Except everyone who casually reads tech news, only vaguely paying attention to headlines written by tech writers, has a completely mistaken impression of what it is and does.
It only takes 97% of the 90K Tesla drivers doing the right thing for there to be thousands of Tesla drivers not doing the right thing.
It's not about efficiency, and it's not about safety, it's about convenience. Though they call it an autopilot, it's most certainly isn't one. It's built for a totally different reason.
The same way the bottom of your tire becomes stationary while you're speeding down the highway. Pick a point on the tread and essentially it drops (almost) straight down out of the sky, stops, and then goes straight up again.
There's a reason why calculus was originally called the study of infintesimals.
Experiments in extending cables down into the atmosphere at orbital speeds say otherwise.
What experiments?
more like a fast airplane at best
500 mph is going to keep you from falling back to Earth?
there's no reason to extend deep into the atmosphere
Sure there is, if you want the hook to reach a cargo airplane.
just far enough to link with a plane/rocket/airship in the extreme upper reaches
Show me an airplane that can lift 25 tons of cargo into the extreme upper reaches of the atmosphere.
The actual escape energy from Earth is 62.5 MJ/kg = 17.375 kWh/kg = $1/kg at wholesale electric rates... We just have been terribly inefficient about how we get to space.
Completely ignores that the energy has to be converted to 40,000 k/h escape velocity.
Nothing is free, especially in space because of not just the resources but the industrial capacity to create those resources -- and in space you'll need a lot, since not only aren't there any on the Moon, but you need to claw out of a really deep gravity well to get that stuff to the Moon -- required to take advantage of that so-called free energy and material resources.
Slashdot Mirror
she was afraid of being put on hold.
The difference is that I'm not advertised as an autopiloted, 70 mph, 4600 lb passenger carrying swamp root eater.
are fully aware that their behavior is reckless. They were not "tricked" by the name of the software.
Yet how many are thinking, "telling us to keep our hands on the wheel at all times is just lawyer CYA"?
Except everyone who casually reads tech news, only vaguely paying attention to headlines written by tech writers, has a completely mistaken impression of what it is and does.
It only takes 97% of the 90K Tesla drivers doing the right thing for there to be thousands of Tesla drivers not doing the right thing.
Hilarity ensues.
It's not about efficiency, and it's not about safety, it's about convenience. Though they call it an autopilot, it's most certainly isn't one. It's built for a totally different reason.
Exactly.
Yes, yes I am.
If the driver has to keep his hands on the wheel, and pay attention, then... it's not an autopilot.
(Not that I'm shocked or anything by deceptive marketing practices.)
Exactly. If you call something autopilot, then people expect it to be an... autopilot.
you'll get some very slow orbital decay that needs to be compensated for
But you said it would go above all atmosphere.
there's no reason the skyhook can't reside completely above it.
Even the Hubble Telescope is exposed to some atmospheric drag, so the skyhook will need to be well above 335 miles.
1,240 miles is the distance I've read which is "completely above" the atmosphere, which is five times the altitude of the ISS.
bring up some problems that actually exist
I did, and you waved them away.
You can't hand-wave away engineering realities.
The same way the bottom of your tire becomes stationary while you're speeding down the highway. Pick a point on the tread and essentially it drops (almost) straight down out of the sky, stops, and then goes straight up again.
There's a reason why calculus was originally called the study of infintesimals.
Experiments in extending cables down into the atmosphere at orbital speeds say otherwise.
What experiments?
more like a fast airplane at best
500 mph is going to keep you from falling back to Earth?
there's no reason to extend deep into the atmosphere
Sure there is, if you want the hook to reach a cargo airplane.
just far enough to link with a plane/rocket/airship in the extreme upper reaches
Show me an airplane that can lift 25 tons of cargo into the extreme upper reaches of the atmosphere.
rolling across the top of the atmosphere
Induced drag will cause unbalanced forces, which will eventually knock the cord out of station.
a momentarily stationary and easily predictable point for pickup
How in the world does a skyhook tip rotating at 9,000 mph become momentarily stationary?
so that planes can rendezvous
The first time that skyhook tip dropped below LEO, the drag would destroy the cable.
A feasible version uses two rotating cables, one in low orbit, and the other in high orbit, with nothing between them but orbit mechanics.
Thanks for the info.
Their combined length is under 2000 km
How would you keep them from vibrating and twisting, thus losing "station keeping"?
You still need a way to get from the ground to half low-orbit energy
Wouldn't those forays into LEO slow down the lower cable due to the same atmospheric drag that plagues the ISS?
even a chemical rocket can do that, easily, with good design margins, and a single stage.
Getting a rocket to meet a hook that's rotating at 3000 m/s seems... tricky.
my favorite, the tumbling cable or wheel elevator
I googled, but no joy.
we may never develop ... potentially ... great potential ... if it can be achieved
The pie is great in this one's sky.
it doesn't require actually spending energy for every launch
Let's pretend that doesn't break physics. The lot of energy still has to come from somewhere, be stored somewhere, and be transmitted to the "car".
and then reabsorbing it when they return.
Friction, among other things, will steal a lot of that energy.
The actual escape energy from Earth is 62.5 MJ/kg = 17.375 kWh/kg = $1/kg at wholesale electric rates ... We just have been terribly inefficient about how we get to space.
Completely ignores that the energy has to be converted to 40,000 k/h escape velocity.
(Don't even mention "space elevator"... https://www.youtube.com/watch?v=iAXGUQ_ewcg)
According to this graph, there isn't too much carbon.
https://en.wikipedia.org/wiki/...
https://en.wikipedia.org/wiki/Geology_of_the_Moon#Elemental_composition "Carbon (C) and nitrogen (N) appear to be present only in trace quantities from deposition by solar wind." No citation, so take it with a grain of salt.
Nothing is free, especially in space because of not just the resources but the industrial capacity to create those resources -- and in space you'll need a lot, since not only aren't there any on the Moon, but you need to claw out of a really deep gravity well to get that stuff to the Moon -- required to take advantage of that so-called free energy and material resources.
but she's not a nerd.
Why must there be a category only for Latin America?
Not just the gibberishly meaningless "Credit Karma of LinkedIn", but another "Credit Karma of LinkedIn". :eyeroll:
No one should really wonder why /. has tanked in popularity...
Assumes that NASA rockets are built by NASA.
Given enough time and money, Microsoft will eventualy[sic] invent UNIX.
Have you forgotten Xenix?
This answers my instant question of whether they'd be viable or not...