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
In 28+ lessons, 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 ...

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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 have read a lot about "space", starting 14 years earlier than Astronaut Hadfield. Watched a lot of videos of rockets blasting off, walks on the Moon etc., and I thought I knew a thing or two about space since the Sputnik of 1957, yet this Master Class by Ast. Hadfield taught me so much and opened my eyes (and the brain cells) even wider open. He is not my HERO for nothing...

Great intro - and super exciting to learn from a pro !

Awesome class! Most of the technical stuff I knew but to hear it from someone who has been there gave me a whole new perspective. Thanks!

Man, I so love Chris Hatfield. This class exceeded my expectations I have to say. It was very well put together and Chris presented fantasticaly.


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.

Bruce A.

Todays Office Hours session was simply FANTASTIC! Many thanks to Chris, Molly, and all the elves involved! p.s. Here's a picture of the Inertial Guidance Platform from the Hound Dog. I wanted to give "kids" an idea of how we navigated to the moon. I've got to finish up that video someday! I was able to buy a Kollman Astrotracker on eBay to go with it. As Deke would say, "Keep The Dream Alive!"

Dennis M.

Hey, commander, what stars would those be? (Canopus, Polaris, Arcturus?) Are they always the same ones?

Russ D.

It’s great to see how the astronauts all train to determine the spaceship’s orientation manually. I knew there was a lot to learn about navigation, but it seems that it would be a great adventure!

Terry W.

I enjoyed learning of the challenges ion orienting a space craft and the solutions available for knowing where you are and how you are oriented. I liked the Soyuz periscope solution, too. I am a bit overwhelmed with all the knowledge that astronauts have to gain and master with so that each one is prepared for "manual" operation and navigation. I felt a little stressed with this lesson, but Cmdr Hadfield made it all seem so matter-of-fact. I appreciated his communication skills as the knowledge becomes more complex.

Vickie R.

PS Also when I first enrolled in the UCLA space program class I wrote him a letter and told him about it. Don't know if he even read it or not because he is so busy but ironically three days later, Prez Trump said he was thinking about investing more money in the US Space Program??? But I haven't heard anything new about the Space Program ever since. That was about 9 months ago?