Mr Perminov said the craft followed the back-up landing plan, a so-called "ballistic re-entry" - a plunge with an uncontrollable, steep trajectory
He said the crew missed the target because they changed their landing plan at the last minute without telling mission control.
Astronauts don't just don't go changing re-entry profiles willy-nilly. If they did it, there was a reason they needed to.
Remember the collision between the Progress supply ship and Mir during the manual docking? The first thing the Soviets did was blame it on the Russian cosmonaut. It turned out the whole operation was poorly planned, rehearsed and was an accident waiting to happen.
There's a lot more to this story than we've heard yet.
But at 10G, the crew's probably not going to be conscious to operated that manual system. 10G is enough to cause G-induced loss of consciousness (GLOC) in anyone, even physically fit, properly trained, and prepared personnel. Even fighter aircraft, where the pilot is in a properly reclined position and is wearing a g-suit, limit maneuvering to 9g, because after that, that pilot's asleep.
In an aircraft, the pilot's head is necessarily somewhat higher than the rest of his body so that he can see outside, especially forward. That's why high G's result in a loss of blood flow to the brain.
An astronaut doesn't have that limitation. I wouldn't be surprised if their seating position makes them less vulnerable to GLOC than a pilot.
The article specifically mentions 138 kelvins as the highest temperature where cuprates still hold on to superconductivity. That's roughly -115 degrees celsius.
I believe you mean -135 degrees celsius.
That last twenty degrees is what keeps Minnesota from superconducting in winter.
A twist on that by which the energy industry could rake in profit is by declaring it unsafe to use compressed air. Instead only compressed CO2 or Nitrogen should be used, to avoid fire hazard.
Actually, there is truth to that in some cases. Airliner tires are filled with nitrogen to prevent the spontaneous explosion of tires - it's a risk at the high temps/pressures that aircraft tires operate at if there's O2 in a rubber tire. A Mexican 727 (IIRC) was lost many years ago when a tire filled with regular air exploded while the tire was in the wheel well.
Compression ratio isn't a product of valve timing. It's a product of how far the piston travels.
Normally, yes. But you can reduce compression by leaving the intake valve open for a portion of the compression stroke so that no compression happens for the first part of the stroke, effectively reducing the compression ratio.
The Prius does this to gain efficiency at the expense of power - it's called an Atkinson Cycle.
I'm not sure how much you could vary the compression ratio by variable valve timing, or whether it would be practical/possible to tune an engine for pure ethanol, then reduce the compression when gasoline was used.
I'd guess that if you're trying to get the most out of your ethanol the turbocharger will be the most practical method of varying compression. Anyone know if the Ford EcoBoost engines are designed to do this?
Pure ethanol can offset the smaller BTU with more efficient combustion. An alcohol engine be ran safely at 12-14 to 1 compression raising efficiency whereas gasoline's upper limit is 10 to 1 in a production vehicle that has to be warrantied.
I didn't know that.
Do any of the flex fuel cars vary valve timing or use some other trick to raise compression? Or are they stuck with the pure gasoline compression ratio?
$1/gallon would be great if it were gasoline, but one gallon of ethanol doesn't store the same amount of energy as a gallon of gas.
How many joules per dollar does that work out to compared to gas?
From wikipedia...
Gasoline - 125000 BTU/gal
Ethanol - 84600 BTU/gal
... or about 67% of the energy content of gasoline. So you could compare it to a claim of $1.50/gallon gasoline.
I have often wondered (living in the mosquito-ridden South), if mosquitoes have any benefit to the ecosystem at all. We often hear about how if you remove one creature from the ecosystem, the whole thing changes. But mosquitoes? I'm not sure they would be missed by any creature.
There are many species of mosquitos, not all (or even most IIRC) of which bite humans. There's no need - and no way - to wipe out all mosquitos. Hammering the specific species that transmit deadly diseases to humans is an ecological engineering project and moral choice that I think most humans are comfortable with, though.
The effort in the article specifically attacks one species - the Aedes aegypti mosquito.
I have a couple of Netgear routers and both shipped with UPnP off by default.
UPnP can be enabled or disabled for automatic device configuration. The default setting for UPnP is disabled. If disabled, the router will not allow any device to automatically control the resources, such as port forwarding (mapping), of the router.
Slashdot Mirror
Just make sure the page is protected by SSL.
Well, that's no ordinary mouse.
Ohh.
That's the most foul, cruel, and bad-tempered rodent you ever set eyes on!
You tit! I soiled my armor I was so scared!
Look, that mouse has got a vicious streak a mile wide! It's a killer!
Zebra mussels are freshwater creatures. If you ever find a freshwater starfish and you'll be famous.
Historically speaking, that's lesson two, since cell phones were invented after credit cards.
Credit cards give data that's more location specific. I'm not sure which data would be available closest to real time. Anyone?
The pictures show up larger in the linked article.
Just not for long.
If so, I want to know... how many gallons per Ballmer?
Mr Perminov said the craft followed the back-up landing plan, a so-called "ballistic re-entry" - a plunge with an uncontrollable, steep trajectory
He said the crew missed the target because they changed their landing plan at the last minute without telling mission control.
Astronauts don't just don't go changing re-entry profiles willy-nilly. If they did it, there was a reason they needed to.
Remember the collision between the Progress supply ship and Mir during the manual docking? The first thing the Soviets did was blame it on the Russian cosmonaut. It turned out the whole operation was poorly planned, rehearsed and was an accident waiting to happen.
There's a lot more to this story than we've heard yet.
In an aircraft, the pilot's head is necessarily somewhat higher than the rest of his body so that he can see outside, especially forward. That's why high G's result in a loss of blood flow to the brain.
An astronaut doesn't have that limitation. I wouldn't be surprised if their seating position makes them less vulnerable to GLOC than a pilot.
I believe you mean -135 degrees celsius.
That last twenty degrees is what keeps Minnesota from superconducting in winter.
Two X chromosones.
Maybe the story of an invention will shed a little light.
Once upon a time there was an invention.
The inventors showed it to a scientist. He said, "Cool, why does it work?"
Then they showed it to a engineer. He said, "Cool, how does it work?"
Then they showed it to a business major. He said, "Cool, how much can we sell it for?"
Then they showed it to a liberal arts major. She said, "Cool..."
"You want fries with that?"
Brings a whole new meaning to the old "Ain't Boeing, Ain't Going" saying.
Now if I can just figure out how to get my bumper stick up to the satellite...
Well, here you go.
Engadget ran a caption contest on these - my favorite was, "Hello, Onstar?"
Denver International Airport tried something along that line.
Things went so badly that when they sent camera equipped luggage to trouble shoot the system, they lost their camera equipped baggage. Forever.
United finally abandoned the system a few years ago, though they're still paying for it.
We spend 60 million to blow up a measly tank of hydrazine in orbit, then turn around and launch kimchi into space.
Let's hope the ISS doesn't de-orbit anytime soon.
Actually, there is truth to that in some cases. Airliner tires are filled with nitrogen to prevent the spontaneous explosion of tires - it's a risk at the high temps/pressures that aircraft tires operate at if there's O2 in a rubber tire. A Mexican 727 (IIRC) was lost many years ago when a tire filled with regular air exploded while the tire was in the wheel well.
Just found a ref on wikipedia: Mexicana Flight 940"
I have no idea if there would be any danger with a carbon fiber tank.
Normally, yes. But you can reduce compression by leaving the intake valve open for a portion of the compression stroke so that no compression happens for the first part of the stroke, effectively reducing the compression ratio.
The Prius does this to gain efficiency at the expense of power - it's called an Atkinson Cycle.
I'm not sure how much you could vary the compression ratio by variable valve timing, or whether it would be practical/possible to tune an engine for pure ethanol, then reduce the compression when gasoline was used.
I'd guess that if you're trying to get the most out of your ethanol the turbocharger will be the most practical method of varying compression. Anyone know if the Ford EcoBoost engines are designed to do this?
I didn't know that.
Do any of the flex fuel cars vary valve timing or use some other trick to raise compression? Or are they stuck with the pure gasoline compression ratio?
From wikipedia...
Gasoline - 125000 BTU/gal
Ethanol - 84600 BTU/gal
... or about 67% of the energy content of gasoline. So you could compare it to a claim of $1.50/gallon gasoline.
There are many species of mosquitos, not all (or even most IIRC) of which bite humans. There's no need - and no way - to wipe out all mosquitos. Hammering the specific species that transmit deadly diseases to humans is an ecological engineering project and moral choice that I think most humans are comfortable with, though.
The effort in the article specifically attacks one species - the Aedes aegypti mosquito.
I have a couple of Netgear routers and both shipped with UPnP off by default.
UPnP can be enabled or disabled for automatic device configuration. The default setting for UPnP is disabled. If disabled, the router will not allow any device to automatically control the resources, such as port forwarding (mapping), of the router.
Great. I can't wait to get more email offering me a new organ...
Since some thin skinned moderator was put off by a little sarcasm...
400 billion works out to slightly over .8 Iraqs (so far...)
Which do you think would be a better national security investment?
From the SA article...
The federal government would have to invest more than $400 billion over the next 40 years to complete the 2050 plan. That investment is substantial...
I dunno. What president in his right mind would ever spend 400 billion on a national security issue?