Canadian astronaut Chris Hadfield temporarily went blind on a spacewalk 17 years ago. Cleaning fluid irritated his eyes during a crucial construction mission on the International Space Station, causing him extreme pain and fogging his vision with tears. To clear the contaminated tears from his face, Hadfield opened a purge valve in his spacesuit.

His move was a success — the tears cleared, and he was able to continue installing the Canadarm2, which is still used today for spacewalks and some spacecraft berthings. Now, he's sharing his knowledge of space in a new MasterClass video series designed to help future astronauts and space tourists with their own missions. Enrollment opens today (April 24).

"I wanted to truly explain the essence of spaceflight, and what it means to us, and what the benefits of it are. I think it's an interesting and timely topic right now," Hadfield told Space.com. His goal was to provide a basic course from which people could follow links for more detailed information on rocket design, living on Mars and the experience of being an astronaut. [15 Space Travel Tips from an Astronaut]

Hadfield and his wife, Helene, were already developing a similar course when MasterClass got in touch with him last year, so he said the partnership was perfect to help people learn more about space.

"There are a lot of people [watching] who would apply to be an astronaut, and the people who will fly [tourist flights] with Jeff Bezos [Blue Origin] and Richard Branson [Virgin Galactic] may be interested, too," Hadfield added. More information and links are available in a course book.

Chris Hadfield shares his knowledge of spaceflight in a new online class.
Chris Hadfield shares his knowledge of spaceflight in a new online class.
Credit: MasterClass

Hadfield was an astronaut with the Canadian Space Agency (CSA) from 1992 to 2013. Although he was famous in his own country, it wasn't until his last flight in 2012-13 that Hadfield caught the world's attention. Hadfield ran the space station's most scientifically productive mission to that point as Expedition 35 commander while sharing his experience in real time on YouTube and Twitter. [How To Become An Astronaut

Hadfield's skill in playing guitar and elegantly explaining spaceflight captivated millions of people. Days before landing in May 2013, his last video from space — a rendition of David Bowie's "Space Oddity" in the space station — went viral.

Hadfield retired from the CSA shortly after coming back home, but his outreach accelerated. He wrote three books, began teaching at the University of Waterloo and took on multiple media projects. Five years after his landing, he remains in high demand as a space speaker and commentator. But this MasterClass was a bit different from his other work, he explained, as it felt "transformative" as part of his spaceflight legacy.

Past class professors on MasterClass, an online education platform based in San Francisco, include tennis player Serena Williams, actor Samuel L. Jackson, performer Usher, filmmaker Spike Lee and writer Malcolm Gladwell. Hadfield's course is the first about spaceflight. ['One Strange Rock': Q&A with Astronaut Chris Hadfield

In classes of about 20 minutes each, Hadfield explains in detail many of the phases of spaceflight, such as spacewalking, launching and landing, as well as going over key places to know, such as the International Space Station and Mars. Where possible, he used props such as a globe and a mock spacesuit, sometimes brought from his own home. He said one of the most emotional moments was describing the mockup spacesuit on camera in detail, because he is so familiar with the real thing: "To put my hands on the suit is to touch my own memories," he said.

"It ends up being a legacy project as well," he added, saying he felt lucky to do a detailed project over three days with a professional film crew available, asking questions to guide him along. "I couldn't help but thinking, imagine if various people in history had their chance … at this stage of life. Imagine if Marie Curie had done one of these when was just finishing all her marvelous work [studying radiation]. Or Da Vinci, or whoever."

While Hadfield is retired from spaceflight, he continues to support CSA astronauts informally. David Saint-Jacques, whom Hadfield helped select as an astronaut in 2008, is scheduled to fly into space for the first time in November. Hadfield won't be at the launch, but he has been giving frequent advice to Saint-Jacques, and he plans to continue doing so when Saint-Jacques is in space.

"He has a tremendous skillset and he's an amazing guy," Hadfield said when asked what would make Saint-Jacques stand apart as an astronaut. "He's a medical doctor, an astrophysicist, an engineer, a triathlete, a guy who speaks five languages, I think, fluently, and he's a devoted husband and father of three. He enjoys learning new things and trying to do things as well as he possibly can. He has a huge capacity for learning, and for getting things done."

Hadfield's MasterClass course is available for exclusive early access on the MasterClass mobile iOS app starting today (April 24). The global release is coming May 1.

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