Scientists await a big splash in the Pacific Ocean as one of the most research-packed Dragon spacecraft to date returns, completing the 34th SpaceX commercial resupply mission to the International Space Station for NASA. Biological and materials samples, along with tested hardware, are heading back to research teams on Earth for further analysis, advancing NASA’s work to prepare humans for exploration beyond low Earth orbit and to deliver benefits back home.

Some samples returning are for NASA’s Hematopoietic Stem Cell Expansion in Space: Pathfinder Investigation (InSPA-StemCellEX-H2), which seeks to use the microgravity environment to scale up the production of stems cells. On Earth, lab-produced blood stem cells lose their ability to form different cell types, like red and white blood cells that are critical to treating patients with certain blood diseases and cancers. In microgravity, researchers believe this ability will be better preserved while also growing these stem cells in greater numbers. The returning samples will undergo further analysis to determine if space-based efforts produce larger quantities of enhanced stem cells suitable for clinical use.

The team behind NASA’s Streptococcus pneumoniae (Spn) Infection of Cardiac Tissue (MVP Cell-09) experiment is awaiting the return of stem cell-derived heart tissues that were intentionally infected with a pneumonia-causing bacterium as part of ongoing microgravity research. Pneumonia increases the risk of heart disease, which is not fully understood. Because bacteria tend to become more active and virulent in microgravity, this experiment could amplify their effects, making it possible to detect cellular responses that cannot be observed on Earth.

NASA’s Megakaryocyte Flying-One (MeF1) samples are returning to Earth to help understand how large cells found in bone marrow, known as megakaryocytes, and the platelets they produce adapt to spaceflight. Megakaryocytes and platelets play important roles in the formation of blood clots and immune responses. The returning samples, including those taken from astronauts, could show us how the human immune system reacts aboard the space station and help prepare for future exploration missions.

Many spacecraft use cryogenic fuels for propulsion, but temperature swings in space can cause these extremely cold fuels to slowly evaporate and escape their tank, reducing fuel efficiency and complicating mission planning. NASA’s Zero Boil-Off Tank Noncondensables (ZBOT-NC) investigation aboard station studies how gases that do not condense into liquids at cold temperatures affect pressure control and fluid behaviors in propellant tanks. Hardware returning aboard Dragon, including drives containing fluid-physics data, could help validate models and contribute to the design of more efficient cryogenic fuel storage systems for long-duration missions.

Semiconductor research samples as part of NASA’s In-Space Production of Semimetal-Semiconductor Composite Bulk Crystals in Microgravity (SUBSA-InSPA-SSCug) investigation are returning to Earth for further analysis. This study manufactured semimetal-semiconductor composite alloy crystals in space, which have applications in many electronics, including sensors and lasers. Researchers believe microgravity could enable the production of significantly greater and higher-quality crystals, supporting the development of next-generation semiconductor technologies.

NASA’s DNA Nano Therapeutics-3 research team will receive tiny, space-assembled DNA-inspired materials that are combined with medicines to create active cancer treatments. Producing these treatments in microgravity can improve how well they perform in the body. This research could improve patient outcomes by helping therapies reach tumors more effectively, stay in the body longer, and improve medicine release.

Tissue models of the brain, heart, liver, and kidney that were tested with novel RNA-based medicines as part of NASA’s InSPA-Sachi Nanoligomer investigation are also returning. Microgravity can accelerate aging and disease processes, giving researchers a unique environment to better observe how well these new drugs work on different organs ahead of clinical trials.

Samples from ESA’s (European Space Agency) Green Bone investigation are returning to Earth to help understand how bone cells grow and develop on a new scaffold made from wood. Designed to mimic real bone, this scaffold was tested in microgravity to understand its ability to heal defects and fractures. Because living in microgravity simulates conditions like osteoporosis, a skeletal disorder which affects millions of people worldwide, the results could help treat patients with these fragile bone conditions. 

NASA’s 3D Bone Marrow Analog research team will analyze the returning 3D-printed tissues that mimic parts of the bone marrow. Spaceflight can cause aging-like changes, including bone and muscle loss. To investigate potential countermeasures, these tissue models were exposed to small vibrations aboard the space station to simulate exercise. After the samples return to Earth, researchers will measure bone-like mineral formations and observe cellular and genetic changes. Findings from this investigation could help develop new strategies to maintain astronaut bone and muscle health during future long-duration missions.

In the United States, more than 900,000 knee cartilage injuries occur annually, with many requiring surgery. NASA’s InSPA-Auxilium Bioprinter-Cell Printing is investigating how to treat these injuries and is returning 3D-printed cartilage tissue samples from space station. This investigation uses the orbiting laboratory’s unique microgravity environment to bioprint cartilage tissues with more evenly distributed cells compared to those printed on Earth. The results could help produce higher-quality cartilage prints to treat joint injuries.