Ep. 803: Mission Tech Series: Engines & Stages

Fraser Cain (0:49)

Astronomy Cast, Episode 803, Rocket Tech, Part 2, Engines and Stages. Welcome to Astronomy Cast, our weekly facts-based journey through the cosmos, where we help you understand not only what we know, but how we know what we know. I'm Fraser Cain, I'm the publisher of Universe Today. With me as always is Dr. Pamela Gay, a Senior Scientist for the Planetary Science Institute and the Director of CosmoQuest. Hey, Pamela, how are you?

Pamela Gay (1:11)

I am as well as I can be. There has been chaos today. I will be posting pictures of the unholy dongle chaos I have created in order to record this show.

Fraser Cain (1:23)

I can't wait to see a picture of the, yeah. You have fashioned together a dongle Frankenstein, the likes of which we have never seen before.

So busy wondering if you could, never stop to ask if you should, and yet you should because that allows the audio that you're speaking to make its way into this computer through some circuitous route. It's glorious.

Pamela Gay (1:44)

Yeah, it is truly, truly glorious.

Fraser Cain (1:46)

Very impressive.

So before we get into this week's episode, I just want to give a shout out to our good friend Dylan O'Donnell, who has posted on Facebook that he is cancer-free. And for those of you who weren't aware, he had cancer of the esophagus, which is like a death sentence. It's a really terrible kind of cancer.

Pamela Gay (2:11)

Get your HPV vaccine, people, get your HPV vaccine.

Fraser Cain (2:17)

And I, you know, and it's so ironic because of course, in every video that he does, he says, life is meaningless and everybody dies, but you know, like not this soon, not Dylan O'Donnell. And he posted that after a lot of treatments and almost dying, he has come out the other side and is feeling a lot better and scans say that he's cancer-free. And it's, you know, it's going to take years for it to go through the full loop. But I'm so glad, man, the world is made better with Dylan O'Donnell on it. And if you are like not familiar familiar with Dylan, he does an incredible YouTube channel, Astronomy. He's one of the best astrophotographers out there and just a wonderful human being. And just I read that post, brought a tear to my eye of the happy variety to see that he's that he's doing okay. And we get to spend more time with Dylan.

But today, our series continues with our deep dive into rockets, their engines and stages. We fall under the tyranny of the rocket equation and discover what it takes to escape Earth gravity and head off into deep space. All right, Pamela, I didn't have to say we're going to stop for a break because we don't do breaks anymore because we are funded by our patrons, advertisers, get lost.

Pamela Gay (3:35)

And we are getting close to 1200 patrons. I haven't looked today to see how close we are, but we could cross 1200 this weekend.

As a reminder, we need to get to 1500 patrons to make sure we never have to add, I mean, we're not going to. To make sure that we can pay everybody and stay ad free, we need to get to 1500 So the ads aren't coming back, but my sorrow and my ability to pay people might come back.

Fraser Cain (4:03)

And if we get to 1500, you will never hear from us again about this.

Pamela Gay (4:06)

It's true.

Fraser Cain (4:06)

So this is kind of like an ad right now, I know, but only to put us into this safe place. Yeah, please do that. Okay.

So first, let's just talk about rockets and how they work, because I think this is going to be really, really important, which is that on Earth, you are able to push against the great fluid that is the atmosphere. Or if you want to be in the water, you can push against that fluid. Or you can just use friction to drive your car down the road. Once you're out in space, there is nothing to push against.

Pamela Gay (4:43)

And that's fine.

Fraser Cain (4:44)

This befuddles some of the science deniers. But how do rockets work?

Pamela Gay (4:51)

I had no idea this befuddled anybody.

I have learned something and it made me very, very sad. You started the episode by making me sad.

Fraser Cain (5:00)

Really? Okay. Yeah. There are people out there who uses their gotcha.

There's no air in space. There's no air in space. How do rockets work?

Pamela Gay (5:08)

Momentum. It's called conservation of momentum people.