Russia's Soyuz-STA rocket successfully launched from the spaceport at Kourou in French Guiana, carrying the European Sentinel-1B satellite, Russia's space agency Roscosmos said in a statement on Tuesday.
The launch was broadcast live on the website of French space launch company Arianespace.
The Sentinel-1B satellite is part of the Copernicus space mission funded by the European Union to monitor Earth.
The satellite will explore the composition and state of the planet's atmosphere.
Sentinel-1A, the first Sentinel-1 satellite, was launched on a Soyuz rocket from French Guiana in April 2014.
The launch of the Soyuz-STA rocket was delayed several times over the past few weeks.
The launch was initially scheduled for April 12, but was postponed to April 23. After that, it was postponed again twice due to poor weather conditions, according to the TASS news agency.