Astronauts welcome NASA's new 'ascans' | On the International Space Station Sept. 22-26, 2025

Orbital observation

On Monday (Sept. 22), NASA named its next class of astronaut candidates during a ceremony held at Johnson Space Center in Houston. In addition to recording a message to the new trainees, members of the Expedition 73 crew also shared a photo (below) of them watching Group 24 being introduced.

"To the newest astronaut class, from the crew of Expedition 73 onboard the International Space Station, congratulations and welcome to the Astronaut Corps!" wrote Jonny Kim, a fellow NASA astronaut.

The "ascans" will become eligible for flight assignments after about two years of basic training.

Science status

Among the research that was conducted by the Expedition 73 crew aboard the space station this week was:

Voyager DNA Decryption — NASA's Jonny Kim sequenced DNA samples as part of a study into using the polymer to securely store and transmit data in space. The results of this research could help enable longer duration missions into deep space by replacing more bulky data storage techniques.

VIRTUAL —The Spatial Orientation and Interaction of Eisodic Systems Under Conditions of Weightlessness (Virtual) investigation collects data on crew members' vestibular functions "on the disposition of gaze and visual tracking during the course of a long-duration space mission." Cosmonaut Oleg Platonov wore virtual reality glasses and "responded to computer-generated visual stimuli as his eye movements and other physiological reactions were recorded," according to NASA.

SPLANKH — Sergey Ryzhikov and Alexey Zubritsky, both Roscosmos cosmonauts, scanned each other’s bellies with an ultrasound device after breakfast on Friday (Sept. 26) to gather data on their digestion, metabolism and nutrient delivery as they adjust to the microgravity environment of space.

Station keeping

The Expedition 73 crewmates also took part in activities to maintain the space station's systems and prepare for future research.

NG-23 Cygnus — Mike Fincke and Kimiya Yui on Friday (Sept. 26) continued to unload new science and supplies delivered aboard the S.S. William C. "Willie" McCool, an uncrewed cargo vehicle.

Cubesat — Mike Fincke installed a small satellite (cubesat) on the NanoRacks external platform that will soon be placed outside the space station.

Dragon reboost —A SpaceX Dragon cargo spacecraft fired its thrusters for 15 minutes on Friday (Sept. 26), reboosting the station’s orbit. The maneuver came a day after a first attempt at the reboost was aborted after it was noticed a change of fuel tanks did not take place as expected.

Astronaut activity

NASA ASTRONAUT DISCUSSES LIFE IN SPACE WITH ADMINISTRATOR OF SOUTH KOREAN SPACE AGENCY - 9-25-2025 - YouTube

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Expedition 73 flight engineer and NASA astronaut Jonny Kim spoke with the leader of the Korea Aerospace Administration (KASA) on Thursday (Sept. 25).

"I believe that the words that you share with us today will be meaningful guidance and inspiration for our future generations who dream of space," said Yoon Youngbin, KASA administrator.

"There is so much to learn about space, and I am very inspired by what Korea is doing to push forward that envelope," said Kim.

The two spoke for about 20 minutes, which you can watch above.

By the numbers

As of Friday (Sep. 26), there are 7 people aboard the International Space Station: Expedition 73 commander Sergey Ryzhikov of Roscosmos; fellow cosmonauts Alexey Zubritsky and Oleg Platonov; Jonny Kim, Zena Cardman and Mike Fincke of NASA; and Kimiya Yui of JAXA, all flight engineers.

There are two docked crew spacecraft: SpaceX's Dragon "Endeavour" attached to the zenith port of the Harmony module and Roscosmos' Soyuz MS-27 attached to the Earth-facing port of the Prichal node.

There are four docked cargo spacecraft: Roscosmos' Progress MS-31 (92P) docked to the space-facing port of the Poisk module and Progress M-32 (93P) docked to the aft port of the Zvezda service module, SpaceX's CRS-33 Dragon spacecraft docked to the forward port of Harmony Node 2 and Northrop Grumman's NG-23 Cygnus XL, the "SS William C. 'Willie' McCool," berthed to the Unity node.

As of Friday, the space station has been continuously crewed for 24 years, 10 months and 24 days.