The former "Two and a Half Men" star said he was supposed to be on the next Virgin Galactic flight but pulled out years ago,
"When I got married and had kids, my wife basically encouraged (me) that it was not a smart family decision to be heading into space when we have young children. So I ended up selling my ticket back to Virgin Galactic," Kutcher, 43, told financial news streaming site Cheddar News in an interview on Thursday.
"I was supposed to be on the next flight, but I will not be on the next flight," he added.
British entrepreneur Richard Branson and five other Virgin Galactic employees on Sunday took the first fully crewed test flight to space.
In 2012, Kutcher became the 500th person to buy a $200,000 ticket for Branson's space tourism venture, according to Branson's blog at the time.
Kutcher began dating "Friends with Benefits" actress Kunis that year, they married in 2015, and they now have two children.
Kutcher said he hasn't given up plans to get to space.
"At some point, I'm going to space," he said.