NASA's Curious Universe - Our Window to the Stars

Episode Date: April 19, 2020

Decades of planning. One heart-pounding setback. Over a million mesmerizing images of space. This is the story of the Hubble Space Telescope, our window to the stars.

We all know what it's like to wander outside and look up at the night sky. On a clear night, when you can see all of the stars perfectly, it's so easy to feel small. It makes you wonder, what's out there, beyond what we can see. The Hubble Space Telescope has helped us answer that question over the last 30 years, revealing that reality is often stranger than fiction. We've seen the births and deaths of stars. and we've found answers to questions we'd never even thought to ask before.

We've learned all of this in incredible detail by looking back in time. Hubble is like a time machine in the sense that we can look farther and farther out into the universe at these fainter and fainter more distant galaxies. And by doing that, we're really looking back in time because it has taken time for that light to get to us

from these stars and galaxies. That's Jennifer Wiseman. She's the senior project scientist for Hubble and says that the telescope is achieving more than scientists originally expected. Hubble has recently contributed to the determination that the expansion of the universe is, in fact, accelerating. That was unexpected. Hubble has become the pioneering telescope

in analyzing the atmospheres of exoplanets. Hubble has found the likely presence of water, and moons around other planets using interesting innovative techniques. That was really not something Hubble was originally designed for. So we're using Hubble now for kinds of science we did not originally anticipate. And after all this time, the discoveries we get from Hubble every day are still knocking us back, telling us more about the nature of our universe and its origins. But Hubble's journey to the stars was a difficult one.

So how did it succeed? Welcome to NASA's curious universe. I'm Patty Boyd, and in this episode, we're exploring a truly iconic NASA mission, the Hubble Space Telescope, our window to the stars. This is the story of how NASA put a telescope in space. Decades before the Hubble Space Telescope was even a possibility,

the idea of looking beyond our own atmosphere was at the forefront of astronomy. Back then, most astronomers believed that the universe consisted of just one galaxy, our own Milky Way. Then, Edwin Hubble came along and changed everything.

From a mountaintop near Los Angeles, he peered up at the night sky with a ground-based telescope, the Hooker telescope, which at the time was the largest one in the world. That's when he spotted something amazing. The fuzzy objects he noticed in our sky were actually other galaxies.

And most of these galaxies he spotted looked like they were moving away from each other. Edwin Hubble was one of the pioneers that determined that our universe is in fact expanding galaxies seem to be moving apart from each other along with that stretching of space. But we couldn't quite discern the rate of that expansion. It's a very difficult measurement.

So the Hubble Space Telescope was able to contribute to a really higher precision measurement of that expansion rate by measuring more carefully the distances of these galaxies and correlating that with other measurements of their apparent velocities and giving us an expansion rate that was much more refined than anything ever before. Edwin's discoveries made scientists wonder. If we could see all that coming from a ground-based telescope, what would happen if we sent one above our murky atmosphere? German scientists Herman Oberth dreamed of what we might learn. If we could look at the heavens with an astronomical telescope in orbit,

unhindered by the shielding sea of atmosphere that blankets the earth, think of the discoveries we would make, the clear vision of the universe we would have. Echoing Oberst's vision, astronomer Lyman Spitzer outlined the detail for how to make it all work in an academic paper that would really set the stage for Hubble. NASA set out on an adventure to place a telescope in space. This telescope would discover things that would revolutionize the way we think of our place in space. Here's what the great astronomer Carl Sagan had to say about this bold experiment. Space telescope is, in a way, a little like Galileo's first telescope.

Wherever Galileo pointed his telescope, he made, made me be able to be. your new discoveries. Look at the moon, you find mountains and craters, look at Saturn, you find rings, look at the Milky Way, you find it is littered and composed of stars. Every one of these discoveries, things that people had not known before, I think it's going to be very similar with the space telescope. It will illuminate celestial objects that we know about. It will discover celestial objects never before guessed. It will provide inside, into the most important questions such as stellar evolution, such as the search for planets going around other stars,

and the grandest cosmological questions of the origin, nature, and fate of the universe. Space telescope is a kind of grand intellectual adventure for all of us, which will cast light not just on the cosmos, but also on ourselves. The telescope was built at Lockheed Martin in California, with NASA's Marshall Space Flight Center

overseeing the telescope's construction. It was named after Edwin Hubble, who paved the way for grand discovery. But actually getting a telescope the size of a school bus into space is difficult, as you might imagine. That's where the space shuttle discovery comes in. NASA's space shuttles were designed to carry

and deploy spacecraft like Hubble. With the space shuttle discovery, NASA astronauts would deploy Hubble at the edge of space in low Earth orbit and return safely to Earth. NASA designed the telescope to fit snugly inside shuttle discovery, which carried and released this precious cargo into space. The shuttle discovery poised at Cape Canaveral for a launch tomorrow morning. It may be the most ambitious and eagerly awaited mission in the history of the shuttle program. On board a giant telescope that will redefine our view of the universe. When it launched in 1990, NASA's Hubble Space Telescope was only designed to last 15 years. In 2020, the telescope celebrates its 30th birthday, and Hubble is still as powerful as ever.

Hubble makes discoveries 24 hours a day. It's up there orbiting the Earth, and it goes around the Earth about once every 90 minutes. That's Michelle Thaler, an astronomer and science communicator at NASA's Goddard Space Flight Center in Greenbelt, Maryland. Goddard is home to Hubble's mission control. The Hubble Space Telescope is something that just changed everything. I think people now have this view, you know, what does space look like? And they don't even realize that what they're thinking of is something that Hubble images brought to our culture, to our imagination. She's right.

When you close your eyes and imagine space, you probably picture stars, beautiful colors, and a sheer vastness. The images that pop into your head are probably star-studded, and full of the colorful clouds of nebulas. That's because the pictures taken by the Hubble Space Telescope are the clearest and closest we've ever come to looking at our universe. They've fundamentally shaped how we think of space. And from space, Hubble can see a lot.

Here's one way of looking at it. Imagine going to a piano concert, and the musician sits down and can only play three notes around Middle Sea. That's the amount of light we can see here on Earth. Then there's a whole spectrum of light our eyes aren't sensitive to. And that's where Hubble comes in. Hubble can see in multiple wavelengths of light, like infrared and ultraviolet. So Hubble's view would sound a lot more like a symphony.

NASA made a huge push in the years leading up to Hubble's launch to promote the Revolutionary Telescope's efforts. NASA promised the public that this project would lead to important discoveries and answers. After all, this was the culmination of decades of work and research, not to mention the financial and emotional investments riding on this mission. On April 24, 1990, the telescope launched. Three, two, one, and liftoff of the space shuttle discovery with the Hubble Space Telescope, a window on the universe.

Back on Earth, mission control monitored the deployment carefully. They knew what was at stake. And this is Hubble Telescope Control in Greenbelt. We have been given the go-ahead to begin commanding release of the forward latches, which hold the solar arrays in place during launch. When the discovery crew set out to deploy the telescope, they were under a lot of pressure. After all, Hubble was set to be the greatest astronomical advancement since Galileo picked up a telescope.

But something went wrong. Of course, when Hubble finally got up and everybody was really excited, There was this amazing sense of deflation when they opened up the telescope, light went through it, and they realized the images were out of focus. And they were out of focus because the curvature of the mirror was wrong. So, I mean, this was just an incredible mistake. I mean, people have been making very accurate telescope mirrors for a long time. And the fact that all of a sudden, up in space, what were we going to do now,

You know, this incredibly valuable instrument was launched, and there was this tremendous problem. The first pictures that NASA saw here on Earth were fuzzy and distorted. And it was all because of an incredibly small, almost undetectable aberration, a tiny error from when the mirror was constructed. Hubble's vision was blurry.

But the telescope was still technically doing its job, at least as far as astronomers like Michelle were concerned. The spectrographs still worked just fine. The images were out of focus, but all of the data, you know, the really detailed data about the universe was still coming in through these spectroscopic instruments. So for people specifically doing my science, Hubble started working beautifully. We were making incredible discoveries. But of course we wanted to get those clear images to see the universe without the distortions. of the atmosphere to see it beautifully, beautifully clear.

From the beginning, Hubble was designed to work hand-in-hand with the space shuttle program. NASA had anticipated that Hubble would need to be modified and expected to send astronauts to do so in the coming years. What was not anticipated was that the first images coming from the Hubble Space Telescope were quite disappointing. There was obviously a problem. ...teloscope system optics. The conclusion we've come to from that is that there's a... The significant spherical aberration appears to be present in the optics, in the optical telescope.

The mirror on Hubble had been ground beautifully, but to a slightly incorrect formula, and this had not been caught in testing. This incredible idea was raised. Why don't we fix it? And then this is one of the grand adventures of NASA. NASA set out on a daring rescue mission to save the Hubble Space Telescope. They came up with a very insightful solution. Basically, in some sense it's been described as putting glasses on Hubble. These glasses were actually an instrument, which was designed to correct Hubble's flaw. A team of astronauts were prepared to service the telescope in space.

A good plan endeavor. Good morning. They made an instrument that actually corrected the light before it went into the cameras, took out the wrong curvature. All of a sudden, they snapped into just beautiful. beautiful focus. Everything was gorgeous. So it is one of the most amazing happy endings in the history of science and the history of technology. Hubble's servicing missions didn't stop with its initial rescue. Over the years, Hubble has been serviced multiple times. John Grunsfeld is one of the astronauts who helped keep Hubble in top shape. For me as an

astronomer, going out in a space suit and working on the Hubble is just the ultimate experience. There's nothing cooler. Hubbell is an incredible icon of science, and so to me it was the holy grail of being an astronaut. John worked on three repair missions to the telescope, earning the nickname Hubble from publications like the New York Times. I was expecting the wonders of space and the beauty of the earth. What surprised me the most was that I kind of discovered my humanity, You know, that being in a tight crew working together as a team with hundreds, thousands of folks on the ground, that there's really nothing, I think, that humans can't achieve if we work together as a team. And if we have good challenges, things that are worth doing, we can do almost anything.

We know so much about our universe now because of people like John, people who were watchful stewards of the telescope and who dedicated themselves to its success. Hubble has lasted a lot longer than we expected. We thought Hubble might last 10 or 15 years if we were lucky. But thanks to the series of astronaut servicing missions over the years, the telescope has been refreshed over and over again with repaired instruments and new batteries and gyroscopes and things like that, refreshed new instruments as well.

And that has made the telescope basically brand new, more or less, every time we've done a servicing mission, and that's kept it at the forefront of scientific discovery. To get a look at the outstanding imagery from the Hubble Space Telescope, visit nassah.gov slash Hubble. You can also follow the telescope on social media at NASA Hubble. This is NASA's Curious Universe. The Curious Universe team includes Elizabeth Tammy and Michaela Sosby.

Our executive producer is Katie Atkinson. Special thanks to the Hubble Space Telescope team. If you're enjoying Curious Universe, consider leaving a review on your podcast app or tweeting about the show at NASA. And in the next episode, astronaut Nick Haig takes us to an underwater training ground.