While not as dramatic or visually striking as the launch, docking the spacecraft was a difficult and potentially dangerous part of the mission, one the astronauts train for extensively.
Flight controllers at SpaceX headquarters and NASA mission control in Houston spent the day communicating with the astronauts on board SpaceX’s Crew Dragon, preparing them for the docking, which appeared to proceed flawlessly
“Yesterday was about the raw power of a rocket flinging a capsule,” NASA flight director Anthony Vareha wrote on Twitter Monday morning. “Today I get to preside over a ballet. The delicate dance of ‘how do you gently put this capsule at a certain spot within a few millimeters.’ It’s easy to throw. Catching is harder.’”
Especially in orbit.
The space station is traveling at 17,500 mph, and circles the Earth every 90 minutes. Since its launch at 7:27 p.m. Sunday, the Dragon capsule, dubbed “Resilience” by the crew, had been chasing it down, burning its engines to align itself. It approached slowly, passing through a series of “waypoints” where controllers monitored conditions and allowed the spacecraft to proceed only if it was safe and all systems were operating correctly.
On board the spacecraft were three NASA astronauts, Hopkins, Shannon Walker and Victor Glover as well as Japanese astronaut Soichi Noguchi. They ended their eight-hour sleep time shortly after noon and reported being in good spirits in the climate-controlled cabin, where the spacecraft was being kept at 75 degrees.
“It was a very nice night on board Resilience,” Hopkins told the ground.
Leading up to the docking, NASA and SpaceX officials said that while the launch went well the mission was far from over.
“We’re not done yet. We need to keep going,” Kathy Lueders, the director of NASA’s human spaceflight directorate, said during a news conference after the launch Sunday evening. “That spacecraft is out there with those precious crew members on it, and we’re going to get them to the International Space Station.”
While the docking was meant to be handled by the spacecraft’s computers, the crew could have taken over the controls at any time and manually fly the spacecraft. That was not necessary, however, and the Dragon docked itself without any problems.
The mission is the first time a privately owned and operated spacecraft certified by NASA to fly humans has made the trip. The May mission, when a pair of NASA astronauts spent two months on the station before coming home, was considered a test flight.
This time, however, the Crew Dragon spacecraft has been certified for human flight and the mission is the first of a series under NASA’s commercial crew program. The four-member crew is expected to be on board the station for about six months.
Below are the updates from the SpaceX’s ISS docking.