Season 3, Episode 4, #AskAbby Space and Science Show: Homeschool Edition
Presented by TheMarsGeneration.org
Challenges of Living in Space
In Episode 4 of the #AskAbby Space and Science Show: Homeschool Edition, Abby will discuss the array of challenges of living in outer space that have to be overcome to allow human-space exploration! Be sure to bring your spacesuit…Abby will also talk about what would happen if an astronaut doesn’t wear one in space (spoiler alert: it’s not pretty).
In this episode, Abby answers questions posed by Chelsea Vasquez’s 7th Grade Science Class from CIS 303 in the Bronx: How big is space? Why is there no gravity in space? Do astronauts ever wish they could go back home? How long can you go out into space without a space suit? If you had to choose between living on Earth or living in space what would you choose? How long does it take to go to space [specifically to the ISS]? Why does water become bubbles in space?
Transcription of “Challenges of Living in Space”
Hi everyone and welcome to #AskAbby: Homeschool Edition!
This is a new series of #AskAbby intended to provide resources–as well as those oh-so-important bad space puns and joke–to students who are now doing distance learning during the COVID-19 pandemic!
Each episode will feature questions submitted by students from around the world.
This episode is focused on living in space, featuring questions submitted by the 7th grade students of Chelsea, a teacher at the CIS 303 school in Bronx, New York.
Question number one: How big is space?
As far as we can tell, space is actually infinite in size. But what’s even harder to wrap your head around is that space is also constantly expanding. The size of the observable universe is 93 billion light years, but what’s past that? We don’t really know.
Question number two: Why is there no gravity in space?
This actually isn’t true. There is still gravity in space. We just probably don’t notice it. You see, every object exerts a gravitational pull on other objects. For some objects, like let’s say, a coffee cup, its gravitational pull is too small for you to notice. It has no tangible effect. But for other objects, such as planets, stars, those types of things, they have enough gravitational force and gravitational pull, that they actually dictate the movement of everything else around them.
But for astronauts who are orbiting around the Earth, they’re actually still close enough to the planet that they’re feeling the effect and experiencing the effect of about 90% of Earth’s gravity.
So, why then do astronauts orbiting the Earth still appear as if there’s no gravity acting on them?
The answer is because astronauts orbiting Earth are constantly in free fall, which is an experience that, for all intents and purposes, mimics microgravity.
Question number three:
Do astronauts ever wish that they could go back home?
Of course, every astronaut is different, and feels differently about this. But, for the majority of astronauts, of course, they do miss home while they’re in space. And especially now that missions are getting longer and longer, missions now can take up to a year, and that’s a long time to be away from home.
You can think about an astronaut’s time in space kind of like you going to summer camp. You’re really happy to be there, you’re having a good time, you want to be there. But that doesn’t change the fact that you still miss home a little bit, and that a small part of you might wish that you could go home.
In order to manage and deal with this homesickness, astronauts actually spend a lot of time talking to people back on Earth, whether it’s mission control who they talk to very frequently. Or, even having video chats, conferences or calls with their families here on Earth.
Think about it, it’s just how right now, you can’t necessarily go hang out with your friends or go to your Grandma’s house, or otherwise see people that you would like to. But you can, and probably are, still video chatting with them.
Question number four: How long can you go out into space without a space suit?
The short answer is not very long at all. But don’t worry, I’ll go into the details of exactly how long not very long is. After about 15 seconds in space without a spacesuit, you’d pass out. And after about 2 minutes, you’d actually die. This would happen because when you’re in space without your space suit, all the oxygen gets pulled from your body. And also, because space is so cold, that you’d eventually freeze solid. Additionally, you’d get a pretty bad sunburn from all that UV radiation from the sun that you’re being exposed to, but I think at that point, a sunburn would be the least of your worries.
Question number five: If you had to choose between living on Earth or living in space, what would you choose?.
Well, it depends… Who am I stuck in space with? That makes all the difference.
No, I’m kidding. In most cases, or most instances, this is actually a pretty easy choice for me. I would choose to live on Earth for the rest of my life. And the reason for that is because space is a really inhospitable place. It’s very difficult for humans to exist and live in space. And we don’t yet have the technological abilities to sustain a reasonable lifespan in space, which means that if you chose to live in space for the rest of your life, it would end up being a pretty short life.
But that said, let’s imagine for a moment that we could sustain a full human life in space. Which would you choose… Earth or space?
Question number six: How long does it take to go to space and specifically to the ISS?
It takes about 8-and-a-half minutes to get from the surface of Earth to outer space. But after that, it can take anywhere from six hours at the shortest to two days in order to actually get to the ISS, or International Space Station.
That might leave you wondering, why does it take so much longer to get to the International Space Station, which is not that far up above Earth, than it does to just get into space?
And the answer is that it’s not actually about the relative distances. It’s about speed. The International Space Station is traveling at roughly 17,500 mph as it orbits around the Earth. And catching something going that fast is a very difficult task. If you were to launch your rocket ship
straight from the planet Earth going at a velocity to match the International Space Station’s Speed by the time you reached its orbit, you’d actually end up passing it by a lot; you’d end up in deep space. You’d completely miss the International Space Station, and that would be a tricky situation to be in.
So instead of launching at the correct speed to catch the International Space Station, astronauts and spacecraft that are headed to the ISS have to do a complex series of orbital maneuvers known as Hohmann Transfers, where essentially they start in a smaller orbit and make engine burns, or orbital maneuvers, to increase the size of their orbit over a time. And they have to do this in a really precise manner. It takes a lot of math and a lot of planning. So anywhere between six hours and two days.
And finally, I’ve saved the best question for last.
Question number seven:
Why does water become bubbles in space?
Water, or H2O, is a really special and unique substance. And one of the reasons for this is because water molecules on a molecular level are attracted to one another. Oooh la la!
Just kidding. Attraction in this case means that water molecules hold onto one another and don’t want to let go. And the optimal shape for this–this being as many water molecules as possible to be as close to each other as possible–is a sphere. This is because a sphere has the highest volume to surface area ratio of any object out there.
You may have noticed that water here on Earth actually does form into a sphere, at least up until a certain point. Have you ever gone outside and seen a dew drop? That’s an example of how water can form a sphere if it’s a small enough amount of water.
Now you might be wondering, why does the amount of water matter? And the answer to that is that the force between water molecules that’s holding them together and trying to keep them close is fighting against the force of gravity, which is pulling them apart. So when you have a small amount of water, all of the water molecules in there are able to exert force on one another, force that’s more than the force that’s being exerted on them by gravity. But when you have a really large amount of water, the water molecules at the center aren’t able to exert or experience as much of that interconnected force with the water molecules that are out towards the edges of the sphere, and suddenly gravity has the upper hand here, and causes the water to flatten out, or to lose the spherical shape, which is what we see when you dump anything more really than a couple drops of water at a time.
You have to keep in mind though that in space, water is experiencing the effects of microgravity. And without the effect of gravity, there’s no force pulling the water molecules apart from one another; there’s only the force that the water molecules are exerting on one another to stay together. This means that there’s nothing causing that sphere to break apart. And you can keep adding water to it with no upward limit of how much water, and it’ll stay in this optimal spherical shape.
Today we answered questions about some of the ways that space is fundamentally different from Earth. Substances like air and water behave differently in space. Unlike Earth, Space is essentially limitless. And even the forces of physics that we take for granted, such as gravity, seem to act different.
Space is full of differences from Earth, and that’s what makes space travel so exciting and interesting. We get to experience all of these differences and then even use them to answer some of the most mysterious questions.
And until next time, keep safe, keep healthy, and keep learning! So long fellow travelers of spaceship Earth!