NASA has unveiled incredible health findings after comparing an astronaut who spent 340 days in space to his twin brother on Earth.

Scott and Mark Kelly are twin brothers who have both had careers as astronauts with NASA.

While both spent time among the stars, Scott was selected for a historic mission in March 2015 - spending an incredible 340 days in orbit aboard the International Space Station (ISS) alongside Russian cosmonaut Mikhail Kornienko.

Over the course of nearly a year, Scott and the ISS crew conducted almost 400 experiments, helping scientists understand how space affects the human body, a critical step in planning for future deep-space missions, including trips to Mars.

While Scott spent nearly a year in orbit, his twin brother Mark Kelly, a former NASA shuttle commander, remained on Earth.

Their identical genetic makeup provided NASA with a perfect control subject, allowing scientists to compare the effects of space on the human body.

Both twins underwent extensive medical tests before, during, and after Scott’s mission. These included blood, urine, stool, and saliva tests, vision and cognitive assessments, and physical performance evaluations.

The results, published in "The Twin Study," revealed some surprising findings:

1. Scott’s body adapted well to space

Despite spending nearly a year in microgravity, Scott did not develop any major long-term health issues linked to prolonged space travel. His immune system remained stable, and stress levels returned to normal shortly after landing.

2. Unexpected telomere changes

One of the biggest surprises involved telomeres - the protective caps at the ends of DNA strands that typically shorten with age.

However, in Scott’s case, his telomeres actually lengthened while in space. Since telomeres are linked to aging and diseases like cancer and heart conditions, this unexpected result left scientists stunned.

Steven Platts, deputy chief scientist with NASA’s Human Research Program, was impressed by the findings.

“The results we’ve seen… show the resilience and robustness of the human body,” Platts explained. “We’ve evolved here on Earth in a one-(gravity) environment, we grow up, we train, we do everything here, and yet, when we go into space… our bodies adapt and continue to function and, by and large, function extremely well.”

Most of Scott’s bodily changes returned to normal shortly after landing, except for a few markers that scientists had already expected to see in astronauts.

“This will guide future biomedical space research and allow us to have a safer journey to and from Mars,” Platts concluded.

Featured image credit: Michael Stewart / Getty

NASA astronauts Barry "Butch" Wilmore and Sunita "Suni" Williams have returned to Earth after what was supposed to be an eight-day mission turned into nine months in space.

With their return to Earth, Wilmore and Williams will have spent approximately 285 days in space, making them the sixth longest-serving NASA astronauts for a single mission.

Their time in space is just shy of Peggy Whitson’s 289-day record, while Frank Rubio holds the longest NASA spaceflight record at 371 days, per the New York Post.

During their time in space on this mission, they completed 4,576 trips around Earth.

However, their extended stay aboard the International Space Station (ISS) has taken a toll on their bodies, as seen in before-and-after images that highlight the physical effects of prolonged exposure to space.

The Physical Toll of Nine Months in Space

As reported by BBC News, the two astronauts splashed down safely in the Gulf of Mexico on March 18 and were immediately stretchered away — a standard procedure for astronauts returning from long missions in microgravity.

In images from their arrival back on Earth, Wilmore and Williams appear thinner and visibly weaker than when they first launched in June 2024.

Before their departure, the pair were photographed looking fit and prepared for their expected short-term mission. Now, their post-mission images serve as a stark reminder of how space travel affects the human body. Take a look below:

What Happens to the Human Body in Space?

Per the BBC, spending time away from Earth’s gravity causes significant physical changes:

Loss of muscle mass and bone density: For every month in space, astronauts lose about 1% of their bone density. After nine months, Wilmore and Williams have likely experienced considerable weakening in their bones and muscles.

Weakened cardiovascular system: Their hearts will have become weaker because they haven’t needed to work as hard to pump blood in microgravity.

Changes to vision: Spaceflight alters the shape of the eye, often leading to deteriorating eyesight for returning astronauts.

Psychological effects: These can include anxiety and depression, due to prolonged isolation in a confined space.

Fluid buildup in the head: Without gravity pulling fluids downward, astronauts often experience a "stuffy head" feeling, similar to having a cold.

Increased radiation exposure: While NASA scientists expect most DNA damage from cosmic radiation to repair itself within a few months, long-term exposure remains a major concern.

Former NASA astronaut Terry Virts has recently described his own struggles upon returning from the ISS and shared what Williams and Wilmore are likely to experience.

“For me, I felt two things: I felt really heavy and really, really dizzy," he said. Virts added that it took time for his sense of balance to fully recover.

NASA astronaut Leroy Chiao explained on NewsNation Prime that the returning crew may experience a painful condition known as "baby feet"

"You basically lose the thick part of the skin on your feet. You kind of have baby feet when you come back," Chiao said.

This transformation makes walking painful and uncomfortable until the skin toughens up again — a process that can take anywhere from a few weeks to a couple of months.

Chiao also echoed Virts' comments regarding severe dizziness and balance disruption. “To me, it feels kind of like having the flu. It takes a couple of weeks to get back to normal,” he said.

Despite the toll Williams and Wilmore have put their bodies through, Joel Montalbano, Deputy Associate Administrator of NASA's Space Operations Mission Directorate, hailed the work they performed in space, saying: “Suni and Butch did 150 experiments and 900 hours of research during their stint on the ISS.”

Montalbano added that the work carried out "benefits the nation" and increases the chance that NASA will be successful in hitting its goal of landing a person on Mars by the end of the decade.

Adjusting Back to Life on Earth

Rehabilitation is now a crucial part of Wilmore and Williams' recovery. They will undergo weeks of physical therapy to regain strength and mobility.

NASA reportedly has a strict post-space rehabilitation program designed to help astronauts gradually reacclimate to Earth’s gravity. This includes:

• Gradual walking reintroduction, starting with soft surfaces
• Strength training and cardiovascular exercises to rebuild muscle and bone density
• Balance training to restore coordination
• Psychological support to help astronauts adjust mentally

Though their extended stay fueled speculation and political controversy, NASA officials have repeatedly denied claims that the astronauts were "stranded" in space.

NASA Administrator Bill Nelson defended the decision to return the Starliner to Earth unmanned in September 2024, stating: "Spaceflight is risky, even at its safest and most routine. A test flight, by nature, is neither safe, nor routine.

"The decision to keep Butch and Suni aboard the International Space Station and bring Boeing’s Starliner home uncrewed is the result of our commitment to safety: our core value and our North Star."

Despite these challenges, their extended mission provided valuable data on the long-term effects of space travel — information that will be essential for future missions to the Moon and Mars.

NASA will continue monitoring the astronauts' recovery, but their return highlights both the incredible resilience of the human body and the challenges of deep-space exploration.

Featured image credit: Joe Raedle / Getty

NASA astronauts Butch Wilmore and Suni Williams may have made it back to Earth, but their bodies are still feeling the impact of nearly 10 months in space.

After a staggering 286 days aboard the International Space Station, the duo has just wrapped up an intense round of physical therapy—but the pain hasn’t let up.

The mission, originally set to last far less, turned into a high-stakes waiting game after Boeing's Starliner spacecraft failed to bring them home.

That left Wilmore, 62, and Williams, 59, stuck in orbit until NASA could arrange a rescue. They finally returned in March, but the real battle began after splashdown.

Physical therapy: Two hours a day, every day

Since returning, Wilmore and Williams have been grinding through at least two hours of strength and conditioning daily. Their main goals? Regain lost muscle mass, adjust to Earth’s gravity, and stop their bones from deteriorating further.

Despite the hard work, Wilmore admitted he’s still not fully healed.

"Gravity stinks for a period, and that period varies for different people," he told Reuters, candidly acknowledging the pain that lingers in his back.

His first public appearance after rehab, on May 22, showed a visibly thinner version of the astronaut, with facial changes that turned heads.

Fatigue, pain, and a brutal reentry to Earth life

Williams, too, struggled through recovery. The physical toll of zero gravity left her so depleted that getting out of bed became a major task.

"It's been a little bit of a whirlwind," she told Reuters, pointing to their ongoing work with NASA’s Commercial Crew Program and Boeing’s troubled Starliner mission.

She described months of disrupted sleep and extreme fatigue, revealing how long it took before she felt normal again.

"Then I'm up at four in the morning, and I'm like, Aha! I'm back," she recalled of her sudden shift back to her usual early bird routine.

Photos from their landing showed Williams looking noticeably greyer, a visual that shocked many. Thankfully, after weeks of rehabilitation, she’s regained her color and energy.

The mission that went wrong

Their long stay in space wasn’t part of the original plan. The duo launched in June 2024 as the first crew aboard the Boeing Starliner, but technical malfunctions grounded their return. They ended up waiting nearly a year for NASA to get a backup ride ready.

"I knew we were going to get home at some point in time. We just got to wait for the right ride and make sure everybody's all good with that and we'll get home," Williams told WFAA.

Even after landing off the coast of Florida, the pain didn’t let up. Wilmore recalled the discomfort hitting almost immediately.

"We're still floating in the capsule in the ocean, and my neck starts hurting, while we still hadn't even been extracted yet," he said.

"I still got a little twinge in one spot in my back after a couple of months."

Life in space isn’t all stars and science

It wasn’t just the physical stress. Wilmore admitted that the mental toll of being crammed in the ISS with three other people for nearly a year also took its toll.

"You're thrown together day and night seven days a week at 24 hours a day, and just like any family there's a point where something rubs you the wrong way or something—that happens anywhere," he said.

But overall, the tensions were "minor."

What’s next for Boeing and NASA?

As Wilmore and Williams settle back into life on Earth, the heat is on Boeing. NASA has insisted that Starliner must undergo a successful uncrewed mission before it's allowed to carry astronauts again.

Despite the high-profile failure, NASA has reaffirmed its commitment to the Starliner project, which has already cost $4.5 billion and has been bogged down by setbacks since its 2010 inception.

NASA emphasized the importance of having two operational launch systems, with SpaceX as the other.

 Featured image credit: Joe Raedle/Getty Images

A routine mission turned tense aboard the International Space Station (ISS) after a medical emergency forced NASA to bring four astronauts back to Earth a month ahead of schedule.

The unscheduled return marked the first time in history that NASA has cut short an ISS mission due to a crew member’s health.

The SpaceX Dragon capsule, dubbed Endeavour, safely splashed down in the Pacific Ocean off the coast of San Diego.

Onboard were American astronauts Zena Cardman and Mike Fincke, Japanese astronaut Kimiya Yui, and Russian cosmonaut Oleg Platonov.

The return capped off a dramatic 10-hour descent from orbit, ending 167 days aboard the ISS.

This was the first medical evacuation from the ISS. Credit: NASA / Getty

NASA has kept the identity of the ill astronaut under wraps “for privacy reasons,” but confirmed the individual is in stable condition. While there have been other early departures in spaceflight history, this incident marks the first ISS evacuation due to a serious medical condition.

"The crew member of concern is doing fine," assured Jared Isaacman, the head of NASA, during a post-splashdown briefing.

Featured image credit: NASA / Getty

Two NASA astronauts who ended up stranded in space for nine months have shared their reactions to finding out their trip had to be extended.

Barry 'Butch' Wilmore, 62, and Sunita 'Suni' Willians, 59, had initially been due to travel to the International Space Station for just eight days.

However, their short mission aboard Boeing's Starliner capsule ended up being a nine-month stint due to technical malfunctions.

The pair finally splashed down on Earth after 286 days in space, and have now spoken out about how they felt when they found out the length of their trip had increased dramatically.

The pair have revealed their first reactions during a new interview with Fox News’ America’s Newsroom.

Williams said: "My first thought was, we just got to pivot, right? I was like, ‘OK, let’s make the best of it.’

"We planned, we trained that we’d be there for some part of a time, so we were ready to just jump into it and take on the tasks that were given to us."

Wilmore revealed that while he was sad to miss out on most of his daughter's senior year at high school, he pushed his own emotions to one side.

He explained: "It’s not about me, it’s not about my feelings. It’s about what this human space flight program is about. It’s our national goals.

"I have to wrap myself, my mind, around ‘what does the nation need out of me right now?’

"Did I think about not being there for my daughter’s high school year, of course… certainly, deal with the personal side of it, but I can’t let that interfere with what I’m called to do."

The pair finally returned to Earth aboard Elon Musk's SpaceX's Crew Dragon on March 18, having blasted off on Boeing's new Starliner last June.

When asked about Musk and Donald Trump's interest in space exploration, Williams responded: "They’ve earned my trust, and for that, I am grateful that our national leaders actually are coming in and taking part in our human space flight program.

"It is hugely important [of] global significance that they take an active role. Based on the past and what we see now with them doing that, it is refreshing, not just refreshing, it’s empowering. It’s strengthening," per the New York Post.

Wilmore and Williams are currently undergoing a comprehensive 45-day rehabilitation program at NASA's Johnson Space Center to combat the effects of such a long time in space.

The absence of gravity in space causes muscle atrophy and bone density loss. According to medical experts, astronauts can lose up to 1% of bone density for each month spent in microgravity, potentially resulting in a 9% loss over their mission duration.

Their rehabilitation regimen includes physical therapy to rebuild muscle strength, cardiovascular exercises, and balance training to restore coordination.

Featured image credit: Joe Raedle/Getty Images