jccooper

65 ms·

691.
by jccooper 11y ago
Amazon's had the same garbage URLs for years. They must be consciously insensitive to the URL experience--and/or it's so deeply embedded they don't care enough to change.
692.
by jccooper 11y ago
Size, noise, maintenance, predictability, simplicity, cost. Haven't seen a power/weight trade study of batteries vs engine+generator+fuel, but it may be closer than you think. There's a lot involved in a ICE power plant, and
693.
by jccooper 11y ago
While it has nothing to do with the invention in the article (which is just about restructuring cabin airflow): air in an airplane is constantly introduced from outside, pressurized taps from the compressor inside the engine(s). Pressure is
694.
by jccooper 11y ago
Those jam an aluminum block into the blade. I'm not sure what the equivalent would be for a car. Perhaps you could line the bottom of the car with rubber and then blow the wheels off. But there's plenty of problems with varying ro
695.
by jccooper 11y ago
I used Google Checkout for payment processing, shopping cart, and order management. Having all that in one package was nice during development. It was a really bad day when I heard I had only six months to replace all that.
696.
by jccooper 11y ago
Certainly anything that's not a core Google product you should think hard about using. I got burned when they shut down Checkout. They gave me six months notice on that, which was just barely enough to replace shopping cart, order mana
697.
by jccooper 11y ago
Sure, but they're not there yet, and probably won't be for decades and several more generations of designs. And a much higher flight rate: remember, this is an industry where no system has more than 1000 flights, and most don&#x27
698.
by jccooper 11y ago
Everyone aboard will be strapped down in a nice flight couch. It probably won't be pleasant, but will be easily survivable--which sitting on an exploding rocket, the alternative, would not be.
699.
by jccooper 11y ago
That's actually fairly mild, as these things go. The Apollo lunar missions experienced max G forces of 6.5-7.2g during reentry. (The Earth orbital missions only went to about 3.3g.) See: http://history.nasa.gov/SP-368&#
700.
by jccooper 11y ago
Many do. I've had several Windows laptops that want to do this.
701.
by jccooper 11y ago
It was intended to on this test, but it failed. Hydraulic issues (just like SpaceX!). No video, presumably because they thought a nice video of part of they system exploding would be bad press.
702.
The ‘startup cities’ of Ancient Greece (and Honduras)(spectator.co.uk)
1 points by jccooper 11y ago|0 comments
703.
by jccooper 12y ago
And all of a sudden Blue Origin looks to be in the lead in the (very long) race to suborbital passenger flights. Scaled/Virgin seemed to be a lock in the beginning, but have been squandering their lead. Until yesterday, I'd have t
704.
by jccooper 12y ago
At the moment, true, and Blue Origin is not renowned for their development speed, but suborbital is clearly just a stepping stone for them. Their suborbital booster uses liquid hydrogen as a fuel, which is a very good fuel but so obscenely
705.
by jccooper 12y ago
Here in Texas, where the roads are clean and we drive a lot, cars with 300,000km (or, let's say, 200,000mi which is a similar milestone) certainly exist, but are somewhat unusual. But they're not worth much and likely nearing the
706.
by jccooper 12y ago
Similar concept, different geometry. It's almost like an inverse Wankel. Perhaps this geometry is easier to handle wrt seals and lubrication. The points of the Wankel triangular rotor have always been difficult.
707.
by jccooper 12y ago
Ah, I see Priceonomics has completed its transformation into Medium. Kind of a strange pivot.
708.
by jccooper 12y ago
A good book basically can't work as a TV show, and vice versa. I'd rather the TV people came up with their own stories that will actually work on TV. (Game of Thrones, which I'm sure is the inspiration for this, is an excepti
709.
by jccooper 12y ago
HN does not take well to joke comments. It's not specifically mentioned in the guidelines, but falls generally under "off-topic". Feeling is "this isn't Reddit."
710.
by jccooper 12y ago
Florida's an awful long way from Brownsville. Take a look at the launch danger zones chart; first stage recovery is just off the coast. Maybe you could finagle a second stage recovery in Florida from Texas, but only from very specific
711.
by jccooper 12y ago
The dang thing is a couple mm thick and ten stories tall. There's no "gentle" option available for tipping over. The solution is to land it right. It'll happen.
712.
by jccooper 12y ago
Recent statements indicate that they've given up on second stage recovery for the F9. Just too hard given current margins. That'll be in some future architecture.
713.
by jccooper 12y ago
It does that. The barge has four thrusters for stabilization. The problem is not the barge moving, but rather control problems. They would have happened on land too--unless by landing on a larger area you have a simpler control problem, whi
714.
by jccooper 12y ago
And here's what it looks like when a rocket of similar class, but fully-fueled, explodes: https://www.youtube.com/watch?v=bx1CeHFeea0
715.
by jccooper 12y ago
From a technical standpoint, it's tough. You've got big expensive machinery that operates at or past any reasonable limits in extreme conditions and moreover gets destroyed with every test if you make the slightest mistake. I know
716.
by jccooper 12y ago
Mostly, I think, because they'd prefer to avoid having several types of engine involved. SpaceX is big on cost savings through commonality. The development and tooling and testing etc. for creating a smaller landing-only engine would p
717.
by jccooper 12y ago
The rocket is, at the very least, a thin pressurized tube full of kerosene vapor and oxygen, and probably some decent amount of liquid kerosene and liquid oxygen. Crack it open and it's gonna make a pretty good flash. But as rocket exp
718.
by jccooper 12y ago
SpaceX seems to be able to stabilize fine with RCS and/or their grid fins. The rocket design must be reasonably stable--even tail-first. I don't think incoming velocity is much of a problem. Terminal velocity is gonna be no more t
719.
by jccooper 12y ago
A drogue would seem unnecessary; a Merlin can scrub off plenty of m/s real fast, and if it can't do it fast enough, they have more of them. In fact, it might be easier if the thing is coming in faster, because you get to run the e
720.
by jccooper 12y ago
Stage separation is somewhere around 100km and Mach 6 or more. The exact figures will depend on the mission profile. There's a "boostback burn" at altitude to slow the horizontal velocity right after separation, an entry burn

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