Enlarge Image NASA/Anne McClain

"The dawn of a new era in human spaceflight," NASA astronaut Anne McClain tweeted Sunday, along with a breath-taking image.

The photo, which she captured as the SpaceX Crew Dragon capsule approached the International Space Station to dock for the first time, sums up the wonder of the history-making test mission.

The dawn of a new era in human spaceflight pic.twitter.com/BHsfg1zYLN — Anne McClain (@AstroAnnimal) March 3, 2019

McClain's artistic view reveals the curved horizon line of the Earth with the Crew Dragon perfectly positioned as a shadow against the glow.

This has been a weekend full of space firsts as NASA's Commercial Crew Program took a big step toward launching astronauts from US soil for the first time since the space shuttle program ended in 2011.

The three current ISS crew members entered the SpaceX capsule in space for the first time on Sunday as part of the SpaceX Demo-1 test mission, which itself was crew-less.

While NASA broadcast video of everything from the launch to the docking, McClain's image of the capsule nearing the ISS should stand out as one of the most memorable documents of the Demo-1 test flight. It's a beautiful photo that ties together all the pieces of the mission: Earth, Crew Dragon and the ISS.

Crew Dragon is scheduled to spend a total of five days docked at the ISS before returning to Earth to land in the Atlantic Ocean. If all goes well with the remainder of the mission, then NASA and SpaceX will look to send actual humans to space as early as mid-year.