Axiom-4 mission: Who are crew members Slawosz Uznanski-Wisniewski and Tibor Kapu?
Four astronauts are ready to embark on a private mission to the International Space Station on Wednesday morning, June 25. This would be the fourth such flight by Axiom Space.
Polish astronaut Slawosz Uznanski-Wisniewski (L) and Hungarian astronaut Tibor Kapu gesture at relatives as he makes his way to Launch Complex 39A ahead of the Axiom-4 mission, with a SpaceX Dragon spacecraft and Falcon 9 rocket, lift off at NASA’s Kennedy Space Center in Cape Canaveral, Florida, on June 24, 2025. (Photo by Giorgio VIERA / AFP)(AFP)
The launch is expected to take place at 2:31 am Eastern time on Wednesday. The crew is set to ride in a SpaceX Crew Dragon capsule on a Falcon 9 rocket, which will lift off from NASA’s Kennedy Space Center in Florida.
The three people aboard the flight are Indian astronaut Captain Shubhanshu Shukla, Slawosz Uznanski-Wisniewski of Poland and Tibor Kapu of Hungary. They will be led by Peggy Whitson, a retired NASA astronaut who now works for Axiom Space as director of human spaceflight.
Who is Slawosz Uznanski-Wisniewski?
Dr. Uznanski-Wisniewski is a scientist and an engineer. He has notably worked at the European Organization for Nuclear Research, or CERN, in Geneva. This included a stint as an engineer at the Large Hadron Collider. He is also a mission specialist.
According to Axion Space, “Sławosz Uznański-Wiśniewski, of Poland, is a scientist and engineer making significant contributions to the fields of science and space exploration. As a member of the European Space Agency’s (ESA) Astronaut Reserve Class of 2022, he emerged from a competitive pool of over 22,500 candidates, securing his place for future missions to the International Space Station (ISS) and beyond.”
The website added, “Sławosz’s educational journey began in Łódź, Poland, where he earned his M.Sc. with honors from Łódź University of Technology in 2008. His academic pursuits extended across borders, as he obtained another M.Sc. from Université de Nantes in France and a Diplôme d’Ingénieur from Polytech’Nantes in the same year. His expertise deepened further with a 2011 doctoral dissertation at the University of Aix-Marseille, focusing on radiation-tolerant designs for space applications”
Uznanski-Wisniewski’s contributions to the European Organization for Nuclear Research (CERN) in Geneva are also well known. He served as a reliability expert and project lead there, and assumed the role of Engineer in Charge for the Large Hadron Collider (LHC) from 2018 to 2020.
Who is Tibor Kapu?
Kapu is also a mission specialist, and a mechanical engineer who has worked across various industries, including pharmaceuticals, logistics and aerospace.
According to Axion Space, “Kapu’s educational foundation was laid at Gyula Krúdy High School in Nyíregyháza. He later graduated from the Budapest University of Technology and Economics, earning a degree in mechanical engineering, followed by a master’s degree, specializing in polymer technology. His expertise extends beyond textbooks, as he contributed to the pharmaceutical and logistical industries, and worked on hybrid car battery development in the automotive industry during his career. His professional journey also took him to Belgium and the United States, where he further honed his skills in advanced technologies.”
Kapu remained focused on space radiation protection at an aerospace technology company from 2022 until the beginning of the Hungarian Astronaut Program. He became one of the Hungarians to be selected from a pool of 247 candidates for the Hungarian to Orbit (HUNOR) Astronaut Program in 2023.
The website added, “This prestigious initiative aims to send a Hungarian astronaut to space, enabling world-class scientific experiments and tests aboard the International Space Station (ISS). Kapu’s rigorous training encompassed everything from aircraft flying to simulating the space environment, alongside mental and physical endurance tests. His studies delved into space engineering, space health, and spaceflight history, and he actively engaged in scientific experimentation.”
