The ANU graduate, formerly of Kaleen, is the team lead for the flight software that manages all the science instruments on the Mars rover Curiosity, which is due to reach the red planet at 3.15pm today, Canberra time.

He has been involved in designing the instrument command sets, spacecraft commands and fault recovery behaviours. Curiosity will be searching for the building blocks of life on Earth's near neighbour.

The crucial seven minutes starts when the spacecraft reaches the top of the Mars atmosphere, going about 23,000km/h, and ends when it lands.

''[It] comes in like a blazing meteorite, slowing to zero velocity just as it reaches the Martian surface,'' Schoppers says.

It takes 15 minutes for radio signals to get from Earth to Mars, and another 15 minutes for signals to get back, so there is nothing anyone can do if something goes wrong. That is why it is so terrifying. The many thousands of scientists and engineers who have spent years of their lives working on the rover can only hold their breath, cross their fingers and hope for the best as their baby plummets towards Mars.

Funnily enough, as a teenager, Schoppers would go swimming and walking around the Cotter River, and yet he never knew the Canberra Deep Space Communication Complex at Tidbinbilla was nearby. For him, the thrill has always been to invent and discover things, and to build things that work. But space enthusiasts the world over will be joining him in those agonising minutes before he knows if this, the biggest of discovery projects, works.

Staff at Tidbinbilla are expecting hundreds to turn out today to follow the mission on a big screen.

Canberra will serve as the main tracking station for Curiosity's landing, as one of three tracking stations in NASA's deep space network, which also includes similar facilities at Madrid, Spain, and at Goldstone, California.

Three of Tidbinbilla antennas, a 70-metre dish and two of 34 metres, will receive signals from the $2.6 billion rover.

Former soldier, now tree surgeon, photographer and amateur astronomer Barry Armstead is so enthusiastic about space, he is building an observatory in the front yard of his suburban home in southern Canberra.

Armstead will likely be up a tree working when NASA's rover Curiosity is due to land on Mars, but he will be hanging out for news of its safe arrival.

''I'll be coming home to check on it straight away,'' he says. News of the landing should arrive about 3.31pm here, or 10.31pm Sunday night in Pasadena, US.

The moment has been a long time coming for Schoppers, who migrated to Australia with his parents when he was eight and moved to Canberra with his mother, Martha, and brother, Andrew, when he was about 16.

The family struggled financially. They lived in government housing and Schopper's mother worked as a cleaner. But Schoppers won a scholarship to ANU, where he completed a Bachelor of Science, focusing on a different subject each year, including physics, applied mathematics, computer science and artificial intelligence.

After a brief stint in the public service, Schoppers wanted to do further study on a kind of artificial intelligence that was not then practised in Australia. However, he was rejected by all the US universities that he applied for, so he did a Master of Science degree at the ANU and reapplied. His determination paid off, and in August 1981, aged 23, Schoppers left Australia for a position at the University of Illinois/Urbana-Champaign.

''I felt like Columbus setting off across the vast ocean blue, not knowing what he'd find or if he'd ever come back,'' he says.

Schoppers started out in the US defence industry, where he spent most of his time working for NASA, then moved to contract work for them. In 1998, he joined NASA's Jet Propulsion Laboratory as a researcher and then moved into engineering. Much of his career has ties with NASA. However, at one point Schoppers considered a move to Silicon Valley during the dotcom boom after feeling disheartened by the cancellation of an earlier Mars mission he had been working on.

He was offered a job, but sensed something was not right. ''I thought, there's something very wrong with this, it feels like the gold rush of the 1850s,'' he says. The dotcom bubble burst and four months later that company had disappeared.

Instinct kept him from leaving NASA, and it paid off. Schoppers has spent seven years working on the rover, and on the day after touchdown he will be back on board as part of the operations team, using all he knows about the software to diagnose any problems with the rover's science equipment. It will be tough going.

Mars days are 25 hours long, so he will start work an hour later each day, until he is starting in the middle of the night and attempting to sleep through the day. But he knows that NASA may not build such a large rover again in the near future, and he says it is ''the accomplishment of a lifetime''.

''I went to Florida to wave it goodbye [to Curiosity], and as it roared off into the sky I found myself in tears, looking back across the years, my long trek around the globe starting with my parent's decision to move to Australia, my instinctive motivation to learn what I needed for this role and the spectacular team of people I work with … I consider myself a fantastically fortunate little boy.''