It's time for another amazing episode of RTEjr Radio's Science show Let's Dive In. This time out, your hosts Julie & Phil journey into space with Astronaut Bruce Melnick. Our mission is to find out how the biggest telescopes get up there, and why they're up there in the first place
Julie tells us more...
Just over a year ago, on Christmas day 2021, the biggest space telescope ever left the Earth and journeyed into space. It’s job, to look deep into the past: to find out how what is going on at the very edges of our universe, and find clues as to how this *points at everything* came to be.
This telescope is the James Webb Space Telescope (JWST). And in the summer of 2021 NASA released the first images of deep space that the JWST had taken. They are, literally, out of this world. Check them out. Images from stellar nebulae, deep space, merging or coupling galaxies. Things that we've never been able to see before, this giant telescope is bringing to our planet.
The JWST is a giant telescope. It's the biggest space telescope ever created, which begs the question: how did we get it up into space? And kudos to Calen for asking this when he visited the UCD Explore Lab last year.
Friend of the show, retired NASA astronaut Bruce Melnick from the Kennedy Space Center Visitor Complex helped us out with this one. The telescope, when fully open, it 22m by 12m. "It's about the size of a tennis court," says Bruce.
How do you get something the size of a tennis court up into space? Bit by bit? All in one go? Just attach some boosters and send it up? These were guesses other kids at UCD Explore had for us.
"First thing you do, is you collapse it down. You have to make everything so that it unfolds. And you make it into really a tight package," Bruce tells us. How do you fold something like this? Something so big, made of so many parts and different materials? Imagine it's a bit like an origami umbrella! Here’s a fantastic little video showing exactly how they designed the JWST to fold up into the rocket to get it into space.
The sun shield and mirrors have been carefully engineered so that they can be folded up very precisely. Using techniques inspired by origami, the mirrors fold around the centre of the telescope, and the sunshield folds up a bit like the sides of an accordion.
You can actually make your own little origami rocket ships at home.
What you'll need:
- Square paper
- A ruler
- A straw
- A grown up to help
Follow the instructions on the video here!
Some things to think about:
- Why is your rocket launching?
- Can you make your rocket launch higher?
We also had a question from 7-year old Izzy, who wanted to know, why do we send telescopes up into space when we have them down here on the ground? The ones on the ground don't need suncream (we’ve talked about this in a previous episode - check it out!), they’re REALLY big and there’s all this extra fuss and folding to do to get them up into space, it’s not so easy to get to one to repair it, and let’s be honest, they ain’t cheap. So, why do we even do it?
The main reason is actually to get a better look at the stars, planets, galaxies and other cool things up in space.
Our planet, planet Earth, has a protective blanket surrounding it, which lets some light through so that we can live and survive and, well, see. But it also blocks other types of light. For the most part, this is great! We won’t get harmed by the rays from the sun and space. But, this safety blanket is a nuisance if we actually want to study those x-rays and gamma rays, those other types of light that come from space.
Also, our atmosphere has shifting pockets of air that interfere with pictures being taken (these pockets of air are actually what causes the stars to look like they are twinkling in the night sky!). This movement of air actually blurs any pictures taken by telescopes on the ground.
Sadly, we can’t just ask the atmosphere to shift over a bit and let some light through in the hope that it might reach our ground-based telescopes…so instead we have to get around it. OR above it!
So, we take telescopes up into space. Telescopes like the Hubble telescope, which has been up in space for over 25 years and has taken over 1.5million images, allow us to see planets being born. We can witness galaxies crashing into each other, and see light from the most distant collections of stars in the universe.