Katherine Bennell-Pegg grew up on Sydney's northern beaches with her feet in the ocean and her head in the stars.
Her childhood dream was to become an astronaut.
Now the engineer and mum of two has made that dream a reality, becoming the first astronaut to graduate under the Australian flag.
"When I grew up in Australia we didn't have a space agency, let alone a human space flight program," she told AAP.
"I had the astronaut dream but I never believed I'd have the chance to do it, while representing Australia, so for me this is the hugest honour."
Australians Andy Thomas and Paul Scully Power both travelled to space as American citizens.
There has never been an Australian woman in space.
Dr Thomas, a retired NASA astronaut, congratulated Ms Bennell-Pegg on her graduation.
"Now you are ready to make the next giant leap as you boldly go where no Australian woman has gone before," he said.
Ms Bennell-Pegg started her training with the European Space Agency in Germany in April 2023.
She was one of six astronauts who graduated from the program on Monday.
The rigorous program takes astronauts through low-gravity flights, robotics, scientific experiments, survival, medical and centrifuge training.
Ms Bennell-Pegg said one of the most memorable exercises was the centrifuge training.
"We get put into a little capsule in the dark and we go through the full g-force profile over a launch and return," she said.
"You just feel this crushing force ... you can imagine yourself in a rocket, on the capsule coming back and you know you can handle that and its effects.
"I was pretty dizzy afterwards - I may have walked into a pole."
Now that she has graduated with her basic training certification, Ms Bennell-Pegg is qualified for missions to the International Space Station, although there are no space missions planned for her yet.
"I would be honoured to represent Australia in space should I ever get the chance," she said.
"It's a really exciting time to be involved in space flight so the future is open, and I'm optimistic, but one step at a time."
Ms Bennell-Pegg is a director of space technology at the Australian Space Agency.
She said she would return to Australia in mid-2024 and hoped to inspire the next generations of children who, just as she had, dreamed of going into space.
"I want to be able to go into schools and tell kids an astronaut dream is a legitimate dream and to dream big," she said.
The head of the Australian Space Agency Enrico Palermo said the organisation was proud of Ms Bennell-Pegg and glad to welcome her back as a fully qualified astronaut.
"Katherine will return to Australia a qualified astronaut brimming with knowledge, insights and connections that will help generate global opportunities for our industry - driving more innovation and economic development here at home," he said.
