Most people Buzz Aldrin's age are ensconced in a nursing home, their travels limited perhaps to an easy visit to the grandkids.
But it should come as no surprise that the second man to walk on the moon is a little different.
He has had trips to the Rio Olympics and the Everest Space Centre in Nepal since the start of August, and in December makes his first visit to the South Pole.
The 86-year-old's place in history was assured more than half a lifetime ago, but his boundless energy has long been focused on the next great space challenge – putting humans on Mars.
His ideas go far beyond a generic support for the mission, instead doing some of the intellectual legwork to help his goal of human colonisation of the Red Planet by 2039 become reality.
And he expects the incoming US president to lead the way, saying he will approach the winner – he has met both Hillary Clinton and Donald Trump previously – soon after November 8 to offer advice.
"July 2019 will be the 50th anniversary of landing on the moon," he said.
"In 2019 we would expect the president to make a commitment within two decades for America to lead international crews to begin to occupy Mars."
He will first visit Australia for a three-city tour, including Canberra, where he will describe his model of cyclical pathways, in essence spacecraft continually cruising between Earth and Mars transporting multiple crews.
His model would first involve assembling bases on the near and far sides of earth's moon, followed by astronauts heading to the Mars moon Phobos, where they would be able to remotely assemble a base on the Mars surface itself.
"Hopefully just one crew at the moon of Mars, for 1.5 – two years, can make the final assembly and can then go and land before the Earth cycler brings in another crew, so we can be landing eight to 12 people every two years at Mars," he said.
The point of it all?
"We're looking for the early signs of life that could have developed on Mars, and it's like the Pilgrims on the Mayflower that came to settle America, this is an expansion of the human race gradually outward to the most habitable location," he said.
"Hopefully others will see this is a challenge of inhabitants of Earth to not just sit here and wait and wonder, but to expand outwards as our technological capabilities can support."
Over time, the asteroid belt between Mars and Jupiter and some of the moons of the bigger planets could be explored by robots and eventually human crews, he said.
The moon, which he stood on for 93 minutes (and was parked on for less than 22 hours) was far from the end of the space connection for the former Korean War fighter pilot.
He has written nine space-related books, most recently a children's work, Welcome to Mars: Making a Home on the Red Planet. Not shy of a celebrity appearance, the first astronaut to hold a doctorate had a brief stint as a contestant on US Dancing With the Stars in 2010, and cameos for The Big Bang Theory and The Simpsons, among many others.
Now a Florida resident, last year he opened the Buzz Aldrin Space Institute at the Florida Institute of Technology, which will harness his Mars vision.
And what is the source of all that energy?
"I think it comes from a mental energy of challenge to use my inventive thinking creating, to be able to envision how things could be more easily or more efficiently accomplished," he said.
Ray Martin will host National Geographic's Mars: The Live Experience, featuring Buzz Aldrin in his first ever ticketed public event in the capital, together with Mars experts from NASA and the European Space Agency on November 7 at Llewellyn Hall in Canberra.