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Posted by: Rob Goldsmith - Fri Jan 21, 2005 7:27 pm
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Post    Posted on: Fri Feb 25, 2005 1:44 pm
slycker wrote:
I didn't know how it worked, previously. Now to look into it to see how well it works...


Heh. It's been around for a decade or so, and the Navy likes it quite a bit. It is, all in all, a very impressive weapon -- also called a "zip gun", if I remember correctly, referring to the sound it makes while firing.

Cathleen -- yeah, find out what kind of stationkeeping equipment they're planning to use, whether rocket, propellor, or turbine. And also ask them what they think of the Jet Stream. Oh, and their FAQ is basically correct: they're talking about wind as a current that you yourself are moving inside of, instead of an external force (which is the way most non-flyers [read: groundhuggers] are used to thinking of it as).

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Post    Posted on: Fri Feb 25, 2005 6:05 pm
spacecowboy wrote:
Cathleen -- yeah, find out what kind of stationkeeping equipment they're planning to use, whether rocket, propellor, or turbine.


According to the Stratellites description on the Sanswire web site they are planning on using solar powered electric "engines" so I'd guess that they would use a special prop design similar to what JPA is working on.

PS: It pains me to see that a company that is trying to develop cutting edge technology would use a complete mis-nomer ie "electric engine" in place of the correct "electric motor" on it's web site. yeah I know that some PR person probably wrote that but I still think it hurts their credibility as a "high tech" company.


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Post    Posted on: Sat Feb 26, 2005 11:32 am
Hello, spacecowboy,

concerning the image of the current DSS etc. are in I think I am familiar to it by usual all-days-experience - or nearly all-days...

I am a rower and have been going by boat down several rivers and along the coast of the Baltic Sea a short distance.

At rivers there allways is a current where the boats are in. Even if the boats are not rowed they are moving - they are moving NOT relative to the water but they ARE moving relative to the ground of the rivers and so on.

Now this causes a special situation that might be of danger. As long as the boats are NOT rowed they are still moving but cannot be controlled - they don't react to the steer. To get control over the direction of the boats they have to be rowed and thus to move WITHIN the current.

This apllies to the DSS and the floating ports too.

Is it that what you meant?

When I read the post that I understood as if DSS etc. actively can prevent to fly above countried that don't wnat that or to fly over regions of bad weather I thought vehicles or stations having equipment to move WITHIN the current at their altitudes. This may have been an error.

jpowell, does the actual DSS have the equipment to move within the current?



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


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Post    Posted on: Sat Feb 26, 2005 5:47 pm
The DSS has propellers and electric motors to move the station within the the air mass. It also has the ability to move 20,000 feet (10,000 feet +-), in the verticial direction.


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Post    Posted on: Sat Feb 26, 2005 6:40 pm
What distance can DSS move within the air mass? Horizontally? That would be interesting because there was the question to avoid to fly above countries that don't want that. It too may be of interest to move around bad weather or to move to a special place.



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


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Post    Posted on: Tue Mar 01, 2005 8:56 pm
They have basically already answered that question back on February 18.

jpowell wrote:
The power cost for true station keeping is impractical on the really large stations. There is enough manuverability to move North and South to avoid country overflight if permission for overflight is denied.


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Post    Posted on: Wed Mar 02, 2005 7:49 am
Ekkehard,
I'm not sure that distance really is any constraint, only rate of movement. JP has previously said that they will be using electronic motors, which implies the use of on-site power production (ie, solar). The power output of these cells would be the main constraint. It seems that you've recognized, with the "within the air mass" phrasing, that this movement will be relative to the air around it, not the ground. At this point, then, distance becomes a rather nebulous concept.

My question for JP would be:

What speeds of 'approach', relative to the ground, have you calculated for the DSS to avoid overflight of a country? In other words, what were the constraints that you took into account when determining that you had this capability to avoid horizontal overflight?
How much planning ahead would be necessary to avoid this overflight? Would this be continually monitored/adjusted, or would it only be adjusted (motors powering props) when a concern looms near?


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Post    Posted on: Wed Mar 02, 2005 1:20 pm
Hello, slycker,

you understand me right.

Hello, Peter,

jpowell has given a number concerning the vertical movability. For such a number I am asking concerning distance.



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


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Post    Posted on: Thu Mar 03, 2005 7:29 am
There are still a lot of variables for the horizontial velocity. For example; the larger stations will have more drag, yet they also have more surface area for solar power production and therefore propulsion, yet more solar cell means more weight, needing a greated volume equating a bigger vehicle, ie more drag, etc.

We are modeling all of this, however, It can't be considered accurate until flight tests give us better base data. The next Dark Sky Station that flies (beginning of next year) will have a propulsion system. The data from that flight will let us hone in the models.

However the current data shows that it a very slow vehicle. Flight path adjustment will likely need to start a quarter the way around the planet to overflight avoidance.

JP


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Post    Posted on: Thu Mar 03, 2005 8:04 am
Thanks JP, that was what I was looking for. I couldn't really see how it would be able to move too quickly. To load it too heavily with the required aparatus for quick movement would likely add far too much weight, making the station useful for little else.

I appologise for my ignorance with your operation in the past, but will this be the first DSS that flies? EDIT: horizontally, that is

Finally, on an aside, it would be nice if, on your site, your movies were in chronological order (of the away missions), and labeled (perhaps even cross-linked to a page describing the mission).


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Post    Posted on: Thu Mar 03, 2005 8:23 am
The next DSS will be the third one to fly. The first was 27 feet in diameter, the second 57 feet in diameter. We have flown several other platform configuration before the settling in on the present five arm DSS.

We used to have a web page for each mission, (there's been over 80). The site was just too big (and disorganized) to maintain. Now the is site is a little sparse. We hope to find a happy medium, (or at least a smiling spritualist). *

*sorry I have a bad case of pun addiction. :)


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Post    Posted on: Thu Mar 03, 2005 8:31 am
Fair enough. How about labels for the movies, then? That would sure get my soothsayer soothed. (just to keep up the tradition)


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Post    Posted on: Thu Mar 03, 2005 8:34 am
Do you mean in the movie itself or the description about the movie?


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Post    Posted on: Thu Mar 03, 2005 8:39 am
In the description for the movie, before it is clicked. I know you have some info there already, but if the mission and flight date were there for each one (perhaps chronological?) it would be nicer. By the way, as I try to look up your site again for reference, the server cannot be found (all this evening)


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Post    Posted on: Thu Mar 03, 2005 8:43 am
Can do.

Our site, e-mail and all has been down for nine hours now. The entire provider is down. I REALLY not very happy with then right now...


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