The Sentinel-1 mission is designed as a two-satellite constellation. Each satellite carries an advanced radar instrument to provide an all-weather, day-and-night supply of imagery of Earth’s surface.
The launch
Date: 03 April 2014 - Sentinel-1A
25 April 2016 - Sentinel-1B first half of 2023 - Sentinel-1C
Site: Kourou, French Guiana
Rocket: Soyuz rocket for Sentinel-1A and -B Vega-C for Sentinel-1C