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28:14getting back into the Aremis 2 mission, I want to talk about the mission architecture, some of the orbital mechanics and the flight profile. Okay, so the space launch system, which we have beautifully recreated here in Legos, it uses a lot of spare shuttle parts. And there's a photo of me in Huntsville, Alabama. Actually, when I first moved from India to America, I settled in Huntsville, Alabama with my family for about a year because my dad was working at Marshall Space Flight Center as a solar physicist. And what you notice immediately is that the space shuttle's architecture is very similar to the
28:56Aremis 2 architecture, right? It's got this orange central part and then these solid rocket boosters on the two sides, right? And that is not a mistake. What they really did was use a lot of the spare shuttle parts to make the space launch system. This SLS, right? The launch vehicle is something called the SLS block one. It's got a liftoff thrust of about 8.8 million lbf pounds per I don't know what the f is actually. I should probably know that. But it exceeds the Saturn 5 really by 15%. The Saturn 5's thrust was only 7.5 million pounds.
29:36>> Yeah. Yes. >> This thing is 8.8 million. >> Yeah. >> Okay. So, it's it's exceeding it by 15%. >> Now, you might be asking like, why is the rocket still so big? That's something that I ask because it's like it's like we we've had 50 years >> and the rocket is still so big. >> Yes. >> What gives? And why more thrust? It actually has less payload. Mhm. >> It's got more thrust, but it's got less payload, >> meaning it can carry less stuff. >> It can carry less stuff. So, I I was I was quite >> confused. Perplexed. Yes. By that by that um by
30:16that number. >> So, here's the idea. >> First of all, the reason why the rocket is so big is because of the rocket equation. Okay? At the end of the day, if you want to like leave the earth, you gota push on something. >> Newton's third law. >> Newton's laws are the laws of the universe, right? Inertia is a thing. And so, in order to you can't just like create electricity really efficiently and then leave. You literally have to expend material in one direction to push away in order for your rocket to leave. >> Mhm. And the amount of material is kind
30:58of a non-negotiable thing if you want to put a giant electronic spacecraft into higher Earth orbit and then go all the way to the moon. >> Okay, so that's one of the reasons why it's about the same scale as the Saturn 5 rocket and why the Starship, the big Starship are about the same size, right? It's because you got to you got to leave enough material to get out there. And the idea is the [clears throat] space is being taken up by primarily fuel >> because that fuel is the thing you're push using to expend to give you the thrust to counteract Earth's gravity to be able to leave. >> Yeah. >> You know, to be able to have enough momentum to get out
31:39>> to get out. Yeah. Exactly. And so, so that's the reason why it's about the same size. Okay. Now, let's get into the why the less payload. The short answer is that the Saturn 5 was actually a three-stage rocket. There was stage one, stage two, stage three. >> And with this three-stage rocket, what you can do is you can get out >> and then you can throw away the heavy things. >> Mhm. >> And keep going >> cuz you have that second stage. >> Yeah. That second stage is not propelling the third stage's mass. >> Yeah. >> You know what I mean? Yep. Yep. Yep. >> But the SLS is a two-stage rocket. >> Got it. >> Okay. There's the first stage which is from here to here >> and the solid rocket boosters and then
32:20the second stage is all the way here. Right. And what that means is with the with the Saturn 5 the first stage only took about 2.5 minutes >> gets out of the Earth's atmosphere and then it leaves. This thing sticks around for 8.5 minutes. >> Oh, that's significantly longer, >> right? >> Yeah. >> So the whole time it's hauling >> all of the >> Yes. sort of mass that isn't really doing anything. >> Right. Right. Right. Right. >> Now, the Saturn 5 dropped its dead weight, its empty tanks early and often. Right. While the SLS carries its massive empty orange core stage, which is this guy. >> Yes. >> All the way to the top.
33:01>> That makes sense, >> right? >> That makes sense. >> Now, when it comes to engines, the engines on the bottom here, right? The Saturn 5 used kerosene which is our hydrocarbon. So carbon with a bunch of hydrogen bonds. Those bonds are very energetic. Meaning that per gram kerosene has a lot more chemical energy. >> Mhm. >> Mhm. >> The SLS uses hydrogen and oxygen. >> I see. >> Okay. It's just H2 and O2. Now, hydrogen is lighter, which means that it'll have a higher exhaust velocity. When it gets out of the rocket, it's going to be moving faster because it's lighter. But at the same time,
33:42>> it's lighter, so you need more of it. The density is lower, right? So, you need a massive sort of thing to hold all that hydrogen. And when you have a two-stage rocket and you're going all the way up, that's a lot of drag. That's a lot of friction that you have to account for. So all of that accounts for this lower weight that I can put on Earth orbit and all the way to the moon. >> The idea is because you need more space for the fuel which is this hydrogen oxygen mix as opposed to uh kerosene and liquid O2. And because you need more of that fuel and you're not dropping stages like it's not a three-stage system, so
34:22you're not able to let go of that dead weight earlier. >> Yeah. you fundamentally have more space