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Giskard

Registered: Feb 04
Posts: 414

so your astronauts are going to make orbital rendevous with 30 different satelites?

03/15/06 23:31

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klreed

Registered: Oct 05
Posts: 58

Re: Boeings

quote:
Originally posted by R. J. Grasser
scheduled to start deployment in 2007. These devices are intended to service other satellites.

A UK firm called Orbital Recovery will use ion drive space tug to 'recover' satellites and place them in their intended orbit. This is of particular use for satellites where the propusion systems ahve failed. The logical extention of this idea is to eliminate onboard propulsion all together except for reaction wheels and use a ion drive space tug to place the satellites. Very cost effective.
http://www.orbitalrecovery.com/cxolev.htm

The problem is current ion drive a drastically underpowered and so are slow as molasses. This can be remedied with 50 kW to 100 kW to the ion drives or upwards of 400 kW for drives in the 30 cm range. You guys know I am a fan of DS4G as regards ion drives or EP in general. 30 cm DS4G is the way to go for placing satellites with no onboard propulsion.

Solar arrays used on spacecraft are nothing like ground based units. They can be either rolled up like a newspaper, or folded multiple times and attached to the body of the satellite prior to launch.

Most solar arrays they use now are rigid solar arrays. Rigid solar cells can be attached to flexible blankets to make them somewhat rollable but the germanium wafers they use as substrate for the most efficent cells are quite brittle and can not themselves be rolled.

Also, problematic for rigid cells on flexible blankets is First Order resonant vibration. 1 Hz resonance is not easily handled by reaction wheels. There are some elegant fixes for vibration resonance (EAPs, MFC or PZT actuators) but most these days prefer to use very lightweight rigid solar arrays as these are more passively stable against resonance.

03/16/06 13:34

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klreed

Registered: Oct 05
Posts: 58

quote:
Originally posted by Giskard
so your astronauts are going to make orbital rendevous with 30 different satelites?

Yes more or less. The satellites would come to the cosmonauts.

The cosmonauts stay in one place such as a Bigelow Aerospace Habitat. Multiple satellites, say 8 to 10 at a time, are sent to the habitat where solar arrays are attached and tested and then the satellites are placed in GEO by Ion Drive Tug(s).

Soyuz will carry 5 or 6 fully assembled Giove B type satellites. I suppose you could LEO 30 or more Giove type micro satellites at once using Space Shuttle.

I would actually propose the cosmonauts get a lot more than 30 satellites to work on. Assembling 500 kW solar arrays, with booms that are fabricated on site, in space, would be one other type of work live humans might oversee better automated than machines.

03/17/06 13:32

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sean1966

Registered: Mar 01
Posts: 64

osbus

try tmortens (sp? apologies) link
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10/03/06 00:29

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