Human Life Research on ISS US Orbital Segment

SLEEP-G Experiment

SLEEP-G experiment is included in the research program conducted onboard the ISS by spaceflight participant Richard Garriott within the framework of the GTA project. The experiment is to be performed under US medical program on the US Orbital Segment using the USOS onboard equipment.


To study effects of space flight on sleep and develop efficient countermeasures to insomnia, both in short-duration and long-duration space flights.


  • 24-hour monitoring of the cosmonaut's motion activity.
  • Taking measurements of illumination levels in cosmonaut's vicinity.

Science Hardware Used:

  • Actiwatch wrist watch
    included in the USOS on-board equipment, which helps to automatically record motion activity of the test subject, as well as lighting levels in his vicinity.

Experiment Results:

Information recorded using Actiwatch (motion activity of the test subject and illumination levels in the cosmonaut's vicinity) and downlinked from ISS to Earth.