To quote the wikipedia page on molten salt batteries

My original comment referred to war between the Soviet Union and the US. I didn't say Russia.

But it was not a formalized declared "shooting war" in which Americans explicitly targeted Soviets and Soviets explicitly targeted Americans. What we saw were undeclared skirmishes. There was no fanning of Soviet public opinion that Americans were killing thousands of Soviets and that Soviet citizens had to enlist to revenge those killings. If Americans were explicitly and publically killing Russians today (or the reverse), it would be the beginning of World War III. Any policy that puts us unnecessarily close to such an incident is reckless.

Assuming that you are implying American boots/bombs on the ground in the Ukraine, are you crazy? I mean seriously. Are you? There is in my opinion a dangerous detachment from reality in some circles of American political discussion about confronting Russia. Perhaps you may feel my language is inflamatory. But I get kind of disturbed when so many people, including those in power, put forward actions which would likely lead to thermonuclear war.

Looking back at history, there has never been a shooting war between the Soviet Union and the US. Never. The Cold War? It was always fought between proxies of the great powers. We would sell arms to pro-US or anti-Soviet interests (like in 1980's Afghanistan), or we would directly confront pro-Soviet interests (like in Vietnam). We came close to a shooting war with the Soviets more than once (the Bay of Pigs in Cuba). But such a war never happened, because those in power knew that such a war would inevitably decay into a thermonuclear war that would likely end western civilization with the press of a button.

The proper response to this is to strengthen military forces in new NATO member states surrounding Russia, including US boots on the ground. This will make a clear line that Russia knows it cannot cross without provoking all-out war. Unfortunately Ukraine is not part of NATO. We might be able to sell arms to Ukraine, but there are risks and limitations to this. What must be made clear to Russia is that if it enters Ukraine, it will face profound economic isolation. If it goes further it must be clear that it will result in WWIII. Thus we end in a stalemate. Not unlike the Cold War.

Here is the PhD thesis of Thomas J. McGuire who is designing the compact fusion device mentioned in the parent comment. This 2007 thesis argues for the need to build compact fusion devices and surveys some options with their strengths and flaws. I don't think it describes in detail the high beta reactor he is currently designing at Lockheed Martin. Still, it shows the idea of him designing this reactor is plausible.

The Skunkworks high beta fusion reactor seems very interesting. 100MW reactor the size of a semi trailer and the complexity of a jet engine. Uses radio waves to heat the plasma (like a microwave oven). Confines plasma in a cylinder as opposed to a torus. In a tokamak reactor the confining magnetic field is created by the motion of the plasma. Thus the strength of the field decreases further from the plasma, creating an inherent instability. This creates a negative stability feedback because if the tokamak plasma expands the confining field gets weaker. I believe this is one of the reasons tokamaks need to be so huge to function.

The high beta reactor has a confining field that increases in strength as you move farther from the plasma, making confinement inherently stable. The machine was designed by Dr. Thomas McGuire who did his PhD thesis on fusors at MIT. It may be possible to build a full reactor by as soon as 2017 for a cost measured in millions, NOT billions.

The nozzle for the Superdraco engine is 3d printed. The alloy is too hard to machine, so 3D printing is the only practical way of manufacturing them. It will be the landing thruster for the propulsive landing Dragonfly crew vehicle. It will land with the accuracy of a helicopter. Here is a video of it being cycled through its various thrust levels. Very cool.

Aside from the horrific cost of the SLS (18 billion dollars) it is worth considering the fundamental flaws of it. If you use it to launch astronauts with the Orion spacecraft, you are using somewhere around a quarter of the SLS's lift capacity. If you want to use it to send things to Mars, you will need to add another stage, which is non-trivial. Overall, this seems like a giant corporate welfare program for NASA's contractors.

Thank you. That was an excellent article.

I have posted before that there is evidence that ULA has initiated a propaganda campaign against Space X. From what I have read, Shockey Scofield Solutions, which is a PR firm hired by ULA is tightly linked with congressional lobbyist culture...they know how to pull particular strings in Washington. This seems to have their fingerprints all over it.

We should really be aware of the reason why ULA was formed in the first place. A few years ago the government decided to bring competition into launch procurement, by creating a bidding process. The dominant/only American players, Boeing and Lockheed responded by merging their launch products into the United Launch Alliance so that in almost all cases there would be only one bidder for American launches. This resulted in an increase in launch costs.

Enter SpaceX, which looks to be a real competitor. ULA can't absorb Space X, so they seem to be doing everything they can to sabotage them instead. From proposing financial rules on bidding companies that are biased against smaller players, to focussing on trivial "anomolies" that put uncertainty in the (simple) minds of Congressional lawmakers, to floating fanciful speculative stories about future vaporware "Space Planes" that will leapfrog SpaceX's cheaper launch platforms, to calling Elon Musk a corporate welfare bum (as if ULA wasn't the queen of queens of welfare queens).

The simple fact is that Space X has taken older proven technology and molded it into what promises to be a robust and reliable launch platform. ULA knows this, and the only thing they know how to do is to make this a gutter fight. They are despicable.

Yes. I think my calculations are conservative. Especially if we are relying on fuel from the tar sands, which are MASSIVELY inefficient in terms of CO2 emissions. They have to melt the tar in order to separate from the sand and refine it. They use natural gas and a large amount of fresh water. Think about that water, Californians. Now much of that wonderful fresh water is languishing in huge pools, mixed with a toxic slew of organic chemicals and heavy metals.

The tar sands are madness. When I think of Alberta tar sands, I think of Mordor.

Let's look at some facts here. First off, the efficiency of a thermal power plant is somewhere around 33% to 48%, at least according to wikipedia. Let's split the difference and say 41% for a thermal plant. The typical thermal efficiency of a a gasoline engine is about 18% to 20%. Let's split the difference and say 19%. Thus, a thermal power plant is more than twice as efficient as a gasoline engine in terms of changing chemical potential energy to useful output.

But there are some caveats. Firstly, the electricity needs to be transmitted. High voltage power lines are extremely efficient, about 94% according to this article. That means that the chemical energy (lets assume from coal) reaching the charging station is 41% x 94% = 38.5%. And then there is the charging process. According to this article, the charge efficiency of a Li-Ion battery is about 97%, which makes sense to me, as batteries usually don't run too hot. The charging devices however probably are responsible for some loss. Let's assume they are 80% efficient. That gives us 38.5% x 80.0% x 97% = 30%. Thus, according to this, 30% of the coal chemical potential energy makes it to the engine.

But what about engine efficiency? Well electric motors run very cool, and have very high efficiencies, typically around 90%. I wouldn't be surprised if Tesla's motor is better. This means that if a coal power plant powered a Tesla, 30% x 90% = 27% of the energy would reach the wheels of the car, compared with a gasoline powered car, where 19% of the gasoline's potential energy comes out of the engine, never mind the losses in the transmission lines. Thus, a coal powered Tesla is 40% more energy efficient than a gasoline powered car.

However, there is one problem. Generating energy by coal produces more CO2 than generating it by gasoline. According to this article, coal generates about 215 pounds CO2 per btu of energy, while gasoline generates 157 pounds CO2 per btu. However, even with this, by my calculations, an equivalent gas powered car still emits 3.8% more CO2 than our coal powered Tesla.

Elon Musk made this claim in an interview, that even if a coal power plant generates the electricity, a Tesla still emits less CO2. My referenced back of a napkin calculations above support this assertion.

As this article indicates, United Launch Alliance, the principle competitor to SpaceX has hired Shockey Scofield Solutions to initiate a propaganda campaign against SpaceX. You can see ULA listed as a client in the website listed above. The campaign is indirectly mentioned in the following very informative article, just past the halfway point in the article. You will also notice another client to Shockey Scofield Solutions as Koch Industries, which is a company notorious for its deceptive propaganda campaigns against action on global warming.

Given this fact, I would tend to suspect many of the anti SpaceX comments as being part of an astroturfing campaign. To be honest, I really don't understand why an actual thinking person would have any problem with SpaceX. They build reliable rockets quickly and cheaply. What on Earth is the problem with that?

OSX in fact precedes windows 95, let alone Windows NT. That's right, because the best parts of OSX originate in NeXT, which was sold as a product in 1988, six years or more before windows 95. And the reason why NeXT/OSX were so great so early was because they were based on the decades old Unix architecture. And don't talk about Mac OS 7. It was dead end garbage. Only the most superficial structures from Mac OS made it into OSX.