Doug Hurley was quarantined for his inaugural space shuttle flight when his wife shared the big news: She was pregnant.

"It was a very, very special moment," he said.

It was also fitting for a child, born in early 2010, whose formative years have been contoured by spaceflight. Just a few months after Jack's first birthday, in the summer of 2011, Hurley flew again, piloting the final shuttle flight. And shortly after Jack turned 3, his mom, Karen Nyberg, 44, would spend six months aboard the International Space Station. She returned to Earth on Nov. 10.

"It's been a whirlwind," Hurley said.

Jack's unprecedented upbringing offers rare insight into the lives of astronauts, who have both off-world lives and live very much in the real world of Houston.

While mom flew overhead in space, Hurley took their son to Moody Gardens, put him to bed and arranged for Jack to talk to mommy on a special phone hook-up.

Theirs is a 21st-century story, a very real reminder that astronauts make more sacrifices than just risking death by flying into space.

It also has raised the question, among some, of why a mother left a toddler at home to follow a dream into space.

In interviews, when asked this question, Nyberg has answered that she doesn't believe she'd set a good example for her only child if she gave up on her life goals.

"There are people who have always thought, 'You're a mother. How can you do this?'" said Hurley, 47.

And truth be told, it's not been easy, he said.

"It's been a huge internal conflict for her," he said.

"She struggled with it every day. But how is that different from any woman or man that has a career and has children? I think it sometimes bothers her that she is somehow singled out. Every other man up on the space station has children, too. Why is it different for her?"

Astronaut Chris Hadfield, who commanded the space station prior to the arrival of Nyberg's crew in May, said he believes that Jack will be stronger for the experience.

"It's not easy, especially with such a young child," he said. "But I also think that Karen's son will maybe have a net positive from the experience. Yeah, his mom will be away for awhile. But the experience that his mother is having, the stuff that she is learning, the example that she is setting both for her son and for people all over the world, is tremendous.

"You can't just be completely aimed at your own particular set of circumstances. You need to make a living, and you need to decide the value of what you're doing. And Karen is doing a magnificent job. The pictures she is taking. The way she is connecting with people on Earth. I'm sure she will be as delighted as a human being can be when she's reunited with her son."

She was. And Jack was delighted, too.

The night she returned home he asked his mom to build a space station out of cardboard. They did the next day. During one evening last week, the family appeared well adjusted and catching up on lost time. When Nyberg left Earth, Jack was scribbling. Now he's drawing faces. When she left, he wasn't potty trained. Now he is.

"That's a huge jump," she said. "I missed that whole jump."

Because Hurley is an astronaut also and understands the allure of spaceflight, he fully supported Nyberg's goal to fly so soon after giving birth to Jack.

Mr. Mom

So, after space shuttle Atlantis landed in July 2011 and Hurley and the three other crew members received a heroes' welcome and toured the country, he shelved the rock-star astronaut persona and became Mr. Mom.

Astronauts training for a shuttle mission had it relatively easy. The 12- to 18-month training period was largely based in Houston, allowing them to spend about 90 percent of pre-flight months at home.

For space station astronauts, who fly into orbit aboard a Russian spacecraft, the nearly three years of training requires as much as six months away from home every year.

'Two full-time jobs'

Nyberg was selected in July 2010 for the space station flight. Beginning a few months after Jack's birth, she was on the road for two to six weeks at a time. Sometimes she took Jack to Russia - when Doug was in final preparations for the last shuttle flight - and sometimes he stayed home.

"Literally from the time Jack was old enough to comprehend things, he was either going to Russia or Skyping with mommy. That's just the way it was," Hurley said.

About six weeks after Nyberg reached the station, the length of her longest previous trips out of the country, Jack began asking when she was coming home.

"He did so for two or three days then stopped doing so," Hurley said. "Whatever that little switch in his head was, it told him she should be coming home now. Kids are amazingly perceptive."

And adaptive. Jack adjusted, eventually counting down the time until mommy returned by the number of naps he would have to take.

While it's not always been easy watching Jack alone, Hurley admits, he's quick to add that it's something single parents do every night and military families deal with all the time. Hurley's been lucky to have a nanny and his parents, who have also helped watch Jack.

"Still, it's like having two full-time jobs," he said. "You work all day and then you go home, and you work until you go to bed. And then you work all weekend. The thing that everybody says: You have the weekends to catch up. Well no, on the weekends you're it 24/7 then. It seems like Sunday nights going into Monday mornings. I was gassed."

Family conversations

He laughs, then adds, "A three-day weekend means you've got to come up with an extra day's worth of material, you know?"

Like most toddlers, Jack loves to swim, go to jumping gyms and run around Kemah. When the space station could be seen flying overhead, he'd wave and say, "Hi mommy."

Once a week, Jack also knew he got to see mommy. NASA gave him a special iPad, with an app that let mom, dad and son chat by video every Sunday for 30 minutes or an hour. That's good, Hurley said, because Jack tended to wander around the house rather than stand still and talk. Nyberg could follow him around.

'Definitely priceless'

"Seeing that video, seeing him once a week was definitely priceless," she said last week, after returning home. "But you don't see the real size."

That's not the only upgrade NASA has made to communications. This spring the space agency upgraded the software on the station's internet protocol, or IP phone. No longer is there a one- or two-second lag between phone conversations. Nyberg called her son a couple of times a day.

'A special place'

She also checked in on her husband by phone, and clearly, she appreciated his effort.

Toward the end of her space station trip, Nyberg posted a photo of a hand-knitted Texas flag to the social media website Pinterest with the following note:

"Simply made. In space. A memento for my husband, made with pieces cut from T-shirts I wore during my stay on Space Station, stitched lightly onto a Russian food container liner. We met in Texas, got married in Texas and had our son in Texas. A special place!"