I finally just got around to reading the report that Colonel "Coyote" Smith (that's Michael Valentine Smith--no kidding) and company came up with on Space Based Solar Power, and will be commenting on it, but I should note for now that the January issue of Popular Mechanics has this as its cover story. I haven't read it yet, but may post some thoughts after I do.

On a related note, while a ten buck per ton carbon tax on coal probably would be good for the nuclear industry, as Randall Parker notes, it wouldn't hurt SBSP, either.

[Update a few minutes later]

OK, not much to the Pop Mechanics piece. I think it's quite an overstatement to say that powersats are "all the rage" at either the Pentagon or in private industry. I would think that something that was "all the rage" would be getting significant funding, and so far the amount that's been appropriated to this recently is...zero. In fact, one of the significant things about the Pentagon report was that it was done with no DoD budget, entirely by volunteers, other than the Colonel's time. It might be a useful model for future such studies that have trouble otherwise finding government champions, but it hardly justifies the notion that this is now a major priority, either within the five-sided building, or in the government in general.

As for the article itself, my only quibble is to note that the seventies studies were jointly by DoE and NASA, not just DoE. It's been noted many times in the past (and Coyote's report notes as well) that one of the reasons that this concept has had trouble getting acceptance and ownership within the government is that it's had no natural home. DoE thinks it's a space program, and NASA thinks it's an energy program, and both agencies consider it to be outside their charters. I do like the idea of the establishment of a quango, perhaps using COMSAT as a model, to provide a government-blessed (and at least initially, funded) focus for this.

[Update a couple hours later]

I see from his comments that Monte Davis now has a blog, which I'll be adding to the sidebar.

The SBSP report is a very respectable look at the state of the not-yet-existent art. What I find more interesting is the almost Pavlovian response at PopMech and in parts of the space blogosphere. Explicitly or implicitly it's "gee, DoD is taking an interest so now things will happen" -- when of course, as you say, interest =/ even minimal appropriations.

As I wrote just yesterday at another blog, "ever since Dyna-Soar days the techno-colonels and brigadiers who project [advanced space programs] are in the same situation as their blue-sky counterparts among planners at Boeing or at NASA. That military R&D budgets are larger doesn’t mean that [space thinkers within DoD] have any greater success at getting more than a white paper’s or Powerpoint briefing’s worth of it."

The nearest thing to an exception was SDI -- and even there, with a strategic motivation second only to that of the 1950s push for ICBMs, a mountain of zoomy concepts labored to bring forth a mouse's worth of productive R&D... and nothing but DC-X in the direction of CATS, which would be necessary to enable anything beyond the very conventional interceptors we've settled for.

C'mon, space fans -- let's get over this plaintive hope that DoD will again provide the mu$cle it did in the glory days of Wernher and the Huntsville team.

Re coal tax: the math is in the quote. If coal produces 1.9 pounds of CO2 per kwh, then it only uses 12/44 of that--call it a half pound to produce the kwh. That means the coal the coal comprises $25/4000 the price of a kwh. Or about 10%. So a $10 tax would bump it to about 15%. No, it would not cause plants to stop being built. No it would not cause wind and nukes to become widespread. Only slightly more competitive. And much of the $10 tax would fall on the producers; that is, the price of coal would fall if demand dropped so coal price might only end up at 12.5% of the electric energy price. Further, the capital will be written down if high coal taxes are anticipated. To get the 4.3 cents/kwh price rise would require more than an 8.6 cents per pound or $172/ton coal tax. Try telling coal producers they are going to be taxed 750%. Win that state in November. Yeah right.

Re SBSP: Like the space elevator, there's a fallacy of chain logic and some smoke and mirrors to hide the critical enabling technology. For the space elevator it's the strength to weight ratio the fiber and the cost of manufacturing it. For SBSP, it's space access cost. At $10,000/lb to GEO (which is a big price cut that is reflected in SpaceX's list prices), we can heft 1,000,000 pounds with $10 billion. Even at 1000 watts per pound (which is a factor of 20-30 better than some com sats) that gets us 1 GW. That's about 10 times the cost of a coal plant. Perhaps 20 times if R&D, overhead, manufacturing, payload preparation, structure and rectenna weight, O&M and GEO to ground losses are factored in. At least with the Space Elevator the business plan includes beaming power from where it's cheap (Earth) to where it's expensive (space).

Monte and Sam both I think fall into the trap of concentrating on problems and not on solutions. I'm pretty sure that is not the way to further progress.

Rand, oddly enough, has stumbled upon a pretty good model in COMSAT. I'd call it SOLARSAT.

Mark: "Progress" as defined by the Popular Mechanics seems to be to hand $10 billion to someone and kiss it goodbye in exchange for a nebulous promise of feasibility and deployment in 25-50 years.

The value of such a facility (if it existed) would be to provide baseload electricity in remote, dangerous terrain.

IIRC, that would include:

Disaster areas in un-networked areas of the world.

Remote military outposts (where the delivered cost of liquid fuels is in the tens of dollars per gallon)

At $10,000/lb to GEO (which is a big price cut that is reflected in SpaceX's list prices), we can heft 1,000,000 pounds with $10 billion.

Sam, surely you don't believe that at that level of activity, the price would remain $10K/lb to GEO, or even within an order of magnitude of it?

I'll take your "concentrating on problems and not on solutions" to mean "not engaging in the cheerleading, wishful thinking and outright fantasy that make up 95% of space discussions."

That leaves me outside the "solutions"-oriented crowd that has had so much success over the last forty years. (sob) I'll survive.

The cost to launch a solar power satellite to GEO might not be nearly as bad as suggested. If you launch it into LEO, you could then use the electricity produced to power electric thrusters (ion, VASIMR, arcjet, etc). That would mean you wouldn't need an upper stage to put it into GTO and an apogee kick motor to circularize the orbit. The tradeoff would be time. Given the high investment in building the satellite, there would be a time value of money aspect to taking weeks or months to get it to the operational orbit.

The value of such a facility (if it existed) would be to provide baseload electricity in remote, dangerous terrain.

IIRC, that would include:

Disaster areas in un-networked areas of the world.

Remote military outposts (where the delivered cost of liquid fuels is in the tens of dollars per gallon)

I spent 1990 in the Aleutians at Shemya AFB. We were 1200 miles out from Anchorage at what the Air Force called (with due understatement) a "remote assignment." All of our electricity was generated using large diesel generators (something like 2-3 MW each). It took two of those geneators to power the Cobra Dane and another to power the rest of the base. The diesel fuel was brough in at considerable expense using barges. I don't know what that cost but it had to be expensive. Other places are much more remote such as the research station at the South Pole. They have to burn several gallons of fuel for every gallon delivered to the site. The same situation - perhaps to a lessor degree due to the distances and weather involved - exists at several remote operating locations around the world.

Solar power satellites might not be cost effective for your neighborhood. However, that doesn't necessarily mean that it might not be cost effective in other circumstances.

"Mark: "Progress" as defined by the Popular Mechanics seems to be to hand $10 billion to someone and kiss it goodbye in exchange for a nebulous promise of feasibility and deployment in 25-50 years."

Sam, I'm against that, of course, but there are things that we could be doing right now for somewhat less than ten billion.

"I'll take your "concentrating on problems and not on solutions" to mean "not engaging in the cheerleading, wishful thinking and outright fantasy that make up 95% of space discussions."

Monte, you could do that, but you would be wrong. All that means is that thinking of solutions is harder than many people think.

"That leaves me outside the "solutions"-oriented crowd that has had so much success over the last forty years. (sob) I'll survive."

Monte, does that mean there are no solutions? I'm not sure I quite comprehend the meaning of that statement.

By the way, Larry, your post was excellent. Not only does you notion of building in LEO, then moving up to GEO seems to answer the launch cost objection, but one suspects that the initial market for SBSP will be pretty much as you suggest, with it expanding as the costs go down.

Widely optimistic concept and just plane wrong in some areas. I hope not much money was spent on that. When NASA gave me less than $2M to study 600kW I made sure that I worked with real engineers who were in the process of building real spacecraft and real high power arrays (not directors of think tanks) so I would get realistic answers. $10B for 10MW (on the ground) in 10 years Ha! Try 5 to 10 times that amount.

Why is everyone talking about lifting the whole mess from Earth surface in the first place? Gerard O'Neill knew better than that in the 1980s!

You don't need to lift all the stuff out of a 4000-mile deep hole. What you do is lift a much smaller amount out, and then use that to gather materials that are already out of the hole, and use them to build what you want.

In other words, a construction shack in LEO (maybe a 500-mile orbit) and a mine and launcher on the Moon. Maybe 100 people working up there in the two places, and (I'm guessing now) 10 kilotonnes of material to lift.

The fact that the DoD would not even scare up a measly $250K to do a basic study (and realistically, a proper study, with engineers actually crunching numbers, would cost more like $1 million), demonstrates that this effort should not be taken too seriously. It looks like some colonel thought this was a good idea and a general gave him the go-ahead in order to make him go away. If they were serious, they would have found some real money. In the Pentagon, the people with power and influence have budgets.

In addition, the people who keep touting this study as some great paradigm shift don't seem to actually understand what the National Security Space Office does or where it fits into the overall milspace hierarchy. They are not an important office when it comes to military space. They do not command large budgets, nor have they been able to force big players (like Strat Command and the NRO) to do what they want. And there have been rumors for years that the NSSO is going to be eliminated. But space enthusiasts hear the words "space solar power" and don't take the time to ask how serious this whole effort really is, and whether it will have any legs.

That's not to say that the study itself is junk. But it's not going to be influential unless a serious sponsor picks it up.

The "1000 W per pound" example - while currently true - doesn't seem like it would apply as a baseline for a major power installation. At least, I don't think _I_ would be using PV if I'm shooting for any sort of economy of scale. And the sheer size of the minimum rectenna inherently means you _have_ to make larger installations to have any hope.

And once you aren't talking PV, the weight of 'light gathering' should drop dramatically. A one meter square of mylar with mild tension provided by a wire shouldn't be in the same ballpark as 'a pound'. And should be able to reflect (as a minimum) 1400 W.

So this turns around (again) to the actual power generation section's weight. Where larger does mean more efficient.

Al, I don't know if you can get that much more out of mylar. The problem as I see it is heat dissipation. The ideal would be to focus all light on a solar furnace. But how do you radiate all that heat to space?

You will need a certain area of radiators per watt to do so. It might be far better than 1000 W per square meter, but the radiator is going to be a lot heavier too. The nice thing about solar cells is that you don't need to worry about heat dissipation. The back of the solar cell automatically does that.

>>"At $10,000/lb to GEO (which is a big price cut that is reflected in SpaceX's list prices), we can heft 1,000,000 pounds with $10 billion."

>Sam, surely you don't believe that at that level of activity, the price would remain $10K/lb to GEO, or even within an order of magnitude of it?

The US Government appears to be able to spend tens of billions on space launchers and space hardware every year without lowering the launch price much.

It's true that 500 tons of GEO payload demand could probably get a pretty good volume discount for 120 heavy payloads, that being a number of times larger than the total global annual launch demand. I hope it gets put out to bid and gets funded if $1000/lb to GEO is the price that comes back. But I wouldn't be surprised if the bid came back as 10-100 MW instead of 1 GW for $10 billion delivered. That's 40-400 times what the ISS has with 8 wings totaling 1600 kg. If we heft 1 million pounds of ISS solar wings, we'd get 284 sets of 8 or 71 MW.

The US Government appears to be able to spend tens of billions on space launchers and space hardware every year without lowering the launch price much.

It does? Appearances are apparently quite deceiving, then...

The US government sends very little to GEO each year, and I doubt if it spends more than a billion on it annually. If there were a bulk buy of ten billion dollars worth of GEO payloads, I'll bet that the price for transportation would be in the range of a few hundred dollars per pound, at most, once the market responded.

>Appearances are apparently quite deceiving, then...

LEO prices don't seem to be coming down much. The vicious cycle seems to be expensive hardware justified by expensive launch prices resulting in few launches. Isn't global space electronics, launch and space defense spending in the $50 billion/year range? That's small solace to the companies trying to divide up $3 billion or less in annual launch spending.

Isn't global space electronics, launch and space defense spending in the $50 billion/year range?

For transportation costs?

No, Sam. Look up the numbers.

OK, launch was $2.7 billion last year not $3 billion according to Futron. They show satellite manufacturing as $17 billion. It looks like DoD is a lot less than I thought per year: $22.5 billion all in. MSM keeps quoting program budgets rather than annual budgets. Pretty lame if all of space represents less than 0.2% of the global economy with spaceborne assets capitalized at 0.03% of the global economy. Looks like a Kelly Act like suborbital teachers in space or suborbital point to point postal mail or an ethanol-level industrial subsidy ($15 billion/year) could have a substantial impact on marginal cost.

If we heft 1 million pounds of ISS solar wings...

Gotta allow for at least 25,000 pounds of blue cheese dip.

I just finished reading Ben Bova's "Powersat". Not too well written fiction, but definitely interesting read.
It has spaceplanes, cheap dumb boosters, everyones favourite geostationary powersat miles wide, oil dependence and terrorists, IOW the whole enchilada.

The comment about Bova's novel reminded me of this 'news' story.