- You can watch down here in the corner. - Man, you are not a particularly good pilot. - Hey I'm not flying it. It's the computer who's doin it. Hi everybody, this is Lee Hutchinson from Ars Technica and I'm here today with astronaut Scott Kelly. Scott has just spent a year on the International Space Station. I'm sure you're glad to be back on Earth with us. - Earth's good. - We're gonna be playing Kerbal's Space Program which is a space simulator, and we're going to be having Scott, sort of, walk us through some aspects of space flight, assuming our rocket doesn't blow up. Ready Scott? - Ready to go. [quiet music] - We're staged up here on our launch pad. We have sort of a nice little fake space shuttle. It's got boosters and everything. It works just like the real space shuttle. - I'm sure. - So before he hit go here, can you tell us very briefly, exactly what an orbital inclination is, what that means in this context. - It's basically the highest point of latitude that you'll get to in your orbital ground track. Latitude relative to the equator. - Here we go. So we're on auto-pilot right now, and the game is gonna take us, hopefully, through this launch sequence. In real life, if you've got quite a bit of atmosphere to punch through and there's that period you always hear the PAO officer call out about max Q. - Max Q. - What is max Q? - It's maximum dynamic pressure. Q is the symbol in aerodynamics for dynamic pressure and max Q is when your combination of your speed and the thickness of the atmosphere gives you the maximum pressure on the vehicle. And it's pretty shortly after launch, engines will throttle down to avoid getting to a too high of a max dynamic pressure and then they'll throttle back up. And the common call you'll hear on the ground is, "Go at throttle up." - Now you don't fly this hands-on. The computer does the assessment right? - Yeah, the computer flies the space shuttle to space. In an emergency if you had issues with the control, you can take over manually after 90 seconds. And I want to point out that this Jebediah Kerman, - Yes, Jeb. - looks like my brother a little bit. [Lee laughs] [music] So apogee is the highest point in your orbit, the furthest away from the surface, and perigee is the lowest point in your orbit. So in this case we are at apogee. And if we were going to circularize our orbit, the best way to do it, I think the most fuel-efficient way to do it, is to do it at at apogee. Actually the space shuttle has two ohms burns generally, and the first one is to give you a little more delta V to get to orbit. The second one is the one that's done at your apogee, or pretty close to it, which then circularizes your orbit so instead of coming back and re-entering the Earth's atmosphere, you're in more of a circle versus an ellipse. - Now we can kinda demonstrate that a little bit by changing our orbit here. If I apply a little bit of thrust here, and then we pop back and look at our orbital map, we can see already - Oh yeah, look at that. - immediately opposite us, this is our period ... I'm actually piling on probably more delta V than I want at this point. We're applying more eccentricity to our orbit I guess. We are making it more egg-shaped. - Eccentric. - There ya go. [Lee laughs] - Which also means we're slowing down, - So as our orbit gets bigger - Yes. - our speed, again counter-intuitive. We've added energy to the system. You would think that would make you go faster, but really, what it does, is it makes you go higher, - Yes. - which in fact then makes you go slower. [quiet music] NASA could probably use this to teach future astronauts orbital mechanics. - Actually I forgot to dump our external tank. Let me do that real quick. - Man, that is a fatal error. Look at you, you are crashing. - Wait a minute. Wait a minute. - We are crashing. - No, no, we're fine. - It's fine. It's all fine. - You bounced off of it. - That's okay. The orbital can do that. - This little nose cap there on the space shuttle, - Uh-huh. - You just crushed it. - I think I may have - Look at that. - I may have scraped our tiles a little bit. - Holy cow. Bad astronaut. - I punched the explosive blots without any, I guess we could probably try to go somewhere a little bit, let's see here. Let's see if I can give us a little bit of a ... O boy, hold on. Wait, wait, wait, wait, wait. - Man. - Ah, there we go, we're fine, we're fine. - Yeah so the way the space shuttle, or really the Soyuz or spacecraft come back to Earth, is you only have to change your orbital velocity by a few hundred miles an hour. So in both the shuttle and the Soyuz's cases, you fire an engine so you turn around backwards, so now instead of going pointing in forward, you're going pointing in backward. And then you fire those engines to slow down and the rest of your velocity is removed from the spacecraft with friction in the atmosphere in the form of heat. - So I was going to try, Scott, to bring us in to landing here. Our ground speed is increasing rapidly. - Well, just get us into the atmosphere - Okay. - We can then just, - Done. - blow the hatch - Done. and we'll jump out, and hopefully survive under our parachutes. - O, I forgot to flip us around prograde. So actually we're entering ... - Ooo, back end first? - Yeah, technically I call this an ass-in first re-entry. Alright Scott, well this has been an excellent demonstration of why you're an astronaut and I'm not. How was that for you? How close to real life was that for you, and did you enjoy it? - It was exactly like real life. Nah, actually I'm just kidding. It was good, ya know. I think it's something that NASA could use to train future flight controllers and astronauts a little bit more about orbital mechanics. - I wanted to give a quick shout-out to Simone Riboldi of the YouTube channel Simon and Simon, thank you for preparing some of the Kerbal Space Program stuff for us today. We really appreciate it. Thank you also to Squad, the Kerbal Space Program developers for helping us out to make this demonstration happen. Much appreciated folks. [quiet music]