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Keith Henson, Sunday, 12-2-12 December 3, 2012

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Keith Henson, Sunday, 12-2-12


Guest:  Keith Henson.   Topics SSP using laser rockets to lower the cost of space access.  Please direct all comments and questions regarding Space Show programs/guest(s) to the Space Show blog, https://thespaceshow.wordpress.com. Comments and questions should be relevant to the specific Space Show program. Written Transcripts of Space Show programs are a violation of our copyright and are not permitted without prior written consent, even if for your own use. We do not permit the commercial use of Space Show programs or any part thereof, nor do we permit editing, YouTube clips, or clips placed on other private channels & websites. Space Show programs can be quoted, but the quote must be cited or referenced using the proper citation format. Contact The Space Show for further information. We welcomed Keith Henson to the program to discuss the use of laser powered rockets for launching space powered satellites to help eliminate the use of fossil fuels as well as lower the cost of space access.  To assist in your following our discussion, check out this laser rocket graphic at http://bit.ly/Uj9Vw9.  Also, Keith has several related published articles on the OilDrum blog.  You can download and read his articles at www.theoildrum.com/search/apachesolr_search/keith%20henson. Finally, our guest has permitted me to upload his recent PPT conference presentation to The Space Show blog, “Laser Propulsion and Space Based Solar Power.”  Please be sure to check out this presentation by visiting our blog, https://thespaceshow.wordpress.com. During our first segment, Mr. Henson talked about the need for low cost energy and said that by using laser rockets and his SSP ideas, the cost for electrical power generation could be as low as 2 cents/Kwh to GEO.  We spent a good portion of our discussion debating Keith’s assumptions behind the 2 cents/Kwh.  I referenced my costs per my PG&E invoice and other listeners emailed and called in regarding their electrical costs per their utility bills.  Keith has asked for people disagreeing to let him know where he may be going wrong so please post your comments on our blog and Keith will respond. He said several times that he wanted your critique and comments.  Many listeners as well as myself pushed him on his assumptions, wanting more factual information on how arrived at his conclusions.  He has this information pending publication with the British Interplanetary Society so for the moment, its under pre-publication boycott but as soon as Keith clears it, I will post his material on the blog and announce it on air. Later in our initial segment, we talked about the laser rocket being a weapon. This discussion sparked lots of listener participation. We also talked about SSP for insitu use rather than power beaming back to Earth.  Keith brought up the new developments with Reaction Engines out of the UK. Here is there recent press release in case you missed it: www.reactionengines.co.uk/news_updates.html. Listeners did call in to tell Keith that SSP did not make sense for a variety of reasons, including not closing a business case, with or without laser rockets.  Jerry offered such comments as did Charles. Also, without consent, AT&T installed call waiting on the toll free line. I finally figured this out & edited out several of the comments & my complaint.  The matter should be resolved for all toll free calls moving forward but about 1hr 30 minutes into the program, you will hear a rough edit where I removed the call waiting rants.
     In the second segment, we continued debating Keith’s costs plus his ROI assumptions. Fusion came up for discussion as well as already existent successful powered sat beamed energy back to Earth.  Toward the end of our program, Keith talked about his target of reducing dollars per gasoline by using laser rockets and SSP.
      Please post your comments/questions on The Space Show blog above. Keith can be emailed at hkeithhensonATgmailDOTcom.
Laser Rockets & SSP


1. Jim Davis - December 6, 2012

I just finished listening to this show. Some impressions:

When Dr. Livingston asked Mr. Henson if there were any prototype laser powered rockets he answered something to the effect that the prototype was built 2000 years ago. He might as well have answered, “I am not a person that needs to be taken seriously.” Answers such as the one he actually gave insult the questioner and listeners and seriously undermine the credibility of the responder.

The discussion about the vulnerability of solar power satellites seemed to miss an obvious point. If we posit the existence of terawatt lasers capable of powering rockets to geosynchronous orbit surely similar lasers could be used to destroy the SSPs?

Henson’s plan stumbles on the “miracles depending on other miracles” problem. Credible business plans (indeed plans of almost any sort) proceed from the known to the unknown, i.e. from these existing goods and services we plan to create the following goods and services. Planning to create hitherto nonexistent solar power satellites from hitherto nonexistent Skylons and laser powered rockets is fantasy.

2. Kelly Starks - December 3, 2012

on your article on http://www.theoildrum.com/node/7898

You mentioned
“….The most promising design is the Falcon Heavy (a proposal of SpaceX), with first launch intended for 2012 at a cost of $100 M per trip….”

Note that SpaceX fail to deliver on that. NASA’s bills from their Falcon/Dragon launches are projected (by the Congressional budget office and SpaceX) to run about $400M per launch, or about 20% higher per pound to ISS then shuttle.

As to your comment that
“And it takes a flight rate of several [Skylons] per hour to get the cost that low.” (a million flights per year) to getting cost to LEO to $75 per kilo. However other designs from Rockwell and McDonnell Douglas did offer lower costs.
Also given SSPS programs were talking about needing millions of tons to orbit, over a decade. ( Again I’m not clear what tonnage you were assuming for your SSPS proposal. ) if you are demanding millions of tons, you’ld need to upgrade the launcher to a much bigger SkyLon or other craft, which would be more economical.

You mentioned space Elevators, which also appear very uncost competitive with traditional launchers, in similar market scales, given the extremely high capital costs. Assuming your interested in the Space Elevators cost issues.

Anyway generic numbers and issues on all my posts here, I can provide more details etc if interested.

Kelly Starks - December 3, 2012

Oh, your assumption that you “Build one power satellite the hard way.”, undercuts your whole concept, since all the capital costs for the first sat, is all the fixed cost that dominates all the launch prices – pretty much for the life of the launcher fleet under current markets. So after the first sat, your launcher infrastructure is pretty much operating toward margin costs.

3. The Space Show - December 3, 2012

Keith’s PPT presentation is on the blog at the bottom of the summary. It is titled “Laser Rockets & SSP.” The link has been tested and works fine.

Kelly Starks - December 3, 2012

Ah! Thats where you put the link!

Downloading it now.

Good luck with the mold removal!!!

4. Kelly Starks - December 3, 2012

Congrats at avoiding the Mormon crowds with torches and pitchforks. 😉

5. Kelly Starks - December 3, 2012

Hi Keith,
Good to see you back in space development.

As to what assumption of yours are questionable;
– Your assumption of the cost to launch with chemical rockets, on the scale of launch your talking about, is incorrect. Its been offered not hundreds of dollars per kilo, but low tens of dollars per kilo to LEO. This was shown to the case in the ’70’s when the DOE investigated the SSPS concept and got proposals from US LV manufacturers. Its due to the fact that launch costs are driven by fixed dev and infrastructure costs (and political costs) not fuel/evergy costs. [This was a critical and systemic fault in the L-5 Society proposals.]

– the rocket equation shows that it costs about $8 (last time I ran the numbers) of Kerosene and LOx to put a pound of cargo into orbit, out of the current thousands to tens of thousands of pound full current launch cost to orbit. So eliminating all fuel and lox costs would have no impact on launch costs unless your market scale drove all the other costs down a hundred fold.

As Elon Musk said on Dave’s show a couple years back, the fuel/energy costs to LEO “….is bellow the level of resolution of accountancy” and “the delta-V is free”. [Obviously LEO to GEO you could reasonably use electro mag thrusters given your booster solar power components.] So your focus on fuel/energy/mass-fractions to lower cost to orbit is mislead.

I was not able to review the details of your presentation, since the power point presentation isn’t on the blog. But I’ve never seen any laser launcher presentations that would reasonably cut costs to orbit dramaticlly under similar launch market scales.

You comment on O’Neil assuming a margin cost of shuttle launches of $50 a pound was mistaken – he was assuming the GAO shuttle margin costs of $200 (in 70’s money) proved true – which it did, but again was completely irrelevant to a project like his.

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