Axiom Mission 4

Axiom Mission 4 (Ax‑4) is a private crewed spaceflight to the International Space Station (ISS) operated by Axiom Space in partnership with SpaceX and NASA.^[1] The mission launched atop a SpaceX Falcon 9 Block 5 rocket, which placed the Crew Dragon Grace spacecraft into low Earth orbit. This was the maiden flight of Grace (C213), the fifth and final Crew Dragon capsule to be built.^[2][3]

The launch was originally scheduled for June 11, 2025, from Launch Complex 39A at the Kennedy Space Center, but was scrubbed due to a liquid oxygen leak.^[4] A separate leak in the ISS's Zvezda module led to an additional two week launch delay.^[4] The mission was eventually launched on June 25, 2025, at 06:31:52 UTC (2:31:52 a.m. EDT).^[5]

The four-person crew includes commander Peggy Whitson, an Axiom Space employee and former NASA astronaut; pilot Shubhanshu Shukla of the Indian Space Research Organisation (ISRO); and mission specialists Sławosz Uznański-Wiśniewski, a European Space Agency (ESA) project astronaut from Poland, and Tibor Kapu, representing the Hungarian Space Office.^[6]

The mission marks the first government-sponsored human spaceflight in over 40 years, and only the second overall, for India, Hungary, and Poland. Each of these countries previously flew one astronaut as part of the Soviet Union's Interkosmos program.^[7] While those earlier missions docked with Salyut 6 or Salyut 7, Ax-4 is the first government-sponsored mission from any of the three nations to reach the ISS.^[a] Among the crew, Shubhanshu Shukla is the first member of India's astronaut corps to fly in space.

Ax‑4 represents a milestone for India's Indian Human Spaceflight Programme, integrating with ISRO's Gaganyaan initiative. While Gaganyaan remains India's independent crewed program, Ax‑4 provides the first opportunity for an Indian astronaut—Shubhanshu Shukla—to fly on a commercial mission to the ISS. Shukla will conduct experiments developed by ISRO and Indian institutions, including studies of cognitive effects of screen use, microbial adaptation, muscle atrophy, and crop resilience in microgravity.^[9][10][11]

The experiments are co-ordinated by Indian Space Research Organization (ISRO).

• Space Microalgae (International Centre for Genetic Engineering and Biotechnology (ICGEB) & National Institute of Plant Genome Research (NIPGR), India)— Impact of Microgravity and Radiation in ISS on Edible Microalgae.^[12][13]
• Myogenesis (Institute of Stem Cell Science and Regenerative Medicine (InStem), India) — Effect of metabolic supplements on muscle regeneration under microgravity.^[12][13]
• Sprouts (University of Agricultural Sciences, Dharwad & Indian Institute of Technology, Dharwad) — Sprouting Salad Seeds in Space: Relevance to Crew Nutrition.^[12][13]
• Voyager Tardigrade (Indian Institute of Science) — Survival, revival, reproduction, and transcriptome of the eutardigrade Paramacrobiotus sp. BLR strain in space.^[12][13]
• Voyager Displays (Indian Institute of Science) — Analyzing Human Interaction with Electronic Displays in Microgravity.^[12][13] The study will compare performance of on board and ground crews with respect to ISO 9241 pointing task, Spatial 2-back task, Perceived Stress and WHO Mental Well Being tests.
• Cyanobacteria in Microgravity (International Centre for Genetic Engineering and Biotechnology (ICGEB)) — Comparative growth and proteomics responses of cyanobacteria on urea and nitrate in microgravity.^[13]
• Food Crop Seeds in Microgravity (Indian Institute of Space Science and Technology & Kerala Agricultural University) — Impact of Microgravity on Growth and Yield Parameters in Food Crop Seeds.^[13]

Ax‑4 also carries Tibor Kapu, Hungary's second astronaut after Farkas Bertalan. Tibor Kapu is the first astronaut since the fall of the Soviet Union and the first hungarian astronaut to board the International Space Station. Although Hungary is also part of the ESA, the HUNOR (short for HUNgarian to ORbit) mission was developed by the Hungarian Space Office (HSO) completely independent of ESA.^[14] HUNOR was first announced in 2021 and in July 2022 the Hungarian foreign ministry signed a preliminary deal with Axiom for the flight,^[14] which was finalized in September 2023.^[14] Tibor Kapu was selected from 247 applicants to fly on the mission, supported by backup astronaut Gyula Cserényi.^[15] Kapu is a mechanical engineer and recreational skydiver, Cserényi is an electrical engineer and amateur steeplechase racer.^[16] Both completed their NASA training in April 2025.^[17] The HUNOR mission has its own patch, separate from the Axiom Mission 4 patch, depicting the Csodaszarvas and four stars representing the final astronaut candidates.^[14]

For Poland, Ax‑4 is the first crewed mission since 1978. The Polish Space Agency (POLSA) and the European Space Agency (ESA) have partnered on the Ignis mission for astronaut Sławosz Uznański-Wiśniewski. He is the second ESA astronaut to fly on a commercial human spaceflight mission. His payload suite includes experiments in technology and life sciences.^{[18][19][20][21]}

The Ignis mission has its own patch, separate from the Axiom Mission 4 patch, depicting an eagle in the Polish colors whose wings trace the contours of the Orla Perć mountain range and a stylized depiction of the Scutum constellation (a tribute to Johannes Hevelius who named the constellation) over the mission's name, Ignis, the Latin word for fire.^[22]

Before the mission, Sławosz Uznański-Wiśniewski has trained at facilities in Europe, Japan, and the United States. At the European Astronaut Centre in Cologne, he focused on the experiments he will perform and on ESA’s Columbus laboratory module. At JAXA’s Tsukuba Space Center in Japan, his training covered the operation of the Japanese Experiment Module Kibō. In the United States, he trained at various NASA facilities, as well as at facilities of SpaceX and Axiom Space. His preparation also included parabolic flights and outdoor survival training.^[23]

• AstroMentalHealth (University of Silesia) — impact of isolation, technology, and limited contact with nature on astronauts' mental health^[24]
• AstroPerformance (Mollis Textus) (Smarter Diagnostics) — studying the impact of spaceflight on the soft tissues of the musculoskeletal system^[25]
• EEG Neurofeedback (Academy of Physical Education and Sport in Gdańsk) — electroencephalography for supporting astronauts' mental resilience and focus^[26]
• Human Gut Microbiota (Military University of Technology) — study of changes in the community of microorganisms in the digestive system during spaceflight^[27]
• Immune Multiomics (Military University of Technology) — effects of the space environment on gene expression and DNA methylation in blood mononuclear cells^[28]
• Leopard Data Processing Unit (KP Labs) — demonstrating AI‑based data processing in orbit to reduce ground infrastructure requirements^[29]
• MXene in LEO (AGH University of Krakow) — stability of MXene-type nanomaterials in space conditions and their use in wearable devices^[30]
• PhotonGrav (Cortivision) — testing functional near-infrared spectroscopy-based brain-computer interface^[31]
• RadMon-on-ISS (SigmaLabs) — scalable radiation detectors^[32]
• Space Volcanic Algae (Extremo Technologies) — survival and adaptation of extremophilic volcanic microalgae in space conditions^[33][34]
• Stability of Drugs (Polish Academy of Sciences) — stability of polymeric drug release systems in space conditions^[35]
• Wireless Acoustics (Svantek) — noise measurements in the ESA Columbus module using an acoustic monitor and a personal dosimeter^[36]
• Yeast TardigradeGene (University of Szczecin, Adam Mickiewicz University, and University of Silesia) — survival and energy state of tardigrade-gene-infused yeast in space conditions^[37][38]

On June 10, 2025, the launch of Ax-4 was postponed after SpaceX detected a liquid oxygen leak in the Falcon 9 rocket during a post-static fire inspection. The mission was put on hold to allow time for necessary repairs. SpaceX officially announced it was "standing down" from the launch to ensure the safety and integrity of the mission hardware. ^[39]

On June 12, 2025, the mission was delayed to allow the crew of the space station to investigate a new potential pressure leak. The potential leak was detected following leak repair and sealing efforts by Russian cosmonauts in the aft segment of the Zvezda module, where multiple previous leaks have occurred.^[40] On June 19, 2025, NASA made the decision to stand down from a launch on June 22, 2025.^[41]

The Axiom-4 crew underwent one of the longest quarantine periods in modern human spaceflight history. While Apollo Moon mission astronauts were isolated for three weeks and today’s standard quarantine for astronauts is typically just two weeks, the extended isolation for the Axiom-4 team significantly exceeded contemporary norms, marking an unusually prolonged pre-flight precaution.^[42]

The mission launched successfully on its third attempt on June 25, 2025 at 6:31 UTC. It docked with the ISS on June 26, 2025 at 10:31 UTC for a two-week stay.

• Timeline of private spaceflight
• List of European Space Agency programmes and missions
• List of ISRO missions

• Ignis mission
• Ignis mission (ESA)
• Ignis launch kit (archived)
• Sławosz Uznański-Wiśniewski: Training for the Ignis mission (ESA Explores podcast)
• Algae to Fly High on the Ignis Space Mission, Plants launching on Axiom-4