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Comment Re:False premise (Score 1) 458

Well, it hasn't happened yet. That said, why would you cancel your cable Internet for this? Yes, cellular Internet will be useful for your Chromebook when you're away from home, but in the same way it is today - a useful supplementary service that fills in the gaps, not as your primary system.

As for how you'd connect to a server at home, there are two options: VPN, or IPv6. The latter tends to get forgotten, but I connect to machines at home directly via IPv6 from my (T-Mobile) cellular connection without any problems. This sounds horrifying in terms of security, but if you imagine the development server being as locked down as a Chromebook or iDevice, without the back doors associated with too many modern IoT devices, it should be fine.

I'm more bothered about having to develop using a web interface, especially in an era in which leaving Firefox open for a day with 20 or so tabs open seems to result in it eating 4+Gb of memory, not the connectivity part. The connectivity part is actually the nice part.

Comment Re:False premise (Score 1) 458

Maybe...

I bought a consumer NAS a year or so ago, which is a collection of servers (software, from Samba to various video streaming DLNA type things) running over GNU/Linux, connected to a big hard drive. It's still a little bit of a nerds thing, but I can totally see people wanting to use things like this to ensure they have control over their own content.

And after I got a Chromebook, I started to wonder how far off we are having similar devices that host IDEs (don't laugh, there are quite a few web based IDEs out there, Eclipse has two such projects, though in my view they're not ready for prime time.) You could, in theory, use your Chromebook as-is in the future, with a third party, locked down, server that has an IDE on it, to develop Android apps. Hell (and I mean hell), if Google gets involved, that might become the recommended development environment.

Comment Am I the only one... (Score 4, Interesting) 127

.... 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) 127

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) 127

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: This will never happen, even if I want it to. (Score 2) 266

Obama has only said he can't. He's never said why. Those claiming he said he can't because of legal reasons related to admissions of guilt or trials are lying (or unwittingly repeating lies) - he's never made any such assertion.

In all honesty, the reason he "can't" probably has to do with setting a precedent. Hopefully the same principle doesn't apply to commuting a sentence, and Obama can commute Manning's before he leaves office.

Comment Re:No Gut no Glory (Score 1) 66

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) 66

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) 60

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) 66

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:All the best research is done in Europe (Score 1) 130

I seriously doubt there's any body of research that says that exercise, or lack thereof, has nothing to do with weight, and the only times I've successfully lost significant amounts of weight (more than 20lbs) were when I combined a more controlled diet with exercise. Simply trying to control my diet has never helped, and I know nobody who successfully lost a lot of weight without either going on a relatively dangerous starvation diet (sometimes necessary) or combining exercise with something more reasonable.

But note that I also pointed out that urban vs suburban living also determines diet.

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