Mile high club...

http://www.newscientistspace.com/article.ns?id=dn8725&print=true

A slim cable for a space elevator has been built stretching a mile into the sky, enabling robots to scrabble some way up and down the line.
LiftPort Group, a private US company on a quest to build a space elevator by April 2018, stretched the strong carbon ribbon 1 mile (1.6 km) into the sky from the Arizona desert outside Phoenix in January tests, it announced on Monday.

The company's lofty objective will sound familiar to followers of NASA's Centennial Challenges programme. The desired outcome is a 62,000-mile (99,779 km) tether that robotic lifters – powered by laser beams from Earth – can climb, ferrying cargo, satellites and eventually people into space.

The recent test followed a September 2005 demonstration in which LiftPort's robots climbed 300 metres of ribbon tethered to the Earth and pulled taut by a large balloon. This time around, the company tested an improved cable pulled aloft by three balloons.

I think this is impressive, even though something happened to the climbing robots...

http://www.liftport.com/ (http://www.liftport.com/)

I have been following these guys for at least 4 or 5 years now. These tests represent their first baby steps into proving potential technologies for space elevators.

As carbon nanotube and nano technology in general improves you will see their tests reach ever increasing altitudes. The construction of “climber” technology is well underway and represents the simplest part of this type of launch system.

For those unfamiliar with space elevator technology it goes something like this.

You launch a multi tonne satellite into geosynchronous orbit. The satellite is essentially one large spool of nano fiber. Somehow, and they really haven’t even come close to figuring this portion of the space elevator out yet, the spool of nano fiber is lowered to a ocean going vessel that acts as the space elevators base station.

They will probably use some type of weight to lower the fiber to the base station. The problem comes with the potential of the nano fiber getting tangled on descent, not to mention the potential for impacts on the fiber from space junk, though this is very unlikely.

The ocean going vessel that acts as the “tie down” mechanism for the satellite in geo-sync orbit uses the properties of water to keep the entire structure stable. Kind of like when you have a drinking glass on a glass table with water in between the two. The water acts like an adhesive keeping the two stuck together until you exert enough force to separate the two ( the sceintific term is adhesion, thanks akipt ;) ).

Once the nano fiber has been secured to the base station a “feeder climber” will be attactched to the main fiber and will start its climb into orbit all the while adding more fiber to the main stem. Over many months and many ascents and descents the main stem will be fortified many times over to strengthen it. This is in essence how they build wire span bridges. You get your base wires laid between the spans then a feeder builds up the wire, making it thicker and stronger.

Once the main stem has been fortified the “launch climber” will be attached and lifeport will start to deliver multi tonne cargo to geo-sync orbit. They estimate the climb to orbit taking between many days to two weeks depending on the weight.

Space lifts are an extremely efficient means of delivering payloads to orbit. All of your costs are up front to build it. After that it’s a cash cow. Payload per pound will drop from ten thousand dollars to one thousand dollars immediately. After you build more than one space lift the economies of scale kick in and the cost per pound drops even more.

Right now there is a concern about buckyballs, small nano tube structures. They have found that if ingested by animals or humans these nano scale structures can lead to health issues such as cancer. These hurdles must be passed before you suspend a 30,000 km tether of nanotube particles above the Pacific Ocean.

Why aren’t space nations such as the U.S. dumping their multi billion space budgets into this technology? Basically because it is unproven technology at this point, once the first space elevator is in production you will see a scramble to get this technology.

Space elevators will be the easiest way for humans to eventually start exploring the solar system en masse imho.

Cheers,

I attended their presentation at DragonCon last year and was impressed, if not entirely convinced. It'll be a damn cool thing if it works -- definitely worth keeping an eye on to see how closely they're able to stick to their schedule.

The water acts like an adhesive keeping the two stuck together until you exert enough force to separate the two ( I don’t know the actual scientific term for this behavior, care to enlighten us?). Fairly certain the scientific term for it is.... adhesion. :) Water attraction to other water pools is cohesion. Water attraction to other materials is adhesion.

Thanks Akipt :) my brain in on C# overload today ;)

2018 might be a little soon. Some people like to yell 'buckyballs!' whenever the question of the cable comes up but that still isn't exactly a solved problem. Definitely cool stuff though.

Very true Malse,

Liftport keeps pushing back their first launch date. There are simply too many technological questions right now and not enough answers.

All I know is that when Liftport or a similar company goes public I will buy as many shares as I can grab. Space elevators are poised to dramatically change how humans access space, its just a matter of time.

"Space elevators are poised to dramatically change how humans access space, its just a matter of time."


and elevators sure beat walking :)

What happens when a plane/jet flys into it?

This would happen...

www.wall-locker.com/images/boom.bmp

The tension of the vibrating wire would be sufficient to cut through nearly anything, even something moving at relatively low speed. Planes would know to avoid it, but it'll likely get a good number of birds.

Will be interesting if we get a 2050 rendition of "motorcyclist decapitated by wire" with hang-gliders.

From what I've read the end line will probably be around a meter in diameter, so it's not exactly invisible, but still very dangerous.

Trilogy of "Mars the red/green/blue" comes to mind...

And what happened to the 1st cable... /shudders

I'm reading way too much sci-fi!! :p

Heh Anterak, that was the series that crossed my mind when I started reading this thread.

Fandros

Ok, the one area I am most confused about is the ocean-going vessel. Just how big is this thing going to have to be to provide a base structure, and at the same time overcome the assorted perils of the sea; I am primarily thinking about the weather related problems faced by any naval craft.

We can easily build ships big enough to weather any sort of major storm, and you wouldn't plop it down in hurricane paths anyway. The reason you want it on water is because it gives you non-destructive slippage to account for the natural and unavoidable variations in the cable tension due to hundreds of factors from the obvious (the imperfect orbit of the satellite, wind, lunar gravity) to the more subtle (atmospheric temperature, varying amounts of drag due to the changing air density above the stratosphere).