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Re^3: "Practices and Principles" to death

by dragonchild (Archbishop)
on Feb 29, 2008 at 18:37 UTC ( #671255=note: print w/ replies, xml ) Need Help??


in reply to Re^2: "Practices and Principles" to death
in thread "Practices and Principles" to death

(Note: you're entering into an area that I have a lot of interest in and have thought about for years, so please be prepared to back yourself up.)

You're presenting very real issues. Sounds like there's a number of excellent industries waiting to spring up. For example, garbage-collecting dead satellites and other debris. No, I have no idea how this would be done. Sounds like the perfect use for a field of some sort on a drone sweeping around the earth in an orbit that traverses the entire spherical shell of a given height. If all known satellites are in a database somewhere (another business opportunity similar to credit bureaus), there isn't a problem. If finding these satellites is a problem, that's another business opportunity. In other words, the cost of managing of all these items can easily be handled by entrepreneurs in the free market.

Now for lift costs. This is an interesting problem because it makes a lot of assumptions that may not be valid for more than a few years. So, let's talk about this.

Lets look first at what cannot be changed - the amount of energy it takes to raise the potential energy of a certain mass such that it is in LEO. That energy needs to be applied to the mass in such a way that it raises the potential energy without damaging the mass. The way that has been done thus far has been to use rockets which are extremely inefficient. And, they're more inefficient the closer to the ground you are. If we could only start our rocket halfway up, we would cut our energy needs by 75% (Inverse Square Law). There are easily a dozen solutions here, but they all have a rather high capital cost. Amortizing that cost is the key.

Now, why do we have to build satellites on Earth? Why can't we build them in orbit? If we could do so, we wouldn't have to make them so sturdy (to survive liftoff), which means they would require significantly less material. Since you'd have a foundry in orbit, you probably have power generation in orbit. Why not share that power generation capacity through beaming (a proven, if unused, technology)? Now, all you need is the actual purpose of the satellite. A lot easier to work with.

Furthermore, why do we have to have people in orbit to build these satellites? The cost of the ISS would drop by about 90% if it didn't need people on it. I'm not advocating a human-free space exploration program. In fact, I'm not advocating a space exploration program at all. I'm coming from the perspective of a space occupation program.

Basically, you find that the marginal cost of a given product (such as a satellite) drops dramatically if the proper infrastructure is in place. Very much like Perl when it comes to programming. I know you've discussed how productive you are in Perl vs. other languages in the past. That's due to the infrastructure you have. That infrastructure cost over 1_000_000 manyears (counting CPAN), but has been amortized into saving that many man-years every year. That's all that's needed in space, too.


My criteria for good software:
  1. Does it work?
  2. Can someone else come in, make a change, and be reasonably certain no bugs were introduced?


Comment on Re^3: "Practices and Principles" to death
Re^4: "Practices and Principles" to death
by ack (Deacon) on Mar 01, 2008 at 03:46 UTC

    Oh, my! Don't get me started...so much of what you wrote is, in my experince, so very true. That is most impressive from one not 'in the business.'

    As you've probably already recognized...I tend to write prolifically and I suspect the rest of the Monks would get both irrateted and bored with all the satellite talk.

    So I'll hold my enthusiasm and just say that I agree with so much of what you said and I thank you for it. It gave me a lot to think about and to cogitate on...and grow from.

    I would also like to note how very cleverly and kindly you brought the discussion back to Perl...which I'm sure the rest of the Monastery appreciates very much.

    Thanks, dragonchild.

    ack Albuquerque, NM
Re^4: "Practices and Principles" to death
by tilly (Archbishop) on Mar 01, 2008 at 04:00 UTC
    Right now something like 30% of the space junk up there comes from one Chinese satellite getting into a collision. We have at the moment no workable ideas for how to get that debris down other than wait a few centuries. And since it is traveling over 10,000 miles per hour, blasting it into smithereens just results in too much sand to track, but even a single grain of the stuff is potentially lethal.

    Before I'd support your approach, I'd want to see answers to how we plan to get rid of the debris from one collision. After that I'd like to see a plan to handle the potential problems from a careless company cutting corners and having a few more space accidents. And before you wave the free market magic wand, with known techniques it takes a lot of work to get a single flying screw down. How do we supply a profit motive to reward private enterprise for that work?

    It is always easy to say, "Oh the market will take care of it." But markets don't work very well for certain kinds of problems, and dealing with litter in near space seems to be one of those problems.

    And for the record I'd love to see a solution to it. Because until we can come up with a solution, I don't think we're going to successfully colonize near space. (The ultimate solution may be to be very, very careful with near space and instead leapfrog human colonization out of low Earth orbit.)

      Before I'd support your approach, I'd want to see answers to how we plan to get rid of the debris from one collision. After that I'd like to see a plan to handle the potential problems from a careless company cutting corners and having a few more space accidents. And before you wave the free market magic wand, with known techniques it takes a lot of work to get a single flying screw down. How do we supply a profit motive to reward private enterprise for that work?

      So true... doesn't work on the ground (yet), so why should it in near space? Just changing a few words...

      Before I'd support your approach, I'd want to see answers to how we plan to get rid of the land mines, cluster bombs and depleted uranium from one war. After that I'd like to see a plan to handle the potential problems from a careless country cutting corners and dispersing their toxic nuclear waste by way of uranium bombshells. And before you wave the free market magic wand, with known techniques it takes a lot of work to get a single land mine defused. How do we supply a profit motive to reward private enterprise for that work?

      Pretty much to do here, yet, to be dreaming of near space occupation...

      Update: It hasn't been a collision, they blew up one of their satellites.

      --shmem

      _($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                                    /\_¯/(q    /
      ----------------------------  \__(m.====·.(_("always off the crowd"))."·
      ");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}
        There are more than enough human beings around to spend a little effort on all those things at the same time.
        I never said it was an accidental collision.

        I don't know the details of the device used, but in general in space there is no need to explode anything. Just kinetic energy from hitting it that fast is enough for total destruction. For instance the recent US effort to destroy their aging spy satellite did not use an explosive, they just ran a rocket into the satellite.

        At the worst you might explode the missile very, very gently before impact to guarantee multiple impacts. I have no idea whether China did that, or just collided them. I assume collided.

      I do not have the experience to solve the problem myself. If I did, I'd be starting a company to do that and not a company that writes software.

      I do, however, have a good idea as to why someone would want to solve the problem. First, assumptions.

      • Putting stuff in orbit is a very profitable goal.
      • A mechanism for putting a kilo into orbit that is below $100. (Costs can run up to $22,000/kilo1.)
      Once you have both of those, then you have the need to clean up what's there for the very reasons you gave2. The cost for this kind of thing now comes under the heading of insurance or paying for police protection. It's just now a cost of doing business and you want to pay one of the 2-3 companies that make it their business to keep the lanes clean.

      As for markets not working well for certain problems, I would submit that they actually work exceedingly well. We just may not like why they aren't doing anything about the problem. For example, shmem brings up landmines in a reply down the thread. If there was a significant number of landmines around 10+ major US cities, there would be dozens of companies, large and small, competing to clear them. Given competition, the costs of removing a landmine would drop from $300-$10003 to, probably, something closer to $10-$50/mine. The problem right now is that there is no financial incentive to remove the mines. All the mines are in places that have no value. Yes, that sucks, but that's what the markets are saying. Otherwise, the mines would have been removed by now. The markets abhor a void. Removing space debris, on the other hand, has a lot of financial benefit.

      1. http://usinfo.state.gov/journals/itsv/0108/ijse/dipasquale.htm
      2. Theoretically, a shield might be invented that can protect a satellite from anything, but so might Star-Trek teleporters. You're welcome to hold your breath.
      3. http://www.mech.uwa.edu.au/jpt/demining/info/probs-solns.html

      My criteria for good software:
      1. Does it work?
      2. Can someone else come in, make a change, and be reasonably certain no bugs were introduced?
        Submit all you want that markets work exceedingly well. Economic theory says otherwise. In particular look at the well-known phenomena of the tragedy of the commons. Or more specifically read the classic but far from dated text, The Logic of Collective Action.

        That applies in spades to space. You see, cleaning up one piece of space junk does very little for helping the overall problem. The cost of cleaning it up is born by the organization that does it. The benefit is shared by all organizations in space. Thus even if the overall benefit makes cleanup worthwhile, cleanup is generally not worthwhile for whoever does it.

        This is not always an insurmountable problem. For instance in many cases (eg environmental protection or maintaining fish stocks) governments have been able to solve the problem by creating artificial regulations that reduce externalities and create incentives that align the free market with the common good. Of course no country has the ability to impose such a solution on space.

        A second common solution is what The Logic of Collective Action calls exploitation of the large by the small. In this situation a single actor, in the case of space probably the USA, gets sufficient benefit from acting in the common good that they will unilaterally do it. And, of course, once that organization does it, the others don't have to. US military policy is a fairly good example of this, as long as the USA is willing to patrol the world, international security is good enough that smaller countries, such as ones in Europe, do not bother to do the same. Nor do they contribute substantially to help the USA. (And, of course, they resent the USA for acting in ways that they don't like, and the USA resents them for not helping. This solution is a recipe for resentment.)

        The third common solution is that a small group can find it worthwhile to cooperate. However the dynamics get very complicated - it is in the group's interest that the task actually be accomplished, but it is in every member's interest that they personally do as little as possible. A classic example of this is provided by OPEC, and the history of agreements within OPEC and their partial enforcement is a testament to how complicated the dynamics get.

        In any case there is substantial economic theory on this exact problem. That theory says very clearly that near Earth space junk is a problem that markets are poor at solving. In addition the simple physics of of the situation make solving the problem very, very difficult. And nobody has come up with any good proposals for how to solve it.

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