Homeward Bound: Starliner Astronauts Prepare for Re-Entry and Readjustment After Extended Space Station Stay
After an extended nine-month sojourn aboard the International Space Station (ISS), astronauts Suni Williams and Butch Wilmore are poised to return to Earth, marking the end of a unique and unexpectedly prolonged mission. The pair, known affectionately as the "Starliner astronauts," embarked on this journey from NASA’s Kennedy Space Center with the anticipation of a shorter stay, but a series of technical issues with Boeing’s Starliner spacecraft ultimately extended their time in orbit. Their return journey commenced early Tuesday morning, as they boarded a SpaceX Dragon capsule docked at the ISS, setting a course for a splashdown just off the Florida coast, anticipated for Thursday evening around 6 p.m. EST.
While the astronauts undoubtedly look forward to the familiar comforts of solid ground, the transition back to Earth will necessitate a period of readjustment, both physically and mentally. The extended exposure to the microgravity environment of space poses a number of challenges to the human body, requiring careful monitoring and rehabilitation. The astronauts will face a range of potential side effects, from skin irritations to more significant issues like orthostatic intolerance and sensory overload.
One of the more common complaints among astronauts returning from long-duration spaceflights pertains to skin health. Reports consistently indicate that astronauts experience itches, rashes, and dryness of the skin. While comprehensive research on the specific stressors impacting skin during space travel is still ongoing, scientists attribute these issues, in part, to the unique hygiene environment of the ISS. The limited availability of water necessitates a simplified cleaning routine, relying on liquid soap, small amounts of water, and rinse-less shampoo. Astronauts use towels to wipe away excess water, and an airflow system ensures evaporation, highlighting the critical need for water conservation in space.
Beyond hygiene factors, other environmental elements contribute to skin irritation. These include temperature fluctuations, limited air circulation, low humidity levels, and even contact with irritating substances like biosensors and tape. The cumulative effect of these stressors can compromise the skin’s natural barrier function, leading to discomfort and potential skin conditions.
Furthermore, astronauts often experience what is known as Spaceflight Associated Neuro-Ocular Syndrome (SANS), particularly during extended missions. SANS encompasses a variety of symptoms linked to the physiological changes induced by spaceflight. These include puffy faces or eyes, decreased near-vision, and headaches. The underlying causes of SANS are multifaceted and related to the unique conditions of space. Cephalad fluid shift, the movement of bodily fluids towards the head due to the absence of gravity, plays a significant role. Increased intracranial pressure, or added pressure on the brain, and alterations in lymphatic drainage systems also contribute to the development of SANS symptoms. NASA estimates that approximately 70% of ISS astronauts experience some form of SANS during their missions. While many symptoms resolve upon returning to Earth, some changes can be permanent, highlighting the importance of ongoing research into the long-term effects of SANS.
Orthostatic intolerance is another challenge that astronauts may encounter upon re-entry. This condition manifests as difficulty or inability to stand or walk due to lightheadedness or fainting. Orthostatic intolerance arises from the body’s struggle to readjust to Earth’s gravity. In the microgravity of the ISS, bodily fluids distribute more evenly throughout the body, whereas on Earth, gravity pulls fluids downwards, pooling them in the lower extremities. When an astronaut returns to Earth, the sudden shift in gravity causes fluids to rapidly descend, potentially leading to a temporary drop in blood pressure and reduced blood flow to the brain.
Beyond the physiological adjustments, the transition back to terrestrial life also presents psychological challenges. Susan Albers, a psychologist at the Cleveland Clinic, notes that astronauts may experience sensory overload upon returning to Earth. After months in the relatively calm and controlled environment of space, the influx of sensory information can be overwhelming. The sensation of gravity itself may feel strange and uncomfortable, natural sunlight could appear excessively bright, and even everyday smells like grass or food might feel intensified. Albers emphasizes that these sensations take time to acclimatize to.
The structured routines of life on the ISS can also make readjusting to a less regimented lifestyle difficult. The ISS operates on a strict schedule for eating, exercising, and working. Astronauts may find the flexibility of daily life back home, particularly family mealtimes and other less predictable events, a little difficult to adapt to.
Despite not having worked directly with astronauts, Albers recommends that Williams and Wilmore prioritize their basic needs upon their return: sleep and nutrition. She underscores the fundamental importance of these two elements for overall well-being and stability during this period of transition.
The extended stay of Williams and Wilmore on the ISS was an unplanned development. They initially arrived in June 2024 as part of the first crewed test flight of Boeing’s Starliner spacecraft. Their mission was intended to be a brief one, but technical issues discovered shortly after their arrival prevented a safe return on the Starliner. In September, they witnessed the Starliner undock from the space station and return to Earth unmanned. Rather than initiating an emergency mission to retrieve the astronauts, NASA opted to keep Williams and Wilmore on the ISS to maintain adequate staffing levels.
Despite the extended duration of their mission, both Williams and Wilmore have expressed positive sentiments about their time in orbit. In an interview earlier this year, they shared the profound impact of witnessing Earth and the cosmos from the vantage point of the ISS. They also emphasized that their extended stay was simply part of the job, rejecting the notion that they were "stuck" on the station, as had been suggested by some observers.
The arrival of SpaceX Crew-10 at the ISS on Saturday night marks both the replacement for Williams and Wilmore and their transport back to Earth. The new crew will remain on the space station for six months, conducting a range of scientific experiments.
As Williams and Wilmore prepare for their journey back to Earth, they do so with a sense of accomplishment and a wealth of experiences. The extended mission may have presented unexpected challenges, but it also offered unique opportunities for scientific research and exploration. The world awaits their return, ready to learn from their experiences and eager to welcome them back to solid ground.
