The second private mission to the International Space Station (ISS) has come to a close as the four Axiom Space Axiom Mission 2 (Ax-2) astronauts returned to Earth on Tuesday, May 30. All four Ax-2 astronauts, along with the Expedition 69 crew, completed over 20 science experiments during their eight days aboard the orbiting laboratory, including microgravity research, biomedical sample collection, and technology demonstrations.
The mission came just over a year after Houston-based Axiom sent its first private astronauts onboard the ISS on April 8, 2022. On top of conducting scientific research, the astronauts also laid the groundwork for future missions that will focus on building private modules on the Station that will eventually detach and become a singular free-flying space station for commercial use.
Returning to Earth
Hatch closure occurred at 9:20 AM EDT (13:20 UTC), followed shortly after by the Dragon spacecraft undocking from the space-facing (Zenith) port of the station’s Harmony module at 11:05 AM EDT (15:05 UTC). The Harmony module is also known as the ‘utility hub’ of the station.
They successfully splashed down around 12 hours later.
The Ax-2 astronauts include commander Dr. Peggy Whitson, pilot John Shoffner, the first female Saudi Arabian astronaut, mission specialist Rayyanah Barnawi, and mission specialist Ali Alqarni, also from Saudi Arabia. The Kingdom of Saudi Arabia sponsored their two crew members aboard the mission.
In a livestream on Monday, May 29, Expedition 69 and Ax-2 crewmembers conducted a farewell ceremony ahead of the private astronauts’ return to Earth. In an emotional farewell speech, which was first said in Arabic, Barnawi said: “Every story comes to an end. This is only the beginning of a new era for our country, so I would just like to thank everyone here who has helped us.”
Pilot John Shoffner thanked the other crew members for their “extreme patience” as Ax-2 marked his first mission into space. “You know, they say that learning to go to space is difficult. Well, being in space is also a challenge for a first-time flyer. I’ve tested the patience of everyone here with my flying skills, but it’s such an honor to be here and have a chance to do this. It’s a thing of a lifetime.”
“Thank you to the Expedition 69 crew; they have welcomed us here with such hospitality; it has been somewhat overwhelming,” said Ax-2 Commander Peggy Whitson.
Eight Days on the ISS
After launching atop a Falcon 9 rocket on May 21 at 5:37 PM EDT (21:37 UTC) from Launch Complex 39A (LC-39A) at the Kennedy Space Center, the Crew Dragon spacecraft, named Freedom, docked with the station on May 22 at 9:12 AM EDT (13:12 UTC). The hatch then opened at 11 AM EDT (15:00 UTC), and the four Axiom astronauts joined the Expedition 69 crewmembers, increasing the number of people on the ISS to 11.
Freedom was used to launch Crew-4 to the ISS in April 2022 while the Axiom Mission 1 astronauts were carried in Crew Dragon Endeavour.
To begin their eight days onboard the Station, the Ax-2 crew practiced station operations, such as preparing food and drinks, conducting hygiene practices, performing safety procedures, and operating lab equipment. Two days later on May 24, an uncrewed cargo mission, Progress 84, arrived at the space station and delivered three tons of food, fuel, and supplies to the astronauts.
While the Ax-2 astronauts were only on the ISS for a short time, the eight days were action-packed. One of the primary focuses for the crew was to continue studying the effects space has on the human body.
One experiment, in particular, was the Gravity Loading Countermeasure Skinsuit (dubbed Skinsuit), which is developed in partnership with the Translational Research Institute for Space Health (TRISH) and Massachusetts Institute of Technology (MIT).
The Skinsuit was developed to simulate some of the effects of Earth’s gravity and could one-day countermeasure the physiological effects of microgravity, such as spinal elongation, muscle atrophy, and sensorimotor changes. Shoffner completed several exercises wearing the skinsuit to demonstrate its potential benefits, as it could supplement exercise during future missions.
Commander Whitson focused heavily on the Cancer in Low Earth Orbit experiment, which studies prospective therapies for breast and blood cancer by testing countermeasure drugs that benefit from microgravity. According to Axiom, this experiment contributes to the goal of creating cellular models that will predict and detect the development of cancer.
Alqarni and Barnawi performed a test run of the Nanoracks Space Kite payload, which demonstrates the aerodynamic behavior of kites in microgravity and was formed as part of the Saudi education outreach program. The Saudi Arabian astronauts also measured their blood pressure, blood oxygen, and heart rate levels to look at how humans adapt and respond to the space environment, which is part of the Nebula Human Research investigations.
The team also worked on the Stellar Stem Cells project, which focused on the growth of stem cells and the impact microgravity has on them. On top of many other experiments, the crew conducted several science, technology, engineering, art, and math outreach events to inspire the next generation of scientists and engineers.
Commercial space stations are the future
The ISS is integral not only to scientific research but the ongoing collaboration between nations in space. While the ISS has served as the pinnacle of microgravity research, human space exploration, and in-space collaboration for over 20 years, it is set to cease operations by the end of the decade, with plans for its de-orbit after 2030.
Geopolitical tensions with Russia after its invasion of Ukraine have also put the Station’s operations into question, as Roscosmos – which is largely responsible for maintaining the ISS’ position in orbit and operating resupply missions to astronauts – threatened to withdraw from the program by 2024 in early 2022. However, in April this year, the Russian space agency said it would commit to its support of the station until 2028.
While the ISS will eventually see its end, commercial space stations are already garnering attention and investment. Axiom Space is preparing for a 2025 launch of the first module of its space station that will operate in low-Earth orbit, like the ISS. The station is being built in collaboration with NASA and Thales Alenia Space and is expected to be nearly double the usable volume of the ISS.
Several other companies have begun plans to develop commercial space stations, like Blue Origin and Sierra Space’s Orbital Reef and Lockheed Martin, Voyager Space, and Nanoracks’ Starlab. However, it should be noted that the commercial space stations that have been announced so far are still in the early stages of development and planning.
(Lead image: the Ax-2 astronauts on the ISS. Credit: Axiom)