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Launch Command Preserved In Power Failure, But Nuclear Designs Still Risky

cmowire Re:Citation needed (167 comments)

Yeah, I'm under-impressed with the site's rigorousness as well. Everything the author talks about is something that's been talked about endlessly in the public literature. With the claims made, I kept thinking there was at least a rumor-mongering hint about something new and different.

more than 3 years ago
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International Effort Brings an Open Standard For Docking In Space

cmowire Re:It's about time (140 comments)

It was.

This is fairly similar to the APAS docking adapter they created for the Apollo-Soyuz test program in the 70s.

Now... why the ISS doesn't use APAS for all links and why the ISPRs (international standard payload racks) that everything in the US section is contained within won't fit inside an APAS docking tunnel... well... heh heh.

about 4 years ago
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SpaceX Unveils Heavy-Lift Rocket Designs

cmowire Re:Shiny! (248 comments)

Well, notice that there are two Falcon 9 cores listed. There's the one with a single Merlin 2.

Given the systems approach that SpaceX has, I suspect that the Falcon X Heavy is slotted the same as the Falcon 9 Heavy -- there if you need it to attract NASA or some customer before the Falcon XX is ready. I'm assuming that the Falcon X's core diameter is sized around some constraint (factory size, transportation, etc) and the Falcon XX is designed under the assumption that funding to exceed said constraint was provided.

I think it's all about options and incremental development. They don't have to qualify the heavy configs until they need them and that's the hard part.

more than 4 years ago
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SpaceX Unveils Heavy-Lift Rocket Designs

cmowire Re:Falcon XXX (248 comments)

Hey, nobody likes a pocket rocket that comes apart after launch.

more than 4 years ago
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SpaceX Unveils Heavy-Lift Rocket Designs

cmowire Re:Shiny! (248 comments)

Doubly so. Notice there are two Falcon 9 boosters. One with 9 Merlin 1 engines, one with 1 Merlin 2 engine.

more than 4 years ago
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Senate Bill Adds Shuttle Flight, New Shuttle-Derived Vehicle

cmowire Re:Proven delivery system (230 comments)

It turns out that in business school classes on running defense contractors teach a fairly simple concept:

If your project isn't far enough along to survive cancellation when the power shifts in the white house, you fucked up.

Thus, NASA's problem isn't changing political whims, it's that the Constellation program was so far behind, overbudget, and mismanaged in 2009 that it got canned by the incoming administration.

more than 4 years ago
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Cross With the Platform

cmowire I'm thinking this is worse with Windows CE... (307 comments)

As far as I can remember from when I did some Windows CE hacking, that's actually worse than the difference between Windows CE and standard Windows.

Wow.

more than 4 years ago
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The Upside of the NASA Budget

cmowire Re:A breath of fresh air (283 comments)

Hindsight is 20/20. NASA was figuring that, if the shuttle was a booming success and drove down the cost of upmass, procuring the necessary bits for a new set of moon missions would be easier. NASA had planned for reduced budgets, it's just that their creative plan to work around that didn't work out.

more than 4 years ago
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The Upside of the NASA Budget

cmowire Re:Economy of Scale (283 comments)

Actually, the ISS is bigger than Skylab at this point.

The problem with the shuttle building the ISS is that it's really the worst of both worlds. You spend billions of dollars a year on the shuttle and build the American part of the ISS on that set of constraints and then wonder why it cost so much. Whereas, If you were to have lofted the American part of the ISS on commercially available boosters, even after the additional hardware to make each module contain a tug, you'd have built it for a lot less.

Especially if you also consider that most everything gets cheaper in bulk and, if you were to place a guaranteed order for a hundred medium lift boosters, you'd get them at a much more reasonable price than the equivalent upmass in ten heavy lift boosters. Especially given that medium lift boosters are the right size for commercial missions and heavy lift boosters are not yet.

The problem is the sunk costs fallacy. NASA had the design and hardware for Freedom and modified it instead of taking a giant step back when they had a chance. The shuttle was there and it worked, even though we might have done much better to have sent it to the museums after the first time we lost one.

more than 4 years ago
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NASA Tests All-Composite Prototype Crew Module

cmowire Re:Taking notes from the bicycle industry (67 comments)

Um, I think you are ascribing far too much engineering expertise to the folks who work in the bike industry. The bike industry spends a lot of money on marketing and throws a few pennies at engineering. And the cyclists of the world eat it up.

There's something to be said for not knowing that what you are doing is something that engineering textbooks teach you not to do. This can lead to great things. But this also leads to carbon fiber parts that fail in all sorts of catastrophic ways. Or tires with colored bits of tread that gets squirley in the rain. Or brake designs that every other brake-using industry (cars, airplanes, etc) rejected as unsafe being sold as the next great thing.

Personally, I'm glad that the transfer of knowledge goes only one way, albeit poorly. I would not want to fly cross-country on an airplane with a Shimano HollowTech Carbon Fiber wing spar that's super light and has the occasional habit of snapping mid-flight leaving the aircraft wingless. You can get away with all sorts of design sins with bikes because most people who can afford high-end carbon fiber bikes don't actually ride them very often and, if they do, gingerly descend only on smooth roads at 15 mph.

more than 3 years ago
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Uranus and Neptune May Have "Oceans of Diamonds"

cmowire Re:Much as I'd love to make a great pun about uran (347 comments)

The shuttle is the way it is because nuclear launch systems are really messy on a populated planet.

A wide variety of nuclear propulsion systems are available and have even been vaguely tested on Earth. Like Project Pluto's nuclear ramjet. Nobody to piss off next door on any of the gas giants.

more than 3 years ago
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Uranus and Neptune May Have "Oceans of Diamonds"

cmowire Re:Much as I'd love to make a great pun about uran (347 comments)

Actually a nuclear powered rocket will do just fine. Nobody there to get pissed off if you pressurize some of the abundant hydrogen into a tank and run it past a fission reactor.

more than 4 years ago
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Uranus and Neptune May Have "Oceans of Diamonds"

cmowire Much as I'd love to make a great pun about uranus. (347 comments)

The possibilities of exploring the outer "ice giants" is massive. I think, at least. I may not even make the pun because I think the idea of exploring them is so interesting.

Submarines are designed to handle a test depth of maybe 1600 ft which means maybe 50 bar of pressure. At that pressure, the atmosphere of Uranus is a little below freezing. The gravity is less than Earth. I suspect that with correct ballasting you could make a metal sphere float in the atmosphere for quite some time by keeping the insides pressurized to a convenient atmospheric pressure. So sticking around for a while isn't hard.

I can't find any good information on the radiation environment there and if you could put humans in the little bubble circling Uranus.. um.. yeah, I lied above.

more than 4 years ago
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NIF Aims For the Ultimate Green Energy Source

cmowire Re:Three points (234 comments)

Fusion that does not produce neutrons.

Eg, D + He 3 -> He 4 + p vs. D + T -> He 4 + n. The first, deuterium and helium-3 produces helium 4 and a proton. No neutrons. But deuterium and tritium produces helium 4 and a neutron.

The problem is, not perfect. With the deuterium hanging around in a reactor, you'd get some degree of neutron-producing reactions anyway.

more than 4 years ago
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NIF Aims For the Ultimate Green Energy Source

cmowire Re:Three points (234 comments)

You do realize that iron would become brittle as steel from the neutron flux if you built your reactor vessel out of it, right? It's a vague problem with fission reactors that required some procedural adjustments once neutron embrittlement was better understood, but with orders of magnitude greater neutron flux...

Nor can you rely on a isotope chart of a single element to predict what's going to occur in a high neutron flux environment.

For example, Fe 58 is stable. Capture a neutron it becomes Fe 59, with a 44 day halflife to Co 59. If Co 59 captures a neutron, it becomes Co 60, which is a long-lived radioisotope.

So I guess you do get a reactor vessel with a certain amount of cobalt isotopes, no?

I wouldn't classify this as an "unsolvable problem" but you can't magically wave your hands and make them go away.

For all the "oh my god radioactivity" crap that's going around, the simple fact of the matter is that you can access the core of a fission reactor while it's online whereas you cannot access the core of a fusion reactor while it's online.

more than 4 years ago
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NIF Aims For the Ultimate Green Energy Source

cmowire Re:Three points (234 comments)

You are clearly not educated enough.

Look up neutron activation. When neutrons are flying around in a nuclear (of any type) reactor core, some of them hit the material in the walls, causing the atoms to absorb a neutron and change isotopes. Which tends to result in a reactor core that is radioactive, even though it wasn't made of radioactive materials and didn't absorb any isotopes.

Fusion reactors put off a hell of a lot more neutrons than fission reactors. You can do aneutronic fission, but not with the sort of reactions people have been talking about....

more than 4 years ago
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NIF Aims For the Ultimate Green Energy Source

cmowire Three points (234 comments)

Point one: Not spending money on fusion research is incredibly dumb. It's not likely to pan out in the near-term future, but there's plenty of ancillary science to be done on the subject. For example, the VASMIR space drive built on fusion research, it's just not hot enough to provoke fusion

Point two: Relying on fusion power to make for a short-term fix is also dumb. Especially if you think it's going to be safe and clean. The problem with fusion is how many neutrons it emits. Even when you use one of the fusion chains designed not to produce neutrons, you produce a good amount. The reactor core is going to be even more radioactive than a fission reactor core. And even if you get to a "Breakeven" point, that doesn't mean that you'll be price-competitive with other forms of power.

Fusion is easy. Just take a GIANT ball of gas, let it collapse into a star, and put solar panels around the star.

Point three: Calling it the Ultimate Green Energy Source is a cover story. A 2007 report by the National Research Council's Plasma Science Committee concluded that "NIF is crucial to the NNSA Stockpile Stewardship Program because it will be able to create the extreme conditions of temperature and pressure that exist on Earth only in exploding nuclear weapons and that are therefore relevant to understanding the operation of our modern nuclear weapons."

In other words, the NIF will be used, at least some of the time, to re-create the conditions inside of an exploding nuclear warhead so we can design new nukes without testing them and therefore violating the test ban treaties.

more than 4 years ago
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MIT Electric Car May Outperform Rival Gas Models

cmowire Re:Outperform? (457 comments)

I did not chose home & job based on bikeability, actually. It's just that if you plot all of the places that I have lived and all of the places I have worked, I've always been no more than a single mass transit trip and no more than 5-6 miles of cycling between me and work.

This includes living in Cincinnati, which is not known for having much in terms of mass transit or bike routes.

I think the only time I've declined an interview solely on the basis of transportation concerns it was neither drivable nor bikeable.

I was worried at one point that I might be suffering from a myopia because I somehow accidentally stumbled into a series of easy-to-bike jobs, but I checked the transportation statistics and discovered random statistics like that 60% of all car trips are under 5 miles.

And yes, I have biked at -20F and windy as well as 100F and humid. In order for me to be here today, my ancestors likely needed to run many miles in both conditions to outrun tigers, chase buffalo off cliffs, and other such tasks. Without the benefits of modern technology.

So, yeah. I don't expect every single person to be able to easily bike all of their trips. One of my co-workers used to live atop a mountain, for example. And sometimes I carry cargo that doesn't fit on my bike. (although in those cases I usually wish for a bakfiets) But I do see that there is a fairly large bunch of people who can bike at least some of their trips with no infrastructure improvements. It's just that most of them are still stuck thinking that it's actually hard to do.

more than 5 years ago
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Armadillo Aerospace Flight Paves Way For Science Payloads

cmowire Re:Still hoping for paraffin (63 comments)

The problem is that just because it's paraffin and an oxidizer doesn't mean it's that much simpler or that much safer than a liquid fueled rocket. Instead of two sets of plumbing, you have one set, but that's still rocket plumbing and it's still awfully troublesome.

Consider how Scaled Composites made a big deal about how safe their rubber+nitrous oxide hybrid engines were.... and then killed a few people in a nitrous oxide plumbing accident while working on SpaceShipTwo.

more than 5 years ago
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MIT Electric Car May Outperform Rival Gas Models

cmowire Re:Offload the capacitor? (457 comments)

Damn you for ruining my nerdy railgun fantasies.

I bet next you are going to tell me that girls don't like it when I talk nerdy to them? :D

more than 5 years ago

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