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Space Solar Power – Recent Conceptual Progress



 
 
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  #1  
Old June 11th 11, 01:14 AM posted to sci.space.tech
Keith Henson
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Default Space Solar Power – Recent Conceptual Progress


About Skylon and laser propulsion to get the cost to GEO down.

http://www.theoildrum.com/node/7898

Keith Henson

  #2  
Old June 21st 11, 03:27 AM posted to sci.space.tech
Sylvia Else[_2_]
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Default Space Solar Power – Recent Conceptual Progress

On 21/06/2011 7:55 AM, Matt wrote:
Skylon, cool as it is, has shown nothing to indicate it has solved the
classic SSTO problem: when you get into building actual hardware and
the design gets toward CDR, the payload mass faction drops rapidly to
zero. There has to be some technological breakthrough to make this
succeed in SSTO while being affordable to build, and I don't see it.


The breakthrough is the SABRE engine.

Sylvia.

  #3  
Old June 21st 11, 03:33 AM
neilzero neilzero is offline
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Quote:
Originally Posted by Keith Henson View Post
About Skylon and laser propulsion to get the cost to GEO down.

http://www.theoildrum.com/node/7898

Keith Henson
A very large number of very powerful lasers are needed on Earth's surface and/or in LEO to send lots of mass to GEO for space solar power. These would worry a lot of people that they might be used for war etc. The energy consumed by the laser stations would not be trivial. Perhaps closer solar synchronous orbits are better as the rectennas or laser light receiving sites could be much smaller and any where on Earth's surface instead of only near the equator, and in the temperate zones. Neil
  #6  
Old June 22nd 11, 03:50 AM posted to sci.space.tech
Steve Hix[_2_]
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Default Space Solar Power * Recent Conceptual Progress

In article ,
Sylvia Else wrote:

On 21/06/2011 7:55 AM, Matt wrote:
Skylon, cool as it is, has shown nothing to indicate it has solved the
classic SSTO problem: when you get into building actual hardware and
the design gets toward CDR, the payload mass faction drops rapidly to
zero. There has to be some technological breakthrough to make this
succeed in SSTO while being affordable to build, and I don't see it.


The breakthrough is the SABRE engine.

Sylvia.


Has it gone past conceptualizing in any way at all?

  #8  
Old June 23rd 11, 10:11 PM posted to sci.space.tech
Sylvia Else[_2_]
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Posts: 458
Default Space Solar Power * Recent Conceptual Progress

On 22/06/2011 12:50 PM, Steve Hix wrote:
In ,
Sylvia wrote:

On 21/06/2011 7:55 AM, Matt wrote:
Skylon, cool as it is, has shown nothing to indicate it has solved the
classic SSTO problem: when you get into building actual hardware and
the design gets toward CDR, the payload mass faction drops rapidly to
zero. There has to be some technological breakthrough to make this
succeed in SSTO while being affordable to build, and I don't see it.


The breakthrough is the SABRE engine.

Sylvia.


Has it gone past conceptualizing in any way at all?


Yes. Amongst other things, they're in the process of building a
prototype heat exchanger. They've developed and proved their frost
control technology. They've also been testing rocket nozzles.

Sylvia.

  #9  
Old June 23rd 11, 10:12 PM posted to sci.space.tech
Keith Henson
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Posts: 34
Default Space Solar Power Recent Conceptual Progress

On Jun 21, 7:50 pm, neilzero wrote:
Keith Henson;1158169 Wrote: About Skylon and laser propulsion to get the

cost to GEO down.

http://www.theoildrum.com/node/7898


Keith Henson


A very large number of very powerful lasers are needed on Earth's
surface and/or in LEO to send lots of mass to GEO for space solar power.


500 MW. 500 one MW lasers for a flow of 60 t/h starting from a
suborbital Skylon.

These would worry a lot of people that they might be used for war etc.


That's correct. The particular design in that article has the lasers
going up to GEO to redirection/tracking mirrors that track the
accelerating vehicle along 7500 km of the equator. They point to
about a meter of accuracy.

If people still want to do wars, it is going to take new tactics when
there is a FOG (finger of God) overhead. Long as you don't have more
than one set of lasers and mirrors, then they are fixed in GEO and can
only hit targets on the half of the earth visible from a fixed spot at
GEO.

And, of course, anything in orbit.

The energy consumed by the laser stations would not be trivial.


That's true, but all the transport energy is repaid in under two
months.

Perhaps
closer solar synchronous orbits are better as the rectennas or laser
light receiving sites could be much smaller and any where on Earth's
surface instead of only near the equator, and in the temperate zones.


I looked into this. The delta V needed to get to SSO is almost the
same as you need for GEO because of the plane change.

Keith Henson

Neil

--
neilzero


  #10  
Old June 23rd 11, 10:12 PM posted to sci.space.tech
Keith Henson
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Posts: 34
Default Space Solar Power * Recent Conceptual Progress

On Jun 21, 7:50 pm, Steve Hix wrote:
In article ,
Sylvia Else wrote:


snip

The breakthrough is the SABRE engine.


Sylvia.


Has it gone past conceptualizing in any way at all?


The hard part is the 2 GW heat exchanger. They have built and tested
sections of it.

Keith Henson

 




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