Stairway to Heaven

That Buck Rogers Stuff

A while back – too long, to be honest, I posted the first part of my interview with Brian Dunbar of the Liftport Company (where you can now buy a one ounce ticket to space) - those magnificent crazies who are attempting to build a Space Elevator.  Part one just got us started, so without any sort of further ado, here is the balance of the interview:

Beyond the technical issues, some other questions:

What obstacles do you see in the way of building a space elevator, assuming a technical solution is available – what legal, bureaucratic and safety issues will have to be overcome before we see a beanstalk?

We’ll need to assure ourselves and whatever government agencies that evolve to regulate us that the thing is safe for normal operation and that when it fails it does so in a safe and controlled manner.

There are legal and bureaucratic issues that encumber a launch operator.  These are probably evolved to deal with an industry that pokes along with a low launch rate; the appropriate agencies are going to have to perk up and move faster or that will be a bottleneck.

If I invented a strong enough material this evening, how quickly could your company build a beanstalk?

If you do that you should contact us soonest.  We can offer you a heckuva deal.

About twenty years.  It’s not just about the material - we need to evolve an organization, design the power delivery system, the lifters, the platform, run tests to make sure this all works in the Real World.  The good news is that the further down this track we go the more work we’re doing that back fills the effort so when the ribbon is done ..

Think of it this way.  You’re at work, waiting for a lengthy process to finish so you can get busy.  You can just sit around playing Solitaire or you can be productive and get other stuff done in the meantime.  We’re doing other stuff right now.

Do you see some sort of threshold for large scale access to space (via rocket) or experience in space construction that needs to be crossed before we can consider constructing a beanstalk?

It would be nice if we had massive experience with construction and assembly in orbit.  We do have MIR, ISS and the lessons learned there are valuable but the work there is somewhat odd in that it’s not being done by ‘construction’ guys but by middle-aged PhDs.  This isn’t bad but what we (as a culture) need are a lot of young guys with experience in
orbit.

We don’t have that.  We’ll have to hire the guys from NASA who have ISS experience and think hard about our choices.

But now - no threshold for heavy lift rockets - the initial seed ribbon can get there using the rockets we’ve got.


Posted by on 03/02/07 at 12:27 PM in That Buck Rogers Stuff
  1. That was a fantastic interview, and thanks to Brian Dunbar for taking the time to answer my perhaps overly long list of questions. 

    And I thank you for your posting the interview - the answers to your questions were many months delayed and your patience is appreciated.

    Any number of developments in the realms of genetic engineering, computing, nanotechnology (or the confluence of any two – like the Remote Control Pigeons of Doom) could overnight transform not just our world, but our perceptions of it, ourselves, and our place in it.

    I loved James Burke’s TV show ‘Connections’.  The general thrust of that series was that things were not always as we perceive them, then Thing A happens, combines with Event B and hey presto we get a ‘modern’ perspective on the universe.  Generally we don’t think much about it happening to us.

    I’d like to comment on a couple items that we discussed.  In part one, I asked Brian if he thought that there is any similarity between the historical development of railroads and the future growth of space elevators.  Brian responded,

    < blockquote > The railroad analogy is flawed, I believe, if you look at the American West in the 19th century.  There the railroad companies gained wealth by owning sections of land adjacent to the tracks, and selling them at a profit.  Towns were created by virtue of their being a railroad stop. This falls down with a space elevator - there isn’t any value in owning space next to the ribbon.  It’s all about the anchor, GEO and the bitter end.</blockquote>

    I think his last sentence is arguing with the ones before.  The space elevator, should it be built, is not just a transportation system.  It will be, in itself, real estate.  Bigelow, with his funding of the orbital space prize and his own development of space habitats, realizes this as well.  In orbit, it is very nearly true that there is no “there” there.  We have to build our own.  Real estate will be constructed habitat space.  At the top of the beanstalk, there will be a space station, and whoever built it will own that land, and control who can rent it.

    Ah. I was not arguing that having a habitat in orbit is useless.  This points up something interesting about a space elevator - there is no portion of it that is in orbit, except at GEO.  It can’t be ‘real estate’ except at GEO - from the point of view of a satellite at any other altitude the damn thing never stays still.

    So, there will probably be value in orbital habitats.  I say ‘probably’ because it hasn’t happened yet so the jury is still out.  But their value won’t come from a proximity to the ribbon.  Except at GEO where station keeping is possible.  We might see a nice little boom town there.

    Posted by Brian  on  03/02  at  06:39 PM
  2. The part of the SE at GEO isn’t in orbit either—it’s under tremendous tension because a huge force is trying to pull it downwards and another huge force, of equal magnitude, is trying to pull it upwards—but it does happen to be moving at exactly the same velocity and in the same direction as would an object in geostationary orbit. So if you let go of the ribbon right at that point, you’ll just hang there relative to it; you’re in orbit, even if the piece of ribbon you just let go of isn’t.

    Something that’s not often mentioned about the SE at GEO is that we’ll be able to dump momentum into it. We’ll be able to use a sling-like contraption called a rotovator to throw things around the solar system, while using the SE to absorb the momentum in the other direction created by slinging the payload.  The hub of the rotovator will be connected to the SE at the GEO point by a cable. When the rotovator, having thrown something toward the Moon or Pluto, moves in the opposite direction it will tug on the SE, causing it to lean slightly toward the rotovator. The forces that hold the SE up will counteract that lean, and cause it to return to the upright position.  In effect, the momentum created by the departing vehicle will be transmitted to Earth, speeding or slowing its rotation.

    The ability to absorb momentum may turn out to be one of the more valuable aspects of space elevators. It’s analogous to having a big heat sink.

    Posted by  on  03/03  at  03:47 AM
  3. Great interview! However, I think we missed one major point.

    If we can build an SE here (Earth), then we can build it everywhere! (as long as the world isn’t as hostile as Venus).

    Although everyone thinks that an SE would be built on the Moon first, I am having my doubts about that. I could be wrong, but wouldn’t the lunar dust static cling kinda ruin for everyone?

    Either way, if an SE could be built, then Mars would easily be within reach. If it could not, then Star Trek may be right about when we head back into space (22nd Century).

    Posted by Darnell Clayton  on  03/03  at  04:49 PM
  4. GREAT!

    One comment I have is that, despite Earth being the largest rock in the neighborhood, it’s probably the easiest one to build a beanstalk (Murdoc’s favorite term for the SE thing) on, obviously because of the installed infrastructure here.

    Building one on the moon would be relatively simple, except for the fact that there’s no one there to do it, all the materials would have to be carted up, and if someone forgot the 7/16” combination wrench they’d have to go back to get it.

    Those obvious facts being pointed out, once we get it working on Earth I would expect them to begin quickly popping up elsewhere.

    I want to see this happen with my kids.  I’m pretty bitter about the 1980s, 1990s, and 2000s being almost totally wasted. When I look back to where we were in the late 70s and what seemed possible to me at the time at age 10, we sure seem to have lost our way.

    Get cracking, Liftport! I ain’t getting any younger.

    Posted by Murdoc  on  03/05  at  03:49 PM

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