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Disc Herniation Risk Analysis (Disc_Herniation)
Principal Investigator
Research Area:
Biomedical countermeasures
Human factors
Species Studied
Scientific Name: Homo sapiens Species: Human

A previous study reported that the risk of developing a herniated nucleus pulposus (HNP) was higher in U.S. astronauts who had flown at least one mission, as compared with those in the NASA Astronaut Corps who had not yet flown. However, the study did not account for the cumulative effect of multiple missions. While many HNPs occurred well into astronauts’ careers or in some cases years after retirement, the higher incidence of HNPs relatively soon after completion of space missions suggests that space flight does increase the risk of HNP. To formally investigate this possibility, the investigators used a competing-risks survival model to analyze reports and dates of first HNP occurrences from 330 U.S. astronauts taking part in 745 space missions over 55 years. In this model, the outcome of interest, time from selection into the Astronaut Corps to first report of HNP is modeled as the minimum of several event times, one following each space mission plus one influenced by astronaut training and general lifestyle irrespective of participation in actual missions.

Although returning crewmembers have higher incidence of disc herniation post-flight, it is unknown if this increased incidence is related or contributes to an increased risk of injury due to dynamic loads. The aims of this study are as follows:

  1. Mine existing human space flight data on the incidence and severity of vertebral disc herniation after space flight.
  2. Analyze data (perform meta-analysis, statistics, etc.).
  3. Determine the correlation of herniation risk to flight duration and landing impact severity.

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Lumbar vertebrae
Cervical vertebrae
Thoracic vertebrae

Data Information
Data Availability
Archive is complete. Data sets are not publicly available but can be requested.
Data Sets+ Request data

Body mass index (BMI)
Herniated nucleus pulposus (HNP) cervical occurence
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Mission/Study Information
Mission Launch/Start Date Landing/End Date Duration
Ground 05/01/2009 In Progress

Human Research Program (HRP) Human Research Roadmap (HRR) Information
Crew health and performance is critical to successful human exploration beyond low Earth orbit. The Human Research Program (HRP) investigates and mitigates the highest risks to human health and performance, providing essential countermeasures and technologies for human space exploration. Risks include physiological and performance effects from hazards such as radiation, altered gravity, and hostile environments, as well as unique challenges in medical support, human factors, and behavioral health support. The HRP utilizes an Integrated Research Plan (IRP) to identify the approach and research activities planned to address these risks, which are assigned to specific Elements within the program. The Human Research Roadmap is the web-based tool for communicating the IRP content.

The Human Research Roadmap is located at:

+ Click here for information of how this experiment is contributing to the HRP's path for risk reduction.

Additional Information
Managing NASA Center
Johnson Space Center (JSC)
Responsible NASA Representative
Johnson Space Center LSDA Office
Project Manager: Pamela A. Bieri
Institutional Support
National Aeronautics and Space Administration (NASA)
Proposal Date
Proposal Source
Directed Research