Planetary Radio: Space Exploration, Astronomy and Science - Solar Probe Plus Will Fly to the Sun

Episode Date: September 13, 2010

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Flying to the Sun, this week on Planetary Radio. Welcome to Public Radio's travel show that takes you to the final frontier. I'm Matt Kaplan of the Planetary Society. NASA is preparing to go to the only star within reach, the one our planet is whirling around right now. We'll talk with program scientist Lika Guhatakurta about how Solar Probe Plus will get to within just 4 million miles of the Sun's surface. Emily Lakdawalla has both kudos and criticism for Discover Magazine this week. We'll hear that and more from her in a minute.

What does the TV series Top Chef have to say about our space exploration priorities? That's the question Bill Nye will explore. And before you know it, we'll be visiting again with Bruce Betts, learning about the current night sky and how you can win a Planetary Radio t-shirt. Asteroids were in the news last week. You probably heard about the two space rocks that passed by Earth just three days after they were discovered. Now, while you certainly would not have wanted one of these to land on you, they weren't nearly big enough to cause more than local or regional heartache.

As it happens, they just zipped on by, though well inside the orbit of the moon. The romantically titled 2010 RF-12 came within just double the distance of geosynchronous satellites. NASA scientist Lindley Johnson is in charge of the agency's near-Earth observations. These are fairly small objects, and they're quite numerous in the inner solar system. There's probably tens of millions of them. We pick these up several times a year, but actually, if we had the capability, we think we'd probably see these on a daily basis.

So go ahead, breathe a sigh of relief. But remember, the one with our name on it is still out there. Let's hear from Emily Lakdawalla. She is the Planetary Society's Science and Technology Coordinator. Emily, several things to talk about and many more in last week's blog entries that we won't have time to get to. Sticking to some of your entries, the first one you wanted to mention is about Deep Impact getting ready to continue its mission. Yeah, this is recycling at its best. They're taking Deep Impact, which is the spacecraft that crashed a large impactor into Comet Temple 1 five years ago.

They're going to fly it past a second comet. This one is called Hartley 2, and that encounter is on November 4th. They've just started imaging the comet. It's just a little fuzzball in the background of stars, but those images will improve over the next two months, and I'm looking forward to that. And we'll track that, of course, on this program. Now let's get to, well, I'll call it a bit of editorializing on your part about an editorial of sorts in Discover Magazine, or at least a commentary. That's right. I try not to editorialize very much on my blog. I try to stick to the facts, but every once in a while something really gets my goat. And this one did. And first, I actually was elated when I saw that

when Discover was looking back over 30 years of science writing and Discover magazine, the number one topic that they picked to lead the article was bad astronomer Phil Plait's little piece on how amazing the changes have been in space science over the past 30 years, how all these dead worlds have suddenly turned into living ones with oceans and possible life, and how robotic spacecraft have really brought all that back to us. And then just eight page turns later, another writer said that NASA was grounded and that Russians had won the space race after all because of the problems with the manned space program. That just really got my goat because so many people equate NASA with the manned space program

and don't realize how successful the robotic space program has been over the last couple of decades and how, in fact, it's really the heyday of robotic exploration right now. Got your dander up. Yeah, we are in a golden age of space exploration. We really are. There's more robotic spacecraft exploring the solar system, exploring more different places, returning more data than there ever has been before. And it's just this great richness that people don't realize. And here's another example of that without just a few seconds left.

Two natural bridges on the moon. Thank you for printing one of them, the 3D image. And everybody out there, put on your red and blue 3D glasses and take a look at this blog entry. Yeah, Lunar Reconnaissance Orbiter is just returning incredible high-resolution views of the moon, and we're seeing artifacts that we left behind there decades ago for the first time. All out there for you to find in last week's blog entries. Be sure to keep track as Emily follows everything going on in space exploration, especially on the Planetary Society.

She is the Science and Technology Coordinator for the Planetary Society and a contributing editor for Not Discover, Sky and Telescope magazine, which would never do that. Thanks, Emily. Thank you, Matt. Bill Nye is also thinking about our glorious robotic exploration successes, but he reminds us in this week's commentary that, like it or not, nothing excites the public like seeing humans go where they've never gone before.

Hey, hey, Bill Nye, the planetary guy here, now the executive director of the Planetary Society. And as I took office, if I may, and looked around, I was amazed again at how many space missions are going on right now. How many spacecraft are out in our solar system having a look around at our own planets, our own objects that be orbiting the sun, and at these distant stars that have planets around them themselves. There are dozens of amazing missions going on right now. But what's the big news story this week? Top Chef. Top Chef is sponsoring a thing with chef testants to make a dish, a food item that will be used on the very last space shuttle mission. And that's big news.

You know why? Because there are people involved. That's why Buzz Aldrin is going around the world right now saying, we got to send people onto these new missions to distant places like asteroids and eventually the planet Mars. These missions are astonishing. The things that people are thinking about, sending people way out in orbits way beyond the Earth, looking at new things and making discoveries that we can't even imagine right now. So what we've got to do, everybody, is do something new and exciting in space. We've got to get the space agencies around the world to get together

and send people to exciting new places to make discoveries. And you know what they're going to find? Nobody knows what they're going to find. That's why we're going. It's an exciting time in robotics, and it will be an astonishingly exciting time in human exploration. I got to fly. Bill Nye, the executive director guy. Wow. guy. Wow. Ray Bradbury once wrote a lyrically beautiful story about astronauts who fly to the sun and scoop up some of its fiery substance. I don't think you'd find many volunteers for such a mission, but there is much that might be learned if we could send a robotic probe plunging through the sun's mysterious atmospheric layer called the corona. NASA is now developing a mission that will do exactly that.

The agency has just selected the teams that will build instruments for Solar Probe Plus, which it hopes to launch by 2018. Lika Guhatakurta says many challenges remain. She is program scientist for the spacecraft. She has studied our star for many years, relying on a variety of instruments and spacecraft. Lika also leads a global effort called International Living with a Star, or ILWS. She called me last week from her office at NASA headquarters in Washington, D.C. Lika, thanks very much for joining us on Planetary Radio, and congratulations on what looks like

a mission to the sun sometime before this decade is out. That's correct. I find this extremely exciting, as do a lot of our listeners, because everyone is fascinated by this concept of going to the sun. I mean, how many hundreds of times have you heard that horrible old joke about NASA sending a mission to the sun? How are they going to do that? They're going at night. Oh, I know.

You don't have that luxury. How will you allow this spacecraft to survive just, what, 7 million kilometers from the sun? Yes, it's scorching heat is what I can say. You know, typically a spacecraft in the Earth environment where we have most of our satellites, it's going to be 500 times more than that. If you think of the closest we have been, it's to Mercury. And Mercury is about 36 million miles from the surface of the sun. And we are going to use it 4 million miles, I mean, from the surface of the sun. So you can see the difference between 36 million miles, 4 million miles. Yes, it's going to be very, very hot. And the question is,

how are we going to protect both our spacecraft as well as our sensors, which are really most important in this endeavor? What we have is kind of a novel design for a spacecraft. And the spacecraft has gone through many iterations over time. over time. And what we have right now is kind of a flat, round disc made of carbon-carbon composite with foam material inside that is very, very resistant to heat. You know, some of these epoxies we even use in shuttle nozzles, etc., where the temperature can be very hot. use in shuttle nozzles, etc., where the temperature can be very hot. The environment that we are going to be in is going to be about 1400 degrees Celsius or about 2600 degrees Fahrenheit. Even steel melts at this temperature, but not this epoxy, again, made from carbon that we are talking about.

All the instruments are going to be put under the shade of this heat shield. Now, we'll put an image of the current conception of this spacecraft up at planetary.org so the people can see how you basically hide the rest of the spacecraft behind this thick shield. I guess one thing that any mission planners headed to the outer solar system must envy you for is you'll have no shortage of light for your solar cells. Rather, we have perhaps a little too much sometimes. So we have to cool our solar panels to keep it from getting too hot. Sometimes maybe we might even have to retract the solar panels. So we have different set of challenges than the ones that people who are robotic spacecraft that are just cruising our

solar system has. We'll have higher intensity of radiation. I mean, I think we will have so many of these so-called superlatives, you know, first ever. Fascinating. It's one of those missions, you know, where both scientists and engineers get so excited. And the public, apparently. Yes. You know, we talk to people with the MESSENGER mission on this program on a pretty regular basis. Have you been able to learn anything from that probe's success? Yes. In fact, you know, what's interesting is that the spacecraft is being built by Applied

Physics Lab at Johns Hopkins University, or part of Johns Hopkins University. They also built the MESSENGER spacecraft. So absolutely, the engineering trades and understanding that comes from having done that mission takes us that much closer in sort of facing the challenges that we have to face when we go much closer from Mercury to the surface of the sun. What will we learn, what do we hope to learn about the sun up close and personal that we can't learn from 93 million miles away? When we look at the sun from 93 million miles away, we use remote sensing observations. What that means is we measure the sun through telescopes in just about every wavelength band that we can put our hands on. And that gives us a very detailed picture of the sun. But remember, this sunlight is coming to us

traversing 93 million miles. And so what it does is that there is a convolution process that goes on through this entire stretch where we have to use theory, we have to use modeling, we have to use deconvolution technique in order to really extract what is it we just saw or measured. We know that the solar wind blows at a pretty high speed beyond some part in the corona. We also know the corona is very hot. But again, these are spectral signatures. What this mission is going to do is actually do not remote sensing, but direct sensing. Another word for it is in situ. And it's going to be there in the environment and actually measure these particles, measure their velocity, measure the magnetic field, the electric field, the waves, everything that we need to know.

So it's no more deconvolution. We have an exact measurement where the spacecraft is going to be. And that's like ground truth validation. So you can put these numbers now in the model and see, did we get it right the first time? And what do we have to change? What are the new theories? And this is sort of, again, you know, approaching it from the conventional science point of view. These are the things we want to understand. But just the fact that we are going to a star allows for discoveries and unanticipated science. We call it serendipitous science. I mean, that's just phenomenal.

We don't know what we don't know, but we've set the mission to go do what we want to do and have a pretty decent idea about it. But we really want to nail those problems. That's Lika Guhatakurta, NASA's program scientist for the Solar Probe Plus mission. She'll tell us more about this amazing effort when Planetary Radio continues. I'm Sally Ride. After becoming the first American woman in space, I dedicated myself to supporting space exploration and the education and inspiration of our youth. That's why I formed Sally Ride Science, and that's why I support the Planetary Society. The Society works with space agencies

around the world and gets people directly involved with real space missions. It takes a lot to create exciting projects like the first solar sail, informative publications like an award-winning magazine, and many other outreach efforts like this radio show. Help make space exploration and inspiration happen. Here's how you can join us. You can learn more about the Planetary Society at our website, planetary.org slash radio, or by calling 1-800-9-WORLDS. Planetary Radio listeners who aren't yet members can join and receive a Planetary Radio t-shirt. Members receive the internationally acclaimed Planetary Report magazine. That's planetary.org slash radio. The Planet the planetary society exploring new worlds welcome back to planetary radio i'm matt caplan someday the solar probe plus spacecraft will dive into the sun's million degree corona and almost literally taste it the preparations are being made right now according to nasa program

scientist lika guhatha kur. The engineering challenges are tremendous, but the scientific payoff may be just as impressive. You went by very quickly the two central mysteries that I guess you're hoping to solve, or at least shed light on, if you'll pardon the pun, with this mission, that solar wind and that incredible heat of the corona, which I guess you don't see down at the surface of the sun.

That's right. So if you stack a thermometer on the surface of the sun, I mean, the temperature is going to be, say, between 4,500 to 6,000 degrees Celsius. Okay. Now, if you took that same temperature and stuck it in the corona, it would be at least a million degrees or more. Our normal understanding of how heat propagates, and this is just basic laws of thermodynamics, is that if you're standing in front of a stove, as you move away from a burning stove,

the temperature would decrease. But that's not the case in the corona, clearly, because as we are receding from the sun, the temperature is increasing, increasing significantly. So what is going on in the corona that makes the corona so hot? This is just not, you know, academic interest. Of course, as scientists, we want to know that. We want to go after the physics and understand the processes that's making corona hot. But it is really important to know this because, as you might be familiar, space weather now has become a buzzword. Just like terrestrial weather, the sun creates an environment in space called space weather. And we, just beyond the terrestrial weather, are affected by that. Our satellites, our astronauts, sometimes ground current, all of this are affected by space weather. So for us to nail the problem of coronal heating also has a societal relevance that's going to be very significant.

The other key question is solar wind. When we are close to the sun, we don't find that there is kind of an organized pattern of wind close to the sun. It seems kind of still, but beyond few solar radii, there is a gust of wind. There is a constant breeze, which is about 400 kilometers per second. And then there are this gusty wind that comes about when we have solar storms. We are trying to understand what creates the conditions in the sun, in the corona, that really generates this wind, gives the wind its momentum, which allows it to propagate not only through our environment, but every planetary body in the solar system. Where it stops is sort of the edge of the solar system, you know, where our Voyager spacecrafts are. And that's where it meets this other challenge. And it's the interstellar medium.

And that's the so-called heliopause? Exactly. Exactly. And so that's where really the influence of the sun stops. Wouldn't want to finish without asking you if maybe Solar Probe Plus, as it tells us more about our star, might also tell us more about those things that stars have such a strong role in creating, planets and perhaps even life. Yes, and those are those serendipitous signs that we hope we will get answers to. We don't know what we don't know. We will leave it at that. A good place to stop with any scientist, and best of luck with this program. Are you on target? I read that you're hoping for a launch before

2018. It's very far away, but we are getting started as rapidly as we can, and at this point, I would say that we are on target. But remember, 2018 is long ways from now. And a lot of challenges still to face, I'm sure. Thank you so much, Lika. Thank you. Lika Guhatha-Kirta is the Solar Probe Plus Program Scientist at NASA headquarters in Washington, D.C.

She's been telling us about that mission to a star, our own star. It happens to be the easiest one to reach. But this is not the only solar research that she does. She also has been the program scientist for the STEREO mission, the Solar Terrestrial Relations Observatory, which is currently observing our star. I also want to thank LECA's colleague Jennifer Rumberg for arranging our conversation. Jennifer and Lika didn't want me to hang up without getting an update on STEREO,

along with the Solar Dynamics Observer, or SDO, launched early this year. We've got STEREO, which launched in 2006, which we're expecting a wonderful milestone in February of 2011, which is basically the spacecraft are going to allow us to see

the far side of the sun. So we'll be able to have a whole picture of the entire sun. And then also the SDO spacecraft, which has given us the most spectacular high resolution images ever, ever seen. So we've got two that are both wonderful, newsworthy missions to talk about. Lika Guhatakurta and Jennifer Rumberg of the Heliophysics Division in the Science Mission Directorate at NASA. What's Up is We are at Planetary Society headquarters. It is time once again for What's Up. We are at Planetary Society headquarters. We're actually in Bruce's office this time

because the new executive director is downstairs in the big room holding his first management meeting. And you're supposed to be in it. Yes, I am. So we'll just stay up here and do radio. Cool! That's far more fun. So tell us, what's up?

Well, in the night sky, we've got over in the west, check out Venus looking like an extremely bright star-like object, still getting lower and lower and challenging to see. But after sunset, if you pull out binoculars or just have really good eyes, you can check out Mars to the right of Venus. And to the far lower right. Tough to see unless you got a clear shot to the horizon. Still Saturn barely hanging in there. Much easier, we've got Jupiter rising in the east in the early evening and high overhead in the middle of the night,

coming up on opposition where it's on the opposite side of the earth from the sun on september 20th now i also want to mention nice star formation easy to see if you're if you're in that pesky northern hemisphere like we are check out the northern triangle as it's sometimes unofficially called three bright stars overhead in the early evening early to mid evening you got vega and altair and teneb making a nice bright triangle pretty much right overhead in the fall in the north all right what else you got vega and uh altair and deneb making a nice bright triangle pretty much right overhead in the fall in the north all right what else you got uh well we've got this week in space history and uh and this one for you matt uh it was uh 35 years ago this week something happened of great importance to you you already did the Star Trek premiere. What else would premiere?

Star Wars? No. That was 12 years later. Not that I know. Lost in Space. Oh, Dr. Smith. Danger, Will Robinson. Danger.

Thank you so much. You're welcome. We move on to random space fact. I knew I should have turned on the limiter. You audiophiles out there, you'll know why. Comets, comets, there are all sorts of comets. They come in two breeds, or at least they're often broken into two breeds. The short periods, like Halley's comet, tens of years period, coming in from the Kuiper Belt. And then we get, coming from the Oort Cloud, we have comets that have periods up to tens

of thousands of years called, not surprisingly, long period comets. I know, creative. Let's go on to the contest because we've got some fun stuff to do with that. Alright, in the trivia contest we asked you what is the smallest constellation in the current defining of constellations? How'd we do, Matt? This was out of, you said, the 88 generally recognized constellations? That is correct. We had a good time with this. Got a huge response, maybe because a lot of people wanted to get a copy of Packing from Mars, which we are giving away to the winner this week. Almost everybody got it right.

The person who got it right and was also chosen by Random.org is Thomas Helm. Thomas Helm of, get this, Tatsuno, Japan, who said simply, crux. Crux. Southern cross. Crux. Yes. The actual boundaries since each of these, as I know at least one of our listeners, Lindsay Dawson, pointed out. You have some constellations that seem smaller, but everyone's given a certain amount of territory as part of their constellation.

Crux, Southern Cross is given the smallest of the 88. And in fact, from a lot of people, including Peter Carr, they named it as about 68 square degrees. Not a measure that I've ever heard of before, but it makes sense. Peter also pointed out that Hydra is therefore the biggest at 1,303 square degrees. Pretty amazing. And John Lease, by the way, sent us a really cool image of the Southern Cross that he took from the island of Morarea. Just trying to make us feel bad. Wow, that is cool.

You know what? A lot of people also took time to say how much they enjoyed the open house video. They enjoyed Ray Bradbury a lot, too. In fact, they enjoyed Ray, oh, I don't know, 6.02 times 10 to the 23rd times more than they enjoyed us. But they did enjoy seeing us in the video. And I wanted to mention a little shout out to Errol Coder, who does planetary TV and actually puts us up as a TV show sometimes. Yeah, no, it's very nice. You can find it on YouTube if you search for planetary radio. and he throws in appropriate stills and such, depending on how the conversation goes. Lovely recurring pictures of both Matt and myself.

It really is radio with pictures. It is, more than just what occur in my brain anyway. All right, so what do you got for us next time? What I think is actually a straightforward question, but I'm usually wrong when I ask that. What is the highest density moon in our solar system? This would be average density for the body. What is which satellite, which moon has the highest density?

Go to planetary.org slash radio. Find out how to enter. You have until Monday, September 20 at 2 p.m. Pacific time to get us this answer. And you might win a Planetary Radio t-shirt. Alright, everybody, go out there, look up at the night sky, and think about squishy stuff. Thank you, and good night. There must be something in your office

that you just, you looked up over there. I don't see anything squishy. No, this all comes out of my mind. The squishy stuff between your ears. All right, it was the squishy juggling toys. And we'll have to get you to juggle for us sometime soon on the radio. Bruce Betts is the director of projects for the Planetary Society.

He joins us every week here for What's Up. Back next week with another tale of the final frontier. And we'll tell you how you can get your voice heard during Planetary Radio, which is produced by the Planetary Society in Pasadena, California, and made possible in part by a grant from the Kenneth T. and Eileen L. Norris Foundation. Clear skies. Thank you.