• Current Research
  • Previous Research


Temperature Regulatory and Cardiovascular Responses to Exercise During Long-Duration Spaceflight

Principal Investigator:
Craig G. Crandall, Ph.D.

The University of Texas Southwestern Medical Center at Dallas

A person???s ability to work is reduced if the body is unable to properly regulate its temperature. Ground-based models suggest that living in the zero-gravity environment of space impairs the body???s ability to regulate temperature. This is a serious concern, especially during periods of physically demanding work such as a spacewalk.

Dr. Craig G. Crandall and colleagues seek to determine if living in zero gravity actually impairs the body???s ability to regulate temperature. They will evaluate temperature regulation during steady-state exercise before, during and after a mission onboard the International Space Station.

The project???s data will lead to improved astronaut safety during missions and possibly increased physical work capacity during events such as spacewalks.

NASA Taskbook Entry

Technical Summary

Appropriate temperature regulation is critical for the safety of astronauts performing physically demanding work, particularly that which occurs during extravehicular activities. Work performance is also greatly reduced if impaired temperature regulation results in large elevations in internal temperatures. Using ground-based models of spaceflight, the prevailing data suggest that temperature control is impaired while astronauts are in space. However, it remains unknown whether these models accurately reflect physiological responses of spaceflight.

Within this context, the project will investigate two key questions:

1) Does spaceflight impair temperature regulation while astronauts are in a zero-gravity environment; and

2) Does prolonged spaceflight impair temperature regulation during extravehicular activities that may occur in a partial-gravity environment of a lunar (one-sixth of the Earth's gravity) or Mars (three-eighths of the Earth's gravity) mission?

The first objective will be accomplished by evaluating temperature regulatory responses in astronauts during steady-state exercise prior to spaceflight, on a monthly basis while on the International Space Station and upon return to Earth. The second objective will evaluate the effects of prolonged spaceflight on temperature regulatory responses during exercise that simulates an extravehicular activity in a Mars or lunar gravitational environment. For both objectives, the astronauts' temperature regulatory capacity will be evaluated by measuring internal temperature, skin-blood flow and sweat-rate responses during the prescribed exercise conditions.

The information collected will be extremely valuable to NASA as it will lead to improved safety and perhaps to improved physical work capacity of astronauts during the indicated exposures.