How the Artemis II crew will splash down on Earth — BBC News

[0:00] NASA says there will be anxious moments as the Artemis 2 crew prepare to re-enter Earth's atmosphere at speeds of around 25,000 miles an hour. [0:09] Let me show you the live feed that we're currently getting from NASA this morning. [0:13] The view from the capsule on board cameras there on the left. [0:17] There's a visualisation of the capsule in space on the right. [0:22] The officials say that they're expecting splashdown off the coast of California at around 8 o'clock Eastern time tonight. [0:30] Here's our science editor Rebecca Morrell who is at Mission Control in Houston. [0:34] Three, two, one. [0:38] It's been a remarkable voyage. [0:41] Booster ignition and liftoff. [0:45] From the blast off at Cape Canaveral in Florida. [0:47] The crew of Artemis 2 now bound for the moon. [0:51] To memorable views of our planet. [0:53] You can actually make out the coastline. [1:03] And a record-breaking close encounter with the moon. [1:06] As well as a solar eclipse. [1:08] It's bright and it creates a halo almost around the entire moon. [1:14] But now it's time for the astronauts to come home. [1:17] And it's the most dangerous part of this entire mission. [1:20] And one of the first press conferences we were asked what are we looking forward to and I said splashdown. [1:24] And I haven't even begun to process what we've been through. [1:29] We've still got two more days. [1:30] And riding a fireball through the atmosphere is profound as well. [1:35] I'm going to be thinking about and talking about all of these things for the rest of my life for sure. [1:40] This is a life-size replica of the Orion spacecraft. [1:43] The astronauts trained in this. [1:45] And inside it's configured to match the layout of the capsule while it's in space. [1:50] So the seats are down ready for re-entry. [1:52] It's kept the crew safe for their entire journey. [1:55] But now it has to bring them home. [1:58] And this is the part that really has to do its job. [2:01] The heat shield. [2:03] During re-entry the heat shield is angled towards the Earth's atmosphere. [2:07] As the capsule hurtles through it will experience temperatures of 2,700 degrees Celsius. [2:13] That's half as hot as the surface of the sun. [2:16] But on the Artemis 1 mission, which had no crew on board, the heat shield was charred and damaged. [2:21] NASA says they've fixed the problem by changing the angle of re-entry. [2:26] We spent a good part of a year or so investigating what we saw and actually able to replicate that on the ground. [2:34] So being able to replicate that condition on the ground was a huge step forward [2:37] because then we could start looking at how can we fly the mission differently [2:39] and preclude this from happening on Artemis 2. [2:43] Another critical mechanism is a cover on top of the capsule. [2:48] Its tests were filmed by a BBC2 documentary. [2:51] It must eject on re-entry to allow a series of parachutes to deploy and slow the craft down. [2:58] For this tight-knit crew who've been through so much together, [3:02] they say they're ready for this final challenge before their extraordinary journey comes to an end. [3:08] Rebecca Morrell, BBC News at Mission Control in Houston. [3:12] Let's talk about it some more with Dr Maggie Liu. [3:15] She's an astrophysicist at the University of Nottingham. [3:18] Good to see you, Doctor. [3:19] Let's talk about the final descent and that moment when they jettison the European Space Module. [3:26] What is that and why will that be significant? [3:30] So the European Space Module carries all the electronics, the plumbing, [3:35] the main engine to do a lot of the thrusting and correction burns and stuff like that. [3:41] It contains all the solar panels that have been providing them power so far. [3:47] It's a lot of weight, so you don't want to kind of carry it through the atmosphere with you. [3:51] So that will be ejecting before the main crew capsule will re-enter through the atmosphere. [3:59] The re-entry itself will take around 16 minutes. [4:04] Rebecca set out for us some of the technology behind it. [4:07] But what is it about that re-entry process that is the most dangerous part of the mission? [4:13] Well, these astronauts are travelling incredibly fast. [4:16] In fact, when they hit the atmosphere, they'll be travelling at Mach 32, [4:21] which is 32 times the speed of sound. [4:24] And then they have to slow down all the way to 19 miles per hour at splashdown. [4:31] But there's a huge amount of friction there. [4:35] So like we heard in that previous segment, [4:39] they are getting heated up to thousands of degrees Celsius. [4:44] And this kind of re-entry hasn't been done the way it's been set out to do before. [4:52] With Artemis 1 previously, three years ago, that mission flew with no astronauts on board, [4:58] tested the re-entry, and they found these problems with the heat shield. [5:03] With that re-entry, actually, the Artemis 1 mission actually kind of skimmed the Earth's atmosphere [5:09] to kind of dissipate some of the energy so that they could get a more precise landing. [5:14] This time, they're going at a kind of more inclined angle [5:18] so that they can pass through the atmosphere more quickly [5:21] so that the heat shields don't kind of get subjected to as long a duration through that heat. [5:29] So let's get started. [5:34] Let's go. [5:38] Let's go.