 Hey everyone, I'm at SciTech in Perth, Western Australia in a mock-up of the International Space Station. Astronauts experience some problems living up here in microgravity, including muscle wastage and a tough time going to the space toilet. So why haven't we put artificial gravity on the space station? You'll find out in today's space pod for May 11th, 2016. Many science fiction movies show people walking around on spacecrafts installed with gravity generators. Unfortunately, those machines don't exist today. The only way to generate usable artificial gravity is to use centrifugal force as a substitute. So what is centrifugal force? Well, let's take this bucket of water here and I'm going to spin it around the top of my head. The water doesn't fall out of the bucket even when it's above me because I'm generating a centrifugal force that's fighting against gravity to keep the water in the bucket and push it away from the center of rotation, which is where my hand is just here. We can calculate the centrifugal force by using the equation f equals omega squared r, where omega is the angular velocity, or how fast you're spinning, and r is the distance from the center of rotation. Now if I start spinning the bucket a little slower so that less force is generated, gravity wins out and I get a little bit wet. So artificial gravity is all about using spin to create a force. So how can we do this in space? Well, there are three main ways to achieve this. The first is to rotate your spacecraft or just a part of it. NASA has concept designs for a vehicle called Nautilus X that would contain a rotating section to provide artificial gravity. A small-scale version of its centrifuge would first be sent to the International Space Station as a technology demonstration. However, there are no concrete plans to do this in the immediate future. The second option is to take your spacecraft and attach it via a tether or a long cord to some sort of counterweight and spin those two objects around each other. This was actually attempted as part of the Gemini 11 mission, where the spacecraft was tethered to a modified Agena upper-stage rocket. However, the astronauts were only able to experience 0.00015 Gs of force. And the third option is to take a centrifuge and put it inside your vehicle. This was actually attempted as part of the NeuroLab experiment on STS-90 in 1998. The centrifuge was placed in the payload bay of the shuttle and was able to give astronauts the feeling of 0.5 to 1 Gs of force. Well, that's great. So why haven't we used these methods in space? Well, unfortunately, there's a few problems with generating artificial gravity in these ways, the first of which being gravity gradient. Now, I know I'm pretty short, but there's about 1.5 meters difference between my head and my feet, which means in a spinning spacecraft, my head would experience a different gravity level to my feet, because my head is 1.5 meters closer to the center of rotation than my feet. This is especially a big problem in small centrifuges, where the gravity gradient can be as high as 20 to 100 percent. I make standing people feel as if they're hunched over. Now, I know astronauts have to exercise in space to stay healthy, but jogging in a spinning spacecraft might not be a good idea. Remember, our equation relies on omega squared or how fast the spacecraft or you are spinning. So theoretically, if you were jogging in the direction opposite to the direction of spin, you'd effectively cancel out that spin and experience no artificial gravity. And vice versa, if you were jogging in the direction of spin, you'd increase your apparent spin rate and increase the artificial gravity you'd experience. Finally, the most practical thing we have to worry about is the Coriolis force. Inside a spinning spacecraft, if you move towards or away from the center of rotation, you experience a force, the Coriolis force pushing you to the side. So we may need to rethink how we designed ladders in a spinning spacecraft. But wasn't there a plan to put a centrifuge on the International Space Station? Well, yeah, there was. And it was going to be called the centrifuge accommodation module, or CAM, and it was actually built by the predecessor of the Japanese space agency, NASDA. It would have been capable of simulating gravity to half to 1g for subjects under the height of 0.62 meters. But it was canceled due to cost overruns and problems scheduling it onto a space shuttle flight. I hope this introductory video to artificial gravity didn't get your head spinning too much. But thanks for watching. I'd also like to thank our patrons who make these videos possible. We are a completely crowdfunded show thanks to the founders, architects, engineers, ambassadors and dreamers of tomorrow. And if you would like more information on how to crowdfund this show, head over to patreon.com. Don't forget to subscribe to our YouTube channel at youtube.com slash tmro and join in the conversation by following us on Twitter, Facebook and our website tmro.tv. My name is Lisa Stojanowski and until next time, keep on discovering.