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Science & Technology

Spaceships: Navigation Systems and Human Variables

Chris Hadfield

Lesson time 13:35 min

Learn how astronauts use stars, planets, and instruments to understand where their spaceship is, how it’s oriented, and where it’s going.

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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How does a spaceship know which way it's navigating? How do you align the gyroscopes to determine which way is up in a spaceship? One of the things we have to learn to do as an astronaut is use the stars. And if you ever look really closely at the front of a space shuttle, there are two funny little oval-shaped doors on the front. And those are, in fact, star trackers. And they're little, super light-sensitive cameras. And one points straight up out of the shuttle, and one points out our left ear. And we, as the astronauts, have to be able to maneuver the ship so that we can line those up with a pair of stars. And then rotate the ship through a certain angle, and line it up with another pair of stars. And if you can know where these two stars were, and then where those two stars were, and you know how many degrees you turn in between the two, then suddenly, you know how your spaceship is aligned in the universe. It's pretty weird. And even harder than that, we have to be able to do it visually. We have a little, tiny telescope, a little optical alignment site sitting out the top of the shuttle. And if those automatic systems fail, we have to learn how to move the ship manually, while staring through a little tiny telescope to find the star we want. And then go, mark. And then rotate the whole ship, and bring it around, and get pointed at another star. And then go, mark. And from that then, be able to build all of the information so that the systems inertial navigation platform can align itself into the three-dimensional reference frame of the universe. Something most people don't think they have to learn when they're showing up the first day as an astronaut. Here's a fundamental question. How do you know where you are? How do you navigate when you're onboard a spaceship? You know, on Star Trek, that was Sulu's job and Chekov's job. I don't know what they were looking at. But they always seem to know where we were in the universe. But onboard, say, a space shuttle or a Soyuz, you're going blisteringly fast. Five miles a second. You're crossing continents in minutes. The world is turning underneath you. Where are you exactly? How do you even tell someone where you are? I'm over top of Poughkeepsie. Or I'm somewhere between the Earth and the moon. Or I'm this, you know-- what reference frame do you even use? It's less clear than you might think. One of the simpler vehicles that I've flown, as far as navigation, was the Russian spaceship, the Soyuz, that I was the left seater. Sort of like the Bort Inzhener, or the flight engineer, or maybe like the co-pilot, whatever you want to call it. Left seater on a Soyuz. It's a beautifully elegant solution to answering the question of where are we. Because you can do it completely visually. They have a periscope on the Soyuz, like-- like you use in a submarine. And you can use it to stare straight out of the ship. So you could pivot and look straight at the horizon, or you can ...

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.

The only way to learn is to learn from the best

Amazing storyteller and very captivating topics ! Anyone can take this class . Chris's rendering leaves me with new respect and awe for astronauts.

Geology student looking to work in space exploration, hopefully as an astronaut.

I adore Chris Hadfield. His teaching style, his storytelling... he's just the best for these kind of courses. And I hope he'll keep telling about his journey and space.


Bernardo F.

I had never thought about that, yet it's one of the most basic things. Of course computers can be programmed to follow a route, but navigating through space is not easy thing. Pretty interesting!

William D.

I feel too much is being made of the Soyuz optical system. Sounds like an elementary version of the sextants we had on Gemini and the MIT developed navigation system of Apollo. Looking at the earth opitacally isn't going to get you the data you need to conduct burns for rendezvous with another orbiting body. Man's been using sextants for over 100 years. Pilots/navigators have used them in airplanes for about 100 years. Nobody should be surprised they're used in spacecraft to navigate with.

Mário Filipe P.

What fascinated me the most in this lesson was the amount of knowledge you must have in order to navigate through Space! Celestial navigation, periscopes and telescopes... it's like we are going back in time when you would go out and explore the Earth by just looking at the Stars. This was kind of a reality check for me. We rely so much on GPS and the Internet nowadays, that we take it for granted in pretty much everything we do. It was really interesting to realize that. Also, I've never noticed that periscope sticking out of the Soyuz spacecraft like that! And now that I know it's there, I can't see anything else! Is so evident! How did I miss it? It's like someone all of a sudden decided to photoshop all of the pictures of the Soyuz spacecraft on the Internet, and placed the god damn periscope right there in the middle! Ahahah!

Maddie W.

Really interesting to learn about the frame of mind you have to have when navigating in space. It might seem unnecessary to have to learn how to do these things by hand but it seems like such a cool and useful skill to be able to know where you are in the universe while everyone else on Earth has to rely on computers and GPS and the internet. Really illustrates how skilled and knowledgeable astronauts are about everything under (and beyond) the sun. Another wonderfully informative and eye-opening lesson from Chris Hadfield.

J W.

Great course - all the lessons well done - Hadfield an excellent teacher.

Rosie G.

All of these lessons are riveting. Chris is such a great speaker. I concur that this is a must for anyone interested in space. I am now an astro-fan-girl!! (an elderly astro-fan-girl....but fascinated by the concepts here)

A fellow student

I really enjoyed all of these lessons. I highly recommend this course to anyone and everyone who is interested in space. Dan Brown, MSRC, RRT-NPS-ACCS-SDS, RPFT

Ronald A.

While explaining how to position oneself with a pair of stras, you have join hands in a 90° angle. Is that some sort of rule of thumb?

Jerry R.

Interesting how we call it a space "ship" and we navigate using stars just like ancient mariners. And we can do that from regular planes, too.


All the things we take for granted like the GPS system... I have a very good sense of direction thankfully but I imagine as an astronaut, they have it too. I bet the stars and planets are beautiful.