NASA has announced the Augustine panel, and the Sentinel got it right. Give ’em hell, Jeff.
The Obama Infatuation
Some thoughts from Robert Samuelson. I guess the infatuation is why so much of the coverage had been so…fatuous.
Space Solar Powerballs
Trevor Brown proposes spherical solar power satellites.
This isn’t a new idea. I wrote a paper on it back in the early nineties for an SPS conference, and I think that Geoff Landis has done some work on it as well (for instance, here’s a report of a talk that he gave on it at the 1996 ISDC, which was the last one that I attended prior to by going to Dallas two years ago — ctrl-F for “spherical”). It does vastly simplify the design issues, because it is no longer necessary to point the panels at the sun. One of the comments there needs some elaboration:
While the surface area of the sphere facing the Sun matches your calculations, the whole side would not be available for power generation. The so-called Beta angle, or the Sun angle, affects the total amount of power converted. Also, while a sphere would not need rigid station-keeping and attitude control to collect solar energy, the transmitter back to Earth certainly will. Also, a large spherical structure would be more taxing on a station-keeping/attitude control system than a more planar design. These caveats in mind, this is a creative alternative.
With regard to the needed area, the beta-angle effect means that at any orientation, you’re only getting the effective solar panel area of the cross-section of the sphere. That is, while the hemisphere has twice the area of the circular cross section, the non-zero beta angle of all points except that at the center of the illuminated area means that you need twice the solar panel that would be necessary if it were a flat circle. Add to this the fact that you have just as much area on the side in shadow, and it means that you need four times the total solar panel area to get the equivalent collection capacity of a pointed flat plate. So you have to postulate very cheap panels for this to make economic sense. But if you can get them, the simplification of the design is worth a lot.
As for pointing the transmitter, that’s actually not so tough a job. You hang it down below the sphere, and it will remain vertical, due to gravity gradient restoring torques. You could point it with control cables all around its circumference, attached to the sphere. In addition to inflating it, I also considered putting a charge on its surface to keep it spherical, but it would take a lot of ions, particularly for a big one, and inflating is probably a better solution, though subject to leaks, and the need for gas resupply.
One other point. I actually considered a fleet of them in MEO, continuously switching from one rectenna to the next as they orbit, to reduce the size of the transmitter antenna, which gets kind of humungous out at GEO.
An Interesting Quote
On the economics of fascism, from self-declared fascist Lawrence Dennis:
Thus we shall see what fascism has to do to make a system of private ownership and management workable, so far as arrangements involving capital income or reward are concerned. The ruling principle must be that capital and management reward must be kept in continuous and flexible adjustment with economic possibilities, and that legal and institutional arrangements—like loan contracts, bonds, legal concepts of just compensation, due process of law, and confiscation—must not obstruct executive action of government to maintain this adjustment otherwise than by the present devices of bankruptcy, foreclosures, reorganization, and cycles of booms and depressions. [Lawrence Dennis, The Coming American Fascism (New York: Harper & Bros., 1936 ), Ch. V. “Can We Reorganize the Present System?”]
Emphasis mine. As Jonah notes, it seems very familiar, somehow.
More On Kurras
Michael Moynihan points out that West German “fascism” was manufactured in East Germany.
DIRECT Rebuttal Thoughts
I had missed this when they were posted, but the Chair Force Engineer had some thoughts on DIRECT a couple weeks ago, here and here.
“Wow.” Are we to believe that ESAS was designed with little or no consideration of what the supporting infrastructure would cost? It would certainly explain why we’re stuck with the unaffordable Ares I and Ares V.
I’d like to say that I’m surprised, but sadly, I’m not.
Further NASA statements such as “Ares I + Ares V uses 15 SRB segments, while two Jupiter 232’s use 16 segments” also reveal an incredibly simplistic approach to cost estimation. Such simple methods might be appropriate for pre-algebra students. Professional cost estimators ought to know better. That’s why cost estimation is so difficult; there may literally be thousands of dependent and independent variables that make up the true cost of the system over its lifetime. Saving a few million in rocket hardware may have bigger reprocussions with development dollars, standing army costs, and infrastructure costs. It’s best summed up on Slide 26, where Jupiter’s higher launch costs (measured in tens of millions per launch) are offset by the savings of billions in development costs.
We’d have to see a full life-cycle cost accounting with assumptions to know whether or not it’s a good saving to cut development cost at the price of higher ops costs. It depends on how much you’re going to fly. But I suspect that it probably is, because the up-front costs are in expensive near-term dollars whereas the flight costs are down stream and discounted, and the flight rate will probably never get big enough to justify spending more on development to reduce marginal cost per flight. That’s always the problem with expendables.
I really need to write up my talk on marginal costs from Space Access.
Danger: Sand
Some thoughts on the uselessness of MSDSs.
Of course, it’s not as hazardous as this toxic substance.
The Other Michigan
Amid all the talk of bankruptcy of the auto companies, it’s easy to forget that there is another, very desirable part of the Great Lake State. The family of a friend of mine in high school had a cabin on the Au Sable River, and I remember how peaceful it was myself, in both summer and winter.
[Update a few minutes later]
Speaking of bankrupt auto companies, Kaus has some good questions:
How many of the UAW’s members are skilled workers? I thought one of the big virtues [of] assembly line work is that it can be done by unskilled workers. Even with all the fancy computer-assisted quality control systems, does most auto assembly work really require skills that can’t be learned fairly quickly?
The unnamed “task force official” implies that Chrysler’s work force (and GM’s) is so precious that it must be protected from sharing in the sacrifice of bankruptcy. Is it? If UAW workers are so distinctly productive then why do virtually all auto manufacturers starting production in the U.S. try to get as far away from the union as possible? Is there any doubt that if all Chrysler’s workers quit tomorrow they could fairly quickly be replaced by workers–from local communities–who were a) cheaper and b) just as good or better?…
Gee, you’d almost think that they were just favoring a Democrat political constituency that gives them lots of campaign donations. Here’s another one:
Why should the government tax unskilled workers making $18 an hour, who haven’t bankrupted their employers, in order to protect unskilled workers making $28 an hour, and who have bankrupted their employers, from having to take a pay cut?
Why indeed? Someone should ask that question of Bob Gibbs. It would be amusing to watch the logical somersaults, to the limited degree that he’s capable of logic at all.
The Cruelty Of The Marketplace
This is one tough recession. Hookers’ rates are down in Amsterdam:
‘Some of the girls are now doing it for 30 euros (S$60). My price is still 50 euros, but the men are playing us off against each other. Some want to pay only 20 euros,’ she told AFP.
Guess they need a bail out. Of course, it’s particularly tough in Europe, where there’s so much competition from women who are giving it away…
A Brief Tutorial On Lunar Resources
From Paul Spudis, who unfortunately (at least for us, if not for him) was not in attendance at the ISDC.