(00:00:01) So what is next for the American space program? We will be talking about that during the hour today with dr. Robert Pepin a physicist from the University of Minnesota who has been involved in space exploration for many years. He is currently chairman of the National Academy of Science committee on planetary and lunar exploration. Dr. Pepper and welcome its pleasure to have you back with us today and (00:00:24) find your bobbins pleasure to be back (00:00:26) coincidentally with your appearance a comment by NASA administrator James Fletcher today out in San Francisco. He apparently told the San Francisco Cisco Chronicle their that the Soviets are likely to beat the United States to Mars. Do you think that's right? Oh, (00:00:42) I'm sure it's right. In fact our next mission to Mars. The Mars Observer mission is now scheduled after a two-year delay to be launched in 1992 and the Soviet Union in collaboration with others has a very ambitious Mission to Mars in 1988, which will Launched in less than one year. So his supposition is a matter of fact, the more important issue is whether he meant that the Soviets will return a sample from Mars before we do and that's very much tied up with long-range planning into the 1990s for both countries, and we will have to wait and (00:01:21) see. Well he seems to think that they'll be able to land people on Mars by the end of the (00:01:25) century. I doubt that we certainly are in no position to do that and it is not just a matter of launch capability or having the technology to do it. It's a matter for both countries of a very fundamental issue of the Health and Welfare of people in space under low gravity conditions for that long a Time the Soviets are very active in doing biomedical experiments in their version of the space station and their results in the results that we have from looking at biomedical reactions to low gravity on shuttle suggests that there are fundamental biological and physiological problems that accrue to Long space exposures and those will have to be solved before we set off for any long-duration expedition to Mars. It takes a minimum of seven or eight months to get to Mars and that much time back and then with the stay on the planet, which is not as dangerous you're talking about a couple of years in space and neither country has had experience that approach. Is that the Soviets have come close with almost a year exposure to zero gravity conditions in their space station or in their earlier efforts and the biomedical reaction of the people in Low Gravity for that long has not been good at (00:02:44) all. Well, I remember hearing about one or two of their astronauts who've had to be taken back to Earth because they fell ill in space. What are some of the adverse effects of being in weightless conditions the most (00:02:57) serious one seems to be really to moment of the body's physiology to the conditions the new conditions in which it finds itself where the heart does not have to work quite as hard to pump blood to the extremities because it is not working against the force of gravity and the bones. This is perhaps the most serious problem the bones of the human structure no longer have to support continually the weight of the of the frame and one of the consequences is the bone starts. Getting their structural material, they start shutting calcium. And so far even for very long space exposures. There seems to be no change in the rate at which calcium is lost from Bones. In other words. It doesn't seem to flatten off after certain period of time. It just keeps on going at more or less the same rate the the consequences of this are serious. So serious that after long space duration, it is necessary for either astronauts and cosmonauts and cosmonauts have the most experience to recuperate under very rigid and carefully thought-out exercise programs to build their bones and muscles back up to the requisite strength to support them in Earth gravity. If they are not very careful. They run the risk of very serious risk of broken bones even trying to conduct the most trivial acts. (00:04:14) Well, it sounds like it's several degrees worse than the ordinary sedentary lifestyle that so many of us Americans are accused of living. (00:04:22) Yes. I think the only thing you avoid is beds (00:04:24) or dr. Robert Pepin is Yes, we're talking about space and space exploration what the u.s. Space program is about and if you'd like to join the discussion, you're welcome to call us in the Twin Cities. The phone number is two two seven six thousand 2276 thousand in the Twin Cities. In other parts of Minnesota toll-free one 800 600 to 900 700 in if you're listening to one of the surrounding states, you can call us directly in the Minneapolis st. Paul area and area code 612 2276 thousand. Well, for those of you who have been listening to ksjn 1330 the bork hearings Welcome to our discussion the bork hearings resume at 1:15 this afternoon, and they will be carried live on ksjn 13:30. I just have one more thing to ask you dr. Pepper and about the the u.s. Soviet race in space. And that is soul. What what difference does it make if they're forced or if we are first other than just a matter of national pride. (00:05:26) I remember being asked that same question once by Diane Sawyer at a time when we had had thought and still think that we have meteorite samples that came from the surface of Mars and she asked me essentially that same question and then I answered by asking if it would be possible to imagine what it is like to stand there and hold a sample of another planet in your hand and I think evidently she she could understand the sort of reaction but it's not an easy one to communicate now as to your question. It's kind of like a mountain climbers question. Why do you climb mountains there? The answer is usually given as because they're there and I think that that's an important component of the American space program. We have always been exploratory animals and there are obstacles that we wish to encounter simply or to overcome simply because there there there is a certain Spirit of exploration in this race, which is carried us a long way. However, I'd like to point out that space exploration in the context and we're talking about it is essentially a profound scientific Endeavor. We are trying to learn about our own Earth by studying other planets because they are Laboratories of systems that have evolved slightly differently than we have which will give us rather profound Clues to where we have been as a planet and where we are going. So we are using space exploration in the sense in which I'm talking about it as a Blue to our past history and as a device to give us some ability to predict how this planet might evolve in the future that in addition to Simply the fundamental excitement of learning what has not been learned before in a scientific sense about the sun and the planets. But in fact, there is an overall theme to the space exploration effort. It is to explore other objects as Clues to the history of our own (00:07:23) University of Minnesota physicist. Dr. Robert Pepin is with us today as we talk about space exploration space science, and we have some phone lines available in the Twin Cities at 2276 thousand Elsewhere One 865 29700. Do we have somebody waiting on the line? All right, let's put you on with dr. Pepper mill. Oh, (00:07:46) yes when it comes to the closest that I've been to space and thinking of that as a last frontier without a g so that I went mock to an F4. Yet our San Clemente and that was a rare experience. I can imagine just experience all of those pull of forces and what it did to muscles and you know pushing against all of that was happening and then to be that high and to try to imagine that you were hurtling through space at Mach 2 it sort of blew your mind particularly. If you didn't know what all the instruments in front of you were registering and what the reason for the test flight was as it turned out they had replaced the right wing and I ever having problems with the airspeed indicator and this didn't become clear until we had the debrief after we get them. The you were talking about the biomedical reactions to Long space zero gravity things and I was comparing while you were speaking to my reactions to the plus G's that I was experiencing. But the if the Russians have the capacity of large weight launches and space station kind of thing and putting several people up there and adding portions on to it and if it's a competition the particular interest that I have is how the human body both responds to the extra G's of launch and then of course the things you comment and on as far as spending that much time when you don't have the pull gravity, and I wish you would pursue that (00:10:03) the Astronauts and cosmonauts undergo, as you know, both experiences the one I talked about before the prolong 0g experience and it's biomedical effects are the ones that concern is most right now the human body seems to be very tolerant to enormous short-term g-loads as you've discovered the shuttle launch is not a gentle experience in terms of over gravity. Its several. Jeez. Also some of its low altitude maneuvering the the effect there with pressure suits and other kinds of safety devices has not been terribly extreme. One of the worst problems that we have faced though is the return of astronauts having experienced long exposure in space and the g-forces that they encounter no matter how they descend as you're probably aware the the American and Soviet programs have taken different tax on on how they bring their astronauts back as you know, we land on the ocean they don't they land on on on on land and Generally their astronauts parachute at an altitude of 10,000 feet or so because the landing is rather rough now the G forces involved in all three of those modes are not small and with physiologically weakened skeletal structures due to long exposure in space that is and has been a very great worry. So there's a variety of experience in the space program that now stands in both in both over G and under G sorts of episodes. (00:11:34) Dr. Pepin the National Academy of Science committee that you chair deals with both planetary and lunar exploration. What more is there to be done with the moon? (00:11:45) We know just about enough about the moon now with the return samples we have to thoroughly whet our appetites for what we don't know we brought samples back from six or seven different sites and for those sites in the processes on the moon that contributed to them. We now know quite a lot but we still have very fundamental questions about how the Moon is a whole originated. And involves we lack a good perception of the overall chemical composition of the Moon because our sampling was in certain discrete sites and the Moon is a chemically variable body. Probably the greatest challenge. We now face is that having to do with the origin of the moon on theoretical grounds. We now think at least this is the latest proposal that the moon formed by the ejection of material from the earth during a giant impact early in the moon's in the Earth's history where the Earth was struck perhaps a few tens or hundreds of millions of years after it started forming with a body the size of Mars and the Collision was so catastrophic that a dejected material into Earth orbit, which eventually condensed move outward and formed the moon now if this is correct, there are in the moon chemical signatures that should tie it very firmly to Earth and we have clues of those from the somewhat skimpy sampling that we have from earlier missions and also from the what we think the overall chemical composition of the body. Is but we don't know and now we are in a position both with this Theory and with the information we have from the return lunar samples to point our questions about the moon much more specifically than we could before and to this end. There is a new mission to the moon on the planning board's. It's not a landing Mission. It's not a sample return Mission. It's an orbital Mission which will with exquisite Precision map the geology the geography and the chemical composition of the surface of the Moon from pole to pole all around the planet. And when we have that information will have a very good perception of the bulk chemical composition of the Moon which turns out to be the one datum. We really need now to feed into theories of the origin of the Moon. (00:13:47) Are there some things on the moon that are totally otherworldly some things that we would not have expected to (00:13:53) find Well, there's a plaque up there now and has now signed by Richard Manuel. (00:13:58) Okay. Yes, (00:14:02) it's hard to be surprised by the moon now. I'm sorry and it's even harder to remember how surprised we were only brought the first samples by because there we found things that we absolutely did not expect now we certain got gotten used to the concept of material on the surface of the Moon that's been hammered into Rubble to a depth of several tens of feet by feet by meteorite bombardment over the last billions of years. We're used to the idea that the sun's emissions directly strike the lunar surface with a do not on Earth because we're shielded by the atmosphere and that implanted into the material on the lunar surface are particles of the sun itself, which are then available for study by simply bringing these samples back and analyzing in the laboratory. And in fact interestingly enough something that we didn't anticipate we have learned a great deal about the history of the Sun by studying the moon simply because it's been exposed to solar radiation for so long and trapped in that material. Is a record going back four billion years of the chemical composition of the sun itself. So that in a sense is unworldly in the sense that it doesn't properly Belong To The Moon, but the Moon is serving here as as a stratum for collection of these particles for the study of a completely different body (00:15:13) moving on to another listener with a question. Hello. Dr. Crippen is listening. (00:15:17) Yeah, this is he dr. Pepper. I'm still here. Oh, I heard your was listening to your program coming up by interstate 94. I'm calling from a gas station in (00:15:27) Albertville good for you. (00:15:30) I think the thing that appeals to the typical non astronaut like myself about the manned space program is that it allows us to enjoy a space exploration vicariously and and that experience of others has of course. Disappeared since the the terrible Challenger disaster. Yes, and now that the space shuttle is about to that program is about to get underway again over the next year or so. At least that sent the anticipated startup time. A lot of Articles have appeared in the newspaper and the and the popular press such as an article that appeared in Newsweek recently about the concept of the big quilt big dumb booster as a cheap way for man to specifically the United States to get back into space again courses Soviet Union using this for many years and the point has been made that the payload price for launching using this this really low budget low technology is one 130th. I believe of what it takes to launch with the space shuttle. Would you comment on that and I'll hang up and go back to my car and (00:16:54) listen, okay. Maybe I can say something inconsequential until you get there. The the figure you gave of 130th is probably conservative the shuttles the launches from shuttle are extraordinarily expensive simply because it is a manned vehicle and therefore to it accrue all the safety precautions. That one has to take if one is launching humans into space a big dumb booster where you are certainly concerned for the payload, but if you lose a payload because a vehicle malfunction it is at least something that you can recover from without loss of life. This means that there are a lot of I don't like to call them shortcuts, but they're a lot of precautions that one normally would take when men are involved one does not have to take in a big dumb booster. So it might be a little bit more hazardous for the plate payload, but it is certainly worth it in terms of the reduction in cost and I would say that the figure 130 is probably conservative now our history in the big dumb booster area is a very interesting one because we had an enormous capability in this in this area. Back in the late 1960s and 1970s when we launched the Apollo missions using the Saturn booster, which is an absolutely enormous vehicle and while it wasn't terribly dumb that was it was in the sense you use the word exactly what you're talking about. The only surviving Saturn rocket is now a lawn ornament at the Johnson Space Center in Houston the Soviet Union, which at that time had nothing like the sort of launch capability decided to build their capability incrementally by by constructing and testing generations of rockets of gradually increasing size, and they now have a new one to re not to replace but to augment their present proton rocket which has just about the capability of our old Saturn V. So they have over the last 15 years built their capability up to that that we want one's head. But abandoned when the shuttle program came in because we chose to put all our launch eggs in that particular basket. Our the big dumb booster is a technique of technology, which we must redevelop and I suspect by 10 years from now. We will once again have at least the launch code capability that we had ten years ago because it is now clear that it's imperative. (00:19:11) Well the Saturn V may not exist, but certainly the designs are still there and it shouldn't be all that tough to build some more of them would it (00:19:18) it probably wouldn't though. I myself have been so have been astonished and appalled at the cost of retooling an assembly line anywhere even to produce a device where the drawings already exists. I think the general approach of the program will take on this is that in many significant respects. The Saturn is an obsolete rocket now because it was built with technology that really dates back to the mid 1960s and there's very strong feeling that with modern technology and modern components one can do it better and probably with a somewhat smaller vehicle was still the same launch capability. So the chances are there's going to be a total redesign one possibility, which is being discussed quite a A lot is to take the shuttle module off the launch assembly for shuttle and replace it with a payload. It's called a shuttle-derived vehicle and we'll look just like the shuttle except there wouldn't be any vehicle on it. There would be a payload instead and it has the capability of launching into orbit something between a hundred and twenty and a hundred and eighty thousand pounds in one shot and that compares with the shuttle payload, which currently around 50,000 (00:20:20) pounds. All right. Let's take some more folks with questions for dr. Robert Pepin. Hello there. (00:20:27) Is it I yes, thank you a couple quick questions. Number one many of the commentators that I've seen or read basically say that space exploration Beyond sense for the Moon is definitely limited by chemical rockets. And so I'm wondering Dr. Pepper could just comment briefly on what I presume are some of the theories hypotheses about other types of propulsion systems. Secondly, could you Briefly on when the Hubble Space Telescope is now scheduled if it has been scheduled for launch and thirdly and the philosophical question. Are you at all concerned that the potential development of arms control and specifically missile controls could have an adverse effect in the space program by reducing all of the rocket research that obviously goes along with that (00:21:26) three. Very good questions. Let me comment on your first one the the in the capability of chemical rockets for exploration beyond. The Moon is limited but not impossible our outer solar system expert scientific exploration vehicles have all been launched chemically the current plans call for all the initiatives to Mars to be chemical launched initiatives both here and in the Soviet Union and the reason this is possible is Well, twofold one is the launching into orbit of vehicles with appropriate upper stages so they can get a Boost after the tremendous expenditure of chemical fuel. Its required to lift them into low earth orbit. The second thing that has made this possible the Explorer with with rather inefficient chemical Rockets is the sheer Ingenuity of that branch of astrophysics that has to do with guiding spacecrafts spacecraft along trajectories where they pick up gravity assists in Boost from other planets. I'll give you an interesting example of this we have a mission that has been many times delayed now scheduled to leave in 1989 to Jupiter. It's called the Galileo Mission. It's a very large very complicated and very heavy rocket originally the shuttle was just barely able to handle this by taking the low earth orbit and launching it on a directed check tree to Mercury several or to Jupiter several things have happened since then the shuttle payload capability has been downgraded for For safety reasons the upper stage the chemical Opera stage that was to be used for Galileo is no longer permitted on this shuttle. Again. It's considered to be a safety hazard. Therefore. We have a spacecraft where the chemical capability that could be lifted in the shuttle was not sufficient to get it to Jupiter the the Wizards of Newtonian astrophysics. I have discovered that we can launch that mission not outward to Jupiter but inward to Venus, it goes around Venus and picks up a velocity boost simply uses Gravity. The gravity of Venus is an assist. It makes two passes around Earth for exactly the same reason and in these three passes around other planets, it picks up enough extra energy to then be able to make it to Jupiter even with the reduced launch capability of shuttle other Transportation Systems. We're working on have to do with with systems that use either solar energy or nuclear energy. Accelerate and exhaust stream to very high velocity and the simply replace this sort of propulsion system with the large amounts of chemical fuel that are now required. Those are in fairly early development stages, but you're quite right in your perception that in the long-term that sort of propulsion system for outer solar system exploration is going to be absolutely essential the Hubble Space Telescope is currently sort of scheduled to be launched in 1989 or I think possibly early 1990 in the meantime, they they are working on that instrument refining and making better some of its basic astronomical capabilities taking it out of its little room and exercising every once in a while because that instrument was never designed to sit in Earth gravity for very long and it is so delicately built that there is a concern that the weight of gravity on the mirror bearings will essentially warp the structure ear. Coverly, so they take it out and exercise and put it through all its little Paces to make sure that this doesn't happen. It's an expensive proposition as long as it's still on the ground your third question on arms control. No, I don't really believe that will happen. The reason is that while much of the research on rocket propulsion has in fact been stimulated by the military buying a great many of these vehicles. There's a significant component of research that's been conducted Elsewhere on Rocket technology and even with an arms control packed. I see no diminution in the need to launch communication satellites and other commercial Ventures and one must include among those surveillance satellites because while we have an arms control packed, we know it's certainly not true that we no longer have the need to at least look so I think the rocket business the low earth orbit High Earth orbit satellite business is going to stay very brisk and healthy perhaps even more so and that will drive the civilian community. Social rocket development program and this is quite aside from the demands that NASA will have in the 1990s. (00:26:01) Dr. Robert Pepin is with us today. He is a physics professor at the University of Minnesota and also chairs and National Academy of Science committee on planetary and lunar exploration. We are talking about the u.s. Space program today and space science and move on to another listener here. Go ahead. (00:26:18) Please good afternoon, dr. Pepper and I have two questions and they're both about recycling the first also overlaps with your just finished question. The first is there any possibility that as our medium-range nuclear missiles are decommissioned in Europe and eventually icbms that these can be modified and used for NASA types launches where you don't you aren't concerned about human safety, but do what heavy boosting (00:26:51) power. That's a good question. I don't think anybody's ever thought of that. There were past people have probably not I don't know very much because the military doesn't want me to know very much about the actual capabilities of those missile. Launch Vehicles. Now are old men Minuteman missiles are attached to two Titans sitting up on their bunkers and The Dakotas and we already know enough about the specification of those launch vehicles to know that they do not really do the job for us. Those those old Titans do have a relatively healthy payload, but not enough to get our modern space science missions into low earth orbit. The new version of the Titan called the Titan for does have that capability and that at the moment is our medium to long range hope for launch capability for space exploration missiles, the the the capability of the launch Vehicles now attached to the medium range missiles in the European theater. Something I don't know I suspect however that it is lower than what we need. Even for relatively modest scientific missions. (00:28:00) Did you have a second question sir? If you still there? (00:28:02) Yeah. I'm curious to know if anyone is making plans to or preparing technology for removing the junk from space orbit. Not not just as a charitable activity, but to maintain the junk that we've put up there and be able to supply steel and light and whatever materials have been left behind up there without the cost of of boosting them into orbit. (00:28:30) Well, you you put an interesting wrinkle on it on an old and very very serious question. I don't I'm not sure that it never occurred to me that the material there might be worth recovering from an economic point of view. It is certainly a hazard you have put your finger on one of the growing concerns in the International Space Science community and that is the effect on on People and on spacecraft of the debris from earlier missions that is now whizzing around a few hundred miles above the Earth and by whizzing I say that advisedly the the space missions that we have set up within the last few years and from which we have recovered material or vehicles are covered with little tiny impact pits that when analyzed turned out to be caused by flakes of titanium Pace paint and what is happening up there is that paint and other debris or spalling off old spacecraft Vehicles some of them actually explode when they're when they're no longer used because of residual fumes in the fuel tanks and that this material with considerable velocity is profound Hazard to other vehicles in the at that same altitude and it is particularly true. If a vehicle in polar orbit going from pole to pole in the earth intersects debris. That is an equatorial orbit that's going around the equator. Because the relative velocities in that case are absolutely immense and even something the size of the BB has no trouble going through at least a half inch of aluminum. Eventually. I'm afraid there's going to be a serious accident involving a quarter-inch bolt or a knot or something like that to wake the International Community in a public sense up to this problem, but it is a very well-known problem among those who are intimately concerned with space ions, and it is not a problem that admits of easy solution because how do you get the junk out of there? If you have a good idea, please let me know because anything from large butterfly Nets to avoiding. The area has has been suggested the the long-term solution is to stop putting material there and to be very careful of what sort of debris 1 spacecraft sheds but we have an immediate problem with the junk that still there as you point out. (00:30:43) A little bit related to this and following up on a comment you made earlier about the likelihood of communication satellite business remaining very good. I have heard that there is really a limited amount of area that those satellites function in and are we getting to the point where you can't put a whole lot of additional satellites up there? Yes, (00:31:05) geosynchronous orbit is getting crowded. There are a few there are a few favored locations in those orbits, which have to do with a very complicated interplay of gravitational forces. There are there are certain points where if you put a vehicle at the twenty two thousand Four Hundred Mile point above the Earth, so it will stay stationary over that same point on the Earth's surface not every point along the geosynchronous orbit is favored because there are gravitational perturbations that will gradually ease spacecraft away from where it's supposed to be but there are a few favorite points where this doesn't happen because they're compensating gravitational forces and those points are getting very crowded indeed. Again relates to the space debris problem because those areas are so crowded any debris that centers on that areas, particularly hazardous, and it was calculated several years ago admittedly before we stop putting a great many things into space that by the year 2000 in geosynchronous orbit any spacecraft launched into a position there would have a 5% chance of being hit by something sufficient to incapacitated in one year, (00:32:08) that would be expensive. Dr. Robert. Pepin is with us. We're talking about space exploration. And if you would like to join our conversation, we have a couple of lines available in the Twin Cities at 2276 thousand 2276 thousand elsewhere within the state of Minnesota, 1-800-662-2386 you listening in one of the surrounding states and want to call do it directly in the Twin Cities at area code 612 2276 thousand now, it's your turn to go ahead please. (00:32:40) All right, I had In about propulsion in general right one question. I hope is Superfluous. I have to admit that I haven't been keeping track of the new test firings of the newly designed shuttle booster, but I was wondering under what conditions that had been fired originally wasn't the problem that the original booster had been the shuttle had been launched when it was too cold or there was some problem with right lower temperatures. And I guess if it's if you could comment on that also, I was wondering if there has been any research done with with mass drivers or laser propulsion Alternatives or whether they're still there. They're just on paper, you know. (00:33:40) Yeah, let me take the second one first. They do still seem to be on paper. There's quite a lot of research on mass drivers having to do with the with the commercial expert exploitation of space. It's very long range mining of asteroids mining the surface of the Moon and how you get the material off these objects into an accessible place in low earth orbit. And there's been quite a lot of discussion of mass drivers from that point of view, but not as spacecraft propulsion mechanisms. What is a mass driver or mass driver is a device that takes let's say a hunk of mass, you know kilogram of lunar rock or something like that and accelerates it to High velocity and simply accelerates right out of the lunar gravitational field in the case of the Moon and makes it a freebody aimed let us say to sort of some sort of Catcher device in low earth orbit. So it's a way to transport amounts of mass commercially feasible amounts of Mass from one point in the solar system to the other without carrying it in the spacecraft ingenious idea and some of them actually been benched tested and can in fact accelerate small part, at least. They're in the bench test small particles of two enormous velocities. As far as I know. There's no particular work on on laser propulsion system. So there probably will be you may remember that one of the very first ideas for for propelling a piloted spacecraft, which I believe derives from Edward Teller 15 or 20 years ago was that you set off a series of controlled through burnt Thermo nuclear blasts at the rear end of your spacecraft and use that for a propulsion mechanism, which I think would be rather hazardous. I see that during oven and and and Larry Niven and Jerry Purnell have just written a book I forgot. I think it's called footfall which which uses exactly this propulsion system and in a dire emergency and the description of it is sort of spine-tingling now on the O-ring problem that which is what I call it. Yes, the the rocket booster the solid fuel rocket booster on Challenger apparently failed because at low temperature the O-ring at the bottom of that rocket assembly that was responsible for confining the hot exhaust gases to the inside of the rocket casing failed because it losses that elasticity at the low launch temperatures that seal has been completely redesigned now and a recent test firing of a full-scale solid-fuel rocket booster by by Morton thiokol showed that the new design worked very well. They had another problem but it wasn't related to any sort of a space by problem. It turns out there ground water cooling system failed. And so the after end of the rocket casing cracked after the test was over but that had nothing to do with the certification of this first flight and as far as I know that new assembly worked very well. And (00:36:17) so the shuttle should be on target for whenever next year. Is it (00:36:21) next year and I read much optimism and what I know of this would mostly from the public pronouncements that the test seems to have been a success. It's very clear though that we are now entering an era where the shuttle becomes a vehicle that will undergo the most Exquisite safety checks and precautions. And I think this is Justified it is a realization that the shuttle is not a commercial launch vehicle. The shuttle is an experimental vehicle and always will be and will always be hazardous but they will be very careful properly. So the effect on our community the science community and on the space station will be that the number of shuttle launches per year must inevitably be lower now than it was scheduled to be before because they simply will not take chances with men on board. That is actually the most compelling reason for an unmanned launch system because you do not have the concern about people. Live so that you do with shuttle. (00:37:17) Let's move on to some more people that want to talk about space exploration with dr. Pepper and go ahead please your (00:37:22) next. I'd like to backtrack to your discussion of space debris. And this is a takes off on that in all the discussion of Star Wars. I have never read anywhere a mention of what would seem to me a mind-boggling problem with space debris. If Star Wars was ever successful in exploding even one weapon in outer space. The cleanup would be impossible would seem to me I wonder what your comments would be about (00:37:56) that. Absolutely correct. The reason that you have not heard much about the connection between space debris debris and the Strategic Defense Initiative and even the early stages of anti-satellite systems is because the military is simultaneously doing two things. Things they are not talking about this in public. It is a profound problem. But it's one that they choose to remain comparatively silent on and in the bargain they are doing their own internal research in a very comprehensive way as to what the effect of space debris from. Let us say a satellite destruction by an anti-slavery satellite missile would be now. I became involved in this two or three years ago because as you may remember one of the very first anti-satellite test was to destroy a functioning satellite. I think it was called. I don't remember it's called Soul wind but I had also had another designation and it was destroyed in a very early test of this nature the space debris from that was tracked by NORAD and theoretically computed for smaller sizes by other people and it was not inconsiderable the space science board on which I said said attempted to discuss the situation with the Air Force not only in terms of the space debris issue, but in terms of what future plans might be and how they would affect space debris and I guess it is fair to state that we have not received a great deal of cooperation so far from the military in discussing this issue. However, it is becoming so serious and becoming such a matter of interest to the National Academy to the space science board and two others who are concerned about space that the issue is certainly going to be shortly very public and very brisk in terms of discussion of possible solutions (00:39:47) any ideas what those Solutions might be Just to press you a little bit further on I'm (00:39:51) afraid that there's really only one solution and that is don't put the debris there in the first place. This stuff is moving at velocities of several miles a second and it's hard to imagine. Any device that you could use to actually sweep the area clean of such debris as I say the butterfly the butterfly net ideas finding something the material goes through the butterfly not there's a problem how to deploy it in the first place. We are fortunate in that most of the material in these orbits is not stable over a fairly long periods of time. It will clean itself just like a polluted river because as I said, there are gravitational forces and in for low earth orbit, there are wisps of atmosphere even at those altitudes which exhaust exert a slow but inexorable drag on this material and eventually the orbits Decay and the material enters the upper Earth's atmosphere and is burned up. So it is it is a self-cleansing sort of environment. That means that if we can't think of any way to speed up the cleaning we can at least cut down the source by stopping our edition of material that feeds this debris belt. And the last the last questioner was was was certainly addressing this issue when he asked about the effect of Major collisional activities which I guess is an interesting way to describe the Strategic defensive initiative in low earth orbit, which in fact would spread massive amounts of high-velocity junk and essentially make low earth orbit untenable not only to the components of our presents Based on data science program, but to the vehicles that are that are supposed to be constructing the Strategic Defense Initiative in the first place. I suspect that the very first encounter would wipe out most of the vehicles that are supposed to be discussing the event to to be conducting the defense simply because they would then find themselves in a debris environment which would probably shoot holes through them in very short order. (00:41:47) Well, we have about 15 minutes left with our guests will take your question next total (00:41:50) there. Hello. My question is related to two things that I've been hearing around but I don't have any I have not read it in journals and it the one is that in the space of struggle to get first two. Peace between Russia and United States the Soviet Union has arrived to Mars with a probe lender which has brought back traces of civilizations in existing and Mars. That's one and the other one. Is that somehow through radio. There's been a signal received from out of the Galaxy our galaxy galaxy which indicates that there's life beyond and also that they are saying that if this be if the u.s. Keeps on with trying to get beyond the limit of this galaxy, they'll be considered as a were psychic signal in the description received received by a famous physicist. Whose name didn't give me so in since these are some kind of maybe the folklore of office Physics (00:42:48) course. Yeah, it is. It's interesting kind of folklore that grows up around this for the space program and like most items of folklore there. There's just a little bit behind this that sort of whets the appetite for example, there's no sign that I know of of civilization a civilization on Mars. On the other hand, it's still possible that there is a very primitive form of Life on Mars that became extinct several billion years ago and it is one of the objectives of both the Soviet and United States programs to investigate this possibility with returned Martian samples. I doubt very much whether the Soviet Union has evidence of anything as striking as a civilization on Mars. And the reason I say that is that the Soviet space program has become very open. They have matured their self confident and assured program. They are LED Now by a two or three remarkable scientist politicians who have made it their business to open the entire program to the Western World. And so we know a great deal about the the Soviet space program. In fact, they are not at all hesitant to come over and tell us about it because they are very proud of it. And in fact, they are doing marvelous things. So I think that in this environment any spectacular discovery that the Soviets had made could not possibly remain a secret on the second issue. Why is signals from other civilizations as you know, that's a serious effort on the part of this nation and of other International communities is called the search for extraterrestrial intelligence seti. And there are considerable efforts devoted to constructing and Manning various kinds of listening devices. That would be sensitive to the reception of such a signal if one is on its way or has been on its way to us. As far as I know. There's been nothing received but it is a serious and legitimate area of what I guess. I would call the the intellectual side of of space research (00:44:44) will move on to your question now. Hello. Dr. Pepin is listening. (00:44:47) Come on. Confirm Star Trek. Junkie, and when Scotty was down in the engine room, it was over. They were always talking about matter/antimatter as the power source for the Enterprise and not too long ago. It seems I remember about in real life scientist and or physicist speaking of antimatter. Is there such a thing as antimatter or is it strictly a creation of the fiction writers? (00:45:16) Oh, no, it's real antimatter exists. It is alive and well and healthy and I'll say this if we could find a way to control matter/antimatter reaction. Scotty is absolutely right. It would be a marvelous power source. It is the property of antimatter that when it comes in contact with ordinary matter both sets of matter annihilate themselves into Pure Energy it's and and there is nothing dubious at all about this process. This is has been observed many times and can be created very nicely in high-energy accelerators. But the problem is an obvious one. What you would like to have is a container of antimatter and a container of matter and mix them together appropriately in a rocket nozzle and you would have a marvelous propulsion system. But think about what you might keep the container of antimatter in if it's property is that whenever it reacts with ordinary matter it annihilates it and that's a mind-boggling problem. In fact, the only way to solve it is you have to make the antimatter which you can using very high energy and then combine it with matter before it has a chance to touch anything else and then you get your energy. Unfortunately. It'll probably always take much more energy to produce the antimatter. Then you will get from annihilating it later. (00:46:28) Let me move with warp speed to our next questioner. Go ahead please you're on the air. Yes. (00:46:35) Hello. Yes. I'm here. Could you keep it in a magnetic bottle but that's not my question many years ago and my misspent youth I spent Tour of Duty with North American Aviation on the old Navajo air breather and then on the X-15 and one of the schemes that was being considered at that time was the use of solar sails for deep penetration of the solar system, you know, the idea being that you would move a hundred feet the first day and 200 feet the (00:47:04) sure right (00:47:06) and by the time you've gone 30 days you're traveling half the speed of light. What is there anything being done about that or has it proved unfeasible or (00:47:14) what? Nope certainly has improved unfeasible. It's it is in fact on NASA's. Listen other people's lists of what they call long-range propulsion Concepts. And theoretically there's absolutely nothing whatsoever wrong with that is there are some rather rigid technical requirements on the area of sale you have to have there's also a very interesting problem, which you're probably aware of As I am and reading the novels of Arthur Clarke who among other among other things such as communication satellites. Also pioneered this idea. The question is how do you stop if you're using solar propulsion you can certainly attain very high velocities outward or even tacking with respect to the direction of solar radiation. And you're also correct in saying that it takes a remarkably short time to build up enormous velocities, but let's suppose you'd like to go to Pluto this way and so you advance out of the inner solar system. And by the time you get out to Jupiter you really are going fast. And now the question is since you like to arrive at Pluto with something less than several kilometers per second of arrival speed because you'd like to survive how do you stop and it would seem that you'd have to have an exhilarating system in order to accomplish both ends of your mission. However, there's nothing ridiculous about the solar sails is a propulsion mechanism. It's slow, but it's an efficient and you can build up very high velocities and I wouldn't be I see that as an operative element of space propulsion within the next 40 or 50 years. (00:48:42) We have about 10 minutes left. And so we'll go on to your question now. Hi there. Hi. Are you good? (00:48:47) I was curious as to what your outlook was for space research in general and in the u.s. At least and what effect this would have on the need for physicists astrophysicist and astronomers in the near future in the 1990s and the early 2000s time frame. (00:49:07) Yeah, you put your finger on a problem that is very much concerned to not only myself but but many of my colleagues and the space science board and NASA the short-term future for space research and by that I defined the last couple of years. In fact, maybe even the last decade and the next few years has not been very good and there are lots and lots of reasons for that and I don't think I'll go into them except to make the obvious point. That our capability for launching space missions is essentially zero has not been very good for a decade and won't be very good for another five years balancing that we have enormous technical expertise and actually constructing spacecraft in the constructing the measurement instrument and instruments on them and in guiding them to where they are supposed to go after they're in space. So we're dealing with a temporary shortcomings a very important one but a temporary shortcoming in the program and the program and as I read it those people who are involved in the space program both scientifically and technically at the NASA centers still have a great deal of self-confidence. They still have rather High morale and they regard this as an awkward in many sense of catastrophic a devastating but a temporary Hiatus in our ability to conduct space science. Now the point that you put your finger on having to do with scientific Manpower in this country and how that relates to the space program has also been a concern to us because with these long Delays, and actually getting things into space with the very long time it is now taking from the time of space mission is proposed until it's actually launched. What is the effect of the best and the brightest of our young scientific Talent who are interested in joining the Space Program in one way or another either a scientists or Engineers, but who are uncertain about the future of the program simply because it is of this present. He ate is in launch capability. We've done some surveys that would indicate that the cert the situation is not as serious as we might have expected The Lure and the romance both scientifically and technologically a space is enormously strong and I think there's a fairly basic confidence on the part of the younger people in the scientific and technical areas that the space program is a long-term matter of substantial National priority and that it will not die because it is facing a temporary. Well I was going to say inconvenience is actually more than that. So there are still bright young people coming into the field. We are still training them in the space program. They not only continue in space but many of them go to other areas that are equally important to our overall National industrial and technological effort. Now. It's no question. There's no question that we have fewer such people coming into the program now than we had. Let us say 10 or 15 years ago. I think there is also no question though that the interest is still there and that with deliberate efforts on the part of this country to make it clear that our exploration of space is a long-term National commitment and not something that lives by the will of president or congress from year to year to the extent that that is done and I think it will be in the next 10 years or so. I regard this as a long-term fundamentally healthy field both for what it does and for the status and the and the workings of the younger and older people who choose to join it (00:52:28) in case you just tuned in today's speaker. Today's guest is dr. Robert Pepin the University of Minnesota physicist. Also chairs the National Academy of Science committee on planetary and lunar exploration. We've got time for a few more questions. I think let's go to you next. Hello. (00:52:43) Hi, I recently read an article that was real critical of NASA and its direction in the last 10 years relying more and more on the media event. And on the sensationalism than on the true scientific worth of the project specifically the article mentioned unmanned. Why just like Voyager hmm where they were dependent more. So on putting a senator in space or whatever rather than on the true worth of the voyage and I was wondering if there's any change in that and I'll hang up and get your comment. (00:53:23) Yeah, you're absolutely right, of course that the leadership of the agency for the last 10 or 15 years has been drifting more and more toward the spectacular and away from the sort of incrementally constructed viable space science program, which may not be terribly spectacular in the way. It works. But in fact does work now in defense of the agency, the the reason that this has happened I think over the last 10 or 15 years and it really has been catastrophic 15 years ago. We were launching five or six space mines missions a year. Now. We are lucky if we launched one every 10 years and in fact There has been no launch of a space science Mission at all since 1978. How did the agency get into this pickle? Well, the reason is that neither the agency nor the country has been willing to commit to a long range plan for what this nation needs to do in space that means that the agency has to live on Congressional and administrative perception of what they're doing on a year by year basis as their budget comes up for Renewal. They have drifted into a mode and you might even argue that this was what they had to do of the so-called space spectacular in order to capture Congressional public and administrative interest in their program to the extent needed to fund it their Theory which I think is wrong but is one that has some some eloquent Defenders is that you need to keep space in the public eye all the time either by lifting Senators into space or by having a spectacular space station or building a great big rocket to send people to the Moon. Or advertising the shuttle as a taxi cab in the space whatever that keeps the agency and what it's doing so much in the public eye that there will be an enormous sympathy for those aims and goals generated in the annual budget process. The Soviets have taken exactly the different Tech courses in the nature of their society wouldn't lend itself to that very well anyway, and they have simply established a long range plan 10 or 15 years and have quietly going about their business with assured funding. That's really what we need to do in order to make progress and to stop leaping from spectacular to spectacular in all of which I might point out science lives on the crumbs that fall off the table of those spectaculars. I'm really I think not complaining about that because some of those crumbs have been absolutely juicy and very very tasty but the spectacular missions that mass amounts the space station the shuttle even Apollo we're not science missions. They were engineering missions. They were public attention missions each of Apollo certainly had a very Large scientific product and in fact the last three Apollo missions really were science missions are unmanned spacecraft now our science missions, but that is not the spectacular business of the agency. That's not where the big bucks go the big bucks going to shuttle men and orbit space station, which are not primarily scientific (00:56:22) Endeavors. Well long range is tough when you've got an election every year every two years. It's exactly the the problem let slip in one more quick question here for dr. Pepper. And before we leave hello there. (00:56:32) Yes, dr. Pepin science fiction writers have long tantalized me and others like me about the possibility of colonizing the moon or other planets at some future date. Do you foresee as realistic any lunar colonization as an option in lunar exploration? (00:56:51) I do indeed. I think it's an entirely realistic. Thought. The only question I think we're talking about is one of time scale as you may be aware both a lunar colony and piloted missions to Mars were on Sally ride's list of long-range NASA objectives. There is an interesting debate occurring within the agency now, but which one of those should have higher priority, in fact probably at the moment neither should have priority over the other two which is exploration of the solar system and Earth observations, but there is nothing conceptually wrong either technologically or from a physiological point of view with the idea of a lunar base and lunar colonization. The only question is how expensive will be what will drive that will it be driven economically, I think at the moment that's don't fool. Will it be driven scientifically, I think of the moments that so total will it be driven militarily? I think that is also doubtful. So we're left with no great driver for it, except the general human instinct to colonize what it does not know that maybe enough that plus some of the other considerations but there's nothing at all unrealistic or even let us say technologically unfeasible about that idea and it will happen. The only question is time scale. (00:58:01) Well, I'm afraid that our time scale has reached the end. I want to thank you very much for coming and visiting. At this with us, dr. (00:58:06) Pepper. It was a pleasure as usual (00:58:08) very very interesting. Dr. Robert Pepin University of Minnesota physicist and chairman of the National Academy of Sciences committee on planetary and lunar exploration the Minnesota Public Radio FM Network system goes off to music broadcasting here in just a minute the bark confirmation hearings resume at 1:15 this afternoon on ksjn 1330 AM in the Twin Cities that's live coverage and polish rotor will have just a little bit of a take up program from 121 15 nice weather forecast for today and tomorrow highs today 60s and 70s with the possibility of some 80's in the southwestern Parts tomorrow. That's our midday broadcast for today. Bob Potter speaking. Minneapolis st. Paul area forecast sunny and pleasant through tomorrow high today around 70 low tonight upper 40s high tomorrow middle 70s, you're tuned to ksjn 1330 Minneapolis-Saint Paul the news and information service of Minnesota Public Radio 61 degrees in the Twin Cities. It's one o'clock.