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Recent peer-reviewed papers in space medicine, each with a plain-English summary, a line on why it matters clinically, and links to related pages on this site. Every citation was checked against PubMed and Crossref.
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Review · Oct 9, 2026 · Eyes & brain
Ocular Changes in Human Spaceflight
Gupta et al. Prog Retin Eye Res. 2026:101535. doi:10.1016/j.preteyeres.2026.101535 · PMID 42855039 · Verified: PubMed + Crossref
A broad review of how spaceflight affects the eye, including spaceflight-associated neuro-ocular syndrome (SANS), damage to the corneal surface, possible radiation-related lens changes, and retinal and choroidal changes. It also covers the limits on eye imaging, pressure measurement and drug delivery in orbit.
Why it matters clinically: A current reference for clinicians who examine crew before and after flight, including what can and cannot be measured in space.
Related on this site: SANS clinical management · SANS topic
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Cohort analysis · Oct 1, 2026 · Bone & muscle
Increased Rates of Hip Fractures Associated With Longer Spaceflight Durations
Taylor et al. Mayo Clin Proc. 2026;101:1700–1711. doi:10.1016/j.mayocp.2026.06.025 · PMID 42820897 · Verified: PubMed + Crossref
Researchers analyzed a survey of all fractures reported by U.S. astronauts. Hip fractures were more frequent in the years after a mission longer than 90 days than after shorter flights or no flight. Rates matched those of people on Earth 8 to 16.5 years older; fracture rates at other sites did not differ.
Why it matters clinically: Returning long-duration crew may carry hip fracture risk earlier in life than their age suggests; bone surveillance should continue for years after flight.
Related on this site: Bone loss topic · Bone loss countermeasures · Post-flight surveillance
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Twin case study (multi-omics) · Sep 28, 2026 · Immune & microbiome
Systemic elevation of gut derived p-cresol during one year in space: implications for brain, heart, bone, liver and microbiome in astronauts
Schmidt et al. Front Physiol. 2026;17:1878680. doi:10.3389/fphys.2026.1878680 · PMID 42866036 · Verified: PubMed + Crossref
Using data from the NASA Twins Study (one twin spent 340 days on the space station), researchers found changes in blood levels of p-cresol, a toxin made by gut bacteria, at certain stages of flight. Gut bacteria that produce it, including Clostridioides difficile, were more abundant in the flight twin.
Why it matters clinically: Hypothesis-generating only (one person in space), but it points to gut bacteria as a possible target for protecting crew health on long missions.
Related on this site: Research studies · Open questions
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Cohort study (MRI) · Sep 24, 2026 · Bone & muscle
Quantitative MRI changes in neck muscle size and composition following long-duration spaceflight
Madrid Fuentes et al. Exp Physiol. 2026:EP093726. doi:10.1113/EP093726 · PMID 42782142 · Verified: PubMed + Crossref
Nine astronauts (about 7 months in flight) had neck MRI before and after their missions. Most of 11 neck muscles kept their size and fat content; more resistance exercise in flight was linked to larger, leaner muscles. Because every crewmember exercised, the study cannot show that exercise prevented loss.
Why it matters clinically: Reassuring for neck strength after modern missions with structured exercise, which matters for landing loads and return to duty.
Related on this site: Exercise countermeasures · Recovery timeline tool
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Commentary / guidance · Sep 21, 2026 · Emergencies & trauma
Terrestrial trauma systems in support of human spaceflight
Lazow et al. J Trauma Acute Care Surg. 2026. doi:10.1097/TA.0000000000005176 · PMID 42767210 · Verified: PubMed + Crossref
The authors argue that local trauma systems near launch and landing sites must be ready for injured space travelers. Responders should expect altered physiology after long missions and chemical or heat exposures. Evacuation from landing sites may take several hours, so care should follow Advanced Trauma Life Support principles with hours of temporizing care.
Why it matters clinically: Emergency departments and trauma centers near launch and landing sites should pre-plan transport, mass-casualty response and spaceflight-specific assessment.
Related on this site: In-flight emergencies & evacuation · Orthostatic intolerance at landing
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Prospective observational study · Sep 15, 2026 · Heart & circulation
Impact of Prolonged Spaceflight on Cardiac Structure and Function: An Exploratory Longitudinal Observational Study
Appadurai et al. Circulation. 2026;154(15):1444–1455. doi:10.1161/CIRCULATIONAHA.125.078665 · PMID 42741837 · Verified: PubMed + Crossref
Thirteen astronauts had heart ultrasound before, during and after space station missions (median 164 days). Heart filling volume and pumping output dropped early in flight, much like standing up on Earth, then drifted back toward baseline. After landing, a tilt that simulated Mars gravity did not stress the heart more than standing did before flight.
Why it matters clinically: With current exercise countermeasures, about six months in space did not cause large lasting changes in heart structure or function in this small study.
Related on this site: Orthostatic intolerance at landing · Orthostatic intolerance topic · Exercise countermeasures
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Review · Sep 7, 2026 · Radiation
Space radiation health risks to hematopoietic, neural, and gastrointestinal systems in astronauts
Zhang et al. Front Public Health. 2026;14:1926972. doi:10.3389/fpubh.2026.1926972 · PMID 42769920 · Verified: PubMed + Crossref
A review of how space radiation may affect the bone marrow, nervous system and gut. Human flight data suggest effects such as lower lymphocyte counts; brain and gut effects come mainly from animal studies and still need confirmation in astronauts.
Why it matters clinically: Helps separate what is seen in astronauts from what is so far shown only in animals when counseling about deep-space radiation risk.
Related on this site: Space radiation topic · Radiation limits & monitoring · Radiation dose estimator
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Case series (ultrasound) · Sep 3, 2026 · Heart & circulation
Physiological adaptation of the jugular venous pulse during long-duration spaceflight
Zamboni et al. Sci Rep. 2026;16:28222. doi:10.1038/s41598-026-69054-9 · PMID 42716986 · Verified: PubMed + Crossref
Ultrasound of the internal jugular vein in four astronauts showed the vein became smaller after flight in three of them, while its pulsing motion increased. A fourth astronaut showed the opposite pattern, which the authors attribute to a probable jugular vein clot, the third such case documented in space medicine.
Why it matters clinically: Neck-vein clots are a known spaceflight finding; jugular ultrasound may help with monitoring, though four people is too few to set practice.
Related on this site: Point-of-care ultrasound · Research atlas
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Computer modeling · Aug 31, 2026 · Radiation
Dose estimation for astronauts using adult mesh-type reference computational phantoms
Cai et al. Radiat Prot Dosim. 2026:ncag099. doi:10.1093/rpd/ncag099 · PMID 42672124 · Verified: PubMed + Crossref
A computer model estimated organ doses for astronauts in the Chinese Space Station orbit: about 1,006 microsieverts per day during spacewalks and 571 inside the station. Trapped protons from Earth’s radiation belts were the largest contributor. The authors note dose cannot be inferred from altitude alone because orbital inclination changes exposure.
Why it matters clinically: Spacewalks nearly double the daily dose in this model; orbit inclination, not just altitude, matters when estimating crew exposure.
Related on this site: Radiation dose estimator · Radiation limits & monitoring
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Drop tests + computer modeling · Aug 15, 2026 · Occupant protection · Emergencies & trauma
Effects of Crew Seat Inclination on Multi-Organ Injury Risk in Astronauts During Off-Nominal High-g Landing Impact
Ma et al. Ann Biomed Eng. 2026. doi:10.1007/s10439-026-04334-z · PMID 42603230 · Verified: PubMed + Crossref
Using crash-test-dummy drop tests (18–45 g) and human body computer models, researchers tested seat back angles from 0° to 40° for hard capsule landings. Standard injury measures worsened as the seat reclined, with the lower spine most sensitive, while individual organs favored different angles.
Why it matters clinically: Off-nominal landings can far exceed normal 8–12 g loads; seat design trade-offs affect which injuries clinicians should expect after a hard landing.
Related on this site: In-flight emergencies & evacuation
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Perspective · Aug 6, 2026 · Immune & microbiome
Long-term major histocompatibility complex class I suppression in astronauts and clinical implications
LeRoy et al. Commun Biol. 2026;9:1053. doi:10.1038/s42003-026-10550-z · PMID 42562863 · Verified: PubMed + Crossref
Genes that let cells display “danger signals” to the immune system (MHC class I) were turned down across missions from the three-day Inspiration4 flight to long space station stays. Tumors and viruses use the same trick to hide. This perspective discusses possible long-term risks and research directions.
Why it matters clinically: A possible mechanism behind viral reactivation in crew; it is a perspective, not new clinical evidence.
Related on this site: Research open questions · Body explorer
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Laboratory comparison · Aug 4, 2026 · Medications
Limited Degradation of Active Pharmaceutical Ingredient After Spaceflight on the International Space Station
Nowadly et al. Wilderness Environ Med. 2026. doi:10.1177/10806032261466966 · PMID 42550782 · Verified: PubMed + Crossref
Eight medications flown to the space station were compared with matched ground samples, all tested after their expiration dates. Most differed from ground controls by 5% or less and more than 90% of samples stayed within 80–120% of labeled strength. Epinephrine was the exception, averaging 10% lower than its ground control.
Why it matters clinically: Supports limited spaceflight effect on most drugs studied, but flags epinephrine potency as a concern for long-mission medical kits.
Related on this site: Drug stability in space · Medical kit builder · Mission medical kits
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Laboratory study (sounding rocket) · Aug 4, 2026 · Medications
Stability of Medicinal Nanoemulsions to Spaceflight: Insights From the StarMed Experiment
Adebowale et al. Adv Healthc Mater. 2026;15(33):e71521. doi:10.1002/adhm.71521 · PMID 42549747 · Verified: PubMed + Crossref
Liquid melatonin formulations flew on a sounding rocket. An uncoated version showed slight droplet growth under all conditions, including ground storage, consistent with ordinary aging rather than a weightlessness effect. A chitosan-coated version stayed essentially unchanged.
Why it matters clinically: Early work on making liquid medications more stable for future mission kits; not yet clinical.
Related on this site: Drug stability in space
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Retrospective analysis · Aug 1, 2026 · Eyes & brain
Identifying Predisposing Factors for Hyperopic Shift in Long-Duration Spaceflight
Aldeghi, Higbee. Aerosp Med Hum Perform. 2026;97(8):627–632. doi:10.3357/AMHP.6896.2026 · PMID 42542336 · Verified: PubMed (Crossref record not yet available)
In NASA data from 85 astronauts on missions longer than 30 days, older age was the strongest predictor of a shift toward farsightedness, a feature of SANS. Longer missions and higher preflight body weight showed weaker links.
Why it matters clinically: Older crew on long missions may warrant closer vision monitoring before, during and after flight.
Related on this site: SANS clinical management · SANS topic
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Pharmacokinetic study · Jul 30, 2026 · Medications · Research methods
Volumetric Absorptive Microsampling During Spaceflight for Analysis of Acetaminophen Pharmacokinetics in Whole Blood
Mampre et al. J Clin Pharmacol. 2026;66(8):e70240. doi:10.1002/jcph.70240 · PMID 42530224 · Verified: PubMed + Crossref
The four Polaris Dawn crewmembers took 500 mg of acetaminophen before, during and after flight and collected finger-prick blood samples. In flight, peak blood levels were several times higher and the drug was cleared differently; some changes persisted three days after landing. The authors call this the first pharmacokinetic study using blood drawn during spaceflight.
Why it matters clinically: Standard Earth doses may produce higher-than-expected drug levels in flight; dosing of common kit drugs needs further study.
Related on this site: Drug stability in space · Commercial flyer screening
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Retrospective cohort · Jul 30, 2026 · Bone & muscle
Shoulder injury and surgery patterns among astronauts across spaceflight phases and mission operations: an analysis of 677 injuries from 1981 to 2024
Ward et al. J Shoulder Elbow Surg. 2026. doi:10.1016/j.jse.2026.07.014 · PMID 42532466 · Verified: PubMed + Crossref
NASA health records from 1981–2024 showed 677 work-related shoulder injuries and 25 surgeries. About 65% happened after flight and 34% before flight. Astronauts with six months or more in space were injured sooner after return, and more hours of underwater spacesuit training were linked to earlier injuries.
Why it matters clinically: Pre-flight conditioning, limits on suit-training load and post-flight shoulder surveillance may prevent injuries, especially as spacewalk demands grow.
Related on this site: Spacewalks and decompression sickness · Post-flight surveillance
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Randomized crossover pilot · Jul 28, 2026 · Eyes & brain · Research methods
Optic nerve sheath diameter increases during 12° head-down tilt in healthy volunteers: a crossover pilot study informing the design of a spaceflight countermeasure trial
Bergauer et al. Front Physiol. 2026;17:1890637. doi:10.3389/fphys.2026.1890637 · PMID 42582054 · Verified: PubMed + Crossref
Eight healthy volunteers lay at 12° head-down tilt (a ground model of weightlessness) or flat. Optic nerve sheath diameter measured by eye ultrasound grew after 90 minutes of tilt, peaking at 150 minutes with an average increase of 0.79 mm.
Why it matters clinically: Sets up a trial of lower-body suction as a SANS countermeasure and supports eye ultrasound as a simple non-invasive marker.
Related on this site: SANS topic · Point-of-care ultrasound · Analogs
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Systematic mapping review · Jul 6, 2026 · Heart & circulation · Research methods
A systematic mapping review of studies reporting the effects of spaceflight on cardiovascular outcomes
Neset et al. Life Sci Space Res. 2026;52:37–44. doi:10.1016/j.lssr.2026.07.003 · PMID 42601158 · Verified: PubMed + Crossref
A NASA-supported team screened over 18,000 records and mapped 3,512 relevant articles. Humans made up about 69% of study populations, but only 28% of articles studied actual spaceflight. Among 855 human spaceflight studies, heart rate, heart measurements and blood pressure were most often reported.
Why it matters clinically: A searchable map of the cardiovascular evidence; useful for finding the actual flight data behind clinical claims.
Related on this site: Research studies · Orthostatic intolerance topic