Before NASA's talented astronauts launch into space, they pose for an official photo shoot.

Most astronauts play it safe: They crawl inside a custom-fit spacesuit, smile for the camera, then get back to their rigorous training. Some, however, choose to bring family, friends, and even pets along for the fun.

During a portrait session by NASA in August 2017, Anne C. McClain — a member of the 21st astronaut class, a decorated US Army Major, an attack helicopter pilot, an aerospace engineer, and a mother — brought her preschool-age son.

"The hardest part about training for space is the 4 yr old I have to leave behind every time I walk out the door," McClain tweeted in March 2018.

McClain arrived at the International Space Station (ISS) on Monday at 12:33 p.m. EST aboard a Russian spacecraft called Soyuz . But at the time of her tweet, McClain was responding to Abby Wambach, a professional soccer player and fellow mom who was seeking support in maintaining a work-life balance.

"I try to remember he will grow up and know what it looks like, behind the scenes, to pursue a dream. He is my 'why,'" McClain said.

The successful mission that McClain just participated in was vital in restoring access to the space station , since NASA has no spaceship and the previous Soyuz mission in October failed in mid-flight . (An automatic emergency escape system carried the crew to safety .)

McClain will now stay on the ISS until June 2019.

In her Twitter thread, McClain posted photos of herself in a spacesuit next to her young son. A representative at NASA's Johnson Space Center told Business Insider that the pictures were taken by photographer Bill Stafford.

Here are the heartwarming images McClain shared, and what her son thinks it's like to have a mom who's an astronaut.

This story has been updated. It was originally published on March 13, 2018.

"[S]ometimes, I bring him to work with me. Not sure who enjoys it more!" McClain said in March when she shared this image.

Bill Stafford/NASA

Source: Twitter

When a Twitter user asked McClain whats more difficult — staying or going — she responded: "No easy answer there."

Bill Stafford/NASA

Source: Twitter

"One provides immediate comfort, the other achieves not only lifelong goals but also teaches lifelong lessons. Gotta play the long game here," she said. "But it doesn’t make missing out on waffles with the kiddo in the morning any easier. Most parents can relate."

Bill Stafford/NASA

Source: Twitter

McClain told a BART-train-driving Twitter user that her son "would trade me for a train driver without a second thought."

Bill Stafford/NASA

Source: Twitter

"He thinks its pretty normal" to be an astronaut, she said. "His teacher asked their class what their parents did, and he told her I am an engineer. I asked if he told her anything else. He responded, Mama, NONE of my friends have ever met an engineer...."

Bill Stafford/NASA

Source: Twitter

McClain isnt the only astronaut to get adventurous with her NASA photo shoots. Former astronaut Leland Melvin, who used to fly aboard the space shuttle, brought his rescue dogs Jake and Scout.

NASA

Source: Gizmodo

But NASAs portraits didnt show the Sokol flight suit that McClain actually wore when she launched to the ISS aboard a Russian Soyuz spacecraft.

Anne McClain/NASA

McClain tweeted this photo of the suit in March, saying: "[O]ne day you come to work and see this, and you realize it is not a costume. It is real. Not for training. An actual space suit — and it's going to actual space. And it has your name on it. 😳"

"[Y]ou have to try out said suit for nearly two hours while pressurized to make sure nothing hurts," McClain said on Twitter. "Well, that nothing hurts too badly. Mission accomplished. My first act in my new real spacesuit was to sit and watch a movie! Oh and play with my gloves."

NASA

Source: Twitter

On Monday, McClain rocketed to the space station with her Expedition 58 crewmates: cosmonaut Oleg Kononenko and astronaut David Saint-Jacques.

Dmitri Lovetsky/AP

After about six hours of flight, the crew safely docked with the space station.

NASA TV

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