Spacewalks
In space
Spacewalks, also called extravehicular activities (EVAs), are one of the most difficult and dangerous tasks for the astronauts who work on board the International Space Station.
However, these spacewalks are necessary. EVAs are conducted when:
- equipment needs to be repaired or installed
- intricate manual work that can only be done by human hands is required
Canadian astronaut Steve MacLean, conducting his very first spacewalk, takes a break to wave to the camera! (Credit: NASA)
Thanks to this maintenance work, the Station remains:
- safe for the crewmembers
- in good condition so that an increasing number of scientific experiments can be conducted
- protected against serious failures and breakdowns affecting essential systems, such as:
- solar energy
- the thermoregulation and survival systems
- the computer networks
- communication and navigation equipment
The stakes are very high: the failure of any one of these components could lead to loss of the Space Station!
A very special spacesuit!
During spacewalks, the astronauts can rely on spacesuits equipped with all the necessary survival functions. These suits are the result of more than 50 years of testing, research and development.
Canadian astronaut Dave Williams on an EVA during Mission STS-118, in . (Credit: NASA)
These very bulky suits protect the astronauts from the deadly threats posed by the vacuum of space:
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Solar and cosmic radiation
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Micrometeorite impacts
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Extreme temperature variations
For example, the NASA spacesuit, called the Extravehicular Mobility Unit (EMU), has a total of 16 layers, divided into three parts:
- Liquid-cooling and ventilation layers, to keep the astronaut cool.
- A pressure bladder layer.
- A thermal micrometeoroid garment, to protect the astronaut from micrometeorites and extreme temperature variations.
SAFER: an additional safety system
The EMU is also equipped with SAFER, a propulsion system that enables the astronauts to return to the International Space Station in the event of accidental separation.
However, there is little chance of that happening: once outside, the astronauts are securely tethered to the Space Station with cables!
Text version - The Spacesuit – Infographic
Learn more about the different parts of the spacesuit in this infographic. (Credit: Canadian Space Agency [CSA])
A spacewalk usually lasts from five to seven hours.
A spacewalk, or extravehicular activity (EVA), is among astronauts' most complex and dangerous activities. (Credit: CSA)
Canadians step into the vacuum of space
On , Chris Hadfield made history when he became the first Canadian to perform a spacewalk.
CSA astronaut David Saint-Jacques conducts his first spacewalk (Credit: CSA/NASA)
Chris Hadfield and American astronaut Scott Parazynski worked for hours to unpack and install Canadarm2 using robotized equipment and other specialized tools.
"It was the most magnificent experience of my life. Alone in a one-person spaceship (my suit), just holding on with my one hand, with the bottomless black universe on my left and the World pouring by in technicolour on my right. I highly recommend it."
Since Chris Hadfield's historic excursion, four other CSA astronauts have walked in space:
- Steve MacLean, in
- Dave Williams, in
- David Saint-Jacques, in
- Joshua Kutryk, in
Dave Williams holds the Canadian record for time spent on EVAs, accomplished in three spacewalks: 17 hours and 43 minutes!