An adorable photo shows 9 astronauts and cosmonauts hanging out in the International Space Station. Here's why the orbiting lab is so crowded.

ESA

ESA astronaut Luca Parmitano tweeted this image of the team gathered for a celebratory dinner in the Russian Zvezda module, the food preparation area of the International Space Station.

• The International Space Station is unusually crowded this week because the station command is changing hands.
• On Tuesday, the nine people onboard crowded into a corner to snap a photo.
• The group won't be together for long, though - three of the astronauts will return to Earth on Thursday.
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Nine people crowded into a corner of the International Space Station on Tuesday to snap an adorable photo.

The orbiting laboratory normally hosts a crew of three to six astronauts, but this week it's unusually crowded because the station is switching command. Russian cosmonaut Alexey Ovchinin, the station commander, handed over that role to astronaut Luca Parmitano on Wednesday morning.

Ovchinin will board a spaceship back to Earth on Thursday, along with with astronauts Nick Hague and Hazza Al Mansouri. The three are scheduled to parachute into Kazakhstan at 5 p.m. local time.

Meanwhile, Al Mansouri - the first astronaut from the United Arab Emirates - arrived at the ISS on Friday (he's just visiting briefly) with astronaut Jessica Meir and cosmonaut Oleg Skripochka. A shuttle with four tons of supplies followed them the next day.

The crew that's staying onboard will gear up for a record 10 spacewalks in just three months.

In the bottom row of the big group photo, Ovchinin sits on the far left, followed by Parmitano (hanging upside-down), Hague, Al Mansouri, Meir, and Skripochka. Up top, astronauts Christina Koch and Andrew Morgan hover, with cosmonaut Alexander Skvortsov on the far right.

The t-shirts they're all wearing commemorate their "space band," called "Kryk Chayky" or "the cry of the seagull," Parmitano said in a tweet on Tuesday.

ESA/NASA

The crew of the International Space Station usually consists of six people at most. This is the group that was there before the arrival of three people on Friday.

Parmitano, Hague, and Ovchinin are all celebrating their birthdays this week, and Koch completed her 200th day in space on Monday. When she leaves the space station in February 2020, she will hold the record for the longest spaceflight by a woman.

This isn't the largest group of people the space station has ever held - a record 13 people have been onboard together several times during crew changes and shuttle re-supplies, according to Space.com.