On Saturday, in the early hours of Earth Day, the crew of the International Space Station drifted peacefully above the surface of the Earth at about 17,000 miles per hour. Their task? Capturing Orbital ATK’s Cygnus OA-7 resupply vehicle as it zoomed alongside the space station.

ISS Commander Peggy Whitson and astronaut Thomas Pesquet sat in the Cupola, where they could see the S.S. John Glenn cargo vessel that had caught up to the ISS. From there they operated the station’s 17.5 meter Space Station Remote Manipulator System (SSRMS) robotic arm to gently welcome the craft. In the microgravity environment of Earth’s orbit, the whole scene appears serene and graceful.

But the video belies just how sensitive this operation is, as the astronauts had to precisely aim the arm at the S.S. John Glenn, all while speeding along their orbital path. The mission went according to plan, though, and at 6:05 a.m. Eastern, NASA confirmed that the cargo vessel, which brought 7,600 pounds of supplies and experimental equipment to the ISS, had successfully berthed.

The operation took place 249 miles above the calm blue marble, where protestors took to the streets to demonstrate in the March for Science. A different kind of tension gripped the ISS crew as they guided the massive cargo vessel into berth with the space station.

From the camera on the end of the robotic capture arm, we can see the Cygnus come into view as Peggy Whitson and Thomas Pesquet make contact

The cargo vessel launched on Tuesday aboard a United Launch Alliance Atlas V rocket, and spent three days catching up to the ISS. It finally arrived at the space station early Saturday morning, where the crew welcomed it with open robotic arms.

Peggy Whitson and Thomas Pesquet guided the 17.5 meter Space Station Remote Manipulator System (SSRMS) robotic arm to grab the S.S. John Glenn cargo vessel.

You can watch the whole docking operation, in all its super-slow glory, here from NASA:

Photos via NASA