Updated 11:50 a.m. Eastern with one-day delay.

WASHINGTON — Axiom Space is set to launch its third private astronaut mission to the International Space Station, although technical issues have compressed the timeline for launch preparations and may have led to a one-day delay.

During a media teleconference Jan. 16, officials from Axiom, NASA and SpaceX said they were proceeding with a planned Jan. 17 launch of the Ax-3 mission to the ISS. A Falcon 9 was scheduled to lift off at 5:11 p.m. Eastern and place a Crew Dragon spacecraft into orbit that will dock with the station about 36 hours later.

However, SpaceX announced less than six hours before liftoff that it was postponing the launch a day to provide more time “to complete pre-launch checkouts and data analysis on the vehicle.” The company did not elaborate on what issue or issues required the additional time. Launch is now scheduled for 4:49 p.m. Eastern Jan. 18.

That media briefing was intended to take place after the completion of the launch readiness review, the final major review before launch. However, officials said on the call they had postponed that review to early Jan. 17 to give teams more time to complete preparations for the launch.

That work was affected by inspections over the weekend that found issues with joints that connect the Dragon spacecraft to the Falcon 9 upper stage. Two of the four joints were tightened with torques “a little out of family,” said Benji Reed, senior director of human spaceflight programs at SpaceX. He did not say if they were too tight or too loose.

SpaceX decided to replace the connections “out of an abundance of caution,” he said, a process that delayed other launch preparations. While SpaceX and Axiom had planned to perform a “dry dress rehearsal,” or walkthrough of launch preparations for the crew, on Jan. 15, that was delayed a day.

Reed said SpaceX compressed the schedule of preparations to prevent a delay, including postponing the launch readiness review to the morning of the launch. “They worked hard through the weekend to keep the launch on Wednesday,” he said of launch teams. “Right now we’re on track.”

A second issue found during preparations for the launch involves the parachute system. Reed said that inspections of the parachutes from the CRS-29 cargo Dragon spacecraft that splashed down Dec. 22 found evidence that straps known as “energy modulators” did not work as designed. The straps, stitched together, are designed to regulate the load on the main parachutes as they are extracted from the capsule by pulling apart.

On the CRS-29 splashdown, some of the stitching did not break apart as designed, resulting in a higher load on the main parachutes. That did not affect the performance of the parachutes, but Reed said SpaceX concluded the problem could be explained if the energy modulator straps are twisted during installation.

Technicians went into the parachute system installed on the Ax-3 Crew Dragon spacecraft and untwisted energy modulators in them. Reed said SpaceX is working with NASA to confirm that twisting can explain what was seen on CRS-29. “We’re ready to fly.”

The mission is the third in a series of private astronaut missions by Axiom Space intended to serve as precursors to commercial modules the company plans to install on the ISS, which in turn will form the core of a future standalone commercial space station after the retirement of the ISS.

Derek Hassmann, chief of mission integration and operations at Axiom, said at the briefing that the company wants to continue flying such missions at a rate of twice a year until its first module is installed in late 2026. The next mission, Ax-4, is tentatively scheduled for the fall of 2024, said Dana Weigel, deputy manager of the ISS program at NASA.

Ax-3 is commanded by Michael López-Alegría, a former NASA astronaut who is now Axiom’s chief astronaut. Walter Villadei, an Italian Air Force officer, will be the mission’s pilot. He served as the backup pilot for Ax-2 in May 2023 and also flew on the first Virgin Galactic commercial suborbital mission in June 2023.

The Ax-3 mission specialists are Alper Gezeravcı of Turkey and Marcus Wandt of Sweden. Gezeravcı will be the first person from Turkey to go to space and Wandt the second from Sweden. The European Space Agency, working with the Swedish space agency, arranged from the flight of Wandt, who was selected as an ESA reserve astronaut in 2022.

While the other three members of Ax-3 will be making their first trips to orbit, the flight will be the sixth for López-Alegría, who previously flew on three shuttle missions and one long-duration ISS mission as a NASA astronaut before commanding the Ax-1 mission in 2022.

“It’s a dream come true for me,” he said at a Jan. 11 briefing when asked how much longer he wants to fly to space. “As long as they ask me to fly, my hand will be raised.”

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...