Astronauts Focus on Exercise Physiology and Eye Health Research Aboard Orbital Laboratory
Exercise research and biomedical science promoting healthy humans on and off Earth topped the schedule aboard the International Space Station on Tuesday, January 6, 2026. Meanwhile, two NASA astronauts are preparing for the year’s first spacewalk, scheduled to begin Thursday, with Expedition 74 crew members dividing time between critical life sciences investigations and extravehicular activity preparations.
Expedition 74 Commander Mike Fincke of NASA spent Tuesday exploring how exercising in weightlessness affects a crew member’s musculoskeletal system, addressing one of the fundamental challenges of long-duration spaceflight. Astronauts experience significant muscle atrophy and bone density loss during extended missions due to the absence of gravitational loading that normally stimulates muscle growth and bone remodeling on Earth.
Specialized Video Equipment Monitors Exercise Device Performance
Fincke first set up specialized video gear and calibrated the hardware to monitor how his body responds to working out on the Tranquility module’s advanced resistive exercise device, commonly known as ARED. This sophisticated exercise equipment is specifically designed to mimic free weights on Earth by providing resistance through vacuum cylinders and flywheels, enabling astronauts to perform strength training exercises including squats, deadlifts, bench press, and calf raises.
Next, Fincke performed a series of squats on the ARED as researchers on the ground monitored his biomechanics, muscle activation patterns, and cardiovascular responses in real-time. The video recording system captured detailed movement analysis data while physiological sensors tracked heart rate, oxygen consumption, and other metabolic indicators providing comprehensive assessment of exercise effectiveness in microgravity.
Insights from this study will allow doctors to adjust and improve spaceflight workout protocols, ensuring astronauts maximize muscle and bone health during missions lasting six months or longer aboard the International Space Station and future deep space missions to the Moon and Mars where crew members cannot return to Earth’s gravity for extended periods.
Earth Applications Include Athletic Training and Rehabilitation Medicine
Potential Earth benefits from this microgravity exercise research include improving athletic training methodologies and advancing recovery and rehabilitation techniques for patients with musculoskeletal injuries, neurological conditions, or prolonged bed rest. Understanding how the body responds to resistance exercise in the absence of gravity provides fundamental insights into muscle physiology that can inform terrestrial exercise prescription.
For example, findings about optimal resistance levels, repetition ranges, and exercise frequency for maintaining muscle mass in weightlessness may translate to improved rehabilitation protocols for elderly individuals at risk for sarcopenia, patients recovering from orthopedic surgery, or individuals with neuromuscular disorders limiting mobility and weight-bearing capacity.
Comprehensive Eye Health Examinations Using Advanced Medical Technology
NASA Flight Engineers Zena Cardman and Chris Williams partnered in the Columbus laboratory module for a pair of eye checks supporting human research understanding visual system changes during spaceflight. This research addresses important medical concerns that emerged during early long-duration missions when some astronauts reported vision changes and post-flight examinations revealed structural alterations to eye anatomy.
Cardman led both examinations, first operating specialized hardware that sent precisely controlled light signals to electrodes attached around Williams’ eyes. Biomedical software then recorded how his retinas and the photoreceptor cells in the back of his eyes responded to the flashes of light, measuring electrical activity generated by light-sensitive neurons through a technique called electroretinography.
For the second eye exam, Cardman operated medical imaging gear that Williams peered into for different visualization of his retina, cornea, and lens using optical coherence tomography technology. This non-invasive imaging technique uses light waves to capture high-resolution cross-sectional images of retinal layers, enabling researchers to detect subtle changes in tissue thickness or fluid accumulation that might indicate space-induced ocular disorders.
Data Analysis Supports Understanding Space-Caused Visual Changes
The downlinked data will help researchers understand and treat potential space-caused changes to eye anatomy and function, a condition termed spaceflight-associated neuro-ocular syndrome or SANS. This condition affects approximately 30 percent of astronauts on six-month missions and nearly 60 percent of those on year-long missions, causing varying degrees of visual impairment including hyperopic shifts, cotton wool spots, and optic disc edema.
Understanding the mechanisms underlying SANS is critical for planning future deep space missions where astronauts cannot be medically evacuated back to Earth within hours or days. Research suggests that SANS may result from cephalad fluid shifts in microgravity increasing intracranial pressure and altering cerebrospinal fluid dynamics around the optic nerve, though the precise pathophysiology remains under investigation.
Spacewalk Preparations for Solar Array Installation Mission
Fincke and Cardman are scheduled to begin a six-and-a-half-hour spacewalk at 8 a.m. EST on Thursday, January 8, with live NASA+ coverage starting at 6:30 a.m. The duo will finalize their preparations on Wednesday by organizing tools, checking spacesuit systems, and reviewing spacewalk procedures with assistance from Williams and Flight Engineer Kimiya Yui of JAXA, the Japan Aerospace Exploration Agency.
During the spacewalk, they will install a modification kit and route cables to set up the station’s port-side truss structure for a future roll-out solar array. These new solar arrays will augment the station’s existing electrical power generation capacity, which has gradually declined as the original solar arrays deployed in 2000-2009 have degraded through normal aging and micrometeorite impacts.
Additional Research Activities Support Respiratory and Maintenance Operations
Roscosmos Flight Engineers Sergey Kud-Sverchkov and Sergei Mikaev studied how living and working in microgravity affects the respiratory system. The cosmonauts took turns wearing an acoustic sensor around their tracheas to record sounds as they forcefully exhaled, enabling analysis of airway function and breathing mechanics in weightlessness.
Results will help doctors and crews monitor the respiratory system and provide early signs of possible space-caused breathing disorders. Changes in respiratory function during spaceflight can result from fluid redistribution affecting lung volumes, altered chest wall mechanics in the absence of gravity, or exposure to trace contaminants in the closed cabin atmosphere.
Roscosmos Flight Engineer Oleg Platonov started his shift photographing his cosmonaut crewmates as they conducted lung research activities for documentation purposes. Next, he cleaned, inspected, and photographed fans and ventilation system components in the Nauka science module, ensuring proper air circulation and carbon dioxide removal throughout the Russian segment of the orbital complex.
