Aspiring scientists and space enthusiasts turned out in force for the start of National Science Week in Canberra.

The inaugural Science in ACTion brings families face-to-face with scientists, engineers and mathematicians.

Melville Hall at the Australian National University was transformed into an interactive play area for young children to learn more about research and discoveries.

Matt from Questacon Technology Learning Centre explains what you can learn from toy dissection and rebuilding. ( ABC News: Clarissa Thorpe )

Chair of the ACT Science Week committee Merryn McKinnon said one of the aims was to encourage young people to consider science as a career.

"There's 17 exhibitors, all with some kind of background or interest in science and technology, engineering and mathematics," she said.

"So there's a whole bunch of hands-on experiences for people to really explore or play, and see or do things they would not ordinarily try."

Hands on with one of the oldest rocks in Australia at the National Dinosaur Museum stall at Science in ACTion. ( ABC News: Clarissa Thorpe )

The Manning Clarke Theatre hosted a series of talks on scientific research and development.

A speech by former NASA astronaut Rick Hieb drew a large crowd interested in everything from what it was like to do a space walk, to whether humans will visit Mars.

NASA astronaut Rick Hieb answers questions about spending time in space. ( ABC News: Clarissa Thorpe )

"Not everyone is going to grow up to want to be a scientist or an engineer, but we are living in a society where we need to understand science, or at least to be able to evaluate information to make informed decisions," Dr McKinnon said.