The Current7:00What it’s like to re-enter Earth’s atmosphere
Canadian astronaut David Saint-Jacques will be watching as the Artemis II crew returns to Earth tonight — and he’s among a handful of people on the planet who know exactly what they’ll be going through.
“Right now they’re literally falling back to Earth … accelerating the whole way, and they’ll hit peak maximum speed as they hit the atmosphere, about 10 kilometres a second,” said Saint-Jacques, who spent 204 days in space before returning to Earth in June 2019.
“And then they’ll turn into a fireball as the atmosphere slows them down.”
After slingshotting around the moon earlier this week, the Artemis II mission is expected to splash down in the Pacific Ocean Friday night. Their capsule will reach a speed of 38,405 km/h just before entering the Earth’s atmosphere, and a temperature of around 2,700 C.
During the re-entry, the crew will lose communication with Earth for six minutes.
Saint-Jacques knows the astronauts aboard: Reid Wiseman, Victor Glover, Christina Koch and Canadian Jeremy Hansen. He spoke to The Current’s Matt Galloway about what they’ll experience, and what those six minutes of silence will be like for everyone watching on Earth. Here is part of that conversation.
What has it been like for you watching this moon mission?
At many levels, it’s been mesmerizing. Obviously, as a Canadian, I’m super proud that our country has made it this far. This is a testament to decades of good work from our engineers, our technicians, our space companies, our space program. When you become an astronaut and you join the space program at NASA, it’s very intimidating. But as a Canadian, you’re welcome because we’re standing on the shoulders of all those giants.
But these are all my friends up there. So this is the mission of my buddies … Jeremy’s kids once all babysat my kids, our families were intertwined. Yesterday, I was looking at the moon and I was kind of geeking out, trying to see exactly where they are in the sky right now.
Right now, they’re literally falling back to Earth, they’ve been falling for four days, accelerating the whole way, and they’ll hit peak maximum speed as they hit the atmosphere, about 10 kilometres a second.
And then they’ll turn into a fireball as the atmosphere slows them down. We’ll lose comms [communication] with them for about six minutes or so. Eventually, at about maybe something like six kilometres altitude, they’ll open their parachute. We can talk to them again. That’s when I think we’ll all breathe a sigh of relief, “Wow, they made it back to the mothership.”
What is it like when you are in that fireball?
While you’re coasting in space, you’re going fast, you don’t really notice it. I mean, you really don’t feel speed, right? You feel [the] change of speed. And right now they’re in free fall.
[When you] jump off the biggest diving board at a swimming pool, while you’re falling, you feel kind of light. That’s what they’ve been feeling like for 10 days.
On their last full day in space, Artemis II astronauts packed up equipment and reviewed procedures for re-entry into Earth’s atmosphere before splashdown on Friday.
But when they hit the atmosphere they’ll be in their spacesuit, with their helmet closed just in case. They’re kind of going backwards … like a child seat that we use to keep kids safe in a car. They’re strapped in, all curled up in a fetal position and they’ve got their back to the Earth … and then someone is braking. So they kind of squish into their seat by the pressure of the air as it slows down the spacecraft from 10 kilometres per second to a more manageable speed, like about 300 kilometres an hour, where they can safely open their parachutes. And so it feels like suddenly you get to meet your good friend gravity again, and you feel squished.
So they’re spending the day today securing everything in the spacecraft, making sure everything is strapped in or put away in a box, configuring the spacecraft, testing their suit, looking through all the possible bad things that could happen and what they would do and reviewing the procedures. And then finally, bit of a break, enjoying the last views before getting into this operational mode. Action starts about an hour before splashdown. That’s when they disconnect from the service module, the kind of technical part with the fuel tanks of their capsule.
And then we’ll all be keeping our fingers crossed.
They really need to hit the atmosphere at a very precise angle. Because if they’re too steep, then it’ll be too warm. It’ll be too brutal a stop for them physically … right now, they’re trying to cap it at about 2,700 degrees.
They’ll dip in, burn some speed. Kind of bounce off a little bit, slow down, and then finally adjust their trajectory, and then they’ll turn into kind of a fireball.
That’s quite a ride. That’s when you realize, “Oh, we were actually going really fast all this time. Now we’re braking really hard.” And when the parachutes open, high five in the cabin! Whoo!
You’ve talked about how you changed when you saw the Earth from a distance. How do you think these four astronauts, including Jeremy Hansen, will be different given what they’ve seen?
I think in two ways. First, this perspective of the Earth. The Earth is beautiful, graceful, the only kind of really living thing out there. But what’s mesmerizing is how we are in the middle of nowhere. And it rekindles your love for the planet and makes it very clear that we’re all earthlings at the end of the day. And I think that’s very significant psychologically: this is where I belong, to Mother Earth.
The other part it does to you is this is a demonstration that when human beings work together to a common goal, there’s like nothing we cannot do. And in this day and age, I think that’s a very strong message that yes, we have differences, but when we choose to focus on what we have in common, we can do superhuman things.
It’s like a message of hope. For me, as a father, as a citizen, that’s maybe what it’s all about.
Roberta Bondar was Canada’s first woman astronaut. She joined CBC News to talk about what might be going through the minds of the Artemis II crew members as they descend to Earth — and how the mission has advanced science.
