Europe’s Sentinel 3B environmental satellite was shipped to the Plesetsk Cosmodrome in Russia’s far northern Arkhangelsk region in March for a month-long campaign to prepare the spacecraft for liftoff aboard a Rockot launcher.
The remote military base, nestled in a forest around 500 miles (800 kilometers) north of Moscow, is Russia’s primary launch site for satellites heading into polar orbit.
The 95-foot-tall (29-meter) Rockot booster, derived from the Soviet-era UR-100N, or SS-19, ballistic missile, will send the Sentinel 3B satellite into orbit at 1757:38 GMT (1:57:38 p.m. EDT). The satellite, built by Thales Alenia Space, weighs approximately 2,600 pounds (1,200 kilograms) fully fueled for launch.
Sentinel 3B carries four instruments to track changes in the oceans, chart vegetation growth, detect pollution and wildfires, and measure sea level and the thickness of polar ice sheets.
The Copernicus Earth observation network is the world’s most ambitious environmental satellite fleet, and Sentinel 3B is the seventh spacecraft to launch in the multibillion-euro program, which is funded by the European Commission, the European Union’s executive body.
The spacecraft arrived at the Plesetsk Cosmodrome on March 18 after shipment from its factory in Cannes, France, via an Antonov An-124 cargo plane. After its arrival at Plesetsk, Sentinel 3B was unpacked, tested, fueled, mated with its Breeze KM upper stage, encapsulated inside its payload fairing, then transported to the Complex 133 launch pad for lifting atop the Rockot booster.
These photos show the satellite’s preparations at Plesetsk.
The 60 satellites SpaceX is set to launch Wednesday night, beginning the build-out of a broadband network of orbiting spacecraft that could eventually number thousands, are based on a new flat-panel design, with krypton-fueled plasma thrusters, high-power antennas, and a capability to autonomously steer away from other objects in space.