Everything is looking good…

This past weekend, the second test of the new, improved Climber / Power-Beaming raceway was held.  As with the first test, everything went really well.  Here is the update from Ben Shelef, CEO of the Spaceward Foundation and organizer of the Space Elevator Games:

Hi folks.

I wanted to update you on the results of the second test in Olympia this past weekend.

As you recall, we made several changes after the tests at Dryden – we changed the helicopter vendor, we mandated use of the GPS hover-aid, and we swapped out the winch with the Virtual Bob (R) motion-arrestor system. We tested everything for the first time with a 1000′ cable two weeks ago, and everything worked very well.

This second test was a general rehearsal for the games – we used the full length cable (total of 4300′ above ground level) and had a battery-powered climber run up to the the top while we checked that tracking was feasible within the parameters we’ve set – not exceeding a 15 degree half angle cone, and not coming too close to the helicopter.  We were able to do all of this successfully.   We also practiced pull-up and set-down of the system several times, and really, there’s nothing much to it anymore.

This is the place to give Keith Mackey his due credit, since without him this would never have come to fruition, to NW Helicopters who have been more than tremendously helpful, and to Doug Uttecht who flew the helicopter for us oh so beautifully.

I’ll be blogging about the details in the next couple of days,

Ben

I’ve included some photos that Nic DeGrazia (from the Chicago video production company Bitter Jester Creative, Inc.) sent me.  The topmost one is unbelievably cool (IMHO) – it shows the Kansas City Space Pirates climber ascending the ribbon.  This picture is the closest thing we have yet to being able to show what a real Space Elevator is going to look like.  I don’t know if Nic composed the shot to show the sunshine spilling into the right half of the picture or not, but it’s a really cool effect.

The second picture is also of the KCSP Climber, this time not too far above the top of the Pyramid.

The third picture is of the pyramid itself while the fourth picture shows the Pyramid, too, this time with some of the base being lifted up by the helicopter.  As Nic mentioned in his email to me that accompanied this picture, “The base of The Pyramid (this was the helicopter’s anchor … you see it here doing it’s job – it plopped back down a moment later)“.  If you don’t know what I’m talking about, with the “Pyramid” and all, check out the official website of the Space Elevator Games for the details.

Thanks for the pictures Nic!

The Lasermotive Blog and Tweet log also has some information sent out during the testing.

So, now all we need is a date for the competition.  It certainly looks like it will be sooner rather than later.  Stay tuned to this blog or the official site of the Space Elevator Games for the latest updates.

(Click on the picture thumbnails to see a larger version of the picture)

6 thoughts on “Everything is looking good…

  1. Tim

    Question:
    Why is there a focus on a tether instead of a cable? I’m thinking that a cable that replaces a tether that also contains a tube for air inside it and the cable is powered to provide electromagnetic travel up/down the elevator for a doughnut shaped container. That way there is no resistance/stress on the cable (other then to keep itself connected to the earth and whatever object in orbit). Can someone explain why we are not looking at it this way?

  2. Markus Klettner

    Congratulations to Ben, his helicopter team and the contestants involved on the very promising tests!

    Tim, the critical, still unsolved and much discussed issue, is the proper design of the real mega-cable into space. Highest possible tensile strength at a minimum mass is key to the mega-cable that holds out even beyond self-support. Thus CNT fibers are jockeyed into the race, still everything else but sure whether this material can do it beyond 40N/tex (see also results of EuroSpaceward’s conference last year at http://eurospaceward.org/index.php?option=com_content&task=view&id=56&Itemid=108). NASA/Spaceward termed the challenge “power beaming” since laser or microwave could be a near future solution for the required energy transfer to the elevator car and for other space applications. However, due to the good electrical conductivity of CNT’s it can’t be excluded IMHO that a kind of maglev train to space with doughnut shaped cars may be the better solution compared to laser!

    Best regards

    Markus Klettner
    EuroSpaceward

  3. Eric Jaderlund

    Don’t forget that the shape of a flat tether makes it more resistant to breaking when hit by space debris. A round cable could snap with only a single hit.

    -Eric Jaderlund

  4. Ted Semon Post author

    Actually, you don’t want a flat tether – it is prone to being completely sheared if it is hit by a piece of space debris traveling in the same plane the tether is in.

    You want a tether that is curved. That way, no matter what the angle the space debris hits it at, the most it will do is poke a hole (or two) in it.

    Maintenance bots (or perhaps gear on the climbers themselves) will need to constantly travel up and down the cable, looking for these holes, and then either repairing or replacing the cable as needed.

  5. Eric Jaderlund

    I think Brad Edwards looked at the shape issue in detail in his book. I’ll have to look at it again, but I seem to recall the cross section for a hit in the same plane as the tether is vanishingly small as long as as a certain tether width to thickness is exceeded. A curved tether does seem to make more sense, but it also increases the cross section and make it more likely to get hit.

    -Eric

  6. Ted Semon Post author

    The tether will probably be on the order of the thickness of a piece of paper – even small debris could completely shear the tether if it hit it in just the wrong spot.

    In Brad’s first book, he proposes a tether with multiple strands, held together by composites. While he doesn’t specifically say it has to be flat, the pictures he includes do lead one to believe it is flat. But I think it’s bound to fail. Sooner or later, something will come by to shear it.

    I really do think you need a curved tether. But that’s still an issue open for discussion…

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