the EChO mission to characterise gas giant atmospheres
http://arxiv.org/abs/1212.5020

Expected results for the cases of hot and warm Jupiters orbiting a sunlike star at 35 pc, and for a hot Neptune orbiting an M-dwarf at 6 pc.

http://arxiv.org/abs/1305.3089

Characterizing Exoplanets in the Visible and Infrared: A Spectrometer Concept for the EChO Space Mission

Transit-spectroscopy of exoplanets is one of the key observational techniques to characterize the extrasolar planet and its atmosphere. The observational challenges of these measurements require dedicated instrumentation and only the space environment allows an undisturbed access to earth-like atmospheric features such as water or carbon-dioxide. Therefore, several exoplanet-specific space missions are currently being studied. One of them is EChO, the Exoplanet Characterization Observatory, which is part of ESA's Cosmic Vision 2015-2025 program, and which is one of four candidates for the M3 launch slot in 2024. In this paper we present the results of our assessment study of the EChO spectrometer, the only science instrument onboard this spacecraft. The instrument is a multi-channel all-reflective dispersive spectrometer, covering the wavelength range from 400 nm to 16 microns simultaneously with a moderately low spectral resolution. We illustrate how the key technical challenge of the EChO mission - the high photometric stability - influences the choice of spectrometer concept and drives fundamentally the instrument design. First performance evaluations underline the fitness of the elaborated design solution for the needs of the EChO mission.

I hope it will be next ESA's choice...

http://arxiv.org/abs/1502.05747

The EChO science case

EChO (Exoplanet Characterisation Observatory) has been designed as a dedicated survey mission for transit and eclipse spectroscopy capable of observing a large and diverse planet sample within its four-year mission lifetime. EChO can target the atmospheres of super-Earths, Neptune-like, and Jupiter-like planets, in the very hot to temperate zones (planet temperatures of 300K-3000K) of F to M-type host stars. Over the next ten years, several new ground- and space-based transit surveys will come on-line (e.g. NGTS, CHEOPS, TESS, PLATO), which will specifically focus on finding bright, nearby systems. The current rapid rate of discovery would allow the target list to be further optimised in the years prior to EChO's launch and enable the atmospheric characterisation of hundreds of planets. Placing the satellite at L2 provides a cold and stable thermal environment, as well as a large field of regard to allow efficient time-critical observation of targets randomly distributed over the sky. A 1m class telescope is sufficiently large to achieve the necessary spectro-photometric precision. The spectral coverage (0.5-11 micron, goal 16 micron) and SNR to be achieved by EChO, thanks to its high stability and dedicated design, would enable a very accurate measurement of the atmospheric composition and structure of hundreds of exoplanets