Category Archives: Space

Space Nuclear Waste Disposal

When I wrote that piece about Three-Mile Island the other week, I forgot to mention my own recollections of the event. It was interesting timing, because it happened in the middle of a senior space systems engineering project that I was involved with at the University of Michigan. It was an annual course taught in the Aerospace Engineering department, required for Aerospace majors, which I took as an elective (though it wasn’t my major, I took many courses there, including several graduate ones, tailoring my own astronautical engineering degree, but without the emphasis on aeronautics). The course was taught by Harm Buning (who died only three years ago — I really ought to write about him some time). The project was to figure out how to dispose of nuclear waste in space. This was a couple years before the Shuttle had its first flight, and we still believed the hype about its cost and safety, so it was the assumed launch vehicle, but the question was what to do with the stuff once it was in LEO.

Having been pretty heavily involved with the L-5 Society (I had actually spent a semester the previous year volunteering at the HQ in Tucson, and had met people involved with the MIT mass driver work, including Henry Kolm and Eric Drexler — the people in that now-classic picture are, from right to left, a twenty-four year-old bearded Eric wearing a Maxwell’s equations teeshirt (one of which I also had at the time), Henry, Gerry O’Neill, someone unknown to me, and Kevin Fine — geek and space enthusiast city — I could write a sad book titled “We Were Space Enthusiasts, And Young…), I suggested that we use a linear synchronous motor to propel it out of the solar system. The class adopted the idea, and we came up with a crude systems design (about what you could expect from college seniors for such a complex project). It was in the middle of the project that TMI occurred, making it seem even more relevant.

The university seems to have put many of these older (typed by department secretaries– no word processors back then) reports on line, including this one. I’m sure I have a dead-tree copy somewhere, but it’s nice to see it on the web. It’s been a long time, and I was distracted at the time because my father had his second heart attack in April of that year, and died a few weeks later. Due to time missed, I had to finish up my sections early in the summer to avoid an Incomplete for the course, so I don’t remember how much of it and which parts I wrote, but it was quite a bit of it (at least the orbital mechanics and the dynamics of the payloads in the accelerator, and how much wall play they would have to have). Dave Steigmann wrote a lot of the structures section, I think. The report says that it’s authored by Kevin Blankinship, but he was probably just final editor, because he was officially the team project manager. One of the things that this course taught was not just engineering, but how to work as an engineering team (including managing with the politics and personal interactions). These were…interesting. I won’t say any more than that, to protect the guilty, whoever they all may be. 😉

Anyway, is it feasible? Probably not, but it was a good project for the purpose of learning how to consider all aspects of a space system, and project teamwork.

[Update a while later]

The project name was pretty good acronymery. I don’t recall whether it was mine, someone else’s, or the result of a brainstorming session. But it was Project NEWDUMP (Nuclear Energy Waste Disposal Using Mass-Driver Propulsion).

For anyone who is willing to read the thing, it is probably entertainingly rife with howlers, from the perspective of three decades later. This one on page four jumped off the page at me:

The Space Shuttle has substantially reduced the cost of space transportation since the Apollo project, with possible improvements for further economy.

Note the tense, and not also that this was written about two years before first flight.

The Extraterrestrial Imperative

Back in the early eighties, I had the privilege of taking a class from Krafft Ehricke at Cal State Northridge (arranged by sociology professor and space enthusiast B. J. Bluth). The course was called “The Extraterrestrial Imperative,” and it had a significant impact on my world view. I still have the class notes, which were extensive. For years, up to and after his death, there had been talk of publishing them in a book. Well, I just discovered, via my Amazon sales, that Apogee Books has done so. Though I haven’t read the book itself, based on my own experience with the class notes on which it is based, I heartily recommend it to all of my readers who are interested in our future in space.
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NASA’s Budget Options

Jeff Foust has a link to a new report from the Congressional Budget Office. It doesn’t paint a pretty picture. I have to agree with “Red” in comments:

…if you consider that the goal of the Vision for Space Exploration was contributions to science, security, and economics in the context of strong commercial and international participations, none of these options will carry that out. They all involve Constellation/Ares, which is more or less the opposite of those goals. One aspect of this opposition is that the options that don’t postpone Constellation involve reducing science and aeronautics missions that actually do contribute to science, security, and economics (eg: using similar launchers and satellites to those used by defense and intelligence agencies)…

…With Science and Aeronautics already having taken huge reductions due to Shuttle and Constellation in recent years, and Obama’s push for Earth observations, fuel-efficient planes, NASA education, etc, I doubt that the science/aeronautics cut scenarios will happen. With such huge Federal debt/deficits and many agencies enjoying tons of money and sure to want to keep it that way, I doubt NASA will get the big budget boost scenario, either.

Basically, the numbers don’t work without major commercial participation, and getting control of out-of-control NASA areas like Constellation, Shuttle, and some larger science mission plans.

Emphasis mine. Unfortunately, there’s no sign that any of that is happening. The Ares zombie continues to plod forward at the cost of billions, and commercial participation remains minimal. And it’s unlikely to happen as long as becoming spacefaring remains politically unimportant, and in an environment in which pork dominates progress.

[Evening update]

Clark has another comment:

NASA needed innovative hardware architectures and mission designs to make Constellation “sustainable and affordable” as instructed in the VSE. Instead it chose Ares I and Orion and now all the budget scenarios are bad.

Funny, that.

How Do The Numbers Work?

Sorry, but I just can’t buy this:

PG&E is pledging to buy the power at an agreed-upon rate, comparable to the rate specified in other agreements for renewable-energy purchases, company spokesman Jonathan Marshall said. Neither PG&E nor Solaren would say what that rate was, due to the proprietary nature of the agreement. However, Marshall emphasized that PG&E would make no up-front investment in Solaren’s venture.

“We’ve been very careful not to bear risk in this,” Marshall told msnbc.com.

Smart move.

Solaren’s chief executive officer, Gary Spirnak, said the project would be the first real-world application of space solar power, a technology that has been talked about for decades but never turned into reality.

“While a system of this scale and exact configuration has not been built, the underlying technology is very mature and is based on communications satellite technology,” he said in a Q&A posted by PG&E. A study drawn up for the Pentagon came to a similar conclusion in 2007. However, that study also said the cost of satellite-beamed power would likely be significantly higher than market rates, at least at first.

In contrast, Spirnak said Solaren’s system would be “competitive both in terms of performance and cost with other sources of baseload power generation.”

I just can’t see how. Unless there are going to be many satellites, the system has to be in GEO to provide baseload power to any given region on earth. They talk about putting up a 200 MW system with “four or five” “heavy lift” launches (where this is apparently defined as 25 tons).

Suppose the conversion efficiency of the cells is a generous 30%, the DC-MW conversion is 90%, the transmission efficiency is 90% and the MW-AC conversion efficiency is 90% (generous numbers all, I think). That gives an overall efficiency of 22% from sunlight to the grid. The solar constant in space is 1.4kW/m2, so that means you need 650,000 square meters of panels to deliver 200 MW to the grid. Suppose you can build the cells (including necessary structure to maintain stiffness) for half a kilo per square meter. That means that just for the solar panels alone, you have a payload of 325 metric tons. Generously assuming that their payload of 25 tons is to GEO (if it’s to LEO, it’s probably less than ten tons in GEO), that would require over a dozen launches for the solar panels alone.

That doesn’t include the mass of the conversion electronics, basic satellite housekeeping systems (attitude control, etc.) and the transmitting antenna, which has to be huge to get that much power that distance at a safe power density.

So even ignoring the other issues (e.g. regulatory, safety studies, etc.) that Clark mentions, I think this is completely bogus until I see their numbers. And probably even then.

Getting It Half Right

Yes, Congress is a problem for NASA. But not because it doesn’t give it enough money. As Clark notes, NASA has plenty of money, if it wanted to, and were allowed to spend it sensibly. The problem with Congress it that it won’t let NASA do so, even if it wanted to. It will always be more important to Congress where the money is spent than how it is spent, which is why government space programs are so cost ineffective (and that was true going all the way back to Apollo). Apollo succeeded because it did have huge bales of cash thrown at it, but it certainly wasn’t politically sustainable or affordable, any more than redoing it will be.

The Beginning Of The Myth

I missed noting it yesterday, but it was the fiftieth anniversary of the announcement of the Mercury 7. It set the pattern for the mythology of the NASA astronaut (with two minor variations — the first in the sixties when it was no longer necessary to be a test pilot, and in the late seventies, when women were allowed into the club). I may have more thoughts later, but to me, it was one of the key events that led us off on a very wrong path that has resulted in the space quagmire we’re in to this day.