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Science & Technology

Mars: How to Get to Mars

Chris Hadfield

Lesson time 20:07 min

Chris explains the technical and societal challenges we face in traveling to Mars, including the ideal flight path required, the physics of slowing down and landing, and the risk of human life.

Chris Hadfield
Teaches Space Exploration
The former commander of the International Space Station teaches you the science of space exploration and what the future holds.
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Getting to Mars isn't only a technical problem. It's also sort of a human societal problem. Not just how do we go to Mars, but why would we go to Mars? And what sort of cost and risk is associated? Right now, we can barely put robots on Mars. And we fail almost as often as we succeed, because it's still brand new, and the distances are so enormous, and the technology is still so primitive. But it's still worthwhile. We're learning about the history of how planets form. We're learning about what is normal for planets. It teaches us about the Earth to see what a different planet head as its history. Why doesn't Mars have oceans? Why doesn't Mars have a magnetic field? Why is Mars the way it is, even though it's the same age as the Earth, and not too much different in size than the Earth, why has Mars had such a different past in the Earth? And what does that mean for us in the long term health and life of our own planet? We learn a lot of science by having sent probes and rovers to Mars. But right now, it is still staggeringly complex to send people to Mars, and with complexity comes risk. It's maybe equivalent to sailing the oceans of the world in the 1400s. People had been in ships and dug out canoes and boats for centuries. We understood how boats worked, but we didn't know how to navigate the world. We didn't have good time pieces in order to be able to figure out what our longitude was. We didn't realize what food you needed to bring, and so many of the early crews were sickened or even killed with scurvy, a thing that happens when you don't know enough vitamin C in your diet. It was dangerous. We lost crews, even though we had boats, and we even had sailing ships, we were not yet ready to sail the oceans of the world. That's sort of where we are in space exploration right now. We have spaceships. We've successfully built a space station orbiting the world. We've sent probes right at the very edge of our capability, with people board, as far as the moon. But the oceans between us and Mars are still staggeringly huge. And if we started firing people off to Mars right now, we could very much expect, just like the early explorers 600 years ago, that we would kill most if not all of them. When Magellan and his crew, the first crew to circumnavigate the world launched out of Spain in the early 1500s, they launched with five ships and 250 people. And after three years, only one ship made it back, with like 18 people on board. Everybody else died in the effort, and they lost four out of five ships. And we just need to decide is it worth it right now to go to Mars with those type of terrible odds and those enormous consequences? But now, you can get on an airplane in Spain and fly to Australia, and you don't even think about it. The risk is extremely low. The distance has stayed the same. The actual numbers of the challenge have not changed at all. The distance from Spain to Australia, the atmosphere is still there, the oceans are s...

Explore the unknown

Impossible things happen. At age nine, Chris Hadfield knew he wanted to go to space. He eventually went there three times, becoming a commander of the International Space Station. In his MasterClass, Chris teaches you what it takes to explore space and what the future holds for humans in the final frontier. Learn about the science of space travel, life as an astronaut, and how flying in space will forever change the way you think about living on Earth.


Students give MasterClass an average rating of 4.7 out of 5 stars.

I loved this class. I love Chris Hadfield's instructor style. Very easy-going but so very informative and insightful. I'm so glad I took the class.

This was my first MasterClass course and I loved it. I learned a lot not just about space, but about challenging yourself and coming up with a plan for what you want to do and the steps required to get there.

Venturing into the unknown gives a unique perspective that can positively inform everything else in our lives.

This was a great class and I learned a lot about really how much work it takes. Chris Hadfield was really friendly and he kept my attention. My favorite MC by far!


Bernardo F.

Not to mention that humans can't survive to a certain value of G-forces, so either decelerating rapidly or crashing into Mars aren't a good way to land. Could it be possible to make an ISS for Mars? Instead of just reaching the surface, to create a "base" orbiting the planet? Maybe that way, when having all the elements and not having wasted that much fuel and resources, it could be cheaper and safer to come down.

A fellow student

This was the lesson that I was waiting for. Interesting to hear his thoughts about the Mars voyage.

A fellow student

Mariano Cejalvo. Spain. Amazing Class. Lot of things I never think about and had been easyli explained by Chris. Thank you so much.

Mary S.

What an amazing MasterClass! Chris brings his world to life in his explanations of space exploration. This is a great class to take while living during this trying time of our world. He gives me a way to escape the reality of today. Thank you so much, Chris.

A fellow student

What a time to be alive and have the honor to take this masterclass from the comfort of my home. Amazing!

Maddie W.

I feel very lucky to be living in such exciting times since we will all hopefully be able to experience–and perhaps take part in–the first human missions to Mars. Very interesting to discuss and think about all the different techniques of landing on the surface. I wonder if there is a way we could build a machine to manufacture fuel or perhaps something that the crew could operate so that the spaceship could spend the 6-month travel time creating what we need to decelerate instead of lugging it all out of Earth's orbit. After this lesson, I had to google a video of how the Curiosity rover landed on Mars. It was so inspiring to watch! It's amazing the things we can do with technology and engineering and I'm so excited to help shape the advancements of the future.

Steve H.

Fascinating to learn of the complexities of extended time/miles necessary to reach Mars. Traveling 35 million miles or more over 6 months is daunting (and there won't be the earth below as a reference point.)

Alexis P.

What would happen if we simply stepped in Mars's orbit (and accelerate a little in precisely the opposite direction the planet is heading to?) waiting for the planet to pick us up? Sort of like waiting for a train at a station, but instead of waiting on the platform, we waited on the railway racks instead. Wouldn't its atmosphere simply pick us up? We'd obviously have to apply several burns to get some matching speed and facilitate the pick-up but seems much more fuel-efficient than orbiting around it. Is this stupid and dangerous or just stupid? :) I mean Mars goes at 54.000 miles. We can do that, or half of it, since it's atmosphere will pick us up like a life net until we match the speed of the planet and then the gravity will pull us down. But at that point, wouldn't we already be low enough for an easy landing?

Lauren C.

Question at minute 8 about the speed the rocket travels in space. The video mentioned 25x the speed of sound, but what is the speed of sound in space? I “know” that space has been referred to as a vacuum, but I also know that it is filled with dark matter. Is that the medium used to measure the speed of sound in space? If that’s correct, what is 25x the speed of sound in space? It would absolutely be different than if measured on earth. Interested to know if anyone can clarify!

Ugo A. D.

Orbital mechanics is rather complex. Puts things into perspective when traveling out in the deep reaches of space. Read the book "Hitchhikers Guide to the Galaxy". I wish those space travellers well.