Cosmic Queries: LightSail with Bill Nye

In May 2015, the Planetary Society will launch its first LightSail spacecraft for a “shakedown cruise” in Earth orbit. So who better to answer fan questions about the program than their CEO, Bill Nye, and comic co-host Chuck Nice?

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:01Neil deGrasse Tyson?

  Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now.

• 0:21Bill Nye?

  Welcome to StarTalk. Bill Nye here, your guest host this week. I'm here with my colleague, charming associate Chuck Nice. Chuck, good to see you.

• 0:30Chuck Nice?

  Hey, Bill. Good to be here.

• 0:32Bill Nye?

  And this week is Cosmic Queries, in which we answer your questions.

• 0:37Chuck Nice?

  That's right. We call the questions from the internet in all of our various incarnations, Twitter, Facebook.

• 0:46Bill Nye?

  The social media that the kids use with the electric computer machines.

• 0:50Chuck Nice?

  Yeah, exactly.

• 0:51Bill Nye?

  So, this week, our focus, thank goodness Chuck, is me! We're talking about the Planetary Society, the world's largest non-governmental space interest organization, advancing space science and exploration.

• 1:06Chuck Nice?

  And in the interest of full disclosure, you are the fearless leader

• 1:09Bill Nye?

  Yes, right.

• 1:10Chuck Nice?

  of the Planetary Society.

• 1:11Bill Nye?

  I'm the CEO, and just so you all know, Neil deGrasse Tyson was involved with this. So I had Carl Sagan for astronomy back in the disco era. Took one classroom, but it redirected my life, changed my life.

• 1:28Chuck Nice?

  Wow.

• 1:29Bill Nye?

  And so I joined the Planetary Society, which he and two other guys started. Lou Friedman, who's an engineer at JPL, and Bruce Murray, who was the head of the Jet Propulsion Lab during the Voyager missions, the Viking missions, the hey hey days of JPL.

• 1:45Chuck Nice?

  Right.

• 1:46Bill Nye?

  And so I got on the mailing list. And then, when Carl Sagan had this misfortune of getting this extraordinary, very difficult to deal with, form of cancer.

• 1:56Chuck Nice?

  Well.

• 1:57Bill Nye?

  He died.

• 1:58Chuck Nice?

  Right.

• 1:59Bill Nye?

  And I was asked to speak at his memorial service because his kid, Sam especially, liked the Science Guy show.

• 2:06Chuck Nice?

  Yeah.

• 2:08Bill Nye?

  And then I got on the board of directors. And then here's, and then Neil was asked to be on the board of directors.

• 2:13Chuck Nice?

  Okay.

• 2:13Bill Nye?

  Because he was this rising star in astrophysics. Now he is, of course.

• 2:17Chuck Nice?

  Yes.

• 2:18Bill Nye?

  Galactic globe.

• 2:19Chuck Nice?

  Galactic, right. Galactic overlord.

• 2:22Bill Nye?

  Yes. So, anyway, then, we, the Planetary Society, because of the...

• 2:29Bill Nye?

  The fame and accomplishments of Carl Sagan.

• 2:33Chuck Nice?

  Right.

• 2:33Bill Nye?

  We, we are recognized enough to give Stephen Hawking an award. The Cosmos Award.

• 2:39Chuck Nice?

  Oh.

• 2:40Bill Nye?

  And so we went to Cambridge.

• 2:42Chuck Nice?

  Oh dear.

• 2:42Bill Nye?

  In the UK.

• 2:43Chuck Nice?

  Of course.

• 2:44Bill Nye?

  It's quite lovely. And that's when you're with Neil, and I don't know how much time he spent, there's a lot of wine.

• 2:50Chuck Nice?

  Yes.

• 2:51Bill Nye?

  There's a lot of.

• 2:52Chuck Nice?

  That's, that's.

• 2:52Bill Nye?

  Flowing wine.

• 2:54Chuck Nice?

  Neil and Bacchus are good friends.

• 2:56Bill Nye?

  Yes, yes, yes, well acquainted. And now I'm the CEO. I don't really, I'm not sure how that happened. But I've been the CEO for over four years. And for the first time since the 1990s, we're growing. And the exciting thing is, uh, this goes back to Carl Sagan, we're gonna launch our own spacecraft. First week of May.

• 3:18Chuck Nice?

  Wow.

• 3:19Bill Nye?

  A solar sail.

• 3:20Chuck Nice?

  A solar sail.

• 3:22Bill Nye?

  Which is a extraordinary thing. If I can use that noun. It gets pushed through space by sunlight.

• 3:30Chuck Nice?

  Yes. Now, that is.

• 3:33Bill Nye?

  That seems crazy.

• 3:34Chuck Nice?

  It does seem crazy. It is really intriguing, though.

• 3:37Bill Nye?

  And you say, Bill, nigh, CEO of the Planetary Society.

• 3:41Chuck Nice?

  Yes.

• 3:42Bill Nye?

  I thought light had no mass. How can it possibly have momentum? When I walk down the street, even if I'm John Denver, and there's sunshine on my shoulders.

• 3:53Chuck Nice?

  Yes.

• 3:54Bill Nye?

  I don't, uh, I don't get high, I don't get a push.

• 3:58Chuck Nice?

  Right. Even if, if I'm walking on sunshine.

• 4:03Bill Nye?

  Yes.

• 4:03Chuck Nice?

  I don't.

• 4:04Bill Nye?

  And, or, or you might as well be walking on the sun. Okay, that's not going anywhere. So the thing is. Uh, whether in.

• 4:12Chuck Nice?

  Once you get to Sting, the references stop, right?

• 4:15Bill Nye?

  Yeah, they should, yeah. Uh, um.

• 4:19Bill Nye?

  Whether in classical physics or through relativity.

• 4:21Chuck Nice?

  Okay.

• 4:22Bill Nye?

  Light has momentum, photons have momentum, and this is a fun little thing you can do in your head if you're out there and you're a physics person of any kind, or just if you've ever watched US football.

• 4:33Chuck Nice?

  Okay.

• 4:34Bill Nye?

  Momentum.

• 4:35Chuck Nice?

  Yes.

• 4:36Bill Nye?

  Is the multiplicative, it's when you multiply, mass times velocity, mass times speed.

• 4:42Chuck Nice?

  Right.

• 4:43Bill Nye?

  And direction. So if you have a football player that is more massive and he's going faster, he has more momentum.

• 4:50Chuck Nice?

  Right.

• 4:51Bill Nye?

  And so along this line, uh, let's take E equals mc squared, which everybody loves. Now let's divide both sides by c in your mind's head.

• 5:03Chuck Nice?

  All right.

• 5:04Bill Nye?

  Then E over c, some packet of energy divided by the speed of light.

• 5:07Chuck Nice?

  Right, which is the constant.

• 5:09Bill Nye?

  Some mass times the speed of light. So some mass times some speed is momentum.

• 5:15Chuck Nice?

  And that's it.

• 5:16Bill Nye?

  So it's just something to think about, it's just, anyway.

• 5:19Chuck Nice?

  So you get those two players coming together?

• 5:20Bill Nye?

  And then.

• 5:21Chuck Nice?

  Concussion, basically.

• 5:22Bill Nye?

  That's right, yeah.

• 5:22Chuck Nice?

  There we go.

• 5:23Bill Nye?

  And then, but unlike, uh, the NFL, we, we're not in denial. So this thing, uh, we're gonna have this very large sail deployed from this almost, you would almost describe it as tiny spacecraft.

• 5:38Chuck Nice?

  So it's like a, like a sailboat, but in space?

• 5:41Bill Nye?

  Yes.

• 5:42Chuck Nice?

  It's a sailboat in space?

• 5:43Bill Nye?

  And furthermore, you steer it by tacking, the same way you steer a sail.

• 5:48Chuck Nice?

  A regular, right. Ah, that's amazing.

• 5:50Bill Nye?

  It really is, and so this goes, Carl, I, we have footage now of, on the website of Carl Sagan in 1976, descri- on the Tonight Show with Johnny Carson, describing solar sail. Uh, and, uh, he had a model of it and so on, and this thing is visually very, very similar. I mean, as, as Mr. Scott would say.

• 6:12Chuck Nice?

  Well, you know, that's funny, you say Mr. Scott, because the first time I learned or knew about a solar sail was from an episode of Star Trek. And I thought it was like so cool that they came up with this crazy idea, and then I read about it, that they did not come up with that crazy idea.

• 6:32Bill Nye?

  With the laws of physics.

• 6:34Chuck Nice?

  Exactly, that they that they they co-opted that crazy idea.

• 6:38Bill Nye?

  So let's uh let's get to the questions.

• 6:40Chuck Nice?

  Okay, so what we have before us is a number of questions from our listeners and sometimes viewers if they're on YouTube. And they've submitted these questions specifically for you to answer, Bill, with respect to the light sail. And um you do not have the questions, only I do.

• 6:59Bill Nye?

  I have not seen the questions.

• 7:00Chuck Nice?

  You have not seen them, so just for the sake of disclosure, uh Bill does not know what I'm about to ask, but these are your questions, let's get to it. This one is from Joe Foster and he comes us to us from at Fos Do Nut or Donut.

• 7:14Bill Nye?

  They're good, they're good donuts.

• 7:15Chuck Nice?

  That's a good donut, the Fos donut.

• 7:17Bill Nye?

  Let's say, let's let's just go with that.

• 7:19Chuck Nice?

  Exactly. Uh here's what uh Joe wants to know. Uh what are you hoping to learn from this launch? I mean, what's what's the purpose in terms of information?

• 7:30Bill Nye?

  So the big, the biggest picture is if you had solar sailing spacecraft that were that were operated very well. You could lower the cost of any mission to any destination in the solar system. By I don't pick a number, factors of tens of thousands, because there's no fuel.

• 7:48Chuck Nice?

  Right.

• 7:49Bill Nye?

  So as we say, you can trade time for money.

• 7:54Chuck Nice?

  Gotcha.

• 7:54Bill Nye?

  If you have time, you're a space agency, for example, Rosetta, that spacecraft took 12 years.

• 8:00Chuck Nice?

  Right.

• 8:00Bill Nye?

  To get out to the comet. Uh if you have time, the solar sail is fantastic uh system because uh it it gets a, when you think of a regular rocket, the engine might run 20 minutes, that's a huge rocket.

• 8:14Chuck Nice?

  Right.

• 8:15Bill Nye?

  Engine might run nine minutes.

• 8:18Chuck Nice?

  It's just full blast.

• 8:21Chuck Nice?

  Wow, that was a smaller one, I'm pretty sure.

• 8:23Bill Nye?

  Yeah, yeah.

• 8:24Chuck Nice?

  The first one was pretty big.

• 8:24Bill Nye?

  Yes. But solar sail is just.

• 8:30Bill Nye?

  In space, and so day and night. Wait, in space, there's no night.

• 8:34Chuck Nice?

  Ah.

• 8:35Bill Nye?

  So, uh, it gets a push, a tiny push continually, for, continuously, rather, for as long as it's in space. And so we're proving, uh, this technology, and the big thing is NASA, and well, the world, now has a standard, uh, called a CubeSat.

• 8:53Chuck Nice?

  A CubeSat?

• 8:55Bill Nye?

  Cubicle satellite.

• 8:56Chuck Nice?

  Cubicle, oh, it's CubeSat.

• 8:57Bill Nye?

  CubeSat.

• 8:58Chuck Nice?

  CubeSat.

• 8:59Bill Nye?

  Ten centimeters by ten centimeters by, ours is thirty centimeters, which is smaller than a loaf of bread.

• 9:05Chuck Nice?

  Okay.

• 9:05Bill Nye?

  It's really weird.

• 9:06Chuck Nice?

  Right.

• 9:06Bill Nye?

  And, uh, when things get that small, the electronics have to be very small, the software has to be very efficient, everything has to be really good. And so we are, we built this spacecraft, estimates vary, for about a fifth of what it would have cost a regular space agency to build.

• 9:22Chuck Nice?

  Wow.

• 9:22Bill Nye?

  Because we just had passionate guys, and we were supported by forty-six thousand members around the world. And so we hope to prove that solar sailing is practical on this scale, which would enable universities, uh, private corporations, everybody to participate in inexpensive, uh, cis-lunar spacecraft that's between the Earth and the moon and out to destinations in the solar system.

• 9:47Chuck Nice?

  Unbelievable. I mean, very believable, and extremely cool. Okay, so now, let's touch on, uh, what you just said, uh, about, uh, getting up to speed and continual speed, because our next question is from Ben Shanker. And Bill says, I mean, Ben says.

• 10:07Bill Nye?

  Ben.

• 10:08Chuck Nice?

  Ben says.

• 10:08Bill Nye?

  I'm Bill.

• 10:09Chuck Nice?

  You are Bill.

• 10:09Bill Nye?

  It's a blur in here.

• 10:10Chuck Nice?

  It really is. It's just, it's all a mush here, uh, up here. That's my mind.

• 10:15Bill Nye?

  That's what your wife was saying. She, at first, she, at first she thought she was kidding. And now she's, what, is she seventeen years into it?

• 10:23Chuck Nice?

  That's right. You are absolutely correct, Bill. Seventeen years in.

• 10:26Bill Nye?

  Well, she reminds me.

• 10:27Chuck Nice?

  She realizes that, uh, she's been.

• 10:29Bill Nye?

  She shakes her head.

• 10:29Chuck Nice?

  Yes, she does. Uh, here we go. Uh, Ben wants to know this. How long would it take for a light sail ship to get to a useful speed? And I'll put an addendum onto that. What exactly is a useful speed?

• 10:44Bill Nye?

  Yeah, so.

• 10:45Chuck Nice?

  Okay, so.

• 10:46Bill Nye?

  So the first thing is you gotta get a chemical rocket, that's our state of the art, to get into above the atmosphere.

• 10:51Chuck Nice?

  Right.

• 10:51Bill Nye?

  And so we're, we are a secondary payload. On an Atlas V.

• 10:56Chuck Nice?

  Okay.

• 10:57Bill Nye?

  A venerable rocket that is descendant of the rocket that launched John Glenn.

• 11:01Chuck Nice?

  Oh, very nice.

• 11:02Bill Nye?

  Engineering descendant.

• 11:04Chuck Nice?

  Nice lineage.

• 11:05Bill Nye?

  Yeah, that's right. So, once you're in space, see, the Planetary Society tried to launch some solar sails, 2005, on a Russian rocket.

• 11:15Chuck Nice?

  Okay.

• 11:15Bill Nye?

  That was leftover from the Cold War.

• 11:17Chuck Nice?

  Mm-hmm.

• 11:18Bill Nye?

  And it didn't work very well.

• 11:19Chuck Nice?

  Oh.

• 11:19Bill Nye?

  And our members would not, they would not let us try that again.

• 11:23Chuck Nice?

  No more leftovers.

• 11:24Bill Nye?

  That's right. So, it's on a real Atlas V, brand-new, uh, smells new. Anyway, and you-

• 11:29Chuck Nice?

  It's got that new rocket smell.

• 11:31Bill Nye?

  Gets above the atmosphere, and then if you, for example, wanted to go to the moon, it would take you about a month to get to the moon.

• 11:38Chuck Nice?

  Okay.

• 11:38Bill Nye?

  Uh, and then if you want to go beyond that, it starts, you start computing years. But, the thing is, you can go to destinations no one's ever thought of, uh, practically. Like, catching up with a comet would take about the same amount of time as the, uh, for example, the Rosetta Mission.

• 11:55Chuck Nice?

  Mm-hmm.

• 11:56Bill Nye?

  Because it's always getting a push.

• 11:58Chuck Nice?

  It's always getting a push.

• 11:59Bill Nye?

  Always getting a push, once you're out, out, out there.

• 12:01Chuck Nice?

  Right.

• 12:02Bill Nye?

  But what we're gonna do with light sail, though, as we call it, light sail, is, uh, go around the Earth, show that the thing deploys, show that the antenna works. It's quite a important thing. You might not have thought about it, but when you're in low-Earth orbit,

• 12:16Chuck Nice?

  Mm-hmm.

• 12:16Bill Nye?

  if you are not a great big space agency with US naval ships all over the world and, uh, the means to have stations on exotic coral atolls in the middle of the ocean, most of the time, you're not over the land.

• 12:32Chuck Nice?

  Right.

• 12:33Bill Nye?

  Most of the time, there's nobody listening to your little beep, beep, beep, beep. And so, these sort of things have to be carefully worked out. And then, we're gonna try steering. Can we twist the sail? Imagine this in your mind's head. You have to go edge on toward the sun.

• 12:49Chuck Nice?

  Right.

• 12:49Bill Nye?

  And then face away, going away from the sun.

• 12:53Chuck Nice?

  Right.

• 12:53Bill Nye?

  And that's how you build orbital energy. So, we're gonna run tests like that.

• 12:57Chuck Nice?

  Wow, that's fascinating. Very, very cool.

• 13:00Bill Nye?

  And it's built just by people, just by people who thought it was cool.

• 13:03Chuck Nice?

  There you go, Ben. There's your answer. Uh, let's move on to Sharon Smith Snodgrass. That's her name.

• 13:11Bill Nye?

  Snodgrass. My dad was a prisoner of war with a guy named Snodgrass.

• 13:14Chuck Nice?

  Really?

• 13:14Bill Nye?

  That's what he told me. I don't know if it's a true fact or a false fact.

• 13:17Chuck Nice?

  Chuck, I wasn't there. He told me that.

• 13:20Bill Nye?

  No, but I mean, grownups tell you stuff.

• 13:21Chuck Nice?

  This is true.

• 13:21Bill Nye?

  I don't know. So, go ahead.

• 13:22Chuck Nice?

  Okay. How far away from the sun can the light sail travel before there's no further means of propulsion? And at that point, can it change direction? Or is it on a one-way trip in the last direction that it was propelled?

• 13:38Bill Nye?

  Well, nominally, it's getting a push indefinitely. I mean, that is to say, as a first cut, uh, you're always getting a push. Consider, for example, that Pluto, which will be visited by a spacecraft in July, the word "visited", flying by, except in space, there's no sound. It just goes, huh, yeah.

• 13:56Chuck Nice?

  That's right.

• 13:56Bill Nye?

  Uh, so it'll, uh, the-

• 13:59Chuck Nice?

  Let's hear that again, shall we? There you go.

• 14:02Bill Nye?

  The Plutonian's atmosphere grows when there's just the tiniest bit of sunlight on it. Everybody believes it's volatilizing some melt, um, making some ice turn to a gas.

• 14:13Chuck Nice?

  Okay.

• 14:14Bill Nye?

  And then, as it moves away from the sun, that shrinks. So, even way the heck out there at Pluto, there's enough sunlight to influence a whole planet.

• 14:23Chuck Nice?

  Right.

• 14:24Bill Nye?

  So, there will be enough sunlight to influence the spacecraft. And then, if you want to go crazy, which is fun to do.

• 14:29Chuck Nice?

  Yeah.

• 14:29Bill Nye?

  We put a laser in your mind's eye on the moon. We launch a solar sail, and we have made an agreement with international governments, and the Federation is running things at that point.

• 14:43Chuck Nice?

  Yeah.

• 14:43Bill Nye?

  And we beam a laser on a spacecraft for-

• 14:48Bill Nye?

  Solar sail spacecraft for 10,000 years and it goes to Proxima Centauri. Goes to the next star system.

• 14:55Chuck Nice?

  Right.

• 14:56Bill Nye?

  Pushed by humankind's 10,000 year, nothing breaks. We all agree this is worth doing laser system.

• 15:04Chuck Nice?

  Right.

• 15:05Bill Nye?

  But if you think about it, it is the only known technology that could take us to another star system. It's quite cool because there's always a push.

• 15:13Chuck Nice?

  Always a push.

• 15:14Bill Nye?

  Always a push.

• 15:14Chuck Nice?

  And we can, for Sharon's question, we could artificially, from what you're saying, we could artificially create that push if necessary.

• 15:23Bill Nye?

  So you'd have solar panels all over the far side of the moon.

• 15:26Chuck Nice?

  Right.

• 15:27Bill Nye?

  Running a laser that somehow redirects itself and is always aiming at the Chuck Nice Memorial Solar Sail spacecraft. I mean, it's, these are some complex issues. I'm not saying it couldn't be done.

• 15:39Chuck Nice?

  It couldn't be done.

• 15:40Bill Nye?

  But it's cool to think about. It really is cool to think about.

• 15:43Chuck Nice?

  Very cool.

• 15:44Bill Nye?

  And it's related to light sail and the Planetary Society.

• 15:46Chuck Nice?

  Absolutely. Okay, well, we've got a couple of minutes here. So let's, let's go to John Thompson and he's coming to us through Twitter. At Aviation is his handle. He says, with respect to the light sail, how are they built? And is there a top speed?

• 16:08Bill Nye?

  Well, everybody's dream is to get to 100 kilometers a second. But this spacecraft's not capable of that. So here's why. To get to those speeds, you'd have to get close, closer and closer to the sun.

• 16:22Chuck Nice?

  Right.

• 16:22Bill Nye?

  And we don't have the materials that can take that right now. But this spacecraft, the sail itself is.

• 16:27Chuck Nice?

  The Icarus Syndrome.

• 16:28Bill Nye?

  That's right.

• 16:28Chuck Nice?

  Ah.

• 16:30Bill Nye?

  But this spacecraft is made of Mylar, aluminized Mylar. It's inexpensive material. In fact, it's so inexpensive.

• 16:38Chuck Nice?

  How inexpensive is it?

• 16:39Bill Nye?

  It's so cheap that they sent us a sample, which was big enough to make the first set of sails. Like it was so, it's so cheap. But anyway, the booms, as they're called, are often called tape measure booms because they resemble a steel tape measure that you use to. Get, size your carpet. Okay. If you're a contractor sawing wood or what have you. Yeah, okay. And they're extraordinarily stiff. They're made of this cobalt steel. Hours were made at the Air Force Research Lab in Kirtland Air Force Base in Albuquerque, New Mexico. And they, we have a proprietary mechanism to wind these things which are four and a half meters long. Mm-hmm. Zzzzz. So they retract? Tiny little, yeah. Well, they extend. They extend.

• 17:24Bill Nye?

  But we have proposed retract and extending. So if you think about it, you ever had, what, when you, you have the tape measure extended? Right. And you let go of the lock, it goes back in. Well, what we do is push them into the thing so they're loaded. Like a spring loaded? It's spring loaded, yeah. And they're extraordinary springs. They're really, um, they're just cool. And they consist of two ribbons stitched welded together. And stitch welding is a term they made up and it's just a laser. Tt, tt, tt, tt, tt, tt, tt, tt. It's very cool. So it's a high-tech thing that guys that have been working on for decades. And we have combined all these technologies and we're hoping for a successful flight

• 18:09Bill Nye?

  the first week of May. Fantastic. You're listening to StarTalk Radio. I'm your host, uh, sitting in this week, Bill Nye, with my co-host Chuck Nice. We'll be right back.

• 18:24Bill Nye?

  Welcome back to StarTalk Radio. I'm Bill Nye, sitting in for Neil deGrasse Tyson. And this week, it is, it's a big one for me. I'm, I'm here with Chuck Nice. Yes. We're taking your questions, your cosmic queries. And it's a big week for me because we're talking about the Planetary Society, of which I'm the CEO, and, uh, specifically our light sail spacecraft. Yes. Our solar sail spacecraft, which we're gonna launch, we, the nominal date is the 6th of May, but these dates slip around. It's, by the way Chuck, I didn't tell you it's, it's an Air Force payload. An Air Force payload? This is to say, the primary payload is, uh, something that the Air Force is doing

• 19:06Bill Nye?

  and they won't really tell us what it is. Uh, there's a lot of speculation that it's just a spy satellite, or it's the X-37B lifting body, but no one's really sure. Anyway, so it's really cool, you guys, when you think about rocket science. This part of it's not that hard. The primary payload, or the thing where they've paid a lot

• 19:28Chuck Nice?

  Right.

• 19:28Bill Nye?

  to load on, is some air force thing, and it's on top. Then below that is the secondary payload, which is where we are. And it's seven of these very small satellites, these CubeSats.

• 19:43Chuck Nice?

  Right.

• 19:43Bill Nye?

  Ten centimeters by ten centimeters by thirty centimeters, smaller than a loaf of bread.

• 19:48Chuck Nice?

  Right.

• 19:48Bill Nye?

  And so, we're on there, and after the primary payload is off, then these seven little ones go spring, spring, spring, spring, off into space with these cool stainless steel sort of Jack-in-the-boxes. So, it's very cool. But let's get back to the questions. Very exciting week for me.

• 20:07Chuck Nice?

  Very cool. All right, let's go to Dan Owens.

• 20:13Bill Nye?

  Dan, how have you been?

• 20:14Chuck Nice?

  Yeah, Dan's doing very well, from what I can tell. And this is what he says. "What is the top speed of a solar sail could feasibly reach before losing the sun's influence?" Now, here's the real question. "After that, could it be propelled by an onboard photon source? Or would that be the equivalent of trying to blow your own sail?"

• 20:37Bill Nye?

  Yeah, it's trying to blow your own sail, exactly.

• 20:39Chuck Nice?

  That's trying to blow your own sail.

• 20:40Bill Nye?

  Yeah. However...

• 20:42Chuck Nice?

  I can't say that I haven't done that.

• 20:43Bill Nye?

  So, think about, Dan Owens.

• 20:46Chuck Nice?

  Yes.

• 20:46Bill Nye?

  Think about it this way. Suppose you had solar panels. And you soaked up sunlight, and you powered a laser onboard your spacecraft. Your solar panels weren't on a spacecraft, by the way, not like on your wristwatch or something. Which, I have one, but that's not really... It's not the same.

• 21:04Chuck Nice?

  It's not the same kind of solar panel.

• 21:05Bill Nye?

  It's not in outer space, for example.

• 21:06Chuck Nice?

  Exactly.

• 21:07Bill Nye?

  So, then you'd shoot the laser off some way, hoping, I mean, and expecting that you'd get a push. Like, if you were holding the famous thing that will stand on roller skates, and you have a bowling ball.

• 21:20Chuck Nice?

  Right.

• 21:21Bill Nye?

  And you throw the bowling ball to somebody, you go off the other direction.

• 21:24Chuck Nice?

  You go left, you go right.

• 21:25Bill Nye?

  Because of the conservation of, or momentum. The momentum of the bowling ball going that way will be equivalent to your momentum going this way.

• 21:32Chuck Nice?

  Okay.

• 21:33Bill Nye?

  All right. Well, imagine you did this. You soaked up sunlight, drove a laser, you shoot the laser.

• 21:39Chuck Nice?

  Well...

• 21:41Bill Nye?

  Back up, back up. It's simpler than that. If you have just a mirror in space.

• 21:47Chuck Nice?

  Right.

• 21:48Bill Nye?

  The photon bounces off the mirror and gives you a push.

• 21:51Chuck Nice?

  There you go.

• 21:51Bill Nye?

  Whoa. And so that's what the solar sails.

• 21:53Chuck Nice?

  So, and so you don't even need the old, uh, fan in the sailboat trick.

• 21:58Bill Nye?

  No.

• 21:58Chuck Nice?

  Where you've got the electric fan in the back of the sailboat. All you need is a mirror.

• 22:03Bill Nye?

  That's right. Uh, in space.

• 22:04Chuck Nice?

  In space, in space.

• 22:05Bill Nye?

  Because you have a fan.

• 22:07Chuck Nice?

  Right.

• 22:08Bill Nye?

  Which is the sun.

• 22:09Chuck Nice?

  Right.

• 22:09Bill Nye?

  The sun is your fan.

• 22:10Chuck Nice?

  There you go.

• 22:11Bill Nye?

  For your push your own sailboat thought experiment. So, uh, it's, anyway, by the way, if you have just a black surface.

• 22:18Chuck Nice?

  Mm-hmm.

• 22:19Bill Nye?

  Uh, there's an expression in physics called a black body, a perfectly absorbent material.

• 22:23Chuck Nice?

  Yes, uh, we have that saying in my family.

• 22:26Bill Nye?

  I, I was gonna let you do it. Uh, anyway, you get a push, uh, but you get twice as much push theoretically perfect. If it was a perfect mirror, you get twice as much.

• 22:36Chuck Nice?

  Twice as much push.

• 22:37Bill Nye?

  Yeah. And so this thing is made of super shiny Mylar.

• 22:41Chuck Nice?

  Right.

• 22:41Bill Nye?

  And, uh, making it out of Mylar, it makes it a little cheaper than if you made it out of other better fancier plastic like

• 22:49Chuck Nice?

  Right.

• 22:49Bill Nye?

  Illuminized Kaptan, polyimid, imid. But the Mylar, the thing's gonna burn up in the atmosphere this first flight. Because the man

• 23:00Bill Nye?

  is only taking our spacecraft. The man is only taking our spacecraft to 250, 400 kilometers.

• 23:09Chuck Nice?

  Okay.

• 23:10Bill Nye?

  You know, 150 miles and stuff. And they're still up there, although you and I would suffocate in a few inst- moments.

• 23:17Chuck Nice?

  Right.

• 23:18Bill Nye?

  There's still a few air molecules and so it will drag it down.

• 23:20Chuck Nice?

  Tiny bit of atmosphere that will.

• 23:22Bill Nye?

  But we are gonna launch a second light sail in May of 2016.

• 23:27Chuck Nice?

  Okay.

• 23:27Bill Nye?

  That one on the mythic modern super Falcon 9.

• 23:32Chuck Nice?

  Ooh.

• 23:33Bill Nye?

  From, uh, SpaceX.

• 23:34Chuck Nice?

  Fancy.

• 23:35Bill Nye?

  And so that one will be at a much higher altitude and we will get solar propulsion much more easily. Now, this first test is the first test.

• 23:45Chuck Nice?

  Ha.

• 23:46Bill Nye?

  That's right. And we're very hopeful that things will, see NASA has tried deploying these sails on another spacecraft called Nanosail D.

• 23:54Chuck Nice?

  Okay.

• 23:55Bill Nye?

  And by the way, NanoSail, Nano Satellite, NanoSat, that's another word they like, but

• 24:01Chuck Nice?

  Instead of CubeSat.

• 24:03Bill Nye?

  But CubeSat is a standard that people have settled on. And by people, I mean mostly universities. And the Air Force is quite interested in CubeSats. Anyway, they uh, they uh, tried this and it didn't deploy right. The, the tape measure booms didn't boom.

• 24:18Chuck Nice?

  Okay.

• 24:19Bill Nye?

  And uh, so we believe we have solved that problem.

• 24:22Chuck Nice?

  Whoa.

• 24:23Bill Nye?

  And of course, the guy who solved it, you know, is 12 years old. He's 26.

• 24:26Chuck Nice?

  Right.

• 24:26Bill Nye?

  Of course.

• 24:27Chuck Nice?

  And he just wrote an app and he's now a billionaire.

• 24:29Bill Nye?

  Yeah, right, yeah.

• 24:30Chuck Nice?

  Right? That's how it works.

• 24:31Bill Nye?

  No, no, but these guys, they're young guys and they're, and men, men and women, and they're passionate and they've just done outstanding work. It's really exciting.

• 24:37Chuck Nice?

  Well, Dan Owens, thank you for that great question. And your answer is, the sun is your fan. Always remember that. All right, let's move on. And uh, let's go to uh,

• 24:49Bill Nye?

  The sun is your fan.

• 24:50Chuck Nice?

  The sun is your fan.

• 24:51Bill Nye?

  I don't want to forget the sun is your fan.

• 24:52Chuck Nice?

  That's right.

• 24:52Bill Nye?

  Take it, Chuck. Sorry, guys. All right.

• 24:55Chuck Nice?

  Joey uh, Pierosko, from uh, and I love it, uh, that Joey writes, uh, from Green Bay, Wisconsin here. Hey, Bill, the light cell technology is phenomenal. However, how will you prevent microscopic space debris from penetrating or completely destroying its fragile mirrors, or as you called it, Mylar, uh, that it needs for propulsion? This is a really great question, Joey. I am interested right now. And Bill, I love the look on your face. Let's have it.

• 25:26Bill Nye?

  So two things, Joey. First of all, three things. First thing, thank you for your question. That's an outstanding question. And uh, many people have wondered that. But we'll start with, there's not that many micrometeorites.

• 25:37Chuck Nice?

  Really?

• 25:37Bill Nye?

  I mean, we all worry about it.

• 25:38Chuck Nice?

  Yeah, cause that's what you hear about when you

• 25:40Bill Nye?

  Uh, and space debris.

• 25:42Chuck Nice?

  Yeah.

• 25:42Bill Nye?

  It's serious freaking

• 25:43Chuck Nice?

  It tore a hole in my suit.

• 25:44Bill Nye?

  Yeah, which, see, that's never happened.

• 25:46Chuck Nice?

  Get out.

• 25:47Bill Nye?

  For example.

• 25:48Chuck Nice?

  Is that, is that all Hollywood?

• 25:49Bill Nye?

  No, it's all sort of common sense. But it's, there's just not that much stuff.

• 25:54Chuck Nice?

  It's just not a lot of stuff out there.

• 25:55Bill Nye?

  With that said.

• 25:56Chuck Nice?

  Okay.

• 25:57Bill Nye?

  The uh, sail manufacturers have embedded this rip stop feature. And when you look at the, and by that, I mean, there's strands or fibers built into the Mylar, into the fabric, into the shiny, plastic, super thin stuff.

• 26:14Chuck Nice?

  Okay.

• 26:14Bill Nye?

  And if you look at it edge on, uh, grazing angle, you can see the lines and they're about Two centimeters apart.

• 26:21Chuck Nice?

  Okay.

• 26:22Bill Nye?

  About a little less than an inch apart. Blah, blah, blah, blah, blah, blah, going this way and blah, blah, blah, blah, blah, going that way.

• 26:27Chuck Nice?

  Okay.

• 26:27Bill Nye?

  And so to keep it from tearing, mostly in just handling it with humans with those cool little white gloves on.

• 26:34Chuck Nice?

  Mm-hmm.

• 26:35Bill Nye?

  When they, they fold it like origami in this clean room. Anyway, uh, it's a great question, but we think we've addressed that. Uh, micrometeorite going at, uh, 10 kilometers or second or seven miles a second, just go right through it.

• 26:51Chuck Nice?

  Right.

• 26:52Bill Nye?

  It won't, it's not like you're up there with a utility knife going, rah, rah, rah.

• 26:56Chuck Nice?

  It's, yeah, like the old pirate.

• 26:59Bill Nye?

  Yeah.

• 26:59Chuck Nice?

  With the knife in the sail.

• 27:00Bill Nye?

  Yeah, that's right. It's, there'd be, just poke a hole, but there is ripstop built into it.

• 27:05Chuck Nice?

  And so this ripstop weave, so, so to speak, actually keeps it from like

• 27:09Bill Nye?

  Tearing.

• 27:10Chuck Nice?

  Like a run in a stocking.

• 27:11Bill Nye?

  Exactly.

• 27:12Chuck Nice?

  Keeps it from continuing on.

• 27:13Bill Nye?

  And this is an old trick and it's called a clay polymer. Mylar is a brand name, like tissue or frisbee. Uh, a clay polymer and, um, polymer's plastic and clay means it has an alkaline.

• 27:25Chuck Nice?

  Mm-hmm.

• 27:25Bill Nye?

  It has a oxygen, hydrogen hanging off the end and it does something to make this plastic have these wonderful properties.

• 27:31Chuck Nice?

  That's fantastic. Hey, Joey Perosco, that was a really great question, my friend.

• 27:37Bill Nye?

  Love you, Joey.

• 27:38Chuck Nice?

  We do love you, Joey. Nice job. Okay, let's see here, um. All right, this is a nuts, these people are thinking, man, this is Eric's.

• 27:47Bill Nye?

  Chuck, you're choosing good ones.

• 27:49Chuck Nice?

  No, you know what, I'm kinda going, well, I am choosing good ones. Uh, this is Eric Shard. Eric Shard would like to know, would light sails be a viable approach to de-orbiting comets to aid in terraforming Mars? Excellent, excellent.

• 28:08Bill Nye?

  Piece of cake.

• 28:09Chuck Nice?

  Excellent.

• 28:10Bill Nye?

  Nothing to it.

• 28:10Chuck Nice?

  Nothing to it.

• 28:11Bill Nye?

  Yeah. They would be ideal for changing the orbit of com- comets.

• 28:16Chuck Nice?

  Okay.

• 28:16Bill Nye?

  Now, along this line, uh, hold it, this isn't Chuck, who's this?

• 28:21Chuck Nice?

  This is Eric Shard.

• 28:22Bill Nye?

  Eric, Eric, along this line, Eric. Uh, keep in mind that there might be a shorter term, more important use of this closely related to your question. Instead of changing the orbit of comets, we might want to change the orbit of an asteroid. That's what I was thinking. So it doesn't hit the earth. That's what I'm saying. Like, for instance, Apophis is actually going to go through that keyhole and we are doomed. God, you're down, Chuck. Exactly. Right? Apophis, name for the god of anxiety, is gonna miss us. The god of worry is gonna miss us, but when it was discovered, it looked like it would not miss us. Exactly. And, uh, we, and as we always like to say, it may be wrong. We may be wrong. There are probabilities here involved.

• 29:06Bill Nye?

  But imagine this, Eric. You would have a solar sail that would catch up with an asteroid, which is not trivial. Catch up with it and then, poof, you know, smother it. Right, right. So, duh, just get on top of it. And then the shininess would change the momentum, would change, take sunlight momentum and change the path of the asteroid just ever so slightly. And so then now to get back to the biggest picture of your question of taking comets, which might be full of ice and smashing them into Mars so that we can terraform Mars. Terraform being a word

• 29:45Bill Nye?

  that to you and me is, makes sense, but if you talk to Og, the cave guy, he would think you'd kinda lost your mind. Okay? It's a whole planet. We can barely manage the planet that we live on. We have enough trouble with managing water here. And we don't do it very well, by the way. Okay, I went with enough trouble. You could go with suck. Yeah, we suck. How about that? Yeah, you could do that. Let's not sugarcoat it. Right, but with that said, uh, you guys, about terraforming Mars, there's a reason Mars doesn't have much of an atmosphere. And that's the solar wind scrapes the atmosphere off. The solar wind are these particles that stream off of stars, and in our case, the sun.

• 30:28Bill Nye?

  And they've scraped the Martian atmosphere away because Mars isn't quite big enough to have a magnetic field, uh, to stay molten, to create a magnetic field, which makes the charged particles come streaming into the poles instead of sideways tangentially across the surface. So you guys, terraforming Mars. That's it. No, but I mean...

• 30:48Chuck Nice?

  It's not gonna happen.

• 30:49Bill Nye?

  It's just not that easy, okay? There's nothing to breathe, there's nothing to eat, and it's freaking cold. You guys, we live in this world, on, on this world where humankind uh, has migrated all over the place.

• 31:04Chuck Nice?

  Right.

• 31:05Bill Nye?

  Everybody's from East Africa. Chuck, your people, much more recently than my people.

• 31:09Chuck Nice?

  Mm-hmm.

• 31:10Bill Nye?

  Went north.

• 31:11Chuck Nice?

  Yeah, my people, uh, East Africa is Detroit.

• 31:15Bill Nye?

  It's like that.

• 31:18Bill Nye?

  It's like that. Uh, but I've actually, well, we can get a whole digression on skin color, but it has to do with ultraviolet light. You go north into Mesopotamia, then you migrate across Eurasia, then there's this, um, what do we, Ice Age, all the snow is frozen up in the mountains, so we can just walk to Sarah Palin's place in Alaska, then south, killing everybody, by everybody, I mean, all the big mammals and eating meat.

• 31:43Chuck Nice?

  Right.

• 31:44Bill Nye?

  And then, uh, we just migrate across, all the way down into South America, it's cool, but we're running out of places to which to migrate.

• 31:52Chuck Nice?

  That is so true.

• 31:53Bill Nye?

  You're not gonna be able just to leave the earth and go to Mars. It's a very complicated and long distance. However, if you wanna send spacecraft to Mars

• 32:03Chuck Nice?

  Mm-hmm.

• 32:04Bill Nye?

  to study its environment, and I recommend that we all do that, I cannot help but recommend solar sailing as a means of inexpensive propulsion for, let us say, citizen research. For people who are interested in interplanetary missions, you could embrace a solar sail spacecraft, not unlike the light sail, which the Planetary Society is gonna launch the first week of May.

• 32:28Chuck Nice?

  Did you see that circle of life there?

• 32:29Bill Nye?

  Brought it back around, Eric.

• 32:30Chuck Nice?

  Did you see that, Eric? That was fantastic. Oh, great, well, there you have it, forget about Mars, not gonna happen. The solar wind comes strolling in across the atmosphere. All right.

• 32:43Bill Nye?

  Take it, Chuck.

• 32:46Bill Nye?

  The musical stylings of Chuck.

• 32:47Chuck Nice?

  Thank you very much. Please avail yourself of some of the mints here in the Stardust Lounge.

• 32:54Bill Nye?

  Tip your servers.

• 32:55Chuck Nice?

  Let's go with a real quick question because we have just a, just a little bit of time left here. With Logan, it's, I guess it's keeps. Logan says, "All the talk is about propulsion of solar sail." My question is, "How does it stop? Make flight path corrections, etc. Standard rockets? Wouldn't that defeat the purpose though?"

• 33:16Bill Nye?

  Uh, yeah. So you seldom stop in space. Um, yes, when you land on the surface of Mars, you stop, but mostly you go into orbit around things. And by that, I mean you start out in orbit around something, Chuck. The big thing you start out in orbit around is?

• 33:30Chuck Nice?

  Earth.

• 33:30Bill Nye?

  The Earth, uh, for our solar sail. Yeah, but everybody actually.

• 33:34Chuck Nice?

  It's the sun or the star.

• 33:35Bill Nye?

  Even when we're on the Earth, we're in orbit around the sun. Even when we're orbiting the Earth, rather, we're in orbit around the sun as well.

• 33:40Chuck Nice?

  Correct.

• 33:41Bill Nye?

  So you seldom stop. You go out there and just the right trajectory to get captured by, let us say, Mars, Mars's gravity or the moon's gravity.

• 33:50Chuck Nice?

  Right.

• 33:50Bill Nye?

  That's the most, it's a much more common thing in a spacecraft mission. And light sail is ideally suited to that. It's ideal for that. So it's going to be an exciting launch. Uh, it's supported by Planetary Society members around the world.

• 34:05Chuck Nice?

  And we don't stop, basically.

• 34:07Bill Nye?

  We don't stop.

• 34:08Chuck Nice?

  Yeah.

• 34:08Bill Nye?

  But the light sail will, I'm sorry, burn up your membership dollars at work. But it's going to be a fantastic mission and we're going to learn a lot about it. And not only that, I'm, I'm Bill Nye, your guest host this week on StarTalk with my co-conspirator Chuck Nice, and we'll be right back.

• 34:31Bill Nye?

  Welcome back to StarTalk Radio. I'm sitting in as your host, Bill Nye. I'm here with my co-conspirator Chuck Nice.

• 34:38Chuck Nice?

  Yes.

• 34:39Bill Nye?

  And it's Cosmic Query Time where we take your questions. But this week, I'm very excited as the CEO of the Planetary Society to, uh, take questions that all have to do with our solar sail spacecraft, our light sail spacecraft.

• 34:53Chuck Nice?

  Light sail.

• 34:54Bill Nye?

  Which launches the first week of May. On an Atlas V, and the Planetary Society, everybody, is the world's largest non-governmental space interest group. We advance space science and exploration, so that citizens, enabling citizens of the world to know the cosmos and our place within it. And so, we advocate in US Congress for good space policy, and it's limited extent in Europe, and a very limited extent in Israel, the meeting this year is in Israel, a very limited extent in India and in Japan, but we have members around the world who have a great interest in advancing space science and exploration, and that's why we built

• 35:39Bill Nye?

  this very cool solar sail spacecraft. Chuck?

• 35:42Chuck Nice?

  Yes, sir.

• 35:43Bill Nye?

  You've got questions?

• 35:44Chuck Nice?

  I've got great questions. So far, I have to say that our audience has been thinking quite in-depth about this light sail, and we've had some really, really interesting questions.

• 35:56Bill Nye?

  You don't have to sound so surprised. They're your fans, okay? They're, they're smart people.

• 36:00Chuck Nice?

  This is true, they are. So, let's, um, well, I don't know if this person's actually screwing with me, you know?

• 36:09Bill Nye?

  This radio, Chuck, don't, like, just don't give them too much information.

• 36:14Chuck Nice?

  All right, so it's, uh, "Dahrik Iswig Chaya", okay? That's it, I did my best.

• 36:21Bill Nye?

  All right, well, it's, uh, using Roman characters to describe a language that they weren't made for originally.

• 36:26Chuck Nice?

  Absolutely.

• 36:27Bill Nye?

  But we're doing our best, go for it.

• 36:28Chuck Nice?

  Okay, how big of a sail is required for this project, and does the size of a sail actually matter? In other words, bigger sail, faster boat?

• 36:36Bill Nye?

  Yeah.

• 36:37Chuck Nice?

  Is that the deal?

• 36:38Bill Nye?

  Yes. And it's more, it's not just the bigger the sail, exactly, it's the bigger the sail relative to the mass of the whole thing.

• 36:45Chuck Nice?

  Gotcha.

• 36:46Bill Nye?

  Right?

• 36:47Chuck Nice?

  Right.

• 36:48Bill Nye?

  Uh, so, uh, this sail is, uh, 32 square meters, it's quite large compared to this thing which, the spacecraft, the bus, as it's called, is smaller than a loaf of bread.

• 36:58Chuck Nice?

  Mm-hmm.

• 36:59Bill Nye?

  And this will be the highest acceleration spacecraft, uh, solar sail spacecraft launched, uh, hi, it'll have the most oomph for its mass. Uh, uh, the Japanese Aerospace Exploration Agency, JAXA, launched this very cool Icarus spacecraft.

• 37:17Bill Nye?

  A few years ago, that was a demonstration that they could do it and it worked fine.

• 37:22Chuck Nice?

  Okay.

• 37:22Bill Nye?

  But it ended, it was intended, the whole spacecraft was intended to end up in orbit around Venus. But it missed and so now it's in a, in an orbit about the same distance from the sun, but uh, not around Venus. About the same distance as Venus is from the sun. So we are, we are close, uh, we're close friends with our buddies at Jaxa who got a lot of, uh, got a lot of experience by deploying this thing. It worked really well.

• 37:48Chuck Nice?

  Really well.

• 37:49Bill Nye?

  But because of the 600 kilo spacecraft, 600 kilogram spacecraft, it didn't get as much acceleration strangely enough as light sail will get here the first week of May.

• 37:59Chuck Nice?

  Well, that's interesting. Now here's the follow-up to that question from the same person.

• 38:03Bill Nye?

  First week of May. It'll be several weeks after that when the sail's deployed and atmospheric conditions have to be just right and so on.

• 38:09Chuck Nice?

  Gotcha.

• 38:10Bill Nye?

  Those are some, some, uh, disclose, just disclaimers.

• 38:13Chuck Nice?

  So I'm not sure if, uh, Dechric is, um, trying to express a disbelief in light sails, but says, in addition, how much funding is put into figuring out an efficient fusion reactor?

• 38:30Bill Nye?

  Uh, that's a separate issue.

• 38:31Chuck Nice?

  That's what I was gonna say. Like, are you saying like, light sails aren't gonna work, so we really need a fusion reactor?

• 38:39Bill Nye?

  Actually, yeah. Uh, the light sail does work on a fusion reactor. That might be his time.

• 38:45Chuck Nice?

  Maybe that's what it is.

• 38:46Bill Nye?

  Where is the fusion reactor Chuck?

• 38:47Chuck Nice?

  Ah.

• 38:48Bill Nye?

  Take a shot.

• 38:49Chuck Nice?

  Take a shot?

• 38:50Bill Nye?

  Where do we have a fusion reactor at a safe distance?

• 38:54Chuck Nice?

  I'm gonna say that would be the bit plasma ball in the sky.

• 38:57Bill Nye?

  The sun.

• 38:58Chuck Nice?

  There you go.

• 38:59Bill Nye?

  That's right. The sun is our fusion reactor. Chuck, he's the ma, he's the real deal. Chuck's the real deal. So it's, um, uh, the sun provides, uh, the hydrogen, the protons combined to make what we'd normally call helium atoms.

• 39:13Chuck Nice?

  Right.

• 39:14Bill Nye?

  And, uh, in that process, release a tremendous amount of energy, photons, which will push the light sail. But investing in a fusion reactor is something we do. Uh, here in the United States is taxpayers all the time. And fusion reaction reactors are always, in my experience, uh, forty years away. They're always forty years in the future. But that doesn't mean-

• 39:36Chuck Nice?

  No matter what time it is that you're thinking about them.

• 39:38Bill Nye?

  My whole life, forty years. But that doesn't mean somebody won't figure it out. I'm not being dismissive.

• 39:42Chuck Nice?

  Right.

• 39:43Bill Nye?

  But the planetary society's not really into building fusion reactors. We're into taking advantage of the natural fusion reactor, which we call the sun.

• 39:53Chuck Nice?

  Very cool.

• 39:54Bill Nye?

  Let's take another question, Chuck.

• 39:55Chuck Nice?

  Alright, let's take another question.

• 39:59Chuck Nice?

  Alright, this is from Denard Springle, coming to us from Google Plus. And Denard says, "The first attempt at the light sail by TPS was sadly a tragedy."

• 40:13Bill Nye?

  TPS, everybody, means the planetary society.

• 40:15Chuck Nice?

  Okay, thanks.

• 40:16Bill Nye?

  Two thousand and five, Cosmos One crashed in the Berens Sea, which I had not really noticed before. It's in the Arctic. It's part of the Arctic. It's an area of the Arctic Ocean. Lead on.

• 40:29Chuck Nice?

  He says, and this is not instilling a lot of confidence there, Denard, "Will there be a third attempt if the same should befall the second attempt?" So if the same fate befalls our-

• 40:46Bill Nye?

  Light sail A.

• 40:47Chuck Nice?

  Our light sail A.

• 40:49Bill Nye?

  We have light sail B, which launches in May of 2016.

• 40:52Chuck Nice?

  Okay, so there you have it. We got to, see?

• 40:55Bill Nye?

  And if you're a planetary society member, thank you, because one of the things that my predecessor did do was get everybody, by sending letters to people, get everybody to build a second spacecraft. Once you have the design, building the second one isn't nearly as difficult as you may imagine. That's how you mass produce cars, for example.

• 41:14Chuck Nice?

  Exactly.

• 41:15Bill Nye?

  And it's, making the hardware is one thing, but it's really, it's the software, man. That's what just takes people a long time to get it to really actually work, actually. You can get it to almost work right away.

• 41:29Chuck Nice?

  Right.

• 41:30Bill Nye?

  But almost work is a lot like not working. But we gotta work it, and so everybody's very excited. So that's a great question.

• 41:37Chuck Nice?

  Almost work is a lot like not working. So there you have it. That was a good question. Way to go there, Denard. I appreciate you.

• 41:47Chuck Nice?

  Pardon me for that. Uh, will the lights, uh, oh, sorry. Let me back up here. This is from Andy.

• 41:57Chuck Nice?

  This is, that gets me every time. I don't care if so.

• 41:59Bill Nye?

  And we're showing our age. I mean, you don't really, there's rewinding now is not a

• 42:03Chuck Nice?

  Isn't that true?

• 42:03Bill Nye?

  Watch a mechanical thing.

• 42:04Chuck Nice?

  Yeah, that's true.

• 42:05Bill Nye?

  It's now click on a click.

• 42:07Chuck Nice?

  Yeah, exactly. Um, Andy Bracken wants to know. Uh, will the light sail be used in the future for missions to the planets? Just our outer planet. Is this basically?

• 42:26Bill Nye?

  The future.

• 42:27Chuck Nice?

  The future. Can we, can you, can you make this the future?

• 42:30Bill Nye?

  Yeah, we claim it is. So as we say, if you have time, uh, you can trade that for money. In other words, light sails, uh, will go wherever you want. Well, as long as you don't get too close to the sun with our current materials.

• 42:43Chuck Nice?

  Right.

• 42:44Bill Nye?

  Uh, will go a long way, um, over a long time. But yes, missions to Mars and Jupiter have been discussed at length. And there's guys who are, people who are into this and they run the numbers. They do calculations on this. And yes, it's all quite doable. But the longest journey, Chuck.

• 43:02Chuck Nice?

  Yes.

• 43:02Bill Nye?

  Starts with but a single step. And so that's why, uh, we're doing light sail A here in May.

• 43:08Chuck Nice?

  Fantastic. So, uh, so basically all of your unmanned missions, this could be.

• 43:14Bill Nye?

  Oh, yes, yes.

• 43:15Chuck Nice?

  This could be the thing for all of your unmanned missions.

• 43:17Bill Nye?

  Yeah, if you're, but the big thing is the cost is so much lower than a chemical rocket that cube sats, as they're called, whether or not they're light sails or not, are made by universities, by small companies. And now, uh, which has really helped things, the air force is quite interested in cube sats and they want to fly, they want to fly an armada of them. A flight of them, I guess, in the air force. We don't have armadas. We have flights.

• 43:45Chuck Nice?

  Right.

• 43:45Bill Nye?

  Uh, things in formation, CubeSats in formation, and they would look for, uh, they'd be used as a wide aperture radar, what have you. And, and along this line, in May, uh, we are gonna have a companion mission. CubeSat is gonna be part of a Georgia Tech proximity, uh, mission where you, the spacecraft keep their stations relative to each other, like ships at sea.

• 44:11Chuck Nice?

  Ah.

• 44:12Bill Nye?

  Yeah, so it's very cool. But Chuck, coming up on four minutes left in the show.

• 44:16Chuck Nice?

  Yes, we are.

• 44:17Bill Nye?

  And I think you know what that means.

• 44:18Chuck Nice?

  I believe that means it is time for our lightning round.

• 44:25Bill Nye?

  Where we take your questions, we answer them very quickly. Here we go. The first question from the lightning round. Chuck Nice.

• 44:31Chuck Nice?

  How easy would it be to repair the light sail if micrometeoroids peppered it like a shotgun shot? So this isn't just one tear like we talked about earlier in the show. This is a shotgun shot, like.

• 44:46Bill Nye?

  Well, it'll still have a little bit of propulsion with the shreds of sail that are still there, but that, uh, that shred, uh, that, uh, ripstop feature, I think, will keep that shotgun eventuality from eventuating.

• 45:01Chuck Nice?

  Sweet. Okay. What is the ideal speed? Oh, oh, oh.

• 45:06Bill Nye?

  First of all.

• 45:06Chuck Nice?

  Lightning round, Chuck. I'm sorry. I'm screwing up the lightning round because I did not give the last person's name, which is Gabe Zabato.

• 45:14Bill Nye?

  Gabe Zabato, thank you. But next question.

• 45:16Chuck Nice?

  Okay, this is from Jesse Robinson, coming from Google Plus. What is the ideal speed of travel? And how long will it take to achieve that speed?

• 45:25Bill Nye?

  Well, first of all, with your lower.

• 45:26Chuck Nice?

  It doesn't matter.

• 45:27Bill Nye?

  Uh, you can go, you know, the, the ultimate goal, by the way, is to get to 100 kilometers a second, where you're going very close to the sun and get slung way the heck out of the solar system. But in the meantime. We're in low Earth orbit. So in nautical miles, you're going seven miles a second. Seven miles a second, just to get started.

• 45:46Chuck Nice?

  There you go. Aaron Kelly, uh, who is coming to us from Twitter, says, "Ocean sailing ships use a keel and a rudder to leverage the wind on the sails and steer." Is there an equivalent for the light sail?

• 46:01Bill Nye?

  I love this question, yes. So what we do, two things. We have, first of all, we have torque rods. These are twist rods that react against the Earth's magnetic field. There's electromagnets. They're about this long, Chuck.

• 46:15Chuck Nice?

  Okay.

• 46:15Bill Nye?

  Uh, 20 centimeters.

• 46:17Chuck Nice?

  20 centimeters.

• 46:17Bill Nye?

  And the very fine wire one. So electricity comes onto solar panels, which are part of the spacecraft, and you twist, uh, uh, uh, against the Earth's magnetic field. Then the other thing is there is an old technology, which we love, gyroscopes, which in spacecraft often go by the expression momentum wheels. They run electric motors, keep them spinning.

• 46:38Chuck Nice?

  Right.

• 46:39Bill Nye?

  And they twist, woo, woo, woo. Twist against gravity and orbital motion.

• 46:45Chuck Nice?

  That is awesome.

• 46:46Bill Nye?

  We are steering and tacking the light sail spacecraft.

• 46:49Chuck Nice?

  Steering and tacking. I love the whole gyroscope thing, man.

• 46:53Bill Nye?

  Oh, it's sexy.

• 46:53Chuck Nice?

  Uh, sexy. Okay. Uh, Nelson is amazing. That's the name of the, that's the name.

• 47:01Bill Nye?

  Nelson is amazing.

• 47:02Chuck Nice?

  Nelson is amazing. "How would you predict a solar sail could revolutionize, okay, life on Earth?" In other words, how does it change international travel for us down here as opposed to travel up there?

• 47:15Bill Nye?

  Well, what it would do, i-if practically, you wouldn't get on a light sail and fly around. You are, you are too massive.

• 47:22Chuck Nice?

  You can't breathe in space.

• 47:25Bill Nye?

  And so you can't breathe in space. But what could practically happen is the future of, let us say, air, air, um, traffic control.

• 47:33Chuck Nice?

  Okay.

• 47:34Bill Nye?

  Could involve CubeSats, flying in formation to make excellent, high-quality, inexpensive, high-reliability radars. Could happen.

• 47:43Chuck Nice?

  Okay. All right, I think we have time for just one more. And this is Brett Shock. He wants to know, can the sail be revved up in orbit for a few years and then hitch a ride?

• 47:52Bill Nye?

  Uh, well, yeah, we're gonna, we're gonna run, uh, for about a month, which is very traditional, because so little of the time are you over land to get telemetry. We're gonna run for about a month before we deploy the sails. And we are also planning... To run tests of extending and retracting the sails, the same way you furl and unfurl sails on ships at sea. You have been listening to StarTalk Radio with your guest host, me, Bill Nye, and my co-conspirator Chuck Nice. That's right. Thank you very much for your excellent questions. They were good. Consider the Planetary Society, our light sail spacecraft, the first week of May. Keep looking up. This is StarTalk Radio.