OBJECTIVES:
NASA suit engineers and the Extravehicular Activity (EVA) Project Office have identified that suit fit in microgravity could become an issue, as evidenced during a recent incident on-board the International Space Station (ISS). It has also been noted that crewmembers often need to adjust their suit sizing once they are in orbit. This adjustment could be due to microgravity effects on anthropometry and postural changes, and is necessary to ensure optimal crew performance, fit, and comfort in space. To date, the only data collected in space to determine the effects of microgravity on physical human changes have been during Skylab, STS-57, and a recent Human Research Program (HRP) study on seated height changes due to spinal elongation, Spinal Elongation (Young, 2011). Skylab and the STS-57 studies found that there is a distinct neutral body posture (NBP) based on photographs. Additionally, Skylab studies found that crewmembers could experience a stature growth of up to 3 percent. The Spinal Elongation study in 2011 identified that the crewmembers could experience about a 6 percent growth in seated height and a 3 percent stature growth when exposed to a microgravity environment. The results prove that not all anthropometric measurements have the same microgravity percent growth factor. In order for the EVA Project Office and the suit engineers to properly update the sizing protocol for microgravity, they need additional anthropometric data from space. Hence, this study was recommended by the ISS and sponsored and funded by the EVA Project Office to gather additional in-flight anthropometric measurements, such as lengths, depths, breadths, and circumferences to determine the changes to body shape and size due to microgravity effects. It was anticipated that by recording the potential changes to body shape and size, a better suit sizing protocol could be developed for ISS and other space missions. In essence, this study aimed to help NASA quantify the impacts of microgravity on anthropometry to ensure optimal crew performance, fit, and comfort. Additional in-flight physical changes due to NBP and the effects of spaceflight on NBP during extended exposure to microgravity also needed to be quantified. This study used simplistic data collection techniques as well as digital still and video data to perform photogrammetric analyses and determine the changes that occur to the body shape, size, and NBP while exposed to a microgravity environment.

The objectives were:
1. To initiate an activity to gather and document microgravity effects on body measurements: lengths, breadths, widths, circumferences, and joint angles of subjects exposed to microgravity in an unsuited condition.

2. To determine if/how the NBP is influenced by the above factors.

3. This was the first time these proposed measures were collected in space. It was anticipated that body measurements would change due to microgravity and fluid shifts. The goal of this study was to gather preliminary data to better understand the magnitude and variability of these changes. This data is important for NASA to be able to determine the changes that may occur during long-duration space flight and once obtained, NASA engineers may be able to apply these changes to suit fit, suit sizing, work station design, etc. for current and near future missions. These changes will help NASA to prevent potential crew injury during extended on-orbit missions.

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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: https://humanresearchroadmap.nasa.gov/