NASA astronauts Sunita Williams and Butch Wilmore are set to face a series of physiological challenges upon their return to Earth following their extended stay aboard the International Space Station (ISS). One of the lesser-known but impactful conditions they may experience is known as “baby feet.” This, along with other well-documented issues such as muscle loss, balance disruption, and bone density reduction, underscores the significant effects of long-term space travel on the human body.

Understanding “Baby Feet”

One of the most immediate and uncomfortable conditions astronauts experience upon returning to Earth is “baby feet.” This term refers to the hypersensitivity and softening of the soles of the feet due to prolonged exposure to microgravity. While in space, astronauts do not walk or bear weight on their feet as they do on Earth. Instead, they float and use their hands to grip handles and bars to move around. As a result, the thickened, calloused skin on the soles of their feet softens significantly due to the lack of pressure and friction.

When astronauts return to Earth, the sudden reintroduction of gravity causes discomfort, tingling, and pain when they begin walking again. The sensation is often compared to walking barefoot after months of wearing only soft slippers, making every step feel uncomfortable until their feet gradually readjust to normal ground contact.

Causes and Effects of “Baby Feet”

The primary cause of “baby feet” is the absence of weight-bearing activities in space. On Earth, the soles of our feet constantly experience pressure from standing and walking, leading to the development of tougher skin. In space, however, this pressure is eliminated, causing the soles to become soft and sensitive.

Upon returning to Earth, astronauts often describe a heightened sensitivity to textures and surfaces. The nerve endings in their feet must readjust to the feeling of standing and walking, while the lack of recent callus development makes movement initially uncomfortable. To help astronauts readapt to Earth’s gravity, a structured rehabilitation program is essential. This includes gradual exposure to walking, specific foot and leg exercises, balance training

Additional Physiological Challenges

Beyond “baby feet,” returning astronauts face a range of other physiological challenges due to prolonged exposure to microgravity:

Chicken Leg Syndrome: Microgravity causes fluids to shift upward, leading to a puffy face and thinner legs. Upon return to Earth, fluid redistribution can cause swelling and discomfort in the feet and legs.

Muscle Atrophy: Since walking and running are unnecessary in space, astronauts experience muscle loss, particularly in their legs and feet. Even with strict exercise regimens aboard the ISS, the absence of normal weight-bearing activities leads to muscle weakening, making it difficult to walk immediately after landing.

Balance and Coordination Issues: The inner ear, which helps maintain balance, adapts to the weightlessness of space. Upon return, astronauts often struggle with dizziness, impaired coordination, and difficulty standing upright as their bodies readjust to gravity.

Bone Density Loss: Long-term exposure to microgravity results in bone loss, particularly in weight-bearing bones such as those in the feet and legs. This increases the risk of fractures and makes post-mission rehabilitation critical.

The Importance of Rehabilitation

NASA has developed rigorous post-mission rehabilitation programs to help astronauts regain strength, balance, and mobility. These programs involve a combination of physical therapy, monitored exercise routines, and nutritional support to ensure a full recovery.

For Sunita Williams and Butch Wilmore, their return to Earth will be marked by weeks of rehabilitation as they work to overcome these challenges and restore their bodies to pre-mission conditions. The insights gained from their experiences will continue to inform NASAs strategies for future long-duration space missions, including those to the Moon and Mars.

SpaceX Delays Their Return

NASA and SpaceX recently postponed the astronauts’ return due to technical issues. The return, initially scheduled for an earlier date, was delayed as a result of a hydraulic system issue with a ground support clamp arm for the Falcon 9 rocket at Launch Complex 39A at NASA’s Kennedy Space Center in Florida. NASA has announced that the next available launch opportunity is no earlier than 7:26 pm EDT on Thursday, pending a review of the issue. This delay means Williams and Wilmore will spend additional time aboard the ISS, potentially extending their exposure to microgravity-related physiological effects.