Skyhook Robot Passes 1000 Foot Mark 325
JhohannaVH writes "MSNBC.com is running a story about yesterday's successful test of the Space Elevator!! Maybe it will become a reality after all." From the article: "This week's testing involved a 12-foot (4-meter) diameter balloon. Safety lines held by team members kept the balloon from floating away. The ribbon dangling from the balloon was made of composite fiberglass, with the robot lifter running up and down the tether ... During the day, the highest altitude reached by the balloon/ribbon/robot combination was 1,000 feet (305 meters). 'It gives us complete confidence that the mile goal is well within reach,' Laine said. Laine said that the Federal Aviation Administration has been very supportive and helpful in orchestrating their test flights. "
1000 feet down... (Score:5, Funny)
Re:1000 feet down... (Score:5, Funny)
Re:1000 feet down... (Score:3, Insightful)
Re:1000 feet down... (Score:5, Funny)
Re:1000 feet down... (Score:5, Interesting)
Hell, the Feds burnt though more than 20 million in Iraq this weekend.
Re:1000 feet down... (Score:2)
Give 'em (Score:2, Funny)
and they'll hang themselves.
Re:1000 feet down... (Score:2)
Re:1000 feet down... (Score:4, Informative)
It doesn't even apply to that. It applies to transistor density. And, now more than ever, speed gains aren't directly proportional to transistor density increases.
So your point might even be stronger than you intended it to be.
To arrive: take a step, repeat (Score:5, Insightful)
The cable is the scientifically hard part, not the climber.
Re:To arrive: take a step, repeat (Score:5, Funny)
Re:To arrive: take a step, repeat (Score:3, Insightful)
Most robot submersibles start their testing in a pool. Then they chuck 'em in an ocean.
--
Evan
Re:To arrive: take a step, repeat (Score:3, Insightful)
Of course, then why test 300 meters? Just hang a line from the ceiling; if it can climb 3 meters it can climb 300.
Re:To arrive: take a step, repeat (Score:5, Informative)
Re:To arrive: take a step, repeat (Score:3, Insightful)
Re:To arrive: take a step, repeat (Score:5, Informative)
The weight and resistance of a wire are proportional to it's length. The resistance of a wire is inversely proportional to its weight.
You understand this thing is going to be, perhaps 30,000 miles long, right? That's a 60,000 mile circuit when the lifting vehicle is at the far end (as for a moon or Mars mission).
Weight and line loss would be two problems.
-Peter
power distribution (Score:5, Informative)
We currently build transoceanic fiber optic cables that can be completely powered from one end using DC power, with the ocean acting as ground (current technologies require a powered repeater every so often), so we have already built power cables within an order of magnitude of the required length (though the energy it would need to carry would likely be much much higher - a single crawler might use several megawatts continuously)
I would be curious to know how a power cable on a space elevator would interact with the Earth's magnetic field. Would it impart a significant force on the cable? Would the cable need to be shielded?
Alternatively, what are the power generation options in space? Could a nuclear powered crawler be built, and/or could power generation facilities be spaced at regular intervals along the cable?
Re:To arrive: take a step, repeat (Score:5, Funny)
But then there's the issue of taking the sharks up there too....
Parts wear out (Score:2)
Re:To arrive: take a step, repeat (Score:3, Insightful)
Publicity stunt (Score:3, Insightful)
Re:To arrive: take a step, repeat (Score:4, Interesting)
The battery won't and can't "hold out". The thing is, current day rockets consist basically of 90% fuel-tanks and fuel, along with maybe 5% engines and 5% cargo. That's how much energy is required to get to orbit. Offcourse most of that energy goes into lifting fuel.
Batteries are atleast 2 orders of magnitude worse in energy/mass than rocket-fuel, and it gets significantly worse by the fact that batteries don't weigth less as they become decharged (a empty fuel-tank is ligther than a full one, nevertheless rockets jettison the empty ones and are multi-stage)
rocket-fuel could do it, with amounts of fuel similar to those consumed by a rocket, but then you hadn't really won much, had you ?
Current plans call for the climbers to be externally powered, perhaps by microwave or laser aimed at them from the ground. The energy delivered will go down as they get higher, but gravity decreases with the square of the distance to the center of earth too, so that works out ok.
SkyDeck 1, Space Elevator 0 (Score:5, Funny)
Re:SkyDeck 1, Space Elevator 0 (Score:5, Insightful)
I believe what I said here [slashdot.org] still applies:
Makes some sense to me.
And me too
Re:SkyDeck 1, Space Elevator 0 (Score:2)
1000 ft and a ballon makes a space elevator (Score:5, Funny)
model rocktry (Score:2)
This makes my launch of my Estes Andromeda a successful test of intergalactic travel.
Ah, the Andromeda was the first model rocket I built when I joined the model rocktry club in high school. Kind of miss those days. Funny thing is is that at the tyme I was living in Mass and when I moved back to Florida, less than an hour from the Cape, there wasn't any rocktry clubs there.
FalconTestflight?? (Score:4, Funny)
If my elivator is in flight I think i'd decide that would be a good time to choose a religion.
Hmm,... (Score:2)
~/Desktop/ $ units
2084 units, 71 prefixes, 32 nonlinear units
You have: 1000 feet
You want: miles
* 0.18939394
/ 5.28
You have:
cally@inego(23:24:09)
One time, I rode the Space Elevator... (Score:5, Funny)
62,000 miles? (Score:3, Funny)
Re:62,000 miles? (Score:5, Insightful)
Yes, why not? In theory you just need to go a short distance past Geosynchronous orbit, which is about half that, but only if you have a very heavy counterweight.
By increasing the distance they reduce the counterweight mass.
Re:62,000 miles? (Score:3, Funny)
Re:62,000 miles? (Score:2)
By the way, who the heck links to articles on msnbc? That's about the worst news site on the internet. Not to mention, the article is just a mirror from the orginal [space.com] at space.com.
Re:62,000 miles? (Score:2)
Because the space elevator has to rotate at the same speed as the Earth. Otherwise it will quickly wrap its self around the Equator.
The moon is in a 28 day orbit around the earth, so in one lunar orbit the earth would have wound the cable up entirely.
Re:62,000 miles? (Score:2)
Yes.
Re:62,000 miles? (Score:2)
Re:62,000 miles? (Score:2, Insightful)
Personally, I'm still impressed that they went ahead and tried out the 1000 foot model, and that it seems to have worked more or less as they expected.
It's a big jump fr
Re:62,000 miles? (Score:2)
Or 17 times the distance between Paris and New York....
Orbit is a WAY up there....
Not to undermine the hard work done here... (Score:5, Insightful)
This thing is of course, pretty cool, but it seems to me to be a pretty basic mechanical device. My understanding is that developing ultra-high tension/flexibility nanofibers capable of stretching from Earth to orbit, and developing the orbital platform was what made construction of a space elevator difficult.
My two cents.
_________
As Diddy says: Don't pull out your wallet [jfold.com] if you ain't going to use it.
Re:Not to undermine the hard work done here... (Score:3, Informative)
It needs to be externally powered (probably by laser or microwave from the ground), it needs to climb *fast* since capacity of the beanstalk is directly proportional to the speed of the climbers. (if the beanstalk can hold 10 climbers and they go 100km/h you can launch one every 2 weeks. If the climbers can do 1000km/h you could launch every 2 days on the same beanstalk.
If you want to use it for space-tourism
Cute test, missing something... (Score:5, Insightful)
Re:Cute test, missing something... (Score:2)
I want more videos like this [worldchanging.com]
Re:Cute test, missing something... (Score:2)
Re:Cute test, missing something... (Score:2)
Mass Produced Carbon Nanotubes [eurekalert.org]
7 meters per minute!
Future Hi [futurehi.net]
Re:Cute test, missing something... (Score:2)
100,000km will take more than 27 years at that rate
You don't get to 1,000,000 feet in one step. (Score:4, Insightful)
Eventually they'll get there, and this is a definite step in the right direction. While the tether may be the biggest unknown of the project, we still don't have much experience with this sort of thing. What safety systems should be on the lifter? How should it be powered? How long will such a thing last before it breaks down? How long will the tether last? How will the system weather storms? How will it weather space debris? How will you find a patch of ground strong enough to anchor the thing to? How do you keep the climber from jumping the track? How do you keep parts from freezing as it goes from wet tropical climate into space? The theoretical engineering may be done except for the cord, but many, many practical engineering considerations remain.
I applaud this team's efforts, and wish them much luck.
Re:You don't get to 1,000,000 feet in one step. (Score:3, Insightful)
Establishing your starting-point can be a useful exersize even if it, in itself, doesn't acomplish anything new.
CNT's still aren't strong enough though... (Score:3, Interesting)
White Elephant (Score:2, Insightful)
Re:White Elephant (Score:4, Informative)
MOD PARENT UP (Score:2)
Re:White Elephant (Score:5, Informative)
With a space elevator, you're no longer required to accelerate several dozens of tons (>90% of which is just fuel) up to 7 miles/second just to get a 500lb satellite in orbit. The cost savings would be huge.
Now granted, you'll still have to haul some fuel up the elevator, but it's like the difference between climbing the stairs to reach the top of the Empire State Building vs. jumping to the top from street level in one bound.
Re:White Elephant (Score:4, Interesting)
Re:White Elephant (Score:5, Informative)
The space shuttle costs 450 million dollars per launch. This would cost much more than that, but the upkeep should cost a small enough amount that it might pay off in the long run (Depending upon it's projected lifespan).
In an article by Bradley Carl Edwards [mit.edu] in the August 2005 print issue of "IEEE Spectrum", he writes "The estimated operational cost for the first elevator is several hundred dollars per kilogram to any Earth orbit, the moon, or Mars, a drop of two orders of magnitude over the cost of current launch technologies. With the completion of subsequent elevators, the cost would drop even further, to a few dollars per kilogram." So using a space elevator to transport whatever is cheaper than using rockets for transportation.
FalconChangelog : Version 18 (Score:5, Funny)
Version 1 Logic: Go up.
Version 18 Logic: Go up.
Re:Changelog : Version 18 (Score:5, Funny)
Version 1.1: Has limited mobility
~
Version 4: Moves in two directions. Left and Right. Damnit.
Version 4.0.1: Rotated lifter. Moves up and down.
~
Version 7: Plays elevator music in MP3 format
Version 8: Moves along rope
~
Version 9: Plays OGG files now
Version 10: By eliminating the "WAIT 30" command we have increased speed by 30x
~
Version 15: Now can read network drives for MP3, OGG, WAV, and AIFF files to play
Version 16: Has sensor to look out for birds. Damn PETA.
Version 17: Auto-updating kernel. We think.
Version 18: Robot goes up.... Robot goes down.... Robot goes up.... Robot does down...
Re:Changelog : Version 18 (Score:2)
Bleh... (Score:5, Interesting)
The climber is trivial, compared to the cable. Wake me up when they have a cable that can hold 100 GPa and is longer than a millimeter.
Warning to Pilots (Score:5, Funny)
I've been editing the video from the 1,000-foot robot test. Since I've been busy lately with grant writing etc., I wasn't involved in activities like making the ribbon. So it wasn't until I was watching the video that I noticed the sentence written in block letters on the 2-inch wide ribbon (which alternates color in 50-foot strips of bright yellow and fluorescent orange) near the top:
ATTENTION PILOT: IF YOU CAN READ THIS, YOU'RE TOTALLY SCREWED.
Our sense of humor (or at least Nyein's) may not (or it may) be visible from far away, but it's there.
correction (Score:5, Funny)
Run it Up a Flagpole ... (Score:2)
Although there are probably a good number of technical reasons for this test, it's probably about as much (or even more) a PR event as a technical test.
Among other things, they still have to come up with a microwave power delivery system before this thing is really gonna fly -- not to mention the ribbon material (hopefully within a decade or two).
Re:Run it Up a Flagpole ... (Score:4, Insightful)
I completed a milestone of my own! (Score:5, Funny)
I'm proud to announce that today I jumped 2 feet- a critical proof-of-concept that demonstrates the feasibility of my claim. Maybe I'll be able to back it up after all!
Cut out the bullshit already (Score:3, Interesting)
ADD (Score:2, Insightful)
A problem with the elevator (Score:2)
Series of balloons (Score:2, Interesting)
Re:And out of the atmosphere you do... what? (Score:5, Interesting)
Re:What keeps it up? (Score:2)
Re:What keeps it up? (Score:5, Informative)
Re:What keeps it up? (Score:2, Funny)
Viagra for space elevators.
Re: (Score:2)
Re:What keeps it up? (Score:5, Informative)
the ribbon recovers for the same reason that it stays up in the first place. Centripetal acceleration is acting on the counterweight pulling it outward, and the lost angular momentum is replaced very quickly (essentially as fast as it is lost). The ribbon will never lose enough angular momentum to even deflect a single degree, let alone fall. The extra angular momentum is stolen from the Earth's rotation; we will have to worry about this effect slowing down the Earth and making the day longer if we ever decide to ship Australia into space.
Re:What keeps it up? (Score:2)
Re:What keeps it up? (Score:2)
Ill-informed question: How do you turn on a computer?
Insightful question: Now that we've invaded Iraq, will the U.S. have the resolve to make a clean break at the "end" of the war? Is such a goal even attainable?
No, the questions have nothing to do with the thread - only as answers to your question...
Re:What keeps it up? (Score:2)
Re:What keeps it up? (Score:2)
Re:What keeps it up? (Score:2)
Re:What keeps it up? (Score:2)
Just "simply" flown back down in case it was attacked? Sounds a bit too easy to me. They also state that terrorists would be unlikely to attack it, but I wouldn't be worried about terrorists, with the US pushing to dominate space, other countries might want to att
Re:What keeps it up? (Score:2)
Re:What keeps it up? (Score:3, Insightful)
Re:What keeps it up? (Score:3, Funny)
Well, HOW? (Score:4, Informative)
But here's the catch: centripetal force is _strictly_ the component pointing at the centre of the circle. It can't accelerate or decelerate the rotation. The reason you can accelerate that small object on a string is precisely because the string is a little crooked, and it pulls a little forward too, in addition to the centripetal force pointing at the centre.
The apparent force pulling it outward, that they mention there, is called "centrifugal" (runs away from the centre), not "centripetal" (pulls it towards the centre). This one doesn't do anything to keep it from losing angular momentum. Hold your hand still after you've made your object on a string rotate. It's seeming to tug outwards is centrifugal force. Note how the item can slow down due to friction anyway.
And things get even more screwy in a gravity well.
Basically what I'm trying to say is that while I'm sure some actual physicists did some actual calculations for that project, and they probably have a very sound theory of how it regains lost momentum (and how much can it safely lose or gain before that string breaks), that quoted explanation isn't it. It's some handwaving that's as "scientiffic" or "informative" as saying that Santa's reindeers keep it up.
"It's kinda annoying to see every space elevator article attract a swag of ill-informed comments that get modded as insightful."
I feel your pain. I found it slightly annoying too to see your quote of that pseudo-science babble modded as "+5 Informative". No offense, since you're not the one who wrote that, but it's got exactly zero useful information, and doesn't answer the question at all.
I'd imagine that the reason people keep asking is precisely because that handwaving doesn't answer it.
Re:What keeps it up? (Score:5, Informative)
"To an extent, Mr. Swartz is correct: As payloads are moved up and down the elevator, the ribbon is distorted, and it would move the counterweight. Nevertheless, looking at the travel time and the relative masses of the climbers, the ribbon, and the counterweight, we find that the distortion is extremely small and would be quickly corrected because of the forces that are felt by the ribbon and the counterweight. The rotating Earth supplies the needed angular momentum through the anchor and the ribbon. The rotation also provides all the restoring forces required--no rockets are needed to move the counterweight. The best way to look at this may be to think of the space elevator as a pendulum. If you pull the ribbon from its normal position--rising straight up from Earth--the forces will always pull it back."
--Brad Edwards
"Yet, it moves..."& other observations (Score:2)
Then, imagine some form of spring tension on the car to emulate the force of gravity (electronic? magnetic? a column of compressible gas? Someone with enough clue, time and resources to build a digital simulator?). Could this be scaled to give
Re:"Yet, it moves..."& other observations (Score:2)
Re:What keeps it up? (Score:5, Informative)
You have your terms mixed up. (Score:2)
Centrifugal force is the force that goes away from the center of the circle.
Centripetal force goes towards the center of the circle. Gravity is a centripetal force.
as their own website points out... (Score:2, Informative)
The tether would be already equipped with thrusters every now and then to counteract natural wind and gravitational forces and the inevitable inaccuracy of the mass ratio that cause it to shift. These same thrusters can reposition the line after a brea
Links to informational resources (Score:5, Informative)
Re:Links to informational resources (Score:2)
In particular, could you write up what sorts of technologies are required, or would be helpful, in the construction of a space elevator?
Could you write up what sorts of technologies would be unlocked by having a space elevator? What sorts of things people would do with it?
Lastly, if you know of estimates on the timing of those things, could you write those up as well? We always appreciate links to reports, studi
Re:Partial space elevator still works (Score:2)
What do you think is going to hold it up?
Re:Partial space elevator still works (Score:2)
Y'know... gas balloons float becaus
Re:missing the point, IMHO (Score:2)
Re:missing the point, IMHO (Score:4, Insightful)
There are a lot of hard parts of the elevator's "baseline design." The climber is one of them. It's not easy to make a robot that can climb 62,000 miles reliably. The first thing you have to do is make a robot that climbs at all. Then you improve its reliability a whole, whole lot - by having the robot climb a whole, whole lot, find out what fails, and improve that piece.
Besides the cable, and the robot, you also have to worry about power delivery, deployment, ribbon design (not strength). Each of those is not an easy problem. You do need to solve all of them.
Re:Looks comforting (Score:2)
Meanwhile, as you posted yourself, this platform is to be stationed in the PACIFIC Ocean, which is relatively more mild when it comes to weather events (well, tsunamis suck, as do typhoons, but the likely point of anchor somewhere off Mexico is relatively smooth
Re:Looks comforting (Score:2)
And, probably more importantly, the anchor will most likely not be fixed. So if some freak hurricane does show up, you can just move it. The elevator will be fine. It's in orbit, you're just dragging a really tiny portion of it.
Re:What I want to know.... (Score:5, Funny)
The plane does, while strumming the lowest note ever played in human history in the process.
-PS
Re:What I want to know.... (Score:2)