Astronauts aboard the International Space Station (ISS) recently welcomed NASA's newest class of astronaut candidates, known as 'ascans.' The Expedition 73 crew members engaged in a week of scientific research, including DNA sequencing and virtual reality experiments, while also managing cargo deliveries and maintaining the orbiting outpost. This period, from September 22-26, 2025, marked a busy time for the seven-person team as they continued their work more than 250 miles above Earth.
The new astronaut candidates, NASA's 24th group, were introduced during a ceremony held at the Johnson Space Center in Houston. The ISS crew congratulated the new recruits, emphasizing the importance of their upcoming two-year basic training before they become eligible for flight assignments. This integration of new talent into the astronaut corps is crucial for future space missions.
Key Takeaways
- Expedition 73 crew welcomed NASA's 24th astronaut candidate class.
- Astronauts conducted DNA sequencing and virtual reality experiments.
- Cargo vehicles were unloaded, and the station's orbit was reboosted.
- A JAXA astronaut photographed Typhoon Neoguri from space.
- International collaboration remains central to ISS operations.
New Astronaut Candidates Join NASA Corps
On Monday, September 22, NASA announced its latest group of astronaut candidates. The ceremony took place at the Johnson Space Center in Houston, Texas. Members of the Expedition 73 crew, currently living and working on the International Space Station, sent a message of congratulations to the new class. They also shared a photograph showing them watching the introduction of Group 24.
"To the newest astronaut class, from the crew of Expedition 73 onboard the International Space Station, congratulations and welcome to the Astronaut Corps!" stated Jonny Kim, a NASA astronaut and current ISS crew member.
These new candidates, often referred to as 'ascans,' will undergo approximately two years of intensive basic training. After completing this training, they will become eligible for future flight assignments, potentially participating in missions to the ISS, the Moon, or even Mars.
Fact: Astronaut Corps
The term "astronaut corps" refers to the group of individuals trained and qualified to travel and work in space. NASA's astronaut selection process is highly competitive, seeking candidates with diverse backgrounds in science, engineering, and medicine.
Scientific Research Continues Aboard Station
The Expedition 73 crew actively engaged in various scientific investigations throughout the week. These experiments are vital for understanding the effects of microgravity on the human body and developing technologies for future long-duration space missions.
Voyager DNA Decryption
NASA astronaut Jonny Kim performed DNA sequencing as part of the Voyager DNA Decryption study. This research explores the potential of using DNA polymers to securely store and transmit data in the challenging space environment. The findings from this investigation could significantly reduce the need for bulky data storage solutions, making deep space missions more feasible and efficient.
VIRTUAL Investigation
Cosmonaut Oleg Platonov participated in the Spatial Orientation and Interaction of Eisodic Systems Under Conditions of Weightlessness (VIRTUAL) investigation. This study collects data on crew members' vestibular functions. Specifically, it examines gaze disposition and visual tracking during long-duration space missions. Platonov wore virtual reality glasses and responded to computer-generated visual stimuli, while his eye movements and other physiological reactions were recorded. This helps scientists understand how the brain adapts to microgravity.
Context: Vestibular System
The vestibular system is responsible for balance and spatial orientation. In microgravity, this system can be disrupted, leading to disorientation and motion sickness. Understanding these changes is critical for maintaining astronaut health and performance.
SPLANKH Study
Roscosmos cosmonauts Sergey Ryzhikov and Alexey Zubritsky conducted the SPLANKH investigation. On Friday, September 26, after breakfast, they used an ultrasound device to scan each other's bellies. This procedure collected data on their digestion, metabolism, and nutrient delivery as their bodies adjusted to the microgravity environment. Such studies are essential for optimizing astronaut diets and health protocols.
Station Maintenance and Orbital Adjustments
Beyond scientific endeavors, the Expedition 73 crew also managed critical tasks related to the space station's upkeep and future operations. These activities ensure the continuous functionality and safety of the orbiting laboratory.
NG-23 Cygnus Unloading
Astronauts Mike Fincke and Kimiya Yui spent Friday, September 26, continuing the process of unloading new science equipment and supplies. These items arrived aboard the S.S. William C. "Willie" McCool, an uncrewed Northrop Grumman NG-23 Cygnus cargo vehicle. Efficient cargo management is vital for the station's ongoing research and crew support.
Cubesat Installation
Mike Fincke installed a small satellite, known as a cubesat, onto the NanoRacks external platform. This cubesat will soon be deployed outside the space station, contributing to various technological demonstrations and scientific observations from orbit.
Dragon Reboost Maneuver
A SpaceX Dragon cargo spacecraft executed a 15-minute thruster burn on Friday, September 26, to reboost the station's orbit. This maneuver helps compensate for atmospheric drag, which slowly pulls the ISS closer to Earth. The reboost came a day after an initial attempt was aborted due to an unexpected issue with a fuel tank changeover. This demonstrates the precision and careful monitoring required for orbital operations.
International Collaboration and Earth Observation
International cooperation remains a cornerstone of ISS operations, facilitating both scientific advancements and global outreach. The crew also took time for Earth observation, providing unique perspectives of our planet.
Typhoon Neoguri Observation
On Monday, September 22, JAXA astronaut Kimiya Yui captured a photograph of Typhoon Neoguri from his vantage point aboard the ISS. The image showcased the station's Canadarm2 robotic arm in the foreground, reaching out from the station, with the powerful storm visible below. Such observations provide valuable data for meteorologists on Earth.
Discussion with Korean Space Agency
Expedition 73 flight engineer and NASA astronaut Jonny Kim held a discussion with Yoon Youngbin, the administrator of the Korea Aerospace Administration (KASA), on Thursday, September 25. The conversation lasted approximately 20 minutes, focusing on future space exploration and international collaboration.
Yoon Youngbin expressed, "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."
Kim responded, "There is so much to learn about space, and I am very inspired by what Korea is doing to push forward that envelope."
This exchange highlights the growing global interest in space and the importance of sharing knowledge and expertise across national borders for advancing human exploration.
Current Status of the International Space Station
As of Friday, September 26, the International Space Station continues its mission as a hub for human spaceflight and scientific discovery. The station has been continuously crewed for over 24 years, 10 months, and 24 days, marking a significant achievement in international cooperation.
- Crew Count: Seven individuals are currently aboard the ISS.
- Crew Members:
- Sergey Ryzhikov (Roscosmos, Commander)
- Alexey Zubritsky (Roscosmos, Flight Engineer)
- Oleg Platonov (Roscosmos, Flight Engineer)
- Jonny Kim (NASA, Flight Engineer)
- Zena Cardman (NASA, Flight Engineer)
- Mike Fincke (NASA, Flight Engineer)
- Kimiya Yui (JAXA, Flight Engineer)
- Docked Crew Spacecraft:
- SpaceX's Dragon "Endeavour" (attached to the zenith port of the Harmony module)
- Roscosmos' Soyuz MS-27 (attached to the Earth-facing port of the Prichal node)
- Docked Cargo Spacecraft:
- Roscosmos' Progress MS-31 (92P) (docked to the space-facing port of the Poisk module)
- Roscosmos' 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)
- Northrop Grumman's NG-23 Cygnus XL, the "SS William C. 'Willie' McCool" (berthed to the Unity node)
The diverse international crew and array of docked spacecraft underscore the complex and collaborative nature of modern space exploration. Each element plays a crucial role in maintaining the station's functionality and supporting its ambitious research agenda.