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Comment Re: Note that what's large... (Score 4, Informative) 73

Venus has multiple "tropopauses" and "stratospheres", depending on how you define them. The atmosphere is like a layer cake with multiple convection zones (like Earth's troposphere) separated by areas of dynamic stability (like Earth's stratosphere). And again, ~50-70km is an awfullly long way from the surface, and surface winds are weak. But, there's a lot about Venus that we don't understand.

Comment Note that what's large... (Score 3, Informative) 73

.... is the size, not the intensity. The air moves only slightly faster or slower than the surrounding atmosphere as one passes through the wave.

They weren't expected on Venus, though. Venus's surface is dozens of kilometers down, thick and "soupy" there, transitioning to thinner layers above. It was surprising to see that surface features that far away, in a fluid that can compress, would still make clear phenomena like gravity waves in the high atmosphere.

Comment This is insanely obvious (Score 1) 295

Manning should get a full pardon and a medal of honour. S/he has done more for this country than Biden ever did, and that was after getting a forcible deployment against regimental doctor's orders.

The worst Manning is truly guilty of is exploiting severe violations of DoD regulations by the unit s/he was in. Those violations, and not her actions,compromised national security, as did Manning's superior officer. Those people were under strict orders on not deploying the severely mentally ill into Iraq and to withdraw clearance from such folk, but violated those orders in order to look pretty. That is a serious crime. A crime they, not Chelsea, are guilty of.

Under DoD regulations, computers holding top secret information may NOT be secured by just a password and may NOT support USB devices. I was working for the military when they did the cutover from passwords to passwords plus Class III digital certificate on a smartcard. The USB restriction has been there more-or-less from the introduction of USB, as it violates Rainbow Book standards requiring enforceable multi-level security.

I should not have to point this out on Slashdot, half the three digit IDers were probably involved in writing the standards! And the rest know all this because we had to look the bloody stuff up to get the NSA's SELinux working!

She was also under orders, remember, to ensure that no war crime was concealed by the military. Concealing a war crime, even if that's your sole involvement, is a firing squad offence under international law. Has been since the Nuremberg Trials. Nor is it acceptable to be ordered to carry out such a cover-up. You are forbidden from obeying such orders on pain of death.

Those are the rules. The U.S. military's sole defence is that nobody is big enough to enforce them. If someone did, the U.S. population would be noticeably smaller afterwards. We know that because of Manning.

But Manning's service doesn't end there. Military philosophers, tacticians and strategists will be poring over those notes for decades, running simulations to see when, where and how the U.S. was eventually defeated in Afghanistan and Iraq. They will compare actions carried out with the military philosophies the U.S. officially abandoned in favour of modern theories. They will search for ways in which the new approaches worked and where they should have stuck with the traditional.

Because modern computers can run millions, even billions, of tactical simulations in just a few hours, it is certain that, inside of a decade, someone will have done this and published a book on where the military went wrong and where the Taliban and Iraqi army went wrong as well. This core material allows for that.

These wars may turn out to be our Sun Tzu Moment, when through cataclysmic defeats at the hands of, essentially, barbarians (and make no mistake, they're defeats), a systematic analysis of all that went wrong will be conducted in order to produce a guide on how to have things guaranteed to go right.

Without Manning's data, this couldn't happen. Direct footage, real-time tactical information, logistics, international political interactions, there's enough there to actually do that.

I'd prefer it to be us, because nothing stops the next terror group to form from performing the same study. Historically, it has been shown that a smart army can defeat a confident opponent with superior technology and ten times the numbers, or with inferior technology and a hundred times the numbers. No reason to assume these are hard limits.

If it is us that figures it out, the Pentagon (still fixated on Admiral Poyndexter and his psychic warriors) won't be involved, it'll be people on the outside with more nous and fewer yes-men. And for that, Manning deserves the highest reward.

Besides, it'll annoy the neoconservatives and that's worth their weight in gold-plated latium.

Comment Re: Bradley Manning needs a HOSTS file (Score 1) 295

Define "male". Not in terms of social norms - those vary between societies. And, since you didn't accept the suggestion of a genetics test, you don't get to use that either. Historical records are of no interest, you weren't there when they were made so you can't vouch for them. Besides, plenty of species have individuals change gender. History proves nothing.

You could try a neurological test, but I'll wager you that it shows Manning to be female. The feelings come from the brain, there's no such thing as a spirit outside of hard liquor.

So what have you got to offer?

Comment Am I the only one... (Score 5, Interesting) 128

.... who can't help but cheer at my screen when they nail one of those landings? Now I finally understand how sports fans feel when they watch a game and do the same thing ;)

One thing nobody can deny about them is optimism. ;) Seriously, their IPS numbers are, pardon the pun, out of this world. $200k per booster launch. $500k per tanker launch. I mean, really? Good luck with that. No, seriously, good luck with that; I won't be expecting anything close to that, but please by all means prove me wrong ;) ITS would be a great system to have, I've been playing around with some Venus trajectories with it recently. Looks like it can do a low-energy transit with nearly 300 tonnes of payload from LEO and back again with the same, over 400 if starting at a high orbit - but from an economics perspective the high energy transfers actually make more sense.

I noticed a lot of people were confused about why Musk wanted the trips to be so short and was willing to sacrifice so much payload to do so - many assumed it had to do with radiation or something. But the issue is, when your craft costs so much but your launch costs are cheap, you can't have it spending all of its time drifting in deep space, you need to get it back for a new mission as soon as possible. There's a balancing point, in that if you try to go too fast, you reduce useful payload below the point of making up for it with going faster - but a minimum energy trajectory is just not optimal when the ratio between launch costs and transit vehicle cost is so extreme. I come up with the same thing from Venus as they were getting for Mars, although for the Venus case you end up aerobraking to a highly elliptical orbit rather than to the surface for ISRU refill (you need ISRU, but for the ascent stages, so it's not realistic to do so for the return stage in the nearer term). So for Venus they get no refill like on Mars, but they also don't have to do a powered landing nor do an ascent on return - it's six of one, half a dozen of the other. Both are quite accessible with it.

Comment Re:Great strides (Score 1) 128

It depends what you mean by "refurbishing"; each element is different.

The solid rocket boosters, for example, suffered a hard impact into salt water. They then had to be fished out of the water. And of course you don't just "refill" a SRB, they have to be taken apart and recast, then put back together.

The ET is disposable, and had to be rebuilt from scratch.

The orbiter was legitimately reusable, but with design flaws.

I don't blame the shuttle program - they were sort of pigeonholed into this dead end by circumstances. The concept came about during the heyday of the Apollo Programme, when NASA budgets were serious. It was supposed to be a much more reusable, much more maintainable, and somewhat smaller system. It was supposed to then have a huge flight rate supporting all of these big projects that were on NASA's docket, including a permanent moon base and a huge manned orbital station dwarfing ISS, which was supposed to replace Skylab.

But of course, Vietnam and the realities of having soundly trounced the USSR in the space race led to their budgets being slashed, which pushed the program into ever more untenable positions until it was nothing more than a jobs programme. Forget full flyback reusability of all parts. Forget the titanium frame for the shuttle, which would have let it run hot and thus not required so sensitive of a TPS. Go begging for money and be forced to modify the design to meet Air Force requirements, pushing you into an inferior design position. On and on.

If I'd fault them for anything, it'd be for going straight for a full reusable workhorse rather than a small-scale pilot programme first. But those were the days of optimism. Optimism which only recently seems to start being regained.

Either way, the Falcon boosters are a very different beast. A vertical soft landing is hugely different from the SRBs, yet the thermal issues are far easier than with the Shuttle. And the Merlins were designed from the start under the principle of preventing the need for a full teardown. That doesn't mean that they will be cheap to reuse. But it does mean that they have the possibility of it.

I do think SpaceX had a rather clever strategy, in that while their goal was reusable, they made a rocket that in the process was cheap as a disposable. So they could get volume and flight history while working on getting the kinks out. They may have flown too close to the sun with the densified propellants and (externally) unlined COPVs, but obviously, with a company like this, their whole existence is to push the envelope.

Comment Re: Awesome (Score 3, Insightful) 128

Most of Europe agrees with you. And even the US agrees with you up through high school plus with various forms of assistance for college, including state-subsidies, particularly for state colleges, and federal subsidies (direct subsidies, tax credits, and tax breaks), roughly $80B/year each. Pell grants alone cost the government $35B.

Comment Re:No Gut no Glory (Score 1) 67

To be clear:

  * Getting the failure rate down in the lower tenths of a percent or better is what they need to be able to ~10x their launch rate and still be economically viable, since a pad explosion will leave them stuck for just as long and scare off just as high a percentage of their customers whether they're launching 12 a year or 120.
  * SpaceX wants to have reliability like airplanes, and has talked about this frequently.
  * What they want to achieve, and what they need to achieve, are not the same thing. They do not need to achieve airplane-like reliability for the Falcon 9 to be viable.
  * That said, if they ever want to achieve their ultimate IPT plans, they absolutely will need airplane-like reliability. Because they're calling for ~1000 launches per booster on that thing with a turnaround cost of ~200k. They really cannot have anything go wrong with it.

Comment Re:No Gut no Glory (Score 1) 67

It most certainly would be extreme reliability by the standards of the launch industry. The only ones that have better reliability than that that don't have nearly a statistically significant enough number of launches under their belt to assert that. Aka, "they haven't had a failure yet but nowhere near the several hundred launches required to assert a lower fraction of a percent or better failure rate".

We're not talking about airplane reliability here, we're talking about economics (the title of the article is "SpaceX Accident Cost it Hundreds of Millions"). Airplane-like reliability is for the future. We're living in the present.

All COPVs use an inner liner. The problem with SpaceX's COPVs is that they have no outer liner to separate the carbon fibre from the LOX. Outer liners are optional. SpaceX didn't use one. They lost a rocket because of it. They're going to keep trying doing without one. I really hope it doesn't cost them another. CF and LOX aren't fast friends.

Comment Re:Permission? (Score 1) 62

It's hard enough to find affordable LOX dewars. Seems like little ones cost about as much as big SUV-sized tanks. Everyone has LN2 dewars for sale, but you don't put LOX in a LN2 dewar as a general rule unless you're absolutely positive it has no organics (and preferably no silicone) in it, or certain metals. Otherwise it can get a bit... "explodey". The simpler, all-stainless LN2 dewars usually don't have lids, which with LOX would be just plain stupid. You can find used LOX converters online for very cheap, but they generally only will take LOX in, you can only get GOX out.

What I'm saying is if anyone happens to run into an affordable LOX dewar, drop me a line.... ;)

Comment Re:No Gut no Glory (Score 2) 67

It's a somewhat problematic business model.

If they $250M per failure and have a failure 5% of the time on a $62M rocket then the per-rocket cost is $12,5M, or 20% of the rocket's value.

Now they're trying for two things: a big scaleup, and greater safety. So let's say that they get the accident rate down to 2%, and they 10x their value. The cost of a failure should scale proportionally to the size of their market because it means a standstill in launches, the same reputation hit, etc. So now it's a $2,5B failure, occurring 2% of the time, or $50M per launch on a $62M rocket, aka 81% of the rocket's value.

Their business model and scaleup plans appear to be built on a premise of extreme reliability. Whether they can ever actually get that, I don't know. I like to hope so; airplanes have done it, and I know they're thinking, "if we launch enough, like them, we'll have gotten all of the potential kinks out". And there's probably some truth to that. But can they scale reliability at the rate they want to scale their launch rate? I have my doubts, and if so, their expansion plans (and thus business model in general) is erroneous.

A particular aspect that concerns me about them getting failure rates down into the lower tenths of a percent is their use of unlined COPVs. I don't trust them. I don't have some massive level of confidence that simply toying around with their pressurization regimen and getting better at void prevention is going to provide some sort of permanent fix; LOX and composites just plain don't play nice together. Their solution is like (to be hyperbolic here) having a nitroglycerine-fuelled rocket and losing one because during pressurization the tank buckled, and the buckling set off the nitroglycerine, and then announcing that you've got a solution and the tank shouldn't buckle anymore. Well, that's great, return to flight and all, but at the end of the day, you still have a nitroglycerine-fuelled rocket.

I'd feel a lot more comfortable about their business model if they announced plans to switch to lined COPVs, and take the (several dozen?) kilogram mass penalty. But as I always say, I would love to be proven wrong on this!

Comment Re:Threatens? (Score 1) 376

I actually love that. Replacing "plans" with "threatens" makes any new announcement better. ;) From Google news today:

Mt. Ashland threatens lodge upgrades, expansion
Fiat Chrysler threatens to invest $1 billion in 2 US factories as it expands ...
Summers Warns of Financial-Crisis Risk From Trump Economic Threats
Defense chief threatens to visit Filipino soldiers in West PH Sea
Local groups announce threat to 'resist Trump-era immigration policies'
Tracee Ellis Ross Threatens to Hide Her Golden Globe in a Future Black-ish Episode
MBTA threatens to part with warehouse ops
Elizabeth Warren Threatens To Introduce Bill To Resolve Trump's Conflicts
Apple to meet Indian officials to discuss iPhone manufacturing threats
Greta threatens 'fair and balanced' show on MSNBC
East Timor threatens to restart border talks with Australia
German Green Party threatens to pay for people to have sex with prostitutes in new scheme

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