Skip entry explained

1:13:04>> And then five and beyond is going to be building the neighborhood, the establishment of a permanent lunar presence. Again, funding agreeable. But I just wanted to quickly recap what the schedule is in relation to to this point. >> that's very good. And the re-entry procedure here is going to be very different. That was was the point with this image because usually when we re-enter like Apollo or like the ISS when they re-enter is just one thing. You just slow down, slow down, slow down. You have a nice little shallow angle that like lets you burn off that heat and then you and then you come come back. Now re-entering from the moon is very different from re-entering from the ISS because the ISS you're not

1:13:44moving that fast. Right? >> Here you you went all the way to the moon and back. You're moving real fast. >> Yeah. >> Okay. You're moving real fast. So you got a lot more energy to dump. They're doing a skip entry sequence. What this means is you're going to come along and it's Have you ever done skipping stones like rocks where you like throw a rock and the rock skips over the water? What's happening is you do it at a shallow enough angle where the sort of surface tension or the the rebound force from the water is going to give you an upward velocity and let you skip over the water. We're doing the same thing with the Earth. With the Earth's atmosphere. >> Mhm. >> We're skipping over the Earth's

1:14:24atmosphere first to reduce velocity. It's a twofold thing. Once you reduce velocity, you also have time for the capsule to to cool down before you try again. Okay, so that's that skip entry sequence. And we've got a few videos from Artemis 1 that actually show this maneuver. So this is from Artemis 1. We've got a camera up here that's looking backwards >> Yes. sorry, upwards. So, you know, the the the Artemis 1 capsule is coming like this and the camera is looking in the opposite direction. And here you can see the Earth is moving moving underneath. >> Yes. >> The speed there is 39,000 km/h. >> It's moving. >> Yeah, that thing is moving.

1:15:06>> Moving. >> And here you can see now it's entering the Earth's atmosphere. This is the first entry. >> Yes. >> And all of that heat >> Yes. >> from the friction of the Earth's atmosphere is creating like a plasma bubble >> Yes. >> above the Artemis, like up here. >> Yes. >> You know? >> Yes. >> It's like all of the heat is down here >> Yes. >> as it's moving through and it is creating a plasma bubble >> Yes. >> behind it, in its wake. >> Yes. >> And that thing is getting hot. >> That is so incredible. >> that thing is getting real hot. >> I as just as as a camera and gear head guy, I I'm loving this. >> This is just so cool. >> Because I'm just there's there's so much hardware engineering that goes into being able to even pull off the like that I know where we're sort of coming

1:15:47from the but like there's the intensity of that environment. >> Yeah. >> And the ability to protect the craft in that high intensity environment is unbelievable. >> unbelievable, right? And here you can also one of the meters there shows that it's zero Gs because you're you're just free falling, right? So, in free fall it's zero Gs, but as you start slowing down the Gs start going up and up. >> And when you say Gs, what do you mean when you say Gs? >> what I mean is like the effect of um acceleration, like you're you're starting to feel your own weight. >> Yeah, yep. >> If you slow down a lot

1:16:27the Gs go up. >> Mhm. >> We want to also minimize the amount of Gs because when Apollo did it just a single just a single re-entry, the the amount of Gs was exceptionally high. We want also lower the amount of Gs, so that's another reason why we're We're the skip entry. Okay? So, this is that first skip. Okay, now the second skip what we'll do is we'll take our aircraft and we will rotate it. >> Okay. >> Okay, so this is after the first skip and you can also see the speed has reduced down to 26,000 km/h. So we've already dumped a lot of kinetic energy in that first skip. Now we turn. >> Yeah, we're rotating. >> We're rotating, we do a roll about the

1:17:07spacecraft and once that roll is finished, again, we're free falling so we've done the skip, we're coming back and now we're back into reentering the Earth's atmosphere. Again, this is Artemis 1. We've already done this and we've tested it and this the skip re-entry does work. >> Yes. >> Okay. >> Yes. >> Now it's not completely full proof. Okay, Artemis 1 had a few issues. >> Okay. >> And um the NASA administrator >> Isaacman >> Isaacman did in fact allude to that issue. >> Yes.

1:17:48>> The next photo shows exactly what he's talking about. Okay, this is the heat