ESA has announced the launch window for its next space telescope, the CHaracterising ExOPlanets Satellite (CHEOPS). The unmanned exoplanet observatory will lift off atop a Soyuz rocket from Europe's spaceport in Kourou, French Guiana, along with a satellite of the Italian Cosmo-SkyMed Earth-observation constellation, between October 15 and November 14, 2019.

Originally slated to fly in 2017, the joint mission by ESA and the Swiss Space Office mission isn't so much an exoplanet hunter as an exoplanet studier. As it sits in Sun-synchronous orbit at an altitude of 700 km (435 mi), CHEOPS will focus its telescope on exoplanets that have already been discovered by Kepler and other missions, with a special emphasis on ones in the super-Earth range. That is, planets are are the same size or larger than the Earth, but smaller than the gas giant, Neptune.

The goal is to study the light curve of the host star that the planet orbits. As the planet passes in front of its star, the characteristic dip in the light will help scientists to better assess such properties as the planet's size, mass, composition, atmosphere, density, and internal structure. Because this requires very precise measurements, CHEOPS will observe several transits of each planet over the course of its mission.

According to ESA, CHEOPS has already completed environmental testing at the space agency's technical center in the Netherlands and is undergoing final tests at Airbus Defence and Space in Spain before delivery to South America.

Source: ESA