Sanswire Demonstrates First Stratellite

Sterling D. Allan writes "Pure Energy Systems News (PESN) reports that GlobeTel Communications Corp. debuted their Sanswire Stratellite last week to over 300 people, including members of the media, personnel from the U.S. Department of Defense, U.S. and international commercial interests, as well as investors and shareholders. Stationed in the stratosphere, well above the jet stream, powered by film solar photovoltaic units, the device will make wireless communications available anywhere in the U.S., including on airline flights. One Stratellite will have a payload capacity of several thousand pounds and clear line-of-sight to approximately 300,000 square miles, an area roughly the size of Texas."

Comments

wow

[sfcat]

This is impressive. Solar powered, but are there weather problems at this altitude? I guess not, but can we put cameras on this thing too. Better maps for google maps, yea. When does it fly by SF again?

Re:Wireless capability is a lot less than 300,000s

[Z0mb1eman]

From TsameFA (actually, just the line above):

# Line-of-sight to a 300,000 square mile area
# Wireless capability (currently) to an area with a radius of 200 miles

Radius 200 miles ~= 125,000 square miles, anyway... not sure if that counts as "a lot" less.

And it seems to imply that the wireless capability will eventually be extended to approach the entire line of sight area...

no word on its bandwidth or safety capabilities

[artifex2004]

I'm leery about the system they're showing, if they aren't ready to discuss bandwidth per customer and total numbers of simultaneous connections, etc.

Also, how heavy is it going to be, and how dangerous will it be for something like that, with its 3,000 pound payload capacity, to land for refueling? What if strong winds hit it, and it drifts off course? Have they built their refueling stations far away from population centers, so that if these start to get carried off by the wind, they can drop them more quickly, without running the danger of landing on buildings, etc.? What if they somehow lose radio contact?

Re:no word on its bandwidth or safety capabilities

[Anonymous Coward]

The winds at the altitude these craft are designed to fly at are negligable. They are not hot air balloons, which don't have any propulsion of their own.

These would have means of controlling themselves thru wind layers just like blimps and derigables do today. Once low enough to the ground you can have ground handlers grab the tethers and haul it in.

Re:"utilizing proprietary lifting gas technology"

[Smidge204]

I've always thought... since Helium produces it's lift because it displaces the denser air, thus making the entire object less dense and buoyant, wouldn't the best lift be had if you created a vacuum inside the vessel?

Obviously there are structural issues associated with this, but I'm almost imagining that you could start with helium at (or slightly below) atmospheric pressure, and use a pump to evacuate the volume as it ascends. That way the pressure inside the vessel can be balanced to the surrounding air and you can get very near the edge of space without too much structure to keep it from exploding/imploding. (And except for the helium molecules being so small, gas leakage would be minimal with no pressure differential across the membrane!)

Maybe that's how they do it... with 3000 pounds of payload capacity they have plenty of room for a vacuum pump, and they didn't say how long it takes to get that high!
=Smidge=

Re:Heads up!

[mbaciarello]

Mmmh... Forgive the metricness, but assuming that: the supporting structure weighs as much as its payload (not sure about this estimate); it has the same drag coefficient as a Boeing 747; its cross-sectional area is a 44.20*26.52 meter rectangle (probably overestimated?); a constant air density of 1.2 kg/m^3 (sea-level, conservative); a gravitational acceleration of 9.72 m/s^2 (troposphere level, conservative)...

The thing should come down at a terminal velocity of 35.12 m/s, corresponding to a kinetic energy of roughly 1,678,399.48 J or 4.11e-10 megatons. For comparison, a .45 bullet has 779.59 J at muzzle level. Too tired to look up grenades and other amenities.

Not much of a WMD even if it weighs ten times as much as I've supposed, anyhow, but still I wouldn't like it to fall on my home... Especially because that 3,000 lbs. payload should be pretty dense.

I hope someone can check this since I'm tired and I haven't been playing armchair physics for a long time...

Re:Great googlie wooglie!

[yotto]

You are, of course, right. The number didn't look right (hence the disclaimer and the different way of looking at it).

More insterestingly (at least to me), at dawn and dust, these things would, for a while, be brigher than the sky (becasue they would be in the sunlight while most of the sky would not). So you'd have a "morning star" and an "evening star" that stays in the same spot, forever.

Of course, they'll likely paint it to look like the Pepsi logo or something.

Re:Too bad...

[Anonymous Coward]

if there was a surplus of electricity during daytime, a fuel cell system would also permit reversibility - leading to the possible production of Hydrogen extracted from the water vapor in the air. And they can use that hydrogen to keep the ship aloft.

Hmmm, actually, this is more interesting than I thought - they can use the gas bag as both buoyancy and fuel storage for the fuel cells. During the day, they reverse the fuel cells, producing hydrogen and oxygen - and at night, they consume a part of the hydrogen and vent the exhaust water vapor. As long as they don't over-consume the hydrogen ;-)

That's pretty self-sustaining.