Chapter 11 of 29 from Chris Hadfield

Spaceships: Navigation Systems and Human Variables


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

Topics include: Orienting the Ship • Navigating the Soyuz Visually • Navigating With Instruments • Propagating State Vectors • The Future of Navigation

Chris Hadfield

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 ...

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.

Learn about the past, present, and future of space exploration with astronaut Chris Hadfield.

Download the workbook for lesson recaps, assignments, and photocopies of handwritten notes that Chris took to space.

Upload videos to get feedback from the class. Chris will also answer select student questions.


Chris Hadfield

Chris Hadfield Teaches Space Exploration