Science & Technology
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.
Topics include: Why Mars? • Evolving Rocket Technology • Using Gravity to Get There • Weigh Time Against Energy Efficiency • How to Slow Down • How to Land • Landing on Thrusters
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...
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.
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In 28+ lessons, the former commander of the International Space Station teaches you the science of space exploration and what the future holds.Explore the Class
This class is definitely a milestone of my journey to space. I see my journey as a team challenge, a constant set of interactions, some direct and some indirect. Like Chris, I believe in these little steps, steadily, towards "impossible" dreams. And I wish to everyone else to find their way, and perhaps some of us will meet. From Australia.
Beautiful overview of what it takes to be an astronaut. Accessible to just about anyone, so not really master-level, but very insightful.
Enjoyed every lesson. Chris has a good way of adding the human touch to something so technical.
I've learned so many things from this class, even things that are not related to space or space exploration at all. I thank Chris for sharing his life experience.