Pfizer seeks full approval of vaccine Out-of-control Chinese rocket to crash Jupiter's Legacy review Mayweather vs. Paul memes Last-minute Mother's Day gifts Stimulus check updates

This is what boarding the ISS looks like

See Scott Kelly, Gennady Padalka and Mikhail Kornienko board the International Space Station, which two will call home for a full year, and get a warm greeting from crewmates already there.

The International Space Station welcomed three new guests on Saturday, with NASA astronaut Scott Kelly and Russian cosmonauts Gennady Padalka and Mikhail Kornienko making the six-hour flight from Kazakhstan to the ISS. NASA released a 15-minute video of the three men boarding the ISS and being greeted by the crew already onboard.

Kelly, Padalk and Kornienko are part of Expedition 43, a significant expedition that will see Kelly and Kornienko remain on the ISS for a full year to conduct extensive research on the effects of long-term space travel on the human body. Most astronauts spend just six months on the ISS during their expeditions. The research will help NASA and other space agencies better understand the effects of space travel as they begin preparations for manned missions to Mars.

The three new astronauts will join station Commander Terry Virts of NASA and flight engineers Anton Shkaplerov of Roscosmos and Samantha Cristoforetti of the European Space Agency, who will serve as their crewmates for the next several months. Check out the video above, which shows the new crew greeting the old and some touching footage of the crew members talking with their families back home.