Before NASA sent astronaut Scott Kelly into space for the first time in 1999, his commander gave him a unique but crucial instruction: take a space diaper home and practice with it.

Thus, Kelly found himself in his bathtub with his legs raised, donned in a government-issued space diaper, attempting to replicate the position he would take in the Space Shuttle. After years of avoiding mishaps, he had to retrain himself to relax and let go — quite literally. In due time, he mastered the technique. Later, as mission commander, he advised his crew to do the same: go home and practice. However, not everyone took this suggestion seriously. One male astronaut declined — and came close to needing a catheter in space.

“Being an astronaut carries significant pressure,” Kelly stated to Mashable, highlighting that the job’s physical and mental challenges can be overwhelming.

This experience partly inspired Kelly to team up with Goodnites, a brand producing disposable nighttime underwear for children. He viewed this partnership as a way to help alleviate the stigma surrounding bedwetting — a concern that impacts one in four 5-year-olds, one in five 7-year-olds, and one in 20 10-year-olds, as noted by the American Academy of Pediatrics.

“Kids have a lot going on,” remarked Kelly, a father to two. “If this makes some of them feel less ashamed, I’m fully on board.”

SEE ALSO: Yes, NASA astronauts will still pee in their new spacesuits

It’s well known that astronauts wear diapers. The subject gained widespread attention in the mid-2000s, largely due to former astronaut Lisa Nowak — but that’s a tale for another time.

Although toilets are available on the Space Shuttle and the International Space Station, there are moments when astronauts cannot access them. During launches, landings, and spacewalks — which can extend to eight hours — astronauts are secured in their seats or confined within their suits. Maintaining hydration is critical, but holding it for that duration can be unfeasible.

This necessity is why diapers, or more specifically, Maximum Absorbency Garments (MAGs), are essential. MAGs, developed in 1988, utilize a super-absorbent polymer that transforms liquid into gel, effectively handling waste. The inclusion of female astronauts prompted enhancements, as earlier urine collection systems were tailored for men and did not suit female anatomy well.

NASA has even given away unused MAGs to the National Air and Space Museum, illustrating their importance in space exploration.

Kiona N. Smith, author of Peeing and Pooping in Space, states that curiosity about these bodily functions in space is normal. “As silly as the questions and answers may sound,” she told Mashable, “it reflects a human instinct to inquire, ‘OK, but how does this happen?’”

Goodnites’ recent campaign, “Mission Dry,” debuted last month and includes a commercial featuring Kelly alongside a young space enthusiast. In the advertisement, the child becomes distracted during a spacewalk because he has soiled his suit and fears mockery from mission control.

“Houston’s probably laughing,” the child remarks.

“They’re not laughing,” Kelly responds.

“How can you tell?”

“Because I just peed.”

“You just did?”

“Right now.”

Kelly, who spent 520 days in space before retiring, received compensation for his involvement. Though NASA does not endorse commercial products, he is not the only astronaut backing the campaign. Retired astronaut Cady Coleman and others with spaceflight backgrounds have also shared their support.

“During one of my missions, I had to pee in my suit — and everything went perfectly,” Coleman said in an Instagram reel. “My suit was clean and dry, prepared to go, and so was I.”

NASA has used the same spacesuit technology for more than forty years, but Axiom Space is now creating a new suit for the Artemis III mission — the first crewed moon landing since 1972. The new suits will include advancements such as dust-resistant materials, a compact life support system, and HD cameras. However, one aspect will remain unchanged: astronauts will still utilize MAGs.

“If it’s not broken, don’t fix it,” remarked Russell Ralston, deputy program manager for extravehicular activity at Axiom Space. “They are a highly effective solution. Sometimes simplicity is optimal.”

This means the legacy of relieving oneself on the moon — initiated by Apollo 11’s Buzz Aldrin — will persist. As author Smith pointed out, Aldrin stepped onto the lunar surface and instantly recognized the need to go. Thus, while he was making history, he was also using his urine collection device.

A fitting reminder that even in space, nature still makes its demands.