Thursday, June 01, 2006

The Problem with SSP

I was asked to write up some thoughts on Space Solar Power, so here they are - stream of conscious and all that. I wrote this even though the last time I had the gall to say such things (in Space News) i was excoriated by members of alt.space for attacking one of the holy grails of space development.

In the sure to be immortalised words of our current War President - "Bring 'em on!"
___

SSP advocates point to the ability geostationary based SSP stations to provide clean abundant energy by harnessing solar power and retransmitting to Earth in the form of microwave energy, to be converted at ground-based stations into cheap energy for terrestrial uses.

There are a large number of factors which, at this time, call into question the feasibility of SSP - these can be grouped into two primary categories: economic and technological.

As I am not an engineer by trade, i will refrain from getting into power efficiency, conversion ratios, or other factors which others have pointed to when comparing SSP to existing terrestrial-based power systems (such as nuclear and wind). These tradeoffs in efficiency and the economics of the power generated by SSP vis a vis terrestrial means are fairly well argued out by others. There is one glaring unknown which also forms the basis for my position against the viability of SSP at this point in time.

Simply put - with today's space technology, we are supremely unprepared for the task of building a SSP generating station. Current designs that have been put out to the masses call for a facility at geostationary orbit which is many times the size & mass of the ISS. There are significant major problems that immediately come to mind:

1) we've never designed and built even a prototype SSP. So even if we wanted to, we couldn't just "build" one today from scratch without first going through numerous teething pains designing, building, and testing prototypes until we finally had it working correctly. And that includes building and testing IN SPACE, not just on the ground.

2) which leads to the second issue - R&D and Operations are two very different things. These are often confused by true believers, or the difference is knowingly trivialised as "just an engineering problem". But work I did studying commercialisation of ISS highlights the same problem. The ISS was touted as a great R&D facility - as was the Wake Shield Facility before it. However, what was never examined was the practicality of production of a material that was first discovered during zero-G research. A practical example: WSF demonstrated that it was possible to create an ultra-pure vacuum environment, which could be used for making better raw materials for computer chips. However, there is a huge gap between making a few test raw material articles in basic R&D and building a zero-G chip fabrication facility in space...

3) so let's assume for a moment that we can actually design and fly a few prototype power stations (big assumption). There do not exist today any launch vehicles capable of lifting a complete item to GEO that is as large or larger than ISS. Which means that we'd need MANY large launch vehicles (likely hundreds) to put the components of this hypothetical SSP into GEO. Then we'd have to assemble it. Except that this assembly would have to be automated, as the last time we had an astronaut at GEO or beyond was in 1972. Which means developing brand new capabilities, as the assembly and ongoing construction of ISS continues to demonstrate just how difficult it is to build a relatively small facility only a couple hundred miles up.

Some day, when we have solved the single most important aspect that is critical to all long term space development - that is cheap, realiable, reusable, access to space (under $100/lb to orbit), THEN things like SSP (and space elevators, and L5 colonies, and insert your favourite space development idea here) will be possible. But for now, it is just another bit of science fiction -- because of economics and existing engineering know how.

20 Comments:

Blogger TomsRants said...

I feel your pain. About 3 years ago, an engineer also affiliated with the NSS chapter here in NY wanted to pitch me his "radically cheaper" method of bootstrapping SSP. I had to sign an NDA and read his business plan. To be fair, his idea did appear to lop a zero from previous cost estimates of SSP systems.

Never mind that there were at least 10 pieces of unobtainium in his plan, including bootstrapping methods involving robotic self-assembly, and the ubiquitous Shuttle External Tank, which can't be recycled for ANYTHING (get over it!)...

...but even this "radical" new plan couldn't deliver power for less than 20 cents/kW, and was the only way to deliver a value proposition for even a forlorn hope of paying back investors. A little web searching determined that I could get off-peak electricity from the grid in NM for 4.8 cents/kW. Thus SSP is still not competitive with terrestrial-based systems, by as much as a factor of four.

Thursday, June 01, 2006 6:33:00 AM  
Blogger Michael Mealling said...

About the only way you can make SSP work is by using small, almost 'man portable' power sats taken up as secondary payloads to provide emergency power to very remote places like Siberia or Antarctica where the winter sun isn't very useful.

Maybe something small for providing reliable power to remotely deployed military units. Something that gets us from where we are to where SSP fans want us to be.

Here's the thing though, even Shubber thinks that it might be possible "Some day" once we've solved the cheap launch issues. But I don't think you have to wait until then before you start working on profitable ways to make money getting from here to there. Its like what some are doing with space elevators, you still don't know if they're doable, but you can make money building other stuff with CNT technologies along the way.

Thursday, June 01, 2006 8:17:00 AM  
Blogger oldspacecadet said...

Power for remotely deployed military units? What is wrong with batteries, fuel cells, or even small generators? Why bother with developing something that would require large cumbersome collectors or antenna assemblies, have beam steering problems, etc. at astronomical cost? You are making your point the hard way, Michael.

Thursday, June 01, 2006 11:44:00 AM  
Blogger TomsRants said...

Besides, if we accidentally "cook" another Afghan wedding party, but this time with a badly-aimed microwave beam, we're going to start wearing out our welcome over there...

Thursday, June 01, 2006 12:00:00 PM  
Blogger Michael Mealling said...

I didn't say it would work, just worth trying out as a small scale experiment. Batteries, fuel cells and generators run out of juice eventually. It'd be interesting to compare the power densities of a small SSP solution vs regular solar cells.

I keep hearing that the microwave beams for space solar power won't cook you but I've never seen any documentation on why/how that's the case. I'd like to see it tested, though.

Thursday, June 01, 2006 2:43:00 PM  
Blogger Shubber Ali said...

First you said:
About the only way you can make SSP work is by using small, almost 'man portable' power sats taken up as secondary payloads to provide emergency power to very remote places like Siberia or Antarctica where the winter sun isn't very useful.

Then you said:
I didn't say it would work, just worth trying out as a small scale experiment.

So it won't work on a large scale, and it may not work on a small scale (but it's worth testing for a few hundred millions or perhaps billions of dollars?)

Thank you for reinforcing my original point.

Thursday, June 01, 2006 3:26:00 PM  
Blogger oldspacecadet said...

Michael -- batteries may run out of juice, but you could air drop more from a fleet of C-130's a lot cheaper than mounting a single SPS experiment in space (and buy the fleet with the savings). Generators may not run out of juice -- consider hand cranked emergency radios in aircraft survival gear. The energy density of gasoline is hard to beat, too.

Thursday, June 01, 2006 5:54:00 PM  
Blogger Kelly Starks said...

Good post.  To bad about the mob of faithful SSPS villagers heading your way with torches and pitchforks…

 

;)
 

>.. . Which means that we'd need MANY large launch vehicles (likely hundreds) to
> put the components of this hypothetical SSP into GEO. ..

Its amazing how this gets overlooked – or folks sidestep that by saying  “we’ll actually build everything in space out of lunar materials”.  The later of course needs the CATS launcher to launch the stuff to build the lunar base, lunar mine, SSP manufacturing facilities, ship to carry the stuff to the moon to build said lunar gear, etc.  And of course stuff made from raw materials boosted up from the moon is almost certainly going to cost more delivered to geo then that made on earth and shipped up.

 

Am I the only one whose noticed the religiously held falicy that “things are 20 times cheeper to launch into space from the moon then from Earth?

 

>.. Then we'd have to assemble it. Except that this assembly would have to be automated,
>as the last time we had an astronaut at GEO or beyond was in 1972. ==

 
Well I don’t think automation is the issue – course we have no infrastructure to assemble large anything in space, and at GEO you need everything shielded against all that extra rad above the van Allen belts….

 

 

> Some day, when we have solved the single most important aspect that is critical to all long
>term space development - that is cheap, realiable , reusable, access to space (under $100/lb
> to orbit), THEN things like SSP (and space elevators, and L5 colonies, and insert your
>favourite space development idea here) will be possible. ===

 
I’ve actually heard a way to deploy a space elevator with current launch craft.  The stumbling block is that the assume they can mass produce nano filament composite cable at 1/100th the current cost of a similar volume of Kevlar.  At the current retail cost for Kevlar of that volume, the cable (not installed) would cost several hundred billion $.  [When I pointed this out to the head of liftport , he stopped responding to my E-mails.]

Thursday, June 01, 2006 8:00:00 PM  
Blogger oldspacecadet said...

Well Kelly, when the head of liftport stopped responding to your e-mails because you listed a "stumbling block," you encountered a typical response to a space cynic. Kool-Aid trumps logic.

Thursday, June 01, 2006 9:22:00 PM  
Blogger kert said...

yes, we havent flown a single tech demonstrator or experiment geared towards solving the technological unknowns with SSPs. my question is, why ? there is that big fat government space agency who is supposed to be pushing the technological envelope and bringing the future closer, why have they done exactly squat in this area ?
Of course SSP would be silly for private investments with current state of affairs, but thats exactly why we have government R&D. But ask either NASA or DOD what have they done in this area ...

BTW, huge GEO powerstations on multiple acre scales is not the only way. Google "Mitsubishi Solarbird". I think they have the right idea, but timing might not be perfect still

Thursday, June 01, 2006 11:27:00 PM  
Blogger kert said...

*DOE not DOD of course, but the point remains the same.
Just as fusion, SSP stands a slim chance of becoming the clean energy source of the future, i think it deserves et least fraction of the efforts going into fusion research.

Thursday, June 01, 2006 11:36:00 PM  
Blogger Kelly Starks said...

> oldspacecadet said...
> Well Kelly, when the head of liftport stopped responding to
>your e-mails because you listed a "stumbling block," you
>encountered a typical response to a space cynic.
>Kool-Aid trumps logic.

Oh yeah! The fact I could find such a wall after a couple minuttes calculation doesn't speek well of them.
Interestingly, if he did meet all his cost projections, he was only projecting a to orbit cost about 25% lower the Musk was for his bigger Falcons. Granted Musk was talking LEO, not GEO -- but he also wasn't talking billions of R&D costs.




>kert said...
> ... there is that big fat government space agency who is
> supposed to be pushing the technological envelope and
> bringing the future closer, why have they done exactly squat
>in this area ?

I working in NASA for about 15 years. I assure you they not only avoid doing anything cutting edge if at all possible, they often arn't even current on the technologies in their field. If ordered y Congress they would at least make a show of SSPS research, but they don't want to take the political risk of trying something that might not work - and hence make them look bad.

Friday, June 02, 2006 7:57:00 AM  
Blogger Michael Mealling said...

Shubber,
My point was that it shouldn't cost billions or even millions to test it out at the man portable level. I'm imagining someone heading up to either ISS or Bigelow's hab and carrying a small SSP testbed with them. Or even someone hitching a ride on JAXA's free small sat launch and testing it out with a slightly modified cubesat.
There are ways to prove bits and pieces of the idea at very low costs so you can decide later if its worth it based on real data, not just hopes and prayers. Just as they can't prove it will work, you can't prove it won't. Figure out a way to fly something cheap/free and get some data first.

Friday, June 02, 2006 11:45:00 AM  
Blogger Shubber Ali said...

My point was that it shouldn't cost billions or even millions to test it out at the man portable level.

So you're saying that it can be done for tens or hundreds of thousands of dollars? Well, if it's such a cheap and valuable thing to do, I wonder why it hasn't been done yet?

I'm imagining someone heading up to either ISS

Not cheap. Cost per launch (STS) is $500m or so, and if you're going as a private astronaut still over $10m even if you don't pay retail. And i don't believe you're allowed to bring up a test space article with you to the ISS to "try out" a power generation device. The safety people are kind of squirrelly that way.

or Bigelow's hab

doesn't exist yet.

and carrying a small SSP testbed with them. Or even someone hitching a ride on JAXA's free small sat launch and testing it out with a slightly modified cubesat.

anyone building one of these that you know of? what about the ground segment?

There are ways to prove bits and pieces of the idea at very low costs

you keep saying that, but show me some actual substantiated numbers

Just as they can't prove it will work, you can't prove it won't.


I don't have to prove it won't work. It's up to those making claims of a great new technology to demonstrate said technology, not for the skeptic to "disprove" it.

Friday, June 02, 2006 8:13:00 PM  
Blogger kert said...

In spirit of helping people do their own research, here are a couple links on what is actually happening in microwave power transmission technology:

Microwave Power Transmission activities in the world


SSPS Reseach in Japan

note that most of the activities in this century are conducted in japan or europe.

Sunday, June 04, 2006 12:11:00 AM  
Blogger kert said...

Here is one more recent doc describing recent relevant activities in the world:
http://www.ursi.org/WP/White_papers.htm

Sunday, June 04, 2006 12:37:00 AM  
Blogger kert said...

http://www.energypulse.net/centers/article/article_display.cfm?a_id=1285

Can we really build SSP now? No company(s) or government agency is chartered or capable of assuming the immense financial risk of initiating construction of an SSPS. It would be like asking a company to build Hoover Dam, the Transcontinental Railroad or the Interstate system without Federal assistance. There are simply too many engineering, financial, regulatory and managerial risks for any group to undertake SSP today

America has faced just such challenges before ... There is a tried and true vehicle, however that could initiate SSP construction today, just as it did in surmounting all those previous challenges. The key is chartering a public/private Congressionally chartered corporation, like Comsat Corp., which was chartered in 1962 to respond to the Russian Sputnik threat - the first communications satellite. It would have all the requisite advantages provided to Comsat. Comsat Corp. opened space to the diverse $100 Billion per year communications satellite business we have today.

Tuesday, June 20, 2006 2:49:00 AM  
Blogger Shubber Ali said...

It would be like asking a company to build Hoover Dam, the Transcontinental Railroad or the Interstate system without Federal assistance. There are simply too many engineering, financial, regulatory and managerial risks for any group to undertake SSP today

America has faced just such challenges before ... There is a tried and true vehicle, however that could initiate SSP construction today, just as it did in surmounting all those previous challenges. The key is chartering a public/private Congressionally chartered corporation, like Comsat Corp.


No, America hasn't. Building the Hoover dam was a known engineering challenge, that had financial constraints solved by having the Federal government step in.

We have NEVER, i repeat, NEVER assembled ANYTHING at GEO that is even a meaningful fraction of the size of a SSPS facility. Our current launch capabilities on Earth are not at all scaled for such a feat. And even if by some miracle of a modern-day manhattan project we did manage to build a single SSPS facility, the cost of that electricity would be so ridiculously high so as to be totally uneconomical.

But never mind all that. Space Solar Power is COOL.

Tuesday, June 20, 2006 4:15:00 AM  
Blogger oldspacecadet said...

In addition to the Kool-Aid factor, something else is in play. That is an apparent inability to prioritize. We cannot do cool things in space until and unless we get cheap, practical access to orbit. That is the critical step. Without seeing a rational way to accomplish that critical step, the dreams are and will remain fantasies. To treat orbital access otherwise is to concentrate on treating the ingrown toenail while ignoring the pneumonia.

Tuesday, June 20, 2006 12:16:00 PM  
Blogger Chris Mann said...

We cannot do cool things in space until and unless we get cheap, practical access to orbit. That is the critical step. Without seeing a rational way to accomplish that critical step, the dreams are and will remain fantasies.

The only way of solving this crucial first step is through private sector involvement and abolishing State Owned Enterprises like NASA.

Sunday, June 25, 2006 7:34:00 AM  

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