Slashdot Mirror

you'll probably need some additional energy to power the communication equipment. A solar-powered plane would already have solar cells for that.

It's a weird looking bird - have a look at http://www.skytowerglobal.com/

It has been flying for a few years now and has a few altitude records etc. They allways promised to put a web cam on one and never did (perhaps the transmission signal is poor ;)

Mike

The folks at SkyTower have a wonderful explanation for why this would be a useful technology. They have a similar technology that is supposed to use solar power and, will, eventually, if they can get it to work, also have fuel cells to store energy for night flying.

The basic idea, if you're too lazy to read their web site, is that they make wonderfully cheap substitutions for satallites with some of the small footprint advantages that the cell phone network has.

The laser powered system would have the advantage of not needing to store energy for night flying.

Of course, it's doubtful that a lowly photovoltaic system could be efficient or light enough for this to scale well. The Canadian SHARP microwave powered aircraft is likely much more practical and has had lots of research behind it.

The folks at SkyTower have a wonderful explanation for why this would be a useful technology. They have a similar technology that is supposed to use solar power and, will, eventually, if they can get it to work, also have fuel cells to store energy for night flying.

The basic idea, if you're too lazy to read their web site, is that they make wonderfully cheap substitutions for satallites with some of the small footprint advantages that the cell phone network has.

The laser powered system would have the advantage of not needing to store energy for night flying.

Of course, it's doubtful that a lowly photovoltaic system could be efficient or light enough for this to scale well. The Canadian SHARP microwave powered aircraft is likely much more practical and has had lots of research behind it.

The Helios unmanned high altitude vehicle was developed cooperatively by NASA's Dryden flight Research and SkyTower Communications A division of Aerovironment These can help you learn more about their research into 3G and broadband deployment over Japan. Also, you can view the press release on the crash here.

Not to be a wet blanket, but while Helios is really neat it's not terribly useful.

You're not a wet blanket, just wrong. They have already completed HDTV trials, lots of other applications to follow. Cell towers will be replaced by these. Cell towers have been unpopular in most areas. No one wants to live next to one. These can be easily launched and can be made cheaply.

It might be cheaper than launching a satellite in some cases,

It's definitely cheaper than launching a satellite

For the cost to build and operate the vehicle it clearly doesn't have any commercial potential

Oh really, can you provide some facts to support that claim? You simply just don't know what you are talking about. Have a look at Skytower Global and look at Aerovironment too.

and because of that and problems when it's windy this is a much better solution:

SkyTower

I suppose time will tell. I'm putting my money on SkyTower.

Here we have a commercial project, done by a private company, and partially funded by the Japanese Ministry of Telecommunications. And there's NASA, taking the credit.

The new homeland security department will require a massive global network. But transoceanic fiber is easily cut and the $800 million TDRS replenishment program with three satellites doesn't have the bandwidth. Intercepted SIGINT data is reportedly transmitted to Earth on a 24 GHz downlink using narrow-beam antennas. But the frequency swaths allocated for links are less than consumers can get on cable television. More bandwidth is needed.

One might speculate that a secret optical/IR satellite network downlinked in Hawaii might be developed. The European Space Agency, not to be outdone, says they're thinking of building miniaturised optical systems that fit onto a microchip. These optical networks might use optical CDMA which encodes each pulse,across a segment of wavelengths.

There is a lot of interest recently in stratosphereric platforms as an alternative to satellites, both heavier and lighter than air.

Geostationary satellites are too far to support high data rates to mobile terminals and also suffer from high latency. LEO satellites require an entire constellation covering most of the Earth before there is continous coverage in any part of the Earth. This all-or-nothing property makes it a dangerous business proposition.

Some links:
StratSat
CargoLifter and Boeing
Yokosuka
AeroVironment

If you read the SkyTower website you will see that the prefered configuration is two planes doing tight circles in a fixed point in the sky. These planes can share the same frequency and provide redundancy. So if one plane fails, you will at most loose half the bandwith.

But if the planes crash into eachother...

Check out this Real animation on their site:
http://www.skytowerglobal.com/anim/sktanim.rm

Uh.. actually, that is *almost* one of the proposed
uses for these things. Check out:
SkyTower Telecommunications
or
AeroVironment

i've been watching this Helios story for a couple of months now. the company that designed & built Helios (w/ NASA) is AeroVironment, founded by Paul McCready (of Gossamer Albatross fame). there are some pretty cool commercial applications intended for this program.