Indian Space Research Organisation (ISRO) astronaut and Group Captain Shubhanshu Shukla, currently on board the International Space Station (ISS) as part of the Axiom Mission 4 (Ax-4), carried out a range of scientific experiments on Monday. These focused on muscle health, digestion in space, and astronaut mental well-being. According to NASA, Shukla utilized the Life Sciences Glovebox in the ISS’s Kibo laboratory to examine how muscle stem cells respond in microgravity. He also recorded an educational video for Indian school students, explaining how the human digestive system functions differently in space.

NASA noted: “Indian astronaut Shubhanshu Shukla created a video aimed at young Indian students, discussing how digestion changes in space. He then worked with muscle stem cell cultures inside Kibo’s Life Sciences Glovebox to study muscle health in microgravity.” The Life Sciences Glovebox is a controlled, sterile environment aboard the ISS, enabling astronauts to handle biological samples safely. It supports clean experiments and can accommodate two astronauts simultaneously. The ISRO experiment, called Myogenesis, studies the regeneration of muscle cells in microgravity. Astronauts typically experience muscle loss during long-duration missions, in part due to the disruption of mitochondrial metabolism. The study tests metabolic supplements to see if they improve muscle repair in space, with potential benefits for treating age-related muscle loss and muscle-wasting diseases on Earth.

NASA explained: “Spaceflight reduces muscle mass and hampers muscle cell regeneration, possibly due to microgravity affecting mitochondrial energy production. The Myogenesis experiment onboard Ax-4 investigates whether certain chemicals that support mitochondria can aid muscle repair in space. The findings could help both astronauts and people on Earth with muscle health issues.” Other Ax-4 crew members also performed key scientific tasks. Mission Commander Peggy Whitson used the Ultrasound 2 device to scan Hungarian astronaut Tibor Kapu’s veins to study the effects of spaceflight on blood pressure, balance, and vision. The Ultrasound 2 is a modified commercial ultrasound machine used to get high-resolution images in space.

Polish astronaut Slawosz Uznanski-Wisniewski tested a brain-computer interface using a special ESA headset and later joined Whitson and Shukla to film a session for a mental health research study. The experiment, PhotonGrav, aims to validate the use of fNIRS (functional near-infrared spectroscopy) to track brain activity and develop brain-computer interfaces in space. NASA commented that the Ax-4 crew had a “science-packed Monday” conducting research for their respective countries. While Ax-4 focuses on private scientific initiatives, the Expedition 73 crew continues NASA and ESA-backed research. NASA astronauts Anne McClain and Nichole Ayers conducted muscle stimulation tests and cognitive assessments to study spaceflight's impact on muscles and the brain. Ayers and Jonny Kim processed blood samples, including those from Whitson and Uznanski-Wisniewski, for ESA’s Bone on ISS experiment on bone loss.

JAXA Commander Takuya Onishi collected his own blood and urine samples for long-term monitoring and checked air quality inside the Kibo module. Meanwhile, Russian cosmonauts Sergey Ryzhikov and Alexey Zubritskiy prepared for the arrival of the Progress 92 cargo spacecraft and packed waste into Progress 90 for disposal. Another cosmonaut, Kirill Peskov, underwent 24-hour cardiovascular monitoring and readied the European robotic arm for upcoming use. Summarizing the week, NASA said the Expedition 73 crew began Monday with brain and muscle research after a restful weekend, while Ax-4 astronauts continued intensive scientific work, including muscle cell and brain-computer interface studies.

On June 26, Shubhanshu Shukla became the first Indian astronaut to board the ISS. The Ax-4 mission includes former NASA astronaut Peggy Whitson, ISRO’s Shubhanshu Shukla, and ESA astronauts Slawosz Uznanski-Wisniewski (Poland) and Tibor Kapu (Hungary). The mission is set to last up to 14 days. Ax-4 launched on June 25 at noon IST aboard a SpaceX Falcon 9 rocket from NASA’s Kennedy Space Center in Florida. The Dragon spacecraft successfully docked with the ISS on June 26 at 4:05 pm IST, ahead of schedule, connecting to the Harmony module’s space-facing port.