Maurice Franklin reflects on the 2008 Space Elevator Conference
- Posted: Aug 08, 2008 at 7:24 AM
- 2,501 Views
Maurice Franklin is a 12-year Microsoft veteran whose career has focused on performance engineering and server scalability. He's also passionate about the concept of a space elevator, and recently organized and hosted a conference held on that topic at the Microsoft Conference Center.
In this interview he discusses reasons to build a space elevator, and describes how the concept, first proposed by Arthur C. Clarke, is evolving toward a practical implementation.
The transcript for this interview appears below. Audio is available at ITConversations.
JU: Maurice, most folks don't know even that there's a serious plan to build a space elevator, and I'm sure even fewer know that those most closely involved gathered this past week for a conference hosted at Microsoft. How did that happen?
MF: Well, I'd qualify the word "plan" ...
JU: Maybe we should call it an intention.
MF: That's a good word. Or aspiration. So, I got involved in the space elevator world in 2002 when I discovered, quite by accident, that there was a conference in Seattle. It was hosted by an entrepeneur, Michael Lane, and a scientist, Bradley Edwards.
Dr. Edwards is the father of the 21st-century concept of the space elevator. He'd heard it was impossible, and didn't believe that, so he got a NASA grant, and came up with something that made everybody say: "Well, that's not how we were thinking about it at all. That's a decades plan instead of a centuries plan."
JU: What was different?
MF: I'd read a 1997 NASA study, it was big science and big engineering. It relied upon a spacefaring technology to get to a space elevator. Those of us who are fans of the space elevator see it as a bootstrapping mechanism to get to that spacefaring technology.
So, for example, one of the prerequisites assumed in the 1997 study was the ability to move an asteroid into earth orbit. And then to put a manned carbon-nanotube-manufacturing station in orbit. Well, you can't do any of that unless you have a space elevator.
As much as anybody has, Dr. Edwards cracked the chicken-and-egg problem. His proposal requires on the order of four or five heavy launches. After that, it self-bootstraps -- if the materials come along, and a lot of other ifs, but that's a game-changing proposal.
The NASA study also required a massive elevator, because there were going to be maglev trains running at high speeds, and that just adds more and more weight.
His plan is much more modest, it only goes 200 kilometers per hour, it's a bit slow, but it's practical, you could reasonably get stuff up pretty quickly.
And he added in remote power beaming, so you don't have to carry fuel for those days of climbing up towards geosynchronous orbit.
In all respects, it's much more practical. If we could get past the technical hurdles, it's something in our lifetime, or at least those of us who are older hope so.
JU: So your role at Microsoft was then, in 2002, and is now...
MF: I'm a performance engineer. No connection with space-related activites at all, just a personal interest. Although that 2002 conference was invitation-only, I showed up. I'd read the NASA study, I'd read Brad's study, I had intelligent questions, and I was accepted, which was very cool.
JU: So how did Microsoft come to be the sponsor and host of the 2008 conference?
MF: One of the collaborators on this project is Dr. Bryan Laubscher. He's an astrophysicist, most recently with Los Alamos National Laboratory. About a year ago he was invited to the visiting speaker program at Microsoft Research. I went to hear him, gave him my card, and invited him to contact me if there was any way I could help.
About a month later he got in touch and said, "I'd like to make Seattle and Microsoft the center of the space elevator universe, so let's get a conference."
Well, Microsoft employees themselves can't usually sign up the Microsoft conference center, so it became my job to find a sponsor. Through various happenstances I got connected with George Spix, now with the Microsoft Institute for Advanced Technology in Governments, who I actually I knew from some work we'd done together in the past, and he said "Sure."
JU: It's interesting how these things play out.
MF: Yes, it is.
JU: So on the face of it, this is a project that has a lot to do with power engineering, and...
MF: ...materials technology...
JU: ...right, and civil engineering. But there are computational spinoffs and synergies too.
MF: Right. One of the subjects that came up at the conference is that even though this ribbon, as we refer to it, will be under more stress and tension than anything ever built by man, it will also -- by virtue of being so darn long -- be very dynamic. It will flutter in the wind over miles rather than feet.
JU: So there will be a need to simulate the resonances.
MF: Yes. It's going to seem to be a simple object, but because of its length and its multiple environments -- gravitational, atmospheric -- it'll be very complex.
Also, it has to avoid what's already up there. If you put something on the equator and then span zero to 100,000 kilometers, you will intercept the orbit of everything, eventually. Repeat those words: Everything, eventually.
JU: Did you say 100,000 kilometers?
MF: Yes, it's very long.
MF: Yeah. It's a significant proportion of the way to the moon.
JU: That's way more than I realized.
MF: To touch the earth and stay in the same spot, it has to more or less orbit at geosynchronous. Once you establish that, you have to put enough mass above geosynchronous, call it a counterweight, that the earth is attempting to eject from orbit, to offset the mass, or in this case weight, below geosynchronous, that the earth is trying to pull down.
So you fix that geosynchronous point at 22,300 miles, I think it is. You then get to decide how big that counterweight is versus how far out it goes.
If you put an asteroid of appropriate side, it can be just the other side of geosynchronous.
JU: Ah. So that's what I'm remembering from the original proposals.
MF: Yes, in the NASA proposal, and also in Fountains of Paradise, the Arthur C. Clarke book, it was a large counterweight very close to geosynchronous.
JU: So that's "big engineering" as you've said, and the modern concept is to go smaller.
JU: In terms of computational challenges, we have this carbon nanotube ribbon which is 100,000 kilometers long, and it's on a collision course with every piece of space junk.
MF: Right. So Dr. Edwards' proposal is make the base movable, by putting it out to sea on an oil-rig-like platform, and then to move it when the computers say it has to move. You induce movement of the base, and then up and up, to miss the space station.
So I think I just described a very complex thing. You've got to move this thing hours or days ahead of a collision that you have to avoide by, say, 5 kilometers to be safe.
JU: That's the safety buffer?
MF: Right. Part of the Air Force monitors every object up there.
JU: Even screwdrivers?
MF: I think they get down to the centimeter, but don't quote me, I'd have to look it up. Anyway they track all this, and call up the space shuttle and say, you need to fly a little bit that way.
But now you have this object that you can't just move on a whim. And when you move one part of it, you move all of it. The space shuttle has a buffer of a kilometer, or 10 kilometers, I don't know, but say it's a cubic kilometer they have to keep clear.
Well if the space elevator's square danger area is a kilometer, it's not a cube.
JU: It's a column.
MF: A column that's 100,000 cubic kilometers, projecting through every orbit known to man. And in order to move it, you have to move it all.
There was a NASA retiree of considerable note at the conference, Ivan Bekey, and he came in and said, "Have you guys really figured this out yet? I don't think you have."
It was a great keynote: "Potentially Fatal Elevator Flaws That Must Be Addressed".
JU: So the strategy you just discussed has been on the table.
MF: Yeah, but not enough to stand up to the scrutiny of somebody like Ivan Bekey, who's saying, no, no, you have to actually figure this out. And people are like, yeah, yeah, you're right, we have to figure it out.
Then there's the question of what kind of communications network runs on the space elevator. There will be radio waves, but you'll want to bring up your browser too, and the latencies will be very different than for a transatlantic cable, so there are interesting computational challenges there.
JU: Fascinating. So as an observer of this scene for some years, what was notable about this year's conference?
MF: Well, for one thing, to see people working through the ideas that Dr. Edwards came up with, for example the collision management problem. On the other hand, there was a presentation on how, having shot the arrow, you get the rest of the material across. He proposed a deployment. But an engineer showed up, somebody working purely on his own time, and he has software to simulate the dynamics, and he said, no, that's probably not going to work, but this might. His idea was to keep the middle and the ends at geosynchronous, then spool out two in-between parts, then let go of the ends.
JU: So the most basic deployment strategy is still very much being discussed and debated.
MF: Yeah. It's such a complex object. This isn't a satellite. It's a thing that sticks through a lot of gravity gradients, in its first 10 kilometers it's beat up by the atmosphere.
So people are digging in, and coming up with different ideas that thematically fit in and move things forward.
JU: People have a general sense of what it would mean to get a several order of magnitude reduction in the cost of moving stuff into space, and of what applications could flow from that, and of the benefits of those applications. What's your take?
MF: Cost is a big deal. We ship things across the country because it costs 15 dollars, but we don't ship things to orbit because it costs 15 million. The space elevator changes the market dynamics completely. Because it acts more like a railroad with high upfront investment and then low operating cost, versus rockets with continuously high operating costs, that drives potential market opportunity.
But as one gentleman pointed out very forcefully, in addition to cost, there's capacity. You can only build and launch rockets so fast. The space elevator not only gets you low price, it's always there, waiting to launch payloads every day. The baseline elevator has, say, a 10-ton capacity every day, versus 15 tons every 3 or 4 months with a fleet of four space shuttles.
He was pointing out that all these big post-Apollo dreams -- going to the moon and Mars, tugging asteroid into orbit to mine them...
JU: ... large-scale orbital solar power collectors and beamers...
MF: ... right, which is one of my favorite applications. So for these things it's not enough to have low cost, you have to lift a lot of stuff up there.
Solar power satellites sound wonderful. Of course there's a whole set of other engineering and environmental problems. But in order to even make a dent, you have to move a lot into orbit. That guy was right. Capacity, capacity, capacity.
JU: What other uses are people talking about?
MF: Space tourism. People go up the elevator for a few hours, see the rim of the earth, that might be a gangbuster business.
JU: How long does it take to get up?
MF: 200 kilometers/hour is kind of slow, I think geosynchronous works out to 6 days. You don't have to go to geosynchronous orbit, though, unless you want to step off and have nothing happen.
A critique that made it to the New York Times was: "If you go to low earth orbit and step off, you fall." True. Of course the comeback is, go past low earth orbit by a bit, then step off and you fall towards the atmosphere, but you don't actually hit it. You bring along a small rocket, fire it, and you're in low earth orbit around the earth.
So you don't have this big fiery explosive launch that gets you to orbit in 20 minutes, but you don't have the dangers that go along with such an enormous expenditure of energy in a short time.
Instead you go up in something that's slower than an Indy racecar but faster than most people drive. It might be several hours to an interesting spot, several days to a more interesting spot.
There are people going up now to look down on the earth at $20 million a pop. If the cost came down to $200K, $20K...
...and there's a sociological argument that it would be a great thing for people to observe the earth from space, because there are no maps.
JU: Yes. It's historically had a powerful effect on the privileged few who have been able to go up and see that.
So there's the solar satellite concept, there's space tourism, what else?
MF: Everything else in between. Things we could do in zero gravity. Today there are experiments with special drugs, special materials processing, but they're experiments. They have to fit in the bay of the space shuttle, it only goes up every 3 or 4 months, you're not going to build an industry that way. But if you could ship your goods up and down every day, to an orbiting manufacturing plant that you just carried up on one of the larger space elevators, that's not necessarily a dream, that could be a business plan.
Two related things I meant to mention. First, it's highly scalable.
MF: If we can build a 20-ton elevator, we can build a 40-ton one. And by the way, the first thing you build with a space elevator is ... a space elevator. The very first payload will be the second space elevator.
JU: To be build in another location?
JU: Which addresses the single point of failure vulnerability.
MF: Yes. It is vulnerable, for all sorts of unfortunate reasons. But while it costs a lot to get the first one up, the second and third are relatively a lot cheaper.
So they scale out. I'm a performance engineer, that's one of our favorite terms.
And they scale up. There's no reason you couldn't scale up to a million pound elevator. And the thing is, there's no particular limit on the size and shape of the thing you carry.
Today things have to fit in nosecones, basically. The shuttle is a long bay, but cylindrical and 15 feet wide. Here you're limited mostly by how much turbulence it can take during the first 10 kilometers of the climb.
After that it's: "Oh, you want to build the space station." Just launch the space space station, tomorrow, and it'll be there in six days. That's a totally different way of looking at it.
It's like container ships. They've totally changed global trade.
JU: I was going to mention that. There's a book called The Box about the innovation of the standard shipping container, which is the physical equivalent to packets in a packet-switching network.
As a result, although it seems silly that some of the things we buy have criss-crossed the world...
MF: ... interesting meta-discussion there...
JU: ... yeah, but because of that technology, it really is economical for a lot of stuff to move around.
MF: I've seen bottled water from New Zealand. It astounds me. But it probably cost more to make the plastic container, which I consider to be heavy and low-value, than to ship water across the ocean.
JU: So the question remains, is this a leap of faith, like with the early space program, where we don't know the benefits but we intuit that there will be all kinds of spinoffs.
This feels like that, so the more you can identify operations that benefit from arbitraging the different between earth and orbit...but it's not crystal clear to me there's a long list of those.
MF: No, I agree. A critic of the space tourism idea pointed out that, yes, airlines and before that steamships were all built on the desire of people to go somewhere interesting: Disneyland, or a business deal, or an exotic location. Currently space only qualifies on the last point. So the chicken/egg problem won't be cracked by space tourism.
There have to be business reasons. We mentioned solar power. Another possibility is mining asteroids for iron and nickel. Those two items -- a lot of energy, and all this material -- there's a whole chapter in Dr. Edward's book that starts by figuring out your individual share of that. It's a lot.
The way I look at it is that a quarter of the world lives at or near the US standard, there's another quarter trying to achieve that in the next generation, another quarter just starting, and then one behind the curve.
Energy and materials are resources that space is full of.
JU: Clean energy in particular.
MF: It's getting a lot of attention lately, yes.
JU: Of course a lot of folks will point out that there are lots of earth-based solutions for clean energy, so why go to space for that. But I guess the answer is that it's not necessarily either/or.
MF: Agreed. But consider this. Scientific American's January cover story is a proposal to do big solar by 2050. Part of it is to use 1/5 of the American desert. The environmentalists have to swallow that, there's an albedo change in the earth, and so on.
Plus, it turns out that having a desert close to your civilization is fairly unique the world. Europe doesn't have one.
Now factor in population growth.
Meanwhile, satellite advocates say that if you had a band of solar cells a kilometer wide -- and that's a lot of solar cells, no doubt about it -- they'd produce, annually, energy equal to all known remaining oil reserves.
JU: It brings to mind one of the Long Now talks, I think by Vernor Vinge, in which he plots human civilization with population on one axis, and the amount of energy available to be used by an individual in the population on the other axis...
MF: ... something similar was done at the conference, by the way...
JU: ... OK, so you get a stepwise progression where each major advance in the level of civilization is tied to the amount of energy that could be mobilized by an individual.
It's tricky to talk about that right now, in an era when it's critical that we conserve.
MF: But you only get to conserve once. Replace all the fluorescent bulbs with LEDs, and do everything else you can, and you bought yourself ten, twenty, maybe thirty percent. If you want to increase your standard of living you don't conserve, you use up more energy.
JU: Right. So, how cool is it to be a performance engineer at Microsoft, take an interest in this topic, and wind up bringing the conference to the Microsoft conference center?
MF: Yeah. By the way, about 10 percent of the attendees were employees.
JU: I was wondering about that. The conference was fairly small, right?
MF: Around 50 people.
JU: Most of whom are practitioners, engaged in the R&D.
JU: But you got to bring it to other folks at Microsoft who, like you, the first time you went to one of these, will make all kinds of connections, and start thinking about the computational aspects.
Well done! And what a treat for you to get the chance to do it.
MF: Thanks. One nice thing was that it got posted on the internal calendar, and a guy I know found it, and he sent his two sons, a junior in high school and a junior in college. One's interested in mechanical engineering, and the other in civil engineering. I think this counts as a fairly large mechanical and civil engineering project!
So I meant to mention one of the interesting side effects of the length of the elevator, which is: What happens when you let go? Remember, everything above geosynchronous is trying to tear the ribbon apart, it's trying to leave the earth. If you let go at the right time of year, and the right time of day, you'll be on your way to Mars really quickly.
MF: I'm serious.
JU: If you climb way above geosynchronous and let go, you slingshot to Mars?
MF: That is the appropriate word. Slingshot. I'm talking about a couple of months. Faster than the fastest stuff we've sent with big heavy boosters for these little bitty probes. You just take the biggest thing you want to send, and just let go, it'll be there in two or three months, for free.
MF: And as a result, guess what's one of the first things you send to Mars using the earth space elevator.
JU: A Mars space elevator.
MF: Yes. There's a book on that, by the way. Science fiction. It's called Red Mars. It has an unfortunate ending involving terrorism. And of course the first space elevator conference, where everybody had read that book, was early 2002. Dr. Edward's said: "We've all read Red Mars, and yes, we have to take this into consideration".
There's been a study of how to defend the space elevator.
JU: I wasn't going to mention this, but that is maybe the worst vulnerability. You're not going to move it out of the way of a 747.
MF: The author's conclusion was that a consortium of private companies would own the space elevator, and the US government would trade defense for access to it.
You'd spend a billion dollars a year parking American assets around the elevator's airspace, and it'd be like, do not fly here, just don't, you will be shot down with no questions asked.
JU: And unlike the problem of defending the ground, this is a relatively well-defined region of the sky that needs to be defended.
MF: Right, it's not the whole continent. But everybody agrees it'll have to be defended. And we have the infrastructure, for better or worse, to do that.
But anyway, the possibility of moving around the solar system using space elevators is a whole other thing. Is that because there's interesting stuff out there? Because we're going to colonize Mars? Because we need more material sent down the elevator?
You might say that's visionary, or you might say it's just being practical.
JU: Well thanks again, this has been fascinating and a lot of fun.
MF: You're welcome Jon!