JOE PALCA, host:
This is SCIENCE FRIDAY from NPR News. I'm Joe Palca. Ira Flatow is away. Later in the hour, when planetary orbits go awry. But first, back in 2004, former President George W. Bush made a speech announcing his vision for the future of NASA.
President GEORGE W. BUSH: Today I announce a new plan to explore space and extend a human presence across our solar system. Beginning no later than 2008, we will send a series of robotic missions to the lunar surface to research and prepare for future human exploration.
PALCA: President Bush was a shade optimistic with his timetable, but now those missions are about to commence. Next week, NASA plans to launch two new spacecraft, the Lunar Reconnaissance Orbiter and the Lunar Crater Observation and Sensing Satellite. Both are intended to pave the way for future exploration of the moon, by humans.
We start this hour with a discussion of the new missions. If you have a question, give us a call. Our number is 800-989-8255. That's 1-800-989-TALK. Or if you're on Twitter, you can tweet us your question by writing the at-sign followed by scifri. If you want more information about what we'll be talking about this hour, go to our Web site at www.sciencefriday.com, where you'll find links to the topic.
And now let me introduce my guest. Jim Garvin is chief scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. He joins us from a studio there today. Welcome to SCIENCE FRIDAY, Dr. Garvin.
Dr. JAMES GARVIN (NASA): Joe, it's great to be here.
PALCA: So we're switching - usually we talk about Mars with you, but now we're talking about the moon.
Dr. GARVIN: Indeed. It's a happening place.
PALCA: Well, what are these - so these missions are intended to pave the way for human exploration. What sorts of things will they be doing that - you know, what do we need to know about the moon that we don't know already in order to send missions back there?
Dr. GARVIN: Well, Joe, the moon's a big place, and I think we may have failed to recognize a planet in its own right, the size of Africa in land area, can hold a lot of mysteries, and of course we haven't read the moon's textbooks completely, even after the brilliantly successful Apollo program.
So the Lunar Reconnaissance Orbiter and its co-manifested satellite, the LCROSS, as we call it, are designed really to breathe a new future into understanding a new moon, and what that means is to look at the moon as if we really are serious about going there, living there and understanding it as a piece of our own history.
And by saying that, I really mean it's a kind of a hybrid experiment. We're used to flying robotic missions to explore Mars, Saturn, wherever, with science as the primary question. In this case, we have an additional set of questions about what will it take to go to the moon safely for people, for humans? What will it take to go to the moon smarter and even less expensively?
PALCA: So how does a robotic mission determine whether, you know, the moon's a safe place for human beings?
Dr. GARVIN: Well, it does that in…
PALCA: I mean, not completely safe. It's still kind of airless.
Dr. GARVIN: Right. Well, we really have a multi-strategy, Joe, and the first thing is to measure the landscape at human scales, and we'll be doing that with a set of sensors, a laser altimeter that can map things the way civil engineers would want them mapped, a camera that can see things the size of a beach ball, and even what's happened since the Apollo Missions, instruments to measure temperature, the hydrogen in the ground, the character of the scattering off the ground, and even whether or not there are resources that would be useful for humans. Those are new things to do at the moon.
PALCA: And you mentioned resources that might be useful for humans. What are we thinking about there?
Dr. GARVIN: Well, there's really several, and the first, of course, and the most exciting, if it were to be true, and LRO will examine that, as well as LCROSS, is water as ice as a real resource, with volume, abundance of the scale we would need here on Earth to live.
Alternately, there are other materials in the lunar soils, including enrichments in titanium oxides, kind of like the stuff in sunscreen, that are so enriched they're almost at ore-body concentration. We could actually use those to strip the oxygen off to make air to breathe or oxidizer for rocket fuel. So the moon is really still a very largely unexplored world in terms of these kinds of questions.
PALCA: So how do you - I mean, now, I understand that one of - part of this is that the booster rocket that's sending these things toward the moon is going to go along for the ride, and then right before it, you know, before it goes away, it's going to be crashed into the moon to sort of kick up a plume and see what's underneath. Is that right?
Dr. GARVIN: Exactly. The LCROSS experiment is co-manifested with LRO because of available mass in the Atlas V rocket, and it will, after LRO goes into orbit, it will later, in fact in October of this year, will come around, back around to the moon, and with a little shepherding satellite make a big bang on the moon surface in a place where we think, we suspect, there may be some of these resources tied to the history of water or other phases we describe as volatiles, and then we'll be able to observe them with the shepherding satellite, as well as with LRO and with telescopes here on Earth.
PALCA: Yeah, I really - I mean, there have been other things that have been crashed into the moon on purpose, haven't there? It seems to me, yes, I'm sure there have been.
Dr. GARVIN: Well, there have. We crashed upper stages from the Apollo missions to basically thump the moon to look at its interior structure. We did that back in the '70s. This will be something of nearly equivalent magnitude.
The other impacts of Lunar Prospector, and most recently Japanese Kaguya, just a day or two ago, were smaller in magnitude, so less energy into the moon to do the job.
PALCA: I see. Well, actually that's interesting that you bring up the Japanese because there's a couple of countries that have sent satellites heading toward the moon recently.
Dr. GARVIN: Oh, indeed. The Japanese just completed a massively successful mission known as Kaguya. It mapped the moon as a real science exploration mission, 14 instruments. Our friends in India have a mission, Chandrayaan 1. It's carrying two U.S. payloads. That's also in orbit, but LRO is actually going to a much harder place, a very low orbit to allow it to make exquisitely high-resolution measurements.
PALCA: How low are we talking about?
Dr. GARVIN: We're talking about 50 kilometers.
Dr. GARVIN: Which is 150,000 feet. Joe, for a scale I like to describe LRO's orbit as the great roller coaster of gravity on the moon.
PALCA: Uh-huh. And why is that?
Dr. GARVIN: Well, the moon is lumpy inside. We discovered that on Apollo, and in fact these large concentrations of mass in these ancient, colossal impact basins actually add accelerations to spacecraft in lunar orbit, and if you're too low, those accelerations will accumulate and you will eventually basically impact the surface, and we learned that the hard way in our early navigation at the moon with Apollo, but now we're going to use that to our advantage to go lower and be able to make measurements and much finer scale by being able to fly in that very unique orbit.
PALCA: All right. Well, let's hear from our listeners and what they're thinking. Our number is 800-989-8255, and let's take a call now from James in Tucson. You're on the air.
JAMES (Caller): Well, yeah. I'm totally fascinated about the subject of conversation here. It's definitely interesting, but my question is - might be a little bit off subject - is why are we spending as much attention on the moon while we're not necessarily focused on the resources that we have on the globe and whether or not here, globally, rather than universally, we're not paying more attention with our taxpayers' money.
PALCA: Yeah, yeah. No, it's an interesting question, but it's been one that keeps coming up in the space program. Jim, what do you say about that? You know, this is an expensive proposition, and as we all know, there's a lot of competing interests for taxpayer dollars. How do you defend this program?
Dr. GARVIN: Well, I think there's two things to remember. Number one, NASA has a diversified portfolio, and we spend, indeed, more than $1 billion a year in researching our own planet, observing it in ways that are routinely seen on the Weather Channel at night and in other ways, in partnership with NOAA and other organizations.
We have a rich program of Earth science research that's produced a legacy. We've observed ozone holes, watching the ice sheets melt, understanding the missing carbon, how our Earth even keeps itself hot and cold. We do that routinely from NASA satellites as part of our Earth observing system and its extension.
So we are taking care of our own planet, and it's a major commitment of our present administration. Furthermore, this investment in reaching beyond Earth is relatively small against the backdrop of these bigger problems that I believe the country is ready to tackle now with our present leadership, and in fact the president's science advisor made a speech yesterday that committed to the research and development to better take care of our energy and environmental future here on Earth as part of the national priority. So NASA's just a little piece of that big piece of attention by our country.
PALCA: Right, but you've been someone who's been associated with some very successful robotic missions to planets, and those are of a scale - I mean, they're still expensive. The biologists drool when they see NASA's budget and say, oh, wish we had a piece of that, but I guess they're doing all right themselves these days. But you know, it's still a lot of - a big chunk of change for science, but it's orders of magnitude more for human exploration.
And so my question is, you know, are you frustrated that that money has to go into the human space program?
Dr. GARVIN: Well, I personally of course am not because human exploration adds value in unique ways. The Apollo program told us about the chronology of our solar system and awakened ourselves to things we would never have learned just living here on Earth, and that required the human in the loop.
Likewise, a couple weeks ago a team of people, humans, I might add, very effectively serviced the most complicated icon of astrophysics, astronomy, the Hubble Space Telescope, in ways that we can't imagine, at least in the foreseeable future, robots doing. And so, you know, my children have benefited from their textbooks containing the record of the Hubble Space Telescope, and that legacy would not be there without human exploration.
But let me point out one thing, Joe, that I think we forget, and it's easy to forget. It's human nature. The investment made in all of NASA, human and robotic exploration, aeronautics, is equivalent to a family of four going to one movie a year. That is the load on us. Now, maybe that's not something the public - you know, that's their choice, of course. But the other thing is the robotic missions we're talking are about the price tag of a large blockbuster movie in terms of total investment.
To extend knowledge forever, that investment is a choice we have to make, and you know, I think that choice is worthy. It's borne fruit. We see it routinely, and as has human space flight. So these are tough questions, and I'm just one guy, so you know, I don't pretend…
PALCA: Right. We're not going to hold your feet to the fire on this one. There's bigger forces at work. But just quickly, this launches next week? When does it arrive?
Dr. GARVIN: Well, the launch is next week. 3:51 p.m. is the beginning of the launch window on Tuesday, the 17th of June. LRO will go into a several day cruise to the moon, and it will arrive, and then it will go and achieve what we call lunar orbit insertion. This is LOI in our lingo, and that will allow it to power itself into orbit, and then slowly it will attain a circular orbit in the 50 kilometer altitude, it's 150,000 feet or so above the moon, over the course of the next month as it commissions itself to begin making these exquisite measurements that I've described.
PALCA: Okay, well when we start getting the data back, we'll be calling on you to help us interpret it, I'm sure. Thanks very much for joining us today.
Dr. GARVIN: Thanks so much, Joe, appreciate it.
PALCA: Okay. Jim Garvin is chief scientist at the NASA Goddard Space Flight Center in Greenbelt, Maryland. He was talking to us about the two new missions heading off for the moon next week.
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