Planetary Radio: Space Exploration, Astronomy and Science - Deep Space 1 / ET Phones Home!

Episode Date: April 7, 2003

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This is Planetary Radio. Hi everyone, I'm Matt Kaplan. Nothing as inconsequential as a cold could keep us from bringing you this week's show with lots in store. Remember Deep Space One, the testbed spacecraft with the ion engine and 11 other leading-edge technologies? We'll talk to Project Director Mark Raymond about an award he and the DS-1 team have just received. We'll get another quick update from SETI at Home Chief Scientist Dan Wertheimer, just back from the Arecibo dish. And on a special What's Up, you'll hear the funniest entries in our first message from E.T. contest. Are you ready for a survivor, the Mars edition?

Emily says there are still a few problems to solve before that live primetime special. primetime special. Hi, I'm Emily Lakdawalla with questions and answers. A listener asked, considering that satellites are used on Earth to transmit TV signals, why can't spacecraft like Cassini, Galileo, or the Mars orbiters and rovers

send back video instead of still images only? A Mars video feed would be very exciting, but it is not yet possible. The main obstacle to receiving video from other planets is that the speed at which data can be sent over such large distances is very limited. The distance between the Earth and Mars is always at least 70 million kilometers, thousands of times the distance between a communications satellite and the Earth. Over these great distances, the radio signal produced by a Mars-orbiting spacecraft is very weak. NASA is currently building an orbiting spacecraft called Mars Reconnaissance Orbiter that will have the largest data return of any Mars mission so far.

It will achieve about 4 million bits per second. By comparison, an ordinary television signal has a data rate of about 30 million bits per second. By comparison, an ordinary television signal has a data rate of about 30 million bits per second. The video that we really want to see is from the surface of Mars. For example, we'd really like to watch a Mars rover interact with its environment. However, the data return rate from Mars' surface is only 100,000 bits per second, much less than 1% of the rate of television transmission. What can we do in the future to get TV from Mars? Stay tuned to Planetary Radio to find out. The American Institute of Aeronautics and Astronautics presented an award a few days

ago. The Space Systems Award is presented, quote, to recognize outstanding achievements in the architecture, analysis, design, and implementation of space systems, unquote. This year, it went to the team that designed, built, and flew a revolutionary spacecraft called Deep Space One. Mark Raymond was project manager for the Deep Space One mission at NASA's Jet Propulsion Laboratory near Pasadena, California. Congratulations, Mark.

Thank you very much. Thanks for having me on your show. Now, was I correct in saying you were a project manager, or should I have said a project manager? I was a project manager. I worked on the mission from the beginning, but I didn't become project manager until we were in operations. So there were two other project managers before me. I see. Deep Space One was not your typical spacecraft mission designed to do a lot of science, even though it did get some science done.

You're absolutely right. The point of the mission was to test high-risk advanced technologies that are important for future space science missions. So NASA wants to have an aggressive, exciting program of space science missions, but it requires new technologies to do those. And new technologies are risky. Deep Space One and the other missions of the New Millennium Program take the risks so that those future missions don't have to.

So in a way, you were almost the opposite of other missions we're familiar with, where people want to be very conservative and go with hardware that they are pretty darn sure is going to last the duration of the mission, let it complete its objective. That was not the idea here. You're right. On other missions, the way that you accomplish your science is to do something that somebody else did before. Well, Deep Space One is now the mission that did it before. So by testing these risky technologies,

we protect the future missions from incurring the cost and risk that would penalize missions that would have to take these chances. If a technology works on Deep Space One, then a future mission can use it. And if it doesn't work, that's also a success because a future mission can avoid it and in either case, avoid the cost and risk. Now you had, I have read, 12 groundbreaking technologies. I think it's safe to say that one in particular got maybe more than its fair share of attention, although it was pretty darn important. In fact, maybe even by getting more attention, it got its fair share.

It was ion propulsion, which I think most people would agree was the most exciting technology. Right out of science fiction, I think this probably applies to many people, certainly it does to me. The first time I ever heard of it was in science fiction. Yeah, me too. But one of the rewards of working on a mission like this is turning that science fiction into science fact. Deep Space One tested the technology, it worked beautifully, and now it's available at low risk for future missions to use. I suppose we need to spend a minute or two doing a little ion energy, excuse me, an ion engine primer here for folks

who aren't familiar with the technology. Let me remind you first how a regular engine works. You take a gas and you heat it up or you put it under pressure and you push it out of a rocket nozzle, and the action of the gas leaving causes a reaction that pushes the spacecraft in the other direction. Ion propulsion works the same way, but instead of heating the gas up or putting it under pressure, we ionize it, which means we give it a little electric charge. And when it has an electric charge, you can accelerate it with a voltage. So we use the gas xenon, which is like helium or neon, but heavier. We ionize it and then shoot it out of the spacecraft by putting a voltage on it,

of the spacecraft by putting a voltage on it, and that causes the xenon to shoot out at very, very high speed, in fact, about ten times the speed of the exhaust of conventional propellants, and so that causes a relatively large push back on the spacecraft. Now, even with that amazing velocity of these ions coming out of this engine, there still isn't very much coming out. You're not talking about a lot of thrust. You're exactly right.

It's very efficient, which means it doesn't take much propellant. But by the same token, we only flow a very small amount of propellant. It takes several days to consume a pound of propellant. And so the thrust is extremely gentle. It's comparable to what you would feel if you held a piece of paper in your hand. That paper would push on your hand as much as the thruster pushes on the spacecraft. But over time, the effectiveness builds up, and instead of thrusting for a few seconds or a few minutes at a time, we thrust for months or even years at a time.

And so, in fact, that's the exact comparison I was going to make. You think of the incredible power of the chemical rockets that drive the space shuttle, but after a few moments or minutes, they're done with, whereas yours is literally designed to go for months. That's right. Conventional systems put the pedal to the metal for a few minutes, and then they coast for years and years. Using ion propulsion is what I like to call acceleration with patience.

Ultimately, you can get to very high speed, but it takes a while. And one of the purposes for testing it on Deep Space One was to show that this really works as well as the theory said it would, and indeed it does. There had been, I believe, some very small ion engines used as thrusters or something on some previous spacecraft, but this was the first application of ion technology for the main propulsion for a spacecraft, right? That's right.

This is the first time ion propulsion had been used as primary propulsion, that is, actually to get the spacecraft someplace, as opposed to making small changes in its orbit or helping it hold its position. We should really spend a little bit of time talking about some of those other technologies and about some of the challenges that you faced in this mission and a glorious success as well as you visited a comet. But I think maybe what we'll do is take a quick break and then come back and continue

this conversation with Mark Raymond about the Deep Space One spacecraft. Planetary Radio will continue in just a minute. This is Buzz Aldrin. When I walked on the moon, I knew it was just the beginning of humankind's great adventure in the solar system. That's why I'm a member of the Planetary Society, the world's largest space interest group. The Planetary Society is helping to explore Mars. We're tracking near-Earth asteroids and comets. We sponsor the search for life on other worlds, and we're building the first ever solar sail. You can learn about these adventures and exciting

new discoveries from space exploration in the Planetary Report. The Planetary Report is the Society's full-color magazine. It's just one of many member benefits. You can learn more by calling 1-877-PLANETS. That's toll-free, 1-877-752-6387. And you can catch up on space exploration news and developments at our exciting and informative website, planetarysociety.org. The Planetary Society, exploring new worlds. Mark Raymond was a project manager for the Deep Space One mission,

which has just received a very prestigious award from the American Institute of Aeronautics and Astronautics. Mark is with us on Planetary Radio. We spent a few minutes talking about the ion engine, perhaps the technology that was most worthy of getting a lot of attention from this groundbreaking mission. But you had a lot of other interesting technologies you were testing out, didn't you, Mark? Yes, we did. I think actually all of them were pretty neat. But another one that I think is particularly interesting is an artificial intelligence system

that determines the spacecraft's location in the solar system, where it is, where it's going, without human intervention. And if it finds it's not on the correct course, it can change its course by adjusting the thrusting with the ion propulsion system. And, of course, we don't have a solar system GPS. Everybody here on Earth is familiar with GPS. But the spacecraft managed to do it, even out in the solar system, by looking at distant asteroids and comparing their positions to the even more distant stars.

That allowed the spacecraft, in a way that's perhaps a little too complicated to explain in this brief interview, but that allowed the spacecraft to figure out where it was. And this is a very powerful technology because, as with all the technologies on Deep Space One, we want to conduct more ambitious missions. And when we think about missions that will be far away in the solar system, where it's inconvenient for them to get help from Earth, or on the far side of a planet where it's impossible, or where they have to respond quickly, the ability to do it by itself is very, very important

to illustrate the effectiveness of combining this autonomous navigation with ion propulsion compared to what we could do before Deep Space One. This would be like having your car find its own way from Los Angeles to Washington, D.C., arrive in a designated parking place, and do it all while getting 300 miles per gallon. That's the kind of advancement that just these two technologies offer. And again, as you said, we have 12 on DS-1. What a great analogy.

Do you want to mention any of those other technologies before we talk a bit more about the actual mission? Do you want to mention any of those other technologies before we talk a bit more about the actual mission? Well, we had a number that reduced the mass and power consumption of spacecraft with microelectronics. We had some that combined different science instruments into very small packages. Again, the purpose of that was to test these instruments to make sure they worked. But then as long as we had them on board when we had the extended mission and went on for our bonus encounter with a comet, we were able to use those technologies to return truly a wealth of scientific data as a bonus.

And I read that you did some interesting things with the solar cells that powered the probe. That's right. Each set of cells had a little lens above it. In fact, there were 720 lenses focusing sunlight down onto the solar cells to let the solar rays weigh less and yet produce more power. And that worked flawlessly from the beginning of the mission to the end. reference a moment ago to your sort of bonus mission to a comet when you launched in 1998. Did you guys have any idea you were going to be getting the closest look yet at a comet nucleus? Well, again, the point of the primary mission was simply to test the technologies. In fact, I shouldn't say simply. It was an extremely aggressive and ambitious mission. But we had in mind that if things went well, we would request that NASA extend the mission. But there was certainly no assurance because it was a very, very high-risk

mission, depending on technologies that were chosen because they're risky. But the primary mission exceeded its success criteria. NASA extended it, and we flew on for another more than two years to get to the comet. By the time our aged spacecraft had gotten there, almost every subsystem had some kind of problem because the mission wasn't designed to last so long. And yet it survived that bold adventure at the comet and really produced some terrifically exciting results. And we should mention that that was Comet Borelli

and that on a future edition of Planetary Radio, we're going to talk with your colleague, Dr. Robert Nelson, who was responsible for a lot of the science that was done by Deep Space One. That will be as soon as that research is published, which I guess is being reviewed right now. You talked about how systems started to have some problems on the way to Comet Borelli. You had one major scare, didn't you? We certainly did.

The primary mission ended in September of 1999. Then we set sail for the comet. That November, a critical device failed, and it deprived the spacecraft of its knowledge of how it was oriented in the zero gravity of space. And it was such a catastrophic failure that everybody's expectation was that we should just terminate the mission and retire the spacecraft, let it rest on its laurels. But one of the philosophies of the Deep Space One team was, if it isn't impossible, it isn't worth doing.

So we actually managed to rescue the spacecraft. It took seven months, and we did it from almost a million times farther away than the International Space Station is from the surface of the Earth. We reprogrammed the computer. We developed a new way to fly the spacecraft, got it going again, and it was really a remarkable effort. And I can tell you when the Star Tracker failed, we certainly didn't expect that that spacecraft was ever going to see a comet.

But the rescue was successful, and the mission continued on beautifully. Amazing accomplishment. We only have a couple of minutes left. You have compared Deep Space One to the old X-15 rocket plane, another groundbreaking tester of many technologies. Do you stand by that? Yes, I do. Again, the point was pave the way for future missions, and just as the X-15 and other aircraft

in the X program developed the technologies and taught us the lessons that we needed to learn in order to undertake more ambitious missions of the future, Deep Space One and the other missions of the New Millennium Program are doing the same thing. Mark, let's pretend it's the Academy Awards. You just picked up the Oscars. Is there anybody else you want to mention as part of getting this or earning this award from the AIAA?

There were many organizations involved besides JPL. Spectrum Astro Incorporated was the contractor that worked with us on the development of the spacecraft. It was actually more a partner than a contractor. There were too many organizations probably to mention that participated in the development of the technologies and their incorporation on the spacecraft. So it was really a large team effort derived from private industry, academia, and NASA. Mark, what are you on to now? I'm now working on a mission called Dawn, a new discovery mission,

which is going to go to the asteroid belt and make a detailed investigation of several, in fact, the largest asteroids. And it's one of the many beneficiaries of Deep Space One, because a mission like this would be truly impossible without ion propulsion. And so Dawn is really benefiting from DS-1's groundbreaking work. Well, we will wish you as great a success with that new mission as you had with Deep Space One. And thank you again for joining us on Planetary Radio. Thank you. I enjoyed talking with you.

Mark Raymond was a project manager for the Deep Space One mission, which has just received a very prestigious award from the American Institute for Aeronautics and Astronautics. Planetary Radio will continue in just a moment. I'm Emily Lakdawalla, back with Q&A. We can't get TV transmission from Mars using existing technology yet. Radio signals become too weak over the tens or hundreds of millions of kilometers separating Mars and Earth. But laser communication is an exciting new technology. A beam of light with the width of a pencil could bring back a lot of data.

A 10-watt laser could transmit 10 million bits per second when Mars is close to Earth. The catch is that a telescope 10 meters in diameter is needed on Earth in order to retrieve the signal. Also, the pointing of the spacecraft's laser would have to be incredibly accurate. It would be like aiming a laser in Los Angeles at a kernel of corn in New York. Fortunately, large telescopes are becoming cheaper and cheaper, and spacecraft can already be pointed with the accuracy and stability needed for laser communications. One engineer is confident that laser communications will permit video transmission from Mars in the next decade.

Got a question about the universe? Send it to us at planetaryradio at planetary.org. Be sure to provide your name and how to pronounce it, and tell us where you're from. And now, here's Matt with more Planetary Radio. We've decided to check in once again, pay a short visit to Dan Wertheimer, the chief scientist for the SETI at Home project, who is now back in Berkeley, I take it, Dan.

Are you at home? We're back in Berkeley. We just came from the Arecibo Telescope in Puerto Rico, the world's largest telescope. And when we talked to you there last week, your observations were on hold because of that little event taking place on the sun. That's right. The sun hiccuped. It vomited a chunk of itself off into interstellar space. It's called a coronal mass ejection, a lot of matter heading towards Earth, and it disturbs the atmosphere and communications.

And that was an interesting enough event for astronomers that they kicked everybody off the telescope. So our observations were postponed for a few days. But you were able to get back on, and you did complete those observations. Yeah, we did get the time, and we were able to look at about 227 actual candidates that we wanted to check on. So we were very pleased with the way the observations went. We had four instruments. They all worked well. We brought back a ton of data to analyze, and that's what we're busy working on now. So 227, you actually more than met your target. Well, we observed some

things besides study-at-home candidates. There were 160 SETI at-home candidates, but we also looked at a few other things that we thought might harbor life, like there's some planetary systems that are nearby. We looked at five of these things that are in nice circular orbits that might have Earth-like planets going around them. We looked at some nearby galaxies. We looked at some candidates from another SETI program called Serendip, and we looked at some nearby stars. SETI program called Serendip, and we

looked at some nearby stars. Anything interesting in the data so far? No, but we've just done a very cursory examination of the data, and there may be something lurking, a faint signal in one of the tapes that we recorded that we'll be sending out to the SETI at-home participants, but it's too early to know. So how soon will that data start to show up on the computers of those 4 million SETI at home users? There are two stages. The first stage is to take the normal data that we record with the SETI at home data recorder and send that out to the users. We've got to make some small tweaks because this is not ordinary data.

We use a different receiver. We scan differently. It's a more sensitive search. So that will take another week or two before we can send it out to the SETI at home users to get that processed. And then we also recorded data in a more thorough way. This is the second phase of the data analysis. Better than the normal way that we record data on a recorder that uses a lot more bits. It's a little more sensitive.

We normally don't record that way because it generates a huge amount of data, but it's okay if you just have a couple days on the telescope. And so we're going to be sending that out using a whole new infrastructure for distributed computing. So those 4 million SETI at home users can look forward to continuing. They're very important, their vital role in this research. Yeah, I think we need them. We can't analyze, even with the small amount of time that we had on the Arecibo telescope, we took so much data that we can't possibly analyze it ourselves with our computers, our local machines, and we need the volunteers to help us dig through this data and hunt for ET. We're just about out of time for this quick update.

Tell folks how they can become part of the world's biggest supercomputer. So if you want to help us hunt for radio signals from ET, you can download the SETI at Home screensaver program, and you go to the website planetary.org and that'll link you to the SETI at Home screensaver. You can download the screensaver,

install it in your computer, and everybody analyzes a different chunk of the sky. And you might be one that gets some of the data from these follow-up observations at Arecibo, which would be pretty exciting. And so sign up and help us hunt for ET. Dan, thanks again for taking a couple of minutes. I'm sure we'll be talking to you and your colleagues again in the near future. Pleasure to talk with you, Matt.

Dan Wertheimer is the chief scientist for the SETI at Home project. Planetary Radio continues in just a moment. Bruce Betts, welcome back from Middle Earth. Well, thank you very much. Middle Earth and Puerto Rico, it's been a lot of travel. It's great to be back in the recording dungeon. What's up this week? Well, we've got a plethora of planets. All five potential naked eye planets are naked eye once again

because Mercury is showing its face low near the horizon shortly after sunset in the west northwest. But it is very bright. So if you see what looks like a very bright star low down in the horizon, it will be Mercury. Mercury, because of its short orbital period, does come and go on periods of days and will fade over the course of the month as it actually gets a little easier to see. Saturn, also up in the evening sky. And if you are looking to try to find Saturn, look, the evening this airs, Monday, April 7th, it will be near the moon. So the bright-looking star near the moon is actually Saturn.

It's also above Orion in the sky. It's another way to look at it. Jupiter, extremely bright, impossible to miss, basically right overhead in the early evening. And in the morning sky, Venus, bright and fairly low in the morning sky. In the east, and Mars has once again returned from its vanishing during our April Fool's show, and you can see it in the early morning, reddish, far to the right of Venus. You had to be there, folks. What else do you have for us?

But it's archived, so if you weren't there the first time, please go back and check planetary.org. We also have This Week in Space History. On April 12th, a very significant date in space history, in 1961, Soviet cosmonaut Yuri Gagarin became the first human in space, and 20 years later was the first space shuttle launch, which included astronauts John Young and Robert Crippen. Let me get ready for the echo here. Random space fact!

Random Space Fact! A blue moon is the second of two full moons that fall in the same month. This can occur because the full moons occur roughly every 29 1⁄2 days, so you can fit two into a month. But a blue moon occurs roughly every two and three-quarter years. So now when someone says once in a blue moon, you'll know exactly how long that is, two and three-quarter years. So now when someone says once in a blue moon, you'll know exactly how long that is, two and three-quarter years. Excellent. Now I think we move on to, well, it's why this is going to be a special extended version of What's Up. We need to spend a little bit more time reviewing the

results of last week's trivia contest, which was not a trivia contest. Exactly. We encouraged humorous entries last week for what will the first message from extraterrestrials say. And we'd like to share some of those with you because of the humor, so we're giving you the extended play dance mix of Planetary Radio. No, we've gotten the best of here. Here you go. This one is from Lee Valance.

Now, we had this one go first because it's visual. You really did have to be there. Lee Valance, who wrote to us, entered from Japan, actually. He sent us what was the original message sent out to the stars from the radio telescope at Arecibo. And it's this great little symbolic thing that was sent out. And according to Lee, the message that came back was a screen from Space Invaders, which is a little disturbing if you think about it.

But Lee, thank you very much for your entry. Yes, now we move on from Henry T. Sanford Crane from Elkton, Mississippi. The number you have dialed is no longer in service. Please hang up and dial again.

The number you have dialed is no longer... Well, you get the idea. You get the idea. Yeah, right. Okay, here's one. This is one of our favorites, folks. This is from Woods Sillroy, and he said, for the pronunciation, he said, take a wild guess, so I just did. He's in Los Angeles, one of our neighbors here.

Here's his first message from ET. Can you hear me now? Can you hear me now? Very clever. Indeed, one of my favorites. Can you hear me now? Can you hear me now? Very clever.

Indeed, one of my favorites. Now, we also have from Paul Boucher in Lafayette, Indiana. Jerry, Jerry, Jerry. Let's see. We're a little out of sync here now because I read one of yours. I screwed up. So now you know the inner workings of planetary reality. You're forgiven. Okay.

Here's one. 50% off a new luxury hyperdrive vessel when you order the new credit card from Intergalactic Express. Terms and conditions apply. And, you know, I want you to do the winner. All right. You go ahead. I'm going to do this runner-up. It's very funny.

And this is from Bill Magnuson of Malden, Massachusetts. And Bill was actually one of our winners already in the trivia contest. So, Bill, we might not have given you a prize anyway this week, but you are right up there. You're our first runner-up. Here goes. Congratulations. You may already be a winner. Be one of the first 1,000 civilizations to respond with your magic activation number,

and you will receive, for the life of your solar system, a free subscription to the Milky Way Times. Shipping and handling charges may apply. Only one entry per trillion inhabitants per solar system allowed. Odds of winning are too high for you to comprehend. Voidware prohibited. It's galactic spam, everyone. Thank you, Bill. That's a good one. And now, our winner. Thank you, Bill. That's a good one. And now our winner. Drumroll, please. Bennett Reagan, nine years old, from Los Angeles, California,

enters that an extraterrestrial would say, Dude, where's my spaceship? Thank you very much. And he was very clever. He also said he's glad that you're back from your travels back from Middle Earth. And he gave us the pronunciation of his name. It's Ray Gunn, which is also very appropriate as it happens. So thank you all very much for your entries.

It made our life more amusing. What are we doing for this week? Well, this week we're, at least for now, going back to a genuinely serious trivia question. going back to a genuinely serious trivia question. And in this case, it is, who is the only astronaut to have flown on board all five space shuttles that have flown in space? There's one astronaut that actually flew missions on all five different space shuttles, and who is that? Okay, there it is, folks.

Bruce, how will they enter this week's contest? Go to planetary.org and follow the links to Planetary Radio and it will tell you how to enter. And remember that that entry must be emailed to us by noon on Thursday, which would be what? Noon on Thursday the 11th, I think, right? 8, 9, 10? No, the 10th.

Noon on Thursday the 10th because that's when we need to get it to do our incredible job of judging. The winner will get a Carl Sagan Memorial Station T-shirt. Absolutely. From the Planetary Society, as Bennett Raygun will get this week. Bruce, we'll talk to you again next week. Thank you very much.

Remember, when you look up in the night sky, think a happy thought about dogs this week. And thank you. Good night. Bruce Betts, everyone, the Director of Projects for the Planetary Society, with his regular segment on Planetary Radio, What's Up? Planetary Radio will return next Monday at 5.30 p.m. Pacific here on KUCI and KUCI.org. Check out the archives of our past shows at Planetary.org

where you'll also find links related to this week's program and the new trivia contest. Matt Kaplan, wishing you a great week.