SpaceX's dearMoon mission has pitted two brothers against each other. One of the siblings said he was shocked to learn they were both competing for a seat on the flight.

• Two British brothers are competing for a seat on SpaceX's all-civilian flight round the moon.
• The pair applied separately, later discovering they'd be competing against each other.
• "I wasn't expecting him to want to go to the moon," said one of the brothers about his sibling.

Sometimes competition is healthy - but perhaps less so when you've unknowingly pitted yourself against your sibling for a chance to take part in a once-in-a lifetime opportunity.

Max and Charlie Denison-Pender are two brothers locked in rivalry for a place on Elon Musk's first civilian flight round the moon, which is slated for 2023. The trip is poised to last six days: three days to get to the moon and loop round the back of it, and three days to return to Earth.

It was first announced in 2018 that SpaceX planned to launch a private passenger named Yusaku Maezawa around the moon.

Earlier this year, Maezawa, a Japanese billionaire, released more details: he would be chartering the flight, now known as the dearMoon project, and was seeking eight people to join him.

He then announced an open competition for people to apply for the tickets. Originally, Maezawa said he would give the seats to artists but is now broadening the search.

The application process is simple and involves filling out a form that asks for basic information like name, email address, and country. It also asks the applicant which of Maezawa's social media accounts they follow.

Eager to acquire a seat on the flight, both brothers entered the competition - separately.

Amid a few giggles, Charlie told Insider: "I wasn't expecting him to want to go to the moon because I've always been the one interested in space. I guess he has too - but unknown to me."

When asked about their rivalry, Charlie said: "We're competitive, but in a very friendly way."

For Charlie, though, entering the competition means more than just traveling on a historic flight round the moon. As a student of aerospace engineering at Brunel University, Charlie has ambitions to transform the future of travel beyond Earth.

"The reason why I'm interested in going on the flight is because one day I hope to start a space airliner," he said.

He added that space travel, in his view, will mimic the nature of commercial travel in the future. He hopes to be one of the first people to contribute to that development. "Going on this trip would provide me with raw inspiration, adventure, but also a first-hand look into the sort of standards that you need to be meeting for commercial space travel," he said.

Meanwhile, Max, an artist, has been hard at work on his end-of-year exhibition. His interest in flying to the moon came as a complete shock to Charlie, given his creative background.

When asked how he'd feel if Max won the seat instead of him, Charlie answered: "I'd be secretly quite annoyed but also very happy for him at the same time."

But such travels are not without risks. There have been several failed landings of SpaceX Starship prototypes, although one did finally land successfully this month. A recent incident involved a rocket exploding upon landing, which sent debris flying in the air.

Also this month, pieces of a runaway Chinese rocket crashed down in the Indian Ocean. Although it was unmanned, it highlighted the dangers of space travel.

But Charlie seems unbothered. "Generally, I'm pretty confident in Elon Musk and SpaceX, because he's been doing groundbreaking things for a long time and throughout the Starship prototypes and the testing, you can see the progress each time," he said.

He added: "I've always been quite adventurous and a bit of a risk-taker so even if there was a risk, I would still do it because I'm passionate about it. So, not too worried about things like that."

As previously reported by Insider, Maezawa said the mission will include 10 to 12 people in total, including the eight civilians he will select.

The crew members will be chosen at the end of June and training will begin shortly thereafter, the website for applications said. Preparation for the mission will last until "lift off," which is scheduled for the first part of 2023.