Planetary Radio: Space Exploration, Astronomy and Science - A Death-Defying Climax for Venus Express

Episode Date: August 5, 2014

Venus Express Project Scientist Håkan Svedhem tells us about the spacecraft’s harrowing descent into the Venusian atmosphere, what it is currently up to, and what he’d like to see next at that forbidding planet.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

A daring plunge into an alien atmosphere, this week on Planetary Radio. Welcome to the travel show that takes you to the final frontier. I'm Matt Kaplan of the Planetary Society. Venus Express survived that dip into the thick air of Venus and is still doing its job. We'll talk with Håkan Svidheim, the probe's justifiably proud project scientist. Bill Nye will join us from halfway around this world. And Bruce Betts braves the thick-width humidity atmosphere of Southern California to join me for a What's Up segment with a couple of special Mars Rover

prizes. We begin with a very excited Emily Lakdawalla, who has been following the Rosetta mission. Emily, there really is a lot to be excited about out at that comet. It's always thrilling to see a strange new world for the first time, and Comet Churyumov-Gerasimenko is really coming into view finally. And we're seeing all kinds of awesome features that remind me a lot of things that we've seen on other comets, like the circular features that we saw in Tempel 1. And so it's really cool to see how this comet is a combination of lots of things that we're familiar with,

and yet, taken all together, it's such a bizarre and different world. You've just written this blog entry as we speak, August 4th entry about the circular features. I guess that's just the beginning. Much more to come. Absolutely. And things are going to be changing very rapidly over the next few days as Rosetta is going to be entering sort of in orbit around the comet,

basically station keeping about 100 kilometers away from the surface. We're just going to see this thing from all sides and try to puzzle out what's made it strange features. The best recommendation that we can make is keep watching planetary.oregon following Emily on Twitter because you've already put up a bunch of posts. I didn't even count them.

With much more to come, I'm sure. Absolutely. I'm going to update it with every new picture. Absolutely thrilling. And we will be devoting, I'm sure, very soon a major segment on this show to the Rosetta spacecraft that is about to go into orbit. The first time ever orbiting a comet. We'll be back in a moment with another European success story. That'll be Håkon Svidheim, the project scientist for Venus Express.

First, though, we'll hear from Bill Nye. You've been listening to the senior editor for the Planetary Society, our planetary evangelist and a contributing editor to Sky and Telescope magazine, Emily Lakdawalla. Bill, it has been a while since we've caught you on the road. Where are you today? Tokyo, Japan, promoting science education. Toshiba is concerned that Japanese science students are not as creative as other science students. Amazing as it may seem. Huh, interesting. And you found an interesting story on the cover of the English language paper.

And you found an interesting story on the cover of the English language paper. The front page of the Japan Times has the SDF, which is the self-defense forces of Japan, are going to join with the United States to look for orbital debris. And I mention it because it's on the very front page. So it shows you the value of a space program. Japanese government, Japanese people, of course, very proud that they have a space program, very proud that they are working with other space agencies because they know the great value of this. It just raises everyone's expectations in your society. It makes you optimistic. Speaking of raising expectations, I think you have some comments about the announcement of the instruments for the next. Yes, everybody. We're going to finally work on in situ resource utilization on Mars as an instrument to see if you can get oxygen out of the Martian rocks, the regolith, the crust of Mars. And this will be on the 2020 mission.

And, you know, Planetary Society is going to be very involved in this. We are, of course, always to uh get another microphone on mars we have one on mars but it crashed on the south pole back in 1999 and uh it's a process it's a long process but jim bell our president and several people from the society are on the team to work on this instrument to see if we can extract oxygen from Martian rocks. It's really extraordinary. It's like science fiction, except it's real. And then, of course, there's that camera, the main camera on the 2020 rover. Yeah, yeah. So I say this all the time. You look at the quality of pictures from Spirit and Opportunity from 2004 and compare those with the quality pictures of Curiosity in 2012 you can see there's the newer ones are sharper and The 2020 ones I imagine are going to be sharper still we're gonna

We're gonna discover things on Mars that right now We can't even imagine very exciting time Matt it certainly is and I know you've got places to go there in Tokyo So yes, the crack of dawn here, and I've got a meeting with science students. I must press on. Domo arigato. Domo arigato. He's Bill Nye, the science guy and the CEO of the Planetary Society. We'll be back in just a moment.

What happened to Venus? Why did this cloud-shrouded world that is our twin in so many ways turn into one of our solar system's nastiest and hottest destinations? The questions remain, but we can thank a series of spacecraft for beginning to pull back the veil. Venus Express is the European Space Agency probe that has been examining the planet for more than eight years. It made its 3,000th orbit a few weeks ago.

That extended stay, and a suite of excellent instruments, has told us more about the planet than any other spacecraft. With its fuel supply almost gone, the mission team recently directed Venus Express into the upper reaches of the Venusian atmosphere for a couple of harrowing minutes. I asked project scientist Håkan Svidheim for a report. Håkan has been in this job for 12 years. How is the spacecraft after this dangerous dip much deeper into the Venusian atmosphere? It's amazingly good condition, actually. We haven't detected any degradation at all of any of the systems on board. The only uncertainty we have is the amount of fuel we have left, but everything is working extremely well on the spacecraft,

just as before we started this risky maneuvering. Now, you told me just before we started recording that you had every confidence that the spacecraft would come through this in reasonably good shape. I guess there were other folks who were less confident. Yes, very much so. And I've been in the project since the very beginning. I was very much involved with the engineers designing the spacecraft. And I know how much care they took to prepare for this aerobraking and how many calculations and

investigations they did to prepare it well, and also the software modes that had been prepared to do this. So I really felt quite confident that the spacecraft would come out well of this. But of course, there are a number of people that see a lot of worries. And of course, one can easily imagine things that can happen in such a situation when we go so deep into the atmosphere we have we have big heat loads on the spacecraft many sites on the spacecraft and the solar panels are heated up much much more than they normally should be heated up and even a small maneuver mistake would of course be very risky if we

would come a little bit deeper than we intend or if the atmosphere would have been a little bit more dense than we expect and we could have come into trouble. But I felt fairly good about this when we started. How about the science that you were hoping for out of this maneuver? Have you already started to see interesting data? Yes, definitely. We were going quite slowly down. We started going to this so-called aerobraking mode. That's when we put the spacecraft in the attitude. So we go in sort of with the thrust aside in the forward direction and flipping out the solar panels. They go against the wind to slow down the spacecraft as much as possible.

We started this at 190 kilometers altitude at the pericenter. At that time, we couldn't see much. The atmosphere was still very tenuous. We saw very little but then gradually we came into denser and denser atmosphere. We started to see signals from accelerometers. We could see what we had already suspected from before and that is very large variability in the density of the atmosphere and that was even becoming more and more clear throughout this exercise. When we came down to our deepest altitude at 129 kilometers, we could see variations

from day to day, that one day it was suddenly twice as dense as the day before without any further explanations. That's very interesting. It may be a signature of some wave activity in the atmosphere. That's something we're looking into now. It certainly sounds like it indicates that this planet, though we may not easily be able to see what's going on down at the surface, except with the kind of radar that Venus Express carried,

that it's a very dynamic place. Yes, it's very much so. We see that in so many different areas. And, of course, in this aerobraking exercise, it was becoming extraordinarily clear because every orbit we got is very clear signals when we're dipping into the depths of the atmosphere. And we could get sort of a profile of a cut through a part of the atmosphere

for those something like 100 seconds that we go deep into the atmosphere. And we can see how much it was varying throughout those 100 seconds and then comparing it to the following day, and it was all the time different. Very interesting. 129 kilometers. It still sounds fairly high up, and yet I read that the atmosphere there was perhaps as much as 1,000 times as dense as what Venus Express had experienced prior to that. Is that correct?

Yeah, that's true. Our previous lowest altitude at present was 165 kilometers. And we could measure even densities there by a somewhat different technique, what we call the torque measurement. We were actually then using also the solar panels to inject sort of asymmetric torque to the spacecraft. And from the compensation of this asymmetry by the reaction, which we could read the densities and get a handle on the densities even at that high altitude. And at 129 kilometers, it was about 1,000 times higher. So what is the spacecraft up to now with that tiny amount of fuel

that it has left to maneuver? After the 11th of July, when we had done the last part of the aerobraking, we were lifting up the spacecraft's paracentral altitude by just burning the thrusters and using the very little fuel we had. During 15 days, we were raising it gradually up, and we are now up to 460 kilometers. And this was quite a nervous thing actually for me more more worrying than the air baking itself because we are so close of running out of fuel

now that we're not sure if we would actually be able to do that but now that we have reached these 460 kilometers we can cruise throughout autumn to say mid-december without using a significant amount of fuel so we're quite confident now that at least we will reach that date. So we will start taking up doing science now in a fairly much similar way that we have done before. We use the spectrometers and the cameras, look at the different aspects of the atmosphere. We'll do occultation measurements. We will do mapping of places we have seen some enhanced temperatures on the surface and many other things. As we said, you have been the project scientist for Venus Express since long before its launch.

Has this mission achieved everything that you hoped for? Yeah, I think it has achieved everything we hoped for and even much more than that. I think one of the things that has really been striking throughout these years is the variability we see on Venus. Of course, there have been plenty of missions in the past to Venus, and we thought we knew quite a lot about it. But the variability we've seen throughout these eight years has been extraordinary. And that's one of the striking things which we have really discovered. There are many other new things too, but from what we set out from the beginning, this was something we had not even thought about.

Of the things that we did plan from the beginning, I think we have basically reached everything. That's Venus Express project scientist Håkan Svidheim. He has more to tell us about the mission and what he'd like to see next at That World when Planetary Radio continues in a minute. Hi, this is Casey Dreyer, Director of Advocacy at the Planetary Society. We're busy building something new, something unprecedented, a real grassroots constituency for space. We want to empower and engage the public like never before. If you're interested, you can go to planetary.org slash SOS

to learn how you can become a space advocate. That's planetary.org slash SOS. Save our science. Thank you. Your name carried to an asteroid. How cool is that? You, your family, your friends, your cat, we're inviting everyone to travel along on NASA's

OSIRIS-REx mission to asteroid Bennu. All the details are at planetary.org slash b-e-n-n-u. You can submit your name and then print your beautiful certificate. That's planetary.org slash Bennu. Planetary Society members, your name is already on the list. The Planetary Society, we're your place in space. Welcome back to Planetary Radio. I'm Matt Kaplan. Håkan Svidheim has been project scientist for the European Space Agency's Venus Express mission for 12 years, beginning well before launch of the spacecraft that is now nearing the end of its more than eight years circling and observing the second big rock from the sun. Håkan was telling us before the break about the surprising level of dynamic activity

or variability Venus Express has observed. When you talk about variability, are you talking only about the atmosphere or are you seeing changes on the surface itself, the surface characteristics, as you fly over a spot for a second, a third, maybe scores of times. Yes, that's right. We've seen several indications of what we think may be volcanic activities, that the surface temperature has been increased from one overflight to one overflight a few days later. We are now focusing in the following overflights of the same region to check those areas again.

The interesting thing is that these particular areas, they coincide with places of so-called hotspots. That's where we have knowledge from the surface and the subsurface from the Magellan radar mission from the early 90s that we think that the subsurface material in the mantle, it's coming up much closer to the surface. And these are places which on other planets typically volcanoes will occur. But we've also seen other places also related to these so-called hot spots,

but in other places where we've seen that the emissivity of the surface, that's sort of a measure of the freshness of the surface, indicates that the surface actually is much younger, at least geologically speaking, than other similar surfaces in other places. So there are several indications that actually there is, even nowadays, active volcanism on Venus. A third indication of that is that we see dramatic increase of sulfur dioxide

that increases on a very short time scale. And one explanation for that would be a volcanic eruption which injects then a massive amount of SO2 into the atmosphere. Sounds like very strong evidence to me. And if so, this would be very gratifying, wouldn't it? I mean, this discovery, if it is a discovery of volcanic activity. Yeah, we haven't had any evidence of that at all on Venus before. Of course, people have speculated that there is volcanism still.

Venus is a difficult planet because we don't know much about the surface, even less about the interior, of course. We know only from a handful of images from the Russian landers from the 80s, from a few pictures how it actually looks down there. And then, of course, from the radar missions, both from the Veneras and from the Magellan radars. We have a picture of, sort of, in the radar domain, how the surface looks like. But it's very difficult to say anything about real volcanism. So this information we have collected with Venus Express has been very valuable, I think. Well, this leads me to my next question, which is now with Venus Express nearly at the end of its life. What would you like to see happen next with a mission to this planet? Of course, the real great thing, if we can get down to the surface

and even move around to the surface to get much more information on the surface composition and the structure and how it really looks down there. This dense atmosphere is very difficult to penetrate. We have, of course, as I said, radar information. We have in the infrared, we have imaging spectrometers on Venus Express. We have been able to see at a very rough spatial resolution information on the surface. But to really get down onto the surface, to really make investigations, in particular for chemistry, measure, for example, noble gases and isotopes to understand better the history of the planet

these are things that really would be a next step but maybe it's a little bit too far to try to do that now so even missions that would go down like on a balloon there has been balloons in the past so we think it should be possible to do that again even if it is very difficult at least to measure things like noble gases and isotopes. That would be very valuable. To get deeper down into the atmosphere, that's really one of the things we have not been able to do, of course, with Venus Express. We have come down to 129 kilometers, but that is still at orbital velocities

and still well above the cloud layer. So to get some information about the evolution of the planet, it would be very useful to go deeper down. Acknowledging the tremendous challenges of putting anything on that intensely aggressive surface, that would be quite a rover, wouldn't it, if you could put something down there that would last more than what was it, the few hours that the Soviet Venera spacecraft lasted? Yes, that's of course the enormous challenge to keep a lifetime there. You need a system that can maintain a low temperature inside the landing vessel in an

environment which has this enormous temperature and this very high pressure. That's indeed an enormous challenge. We need a cooling system which has not been developed so far. But even a mission that would only last a few hours, like the Venera and Vega landers that would give us information with modern instrumentation would also be very valuable. But of course, the dream would be a rover that drives around there and collects data for months.

That would be a fantastic thing. Something for the future. Speaking of your future, you told me also just before we started speaking something I had not read, which is that after so many years as the project scientist for Venus Express, you've moved out further into the solar system. You've skipped by our home planet, and you're now the project scientist for Mars Express,

still doing great work at the Red Planet. Yes, that's right. That's a new challenge for myself. And Mars Express was actually launched before Venus Express, and they are really two sister spacecraft, very similar to each other. Of course, Venus Express was adapted to the different environmental conditions around Venus. We have somewhat changed payload, but most of the payload is also very similar. So that makes it interesting to compare the two planets with spacecraft and instrumentation,

which is very similar. And we're really learning a lot from that. So it was sort of a fairly easy change to go over to that mission, but by now I have left my Venus by itself. I'm really following that very closely. I've even read that the Rosetta spacecraft shares some

technology with its Venus and Mars Express sisters. It sounds like you feel that you've pretty well proved out that this is a pretty good way to, if nothing else, hold down the cost of doing these planetary science missions. Yeah, I think it's an excellent concept. And unfortunately, it hasn't been followed up with other missions. The Rosetta mission was basically the thing that kicked everything off because we took several of the subsystems and design ideas from Rosetta spacecraft,

even though, of course, Rosetta spacecraft is much larger than Venus Express and Mars Express. But because of this sequence of designing and manufacturing these spacecraft, we've been able to keep the costs down quite a lot. And also it hasn't had an implication on the lifetime, because as we have seen, Mars Express is still in orbit, even after 10 years after the launch, Venus Express has been now in orbit for 8 years. So it's been very successful, I think.

It's a wonderful record of success and quite a legacy as you do move on out to Mars now. I want to thank you again for coming on Planetary Radio to tell us about this most recent adventure by Venus Express, but also to celebrate this 8 years now, more than eight years, of delivering back-to-Earth terrific science from the planet Venus. Thank you so much. Thank you. I enjoyed it very much.

Håkon Svidem is, as you've heard, or has been, the Venus Express project scientist for the last 12 years. And it's just the last eight of those that it has been up there at Venus, and now has moved on to be the project scientist for Mars Express. He's been with the European Space Agency, ESA, for 30 years and has contributed to many, many other missions. Maybe Bruce Betts will tell us about where to find Venus in the night sky here on Earth as we check in with him for another edition of what's up in just a few moments it's a hot august night in southern california why not talk to bruce betts at least it'll take our minds off the heat and humidity hi there hi man it's so hot and humid and hotter where you

are inland at least i'm a little bit closer to uh to the beach hey don't think about that tell us about the night sky oh the night sky if only i could see it through the cloud cover then i would be seeing lovely uh mars and saturn and watching them as i will over the the rest of august mars and saturn in the evening southwest are getting closer and closer but only in the sky, not in some kind of personal way because they really don't like each other. You can also maybe catch

Venus in the pre-dawn but pre-dawn is going to be heating up soon but for now I'd focus on Mars and Saturn in the evening sky but don't miss the Perseid meteor shower August August 12th, 13th, but is a fairly broad peak, so you can do well from a few days before that to a few days after it, but the peak is on the night of the 12th and 13th.

Always good. Second highest average meteor shower of the year. So I'll remind you of that again next week. I hope it clears up here by then. That's why the broad peak is kind of nice. If it really is clouded out that night, you can check out the night after or go back in time and see the night before. We move on to this week in space history. It was two years ago that Curiosity landed successfully on the surface of Mars. Yeah, there's some celebrations going on around that.

Earth years, of course, is what the guy is talking about there, folks. That's true. It already passed its one-year Mars year anniversary, and we'll have to wait a while for the two aereo years, University. And very nicely, we have some Curiosity-related prizes for today's trivia contest. You'd almost think we'd coordinated. Almost. Yeah, well, maybe not.

On to... Random Space Fact! Now, that may have sounded strange to you, but that's really how everyone in Southern California is right now, because we're not used to living as if it's Nolans. So when the Magellan spacecraft was launched to Venus by the space shuttle in 1989, it ended an 11-year gap in U.S. interplanetary spacecraft launches. Wow. And kind of interesting side random space fact, the previous one had also been a launch to Venus,

the Pioneer Venus multi-probe atmospheric probe mission in 1978. Let's not ever do that kind of gap again, huh? What do you say? Yeah. All right. Everyone listen to Matt. All right. Now, before we go on to the contest, would you just say a word, maybe two or three, about our involvement, speaking of planetary exploration missions, in the instruments for the 2020 rover. We go Mars! Well, that's three. That's very well done.

But take a little bit more. You can expound. We are excited and ecstatic that Planetary Society is a partner on Mastcam-Z, The Mast cameras that were just selected for the Mars 2020 rover, which will be a Curiosity copy, but not in the instruments. And Jim Bell, the Planetary Society president and in his other life,

Arizona State University professor, is the head of that camera system. And we cooked up a bunch of groovy ways to reach out to the public and involve the public and we'll drag you into it Matt and we've got a few years to make things fun and then a few years of fabulous images from the surface of Mars this camera gets the zoom that got dropped off of the last set of cameras. Ergo the Z

Yes, I was hoping it was zombies. Martian zombies. I keep being told it stands for Zoom. Martian zombies want women. And men. Anybody with brains. So anyway,

back to people with brains. So we'll be doing fun stuff with Mastcam Z. It's going to be groovy. I've got a blog up from this last week if you want to learn a wee bit more. Excellent. All right. Now on to the contest. We asked you on Apollo 11, what was used to make a broken circuit breaker work in the lunar module to enable liftoff from the moon? How'd we do, Matt? Another terrific response. Bigger than normal, but maybe this is the new normal. Who knows? Kevin Hecht. Kevin Hecht in Illinois. He did not win, but he did. I think he may have been the only person who identified what this particular circuit breaker was for. It was labeled engine arm. So they really needed to fix this. Minor, minor detail.

Here's our actual winner first time winner to Marcus Matson Marcus Matson from Finland and he said that Buzz Aldrin used a felt pen an AG 7 pen and that buzz says that he still owns that pen as so Marcus we're gonna send you a planetary radio-shirt, as you probably knew. I got one other I want to read to you. This is pretty funny. It's from Dan Campbell in Georgia. And he got it right.

He said, yeah, Buzz used a felt-tip pen to push the loose breaker back into place. It had been knocked off when one of the astronauts bumped it as they were getting ready to go out and have a little walk on the moon. getting ready to go out and have a little walk on the moon. Dan says, boy, were they grateful that they weren't cosmonauts having to jab a graphite pencil into the electrical panel. It's that old joke, you know, the pencils and instead of developing and never mind. They put covers over those things for future flights, is my understanding. Smart move, NASA. Okay, what do you got for next time?

Who was the first Mars rover named after? Who was the first Mars rover named after? Go to planetary.org slash radio contest. Get us your entry. By when, Matt? By the 12th, by August 12th at 8 a.m. Pacific time. And here are some very cool Mars rover-related prizes. Have you heard of Rod Pyle's book, Curiosity?

Yes, I have. Yeah, it's out now. It's done pretty well, I think. An inside look at the Mars rover mission and the people who made it happen. It's quite a document about this mission, which is still underway, of course. But wait, that's not all.

We also have a Mars Science Laboratory mouse pad for your enjoyment, and that's going to go to the winner of this round. That's awesome. I agree. Well played, sir. All right, everybody, go out there, look up at the night sky, and think about your favorite comic book hero. Thank you, and good night.

Superman. All the way. Superman. He's Clark Kent, you know. That's Bruce Bett. He's the Director of Science and Technology for the Planetary Society, who joins us every week here for What's Up. Stay cool. Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by the hot-as-molten-lead members of the Society.

Clear skies. Thank you.