SpaceX' vacuum engines (second stage) are radiation cooled. No ablative, no regenerative circulating coolant. Just radiation to the 4°K background.
32 posts • joined 30 May 2015
It of course depends on the root cause.
If copper is vaporizing, you'd look to cool it better as one fix.
a) Make the copper liner *thinner*, which would reduce thermal resistance between the hot liner surface and embedded regenerative cooling channels.
b) Redesign the size/shape/placement of the cooling channels for the same reason as in a).
c) Maybe it's cavitation bubbles in the coolant channels inhibiting heat transfer, in which case, modeling and redesign to eliminate cavitation would be the thing.
Somewhat similar events made me look like a hero.
My dear wife likes a cuppa in bed before breakfast. She dozed off while holding said full cuppa, spilling it on the MacBook Pro she was using at the time. Result: a drowned & totally dead machine. Extremely expensive to fix, so she migrated to an old iPad.
I kept the dead MBP. About a year later, I decided to get rid of it and wanted to scrub its internal drive before I did. I plugged in the charger in the faint hope it would power up and let me clean the drive without having to disassemble the machine. To my surprise, it booted up. A year of drying out did the trick.
So my wife thought me a techie god when I brought the resurrected laptop to her. She nicknamed it Lazarus.
I'm with you.
My anecdata experience with Apple since the Mac Classic has been nothing short of excellent. Even when things went wrong.
I took a G4 laptop in for the nth time to replace a problematic hard drive. The Apple rep had seen me before at the Palo Alto store and said "not again? - give me a minute".
He came back with a new MacBook (or whatever it was called back then) that skipped me ahead two hardware generations and just gave it to me. He asked me to bring my old one back after I'd migrated my stuff to the new machine. Didn't even take my name.
This was three days before AppleCare on my G4 laptop would have expired. The guy could have blown me off for 72 hours and it would have become my problem.
Experiences like that really cement customer loyalty. I've had so little trouble with Apple gear that I don't know what the current customer experience is like, but I hope they're using their enormous cash position to treat their customers the way they treated me.
DDoS of an airport could be done with ~ two hundred drones, each carrying a 100g tungsten carbide ingot. Put ten up at hourly intervals, flying inertial paths (no GPS needed) intersecting the departure routes and nobody's going anywhere. Capital cost ~$300/drone. Operation capital cost ~ $US7K for 10 drones x 24 hr.
The rapid pace of technology is showing us how fragile our infrastructure really is.
There are too many circumstances in which automation can be in control of some aspect of aircraft operation. If one of these instances goes wrong, it takes too long to identify which one has gone bad and run the appropriate procedure while under high crew task load. And that's if the aircraft builder has actually kept documentation up to date.
There should be a single switch that unconditionally inhibits all automation, returning full manual control to a pilot. Not a panacea, but it might have prevented this accident.
Traditions and aspirations do change with generations. But on such a ship, the range of aspirations which new generations can adopt will be constrained to those that include survival, which will pretty much limit them to continuing the mission, however grudgingly.
They may hate us, they may feel no zeal whatever for exploration. Could get ugly. But they will carry on - or die. Survivors get to boot up a new world with an expanded range of opportunities. Others disappear in the deep void. Darwin at work.
The latency required for this problem to rear its ugly head might indicate thermal cycling that's slowly degrading a critical thermal interface. Too many thermal cycles might separate an interface, increasing thermal resistance and the temperature of whatever component depends on that thermal interface as part of its heat transfer chain.
It might be interesting to run an ice cube slowly over the back of one of these that's showing the problem to see if the "freeze fix" can be localized. That might give a clue to what's failing.
Meanwhile, as an earlier contributor said, I'm on a MacBook.
It isn't that the west coast is dead. It is that there's no longer the ability to allocate power between widely separated areas.
Those areas with an insufficiency of power will shed load until demand matches the isolated supply. Obviously, the folks who comprise "shed load" will go dark.
But it is not the case that taking down large HVAC or HVDC distribution lines will black out the west coast. There have been many lessons learned from the blackouts of 1977 and 2003.
Some grid reconfiguration is done in response to solar coronal mass ejection events of sufficient magnitude. We get at least one day's warning of these.
I'm not sure what could be done within the less than half an hour maximum time between launch and impact of a NOK nuclear ICBM.
So, just to conform to the adage that 90% of statistics are made up on the spot - just like this one -
I'll say that 90% of the readers of this article secretly admire Snowden for what he's done and for his forthcoming appearance in the entertainment world.
If *you* could have done it, wouldn't you?
Khosla has fallen to short-sightedness.
Given our progress, it's likely that "coding" as a specialized skill will not be broadly required in a decade or so.
By 2026, it's highly likely that I'll be asking my computer (phone or cerebral implant) to bring up Kenneth Branagh's Hamlet or please model a particular configuration of microwave power and gas mixture in a plasma CVD process rather than thrashing out the code myself.
All the same, in 2026, I expect still to be settling in with my paper copy of Will's compleat works for an evening in front of the fire, a glass of port, and some of humanity's finest and most insightful writing.
It's so easy to fall off the exponential curve. Hasta la vista, Vinod.
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