During their six-month mission, the Crew-4 astronauts worked on numerous science experiments and technology demonstrations, many of which were sponsored by the International Space Station (ISS) National Laboratory. The results from these research investigations will not only benefit people back on Earth but will also help to prepare humans for future deep space missions.
“We’ve had an extraordinary experience up here and done a lot of exciting science,” NASA astronaut Kjell Lindgren said ahead of the crew’s return.
The crew—NASA astronauts Kjell Lindgren, Bob Hines, and Jessica Watkins and European Space Agency (ESA) astronaut Samantha Cristoforetti—returned to Earth on Friday, October 14 after launching to the orbiting laboratory in April.
Here’s a look back at some of their scientific achievements.
Radiation exposure is a primary concern for space exploration and ensuring that astronauts have the ability to live and work effectively—and safely—during future Moon missions is crucial. To that end, a special vest developed by StemRad and Lockheed Martin was sent to the ISS to study how well it can protect astronauts from space radiation.
Over the last two years, multiple astronauts onboard the ISS, including Crew-4’s Jessica Watkins, have tested a prototype of the AstroRad vest for comfort and wearability. A second prototype vest will fly on the upcoming Artemis-1 mission to provide crucial data on the vest’s ability to protect astronauts on long-duration missions.
Spaceflight and aging
Funded by the National Institute of Health’s National Center for Advancing Translational Sciences (NCATS) through the Tissue Chips in Space initiative in collaboration with the ISS National Laboratory, this investigation studied the relationship between immune aging and healing outcomes in space.
The experiment, from a team of researchers at the University of California, San Francisco, will help shed light on the effects of microgravity on the body’s immune system and how those effects play into the aging of immune cells. By observing immune function in microgravity and during cell recovery back on Earth, the research team hopes to better understand not only how immune cells change but also how the immune aging process could be reversed.
Tide in Space
The microgravity environment of the space station provides a unique platform to study how fluids interact on a fundamental level. Such research can lead to better products for consumers here on Earth. To that end, Procter & Gamble sent several of its Tide products to the ISS to see how well they perform in microgravity.
The experiments tested not only how well the products held up in the harsh microgravity environment, but also how well they worked against several staining agents commonly found on the space station. Results will help lead to potential new laundry options for astronauts and more sustainable products terrestrially.
This student-led experiment tested the foundation for what could be a new type of biosensor to test water quality. Such a sensor would streamline water quality testing, providing a valuable tool for both space travelers and people in remote or low-resource communities on Earth who do not have access to sophisticated equipment.
The sensor relies on a molecular tool called BioBits, which can create a variety of proteins inside a test tube without the need for cell culture. The experiment, which was designed to test how efficiently the BioBits work in space, was proposed by Selin Kocalar, a high school student as part of the Genes in Space program.
Conducted by NASA astronaut Bob Hines before his departure from the ISS, the Rhodium Space Microbiome Isolates investigation is looking at bacterial species in the human gut microbiome that are known to change during spaceflight. Previous research has shown that changes in the gut microbiome are related to chronic and acute diseases.
A better understanding of this connection and changes in the gut microbiome could lead to the development of new tests for identifying changes to gut microbes that contribute to overall health. Results could help lead to personalized treatment options for future astronauts as well as patients on Earth.
ISS HAM Radio
Students can chat with the astronauts onboard the ISS via HAM radio through a program called Amateur Radio on the International Space Station (ARISS). During her flight, Cristoforetti spoke to many students, including a group of Italian students at the Istituto Comprensivo Tolfa, in Tolfa, Lazio.
ARISS, an ISS National Lab educational partner program, arranges 60-80 of these calls each year, connecting students from around the world with astronauts on the space station.
The Sally Ride EarthKAM, named after NASA astronaut Sally Ride, is designed as an educational outreach program to help students and the public learn about the Earth by viewing it from space.
The astronauts set up the camera, which then allows students to photograph and view the Earth from an astronaut’s perspective. The students control the camera from their classrooms, snapping pictures of the Earth that will later be posted online for the public and other classrooms around the world to view.
Microgravity and Skin Healing
An investigation from researchers at the Center for Military Psychiatry and Neuroscience looked at skin healing in microgravity. Mice are used as a model organism because they have many similarities with humans and researchers can use them to study fundamental biological processes.
Through this experiment, the research team studied the effects of spaceflight on systemic and local responses of skin healing to better understand the biological changes that happen in the healing process. Identifying changes that affect tissue regeneration could help researchers discover therapeutic targets for improved treatments.