Axiom Mission 4


Axiom Mission 4 was a private crewed spaceflight to the International Space Station operated by Axiom Space in partnership with SpaceX and NASA. The mission launched atop a SpaceX Falcon 9 Block 5 rocket, which placed the spacecraft into low Earth orbit. Ax-4 was the first mission to fly aboard the Crew Dragon capsule 'Grace', which is the fifth and final Dragon capsule manufactured.
The launch was originally scheduled for June 11, 2025 from Launch Complex 39A at the Kennedy Space Center, but was scrubbed for a liquid oxygen leak. A separate leak in the ISS's Zvezda module led to an additional two week launch delay. The mission was eventually launched on June 25, 2025 at 06:31:53UTC for an 18-day stay at the ISS before undocking and splashing down in the Pacific Ocean off the coast of San Diego on July 15, 2025 at 09:31:41UTC.

Crew

The four-person crew included commander Peggy Whitson, an Axiom Space employee and former NASA astronaut; pilot Shubhanshu Shukla of the Indian Space Research Organisation ; and mission specialists Sławosz Uznański-Wiśniewski, a European Space Agency project astronaut from Poland, and Tibor Kapu, representing the Hungarian Space Office.
The mission marked 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. While those earlier missions docked with Salyut 6 or Salyut 7, Ax-4 was the first government-sponsored mission from any of the three nations to reach the ISS. Among the crew, Shubhanshu Shukla was the first member of India's astronaut corps to fly in space.

Gaganyaan

Ax‑4 represented a milestone for the Indian Human Spaceflight Programme, integrating with ISRO's Gaganyaan initiative. While Gaganyaan remained India's independent crewed program, Ax‑4 provided the first opportunity for an Indian astronaut—Shubhanshu Shukla—to fly on a commercial mission to the ISS. Shukla conducted experiments developed by ISRO and Indian institutions, including studies of cognitive effects of screen use, microbial adaptation, muscle atrophy, and crop resilience in microgravity.
According to ISRO, the mission provided practical experience in the intricacies of crew-ground coordination, real-time health telemetry, medical and psychological preparation, international crew integration, and experiment execution. For the Indian Human Spaceflight Programme, it will have a direct impact on astronaut preparedness, safety validation, and mission planning.

Experiments

The experiments are co-ordinated by ISRO.
  • Space Microalgae & National Institute of Plant Genome Research — Impact of Microgravity and Radiation in ISS on Edible Microalgae.
  • Myogenesis — Effect of metabolic supplements on muscle regeneration under microgravity.
  • Sprouts — Sprouting Salad Seeds in Space: Relevance to Crew Nutrition.
  • Voyager Tardigrade — Survival, revival, reproduction, and transcriptome of the eutardigrade Paramacrobiotus sp. BLR strain in space.
  • Voyager Displays — Analyzing Human Interaction with Electronic Displays in Microgravity. 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 — Comparative growth and proteomics responses of cyanobacteria on urea and nitrate in microgravity.
  • Food Crop Seeds in Microgravity — Impact of Microgravity on Growth and Yield Parameters in Food Crop Seeds.

    HUNOR

Ax‑4 also carried Tibor Kapu, Hungary's second astronaut after Bertalan Farkas. Tibor Kapu was 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 mission was developed by the Hungarian Space Office completely independent of ESA. HUNOR was first announced in 2021 and in July 2022 the Hungarian foreign ministry signed a preliminary deal with Axiom for the flight, which was finalized in September 2023. Tibor Kapu was selected from 247 applicants to fly on the mission, supported by backup astronaut Gyula Cserényi. Kapu is a mechanical engineer and recreational skydiver, Cserényi is an electrical engineer and amateur steeplechase racer. Both completed their NASA training in April 2025. The HUNOR mission had its own patch, separate from the Axiom Mission 4 patch, depicting the Csodaszarvas and four stars representing the final astronaut candidates.

Experiments

  • ATMP — development of heart muscle cells in space environment
  • CINCINNATI — simulation of thermal comfort for astronauts
  • DIROS — contributes to better understanding of the Saturn's hexagon cloud pattern and flows in gases or liquids
  • DNA-REPAIR — reducing damage to DNA-molecules to protect astronauts from cosmic rays using genetically modified fruit flies, that are to be tested and compared with specimens on Earth
  • END-SANS — experiment to treat astronauts' visual impairment that is caused by long periods in space
  • ENPERCHAR — the research explores the interaction between humans and their physical environment on the International Space Station
  • ESEL3D — impact of space conditions on 3D printed devices
  • IMU-DRS — positioning in space using accelerometers
  • KRIJAP — crystal growth from new organic material in zero gravity, with resulting crystals to be brought to Earth where their atomic structure is to be determined
  • M4D — medicine tester that uses capillary action to make sure ingredients mix precisely at the right time and place
  • MAGOR — examining damage to the astronauts' microbiome and negative impact on their health caused by weightlessness, cosmic radiation and special diets
  • MAGYAR — testing brain function in weightlessness using VR
  • MICATO — testing ion engines in microgravity
  • ORBGEO — tracking the orbit of spacecraft using photographs
  • POSITIVE — foaming of building material from lunar regolith
  • RANDAM — usage of a new, tiny, energy-efficient radiation dosimeter that also records scientific data on other environmental factors
  • SAET — the impact of space travel on associative learning
  • SINGREAD — studying the human voice in space
  • SIS — 3D footage of the astronaut's daily activities
  • TESH, Canadian Space Agency ) — health assessment of astronauts
  • UHU — photographing upper-atmospheric lightning, namely sprites, blue and gigantic jets from the ISS
  • VISPRO — vascular ultrasound examination in weightlessness
  • VITAPRIC — examining space conditions on vitamin, mineral and protein content of plant samples

    Ignis

For Poland, Ax‑4 was the first crewed mission since 1978. The Polish Space Agency and the European Space Agency have partnered on the Ignis mission for astronaut Sławosz Uznański-Wiśniewski. He was the second ESA astronaut to fly on a commercial human spaceflight mission. His payload suite included experiments in technology and life sciences.

Mission patch

The Ignis mission had 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 over the mission's name, Ignis, the Latin word for fire.

Training

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.

Experiments

  • AstroMentalHealth — impact of isolation, technology, and limited contact with nature on astronauts' mental health
  • AstroPerformance — studying the impact of spaceflight on the soft tissues of the musculoskeletal system
  • EEG Neurofeedback — electroencephalography for supporting astronauts' mental resilience and focus
  • Human Gut Microbiota — study of changes in the community of microorganisms in the digestive system during spaceflight
  • Immune Multiomics — effects of the space environment on gene expression and DNA methylation in blood mononuclear cells
  • Leopard Data Processing Unit — demonstrating AI‑based data processing in orbit to reduce ground infrastructure requirements
  • MXene in LEO — stability of MXene-type nanomaterials in space conditions and their use in wearable devices
  • PhotonGrav — testing functional near-infrared spectroscopy-based brain-computer interface
  • RadMon-on-ISS — scalable radiation detectors
  • Space Volcanic Algae — survival and adaptation of extremophilic volcanic microalgae in space conditions
  • Stability of Drugs — stability of polymeric drug release systems in space conditions
  • Wireless Acoustics — noise measurements in the ESA Columbus module using an acoustic monitor and a personal dosimeter
  • Yeast TardigradeGene — survival and energy state of tardigrade-gene-infused yeast in space conditions

    Mission

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.
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. On June 19, 2025, NASA made the decision to stand down from a launch on June 22, 2025.
Because of the multiple stand downs in close succession, Axiom-4 crew remained in quarantine for nearly four weeks, one of the longest periods in modern human spaceflight history. The standard quarantine for astronauts is typically just two weeks, although the Apollo Moon mission astronauts were isolated for three weeks.
The mission launched successfully on its third attempt on June 25, 2025 at 06:31:53UTC. Grace docked with the ISS on June 26, 2025, at 10:31:47UTC for a two-week stay.
After 18 days at the ISS, Grace undocked on July 14, 2025, 11:15UTC, commencing a 22-hour return back to Earth. The spacecraft splashed down in the Pacific Ocean off the coast of San Diego on July 15, 2025 at 09:31:36UTC.
Axiom Mission 4 marked the first time astronauts from India, Poland, and Hungary flew to the International Space Station and the first human spaceflight for each nation in over 40 years.