TBone: Effects of microgravity on bones

Health Science

The Canadian TBone experiment uses new 3D imaging technology to study changes in astronauts' bone health caused by the time they spend in space.


Our bones constantly undergo a reshaping process in response to everyday use. On Earth, bones are optimized for working in gravity, the force they must work against to support our body weight.

Due to weightlessness and reduced exercise, more bone is being lost than replaced during extended space flight.

While adults past age 50 typically lose about 1% of their bone mass each year (a process that can eventually lead to osteoporosis), astronauts in space can lose up to 1.5% each month. Fortunately, much of this loss is reversed when astronauts return to Earth. TBone's scientists want to determine how this cycle of loss and regain affects the long-term strength and quality of bones.

Results from this research could help space travellers stay healthier during longer missions and could enable us to travel farther into space.

TBone - Effects of Microgravity on Bones with Astronaut Tim Peake

Credits: Canadian Space Agency, NASA, European Space Agency


Using high-resolution imagery, TBone's researchers will:

 Impacts on Earth

"What we can learn in six months of space flight would take us a decade on Earth," says Dr. Steven Boyd, TBone's Principal Investigator.

TBone's results will give researchers a better understanding of diseases like osteoporosis, a bone loss disorder that affects approximately 10% of the Canadian population aged 40  and over. The findings of this study could help identify those who are prone to bone loss, and design individualized treatment strategies to predict and prevent fractures caused by low bone density.

How it works

Fifteen astronauts will participate in this study.

  1. Participants will undergo high-resolution 3D imaging of their wrists and ankles before and after their missions. This creates a comparative picture of the microscopic shapes and structures inside the bones.
  2. During their stay on the ISS, astronauts take blood and urine samples for many studies. The data from these tests is shared under an international agreement, and will be used for TBone to understand the cellular activities related to bone adaptation.
  3. Scientists also keep careful records about factors that could affect the results, such as food intake, medication, supplements, and exercise routine.

Human bones contain a honeycomb-like structure that helps give support and strength. When we walk, dance, play hockey, and enjoy other forms of exercise, the force required for us to work against gravity in order to carry our own body weight regenerates our bone tissue, and makes our skeletal system stronger. When we are less mobile, our bones lose density and strength.


The TBone team began collecting data in 2015. The research is expected to be completed by the end of 2020.

Astronauts in space get about 2 hours of exercise each day

Astronauts in space get about 2 hours of exercise each day, which helps maintain their bone mass. (Credit: NASA)

Research team

Principal investigator


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