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The Astronomy Thread
- Thread starter Araxen
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Guest, it's time once again for the massively important and exciting FoH Asshat Tournament!
Go here and give us your nominations!Who's been the biggest Asshat in the last year? Give us your worst ones!
Mudcrush Durtfeet
Hungry Ogre
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I don't think they're going to be able to make a full scale version of this technology.
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The concept is hilarious so I did some napkin math. If you have a launcher with a 50-foot radius, in order to achieve escape velocity of 11.2 km/s (ignoring air resistance) your payload is going to experience centripital acceleration of about 840,000 G's. A solid metal payload would be a pancake even if we had a device capable of generating/resisting such forces, which we don't. In order to limit the centripital acceleration to 10 G's you'd need a launcher the radius of the continental United States.
Maybe there's some hybrid version where you catapult an actual rocket at the limit of its structural integrity and it goes the rest of the way up under thrust. I think there are good reasons we're not already doing this, though.
Edit: On a closer watch, they are going for a hybrid approach with a 2 km/s release speed and 50-meter radius. That's still 8200 G's. I also can't wait to see the timing failures when your 7200 km/hr fuel-laden rocket hits the sides of your launch facility.
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Gravel
Mr. Poopybutthole
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Big Phoenix
Pronouns: zie/zhem/zer
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That level of G force wont be a problem for electronics, thats comparable or less than what artillery shells experience on firing and theyre filled various electronics.
But at the end of the day yeah its almost certainly a concept that has no use on Earth without significant advances in materials science. But on Luna or any other similar body with no atmosphere it will probably have use whenever we get around to getting off this rock.
Also heres some youtube neckbeard shitting all over it;
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BrutulTM
Good, bad, I'm the guy with the gun.
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There are electronics in artillery shells but I wouldn't say it's not a problem for them. The G forces are probably the primary design consideration and there are a LOT of downsides to it.
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Big Phoenix
Pronouns: zie/zhem/zer
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Yeah that's one of the red flags about this concept, it would never launch a currently designed satellite but they don't tell you that.
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BrutulTM
Good, bad, I'm the guy with the gun.
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phisey
Buzzfeed Editor
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Could just be used to make for more efficient hypersonic engines. Scramjets usually need to be at mach 3-5 to start so they're normally bootstrapped by a rocket or a plane, which means they're at very thin atmospheres. If they could just yeet it to mach 1 or 2 within one atmosphere of pressure it could get the scramjets ignited outta the gate that's a massive benefit since the scramjets have no moving parts and are vastly more efficient than rockets or regular ramjets and turbojets once they get started.
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LachiusTZ
Rogue Deathwalker Box
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Mending fences and voting Hillary make you a physicist?
How many g's does a phone experience going from 4ft to the ground, on concrete or tile? I've dropped several phones like that without even breaking the screen.
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BrutulTM
prolly can't do the math, if someone wants do the math...- 1
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BrutulTM
Good, bad, I'm the guy with the gun.
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Mending fences and voting Hillary make you a physicist?
How many g's does a phone experience going from 4ft to the ground, on concrete or tile? I've dropped several phones like that without even breaking the screen.
Since
You probably didn't know this, but before I came back to the ranch I spent 10 years designing telemetry systems for bombs and missiles. I never personally did one for an artillery shell but I know people who did and dealing with the acceleration was a nightmare and dictated the entire design. Also I would rather be branded than vote for Hillary.
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LachiusTZ
Rogue Deathwalker Box
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I don't give a fuck.
But since your capable, do the fucking math.
Call me crazy, but I trust Scott Manley on this crap more than I do you.
Now, you could easily convince me. By doing the fucking math.
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LachiusTZ
Rogue Deathwalker Box
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Which sort? The fantastic numbers said in this thread?
Or the numbers from spin launch?
Or the estimated from Manley?
I don't think I ever said a phone could be fired from a gun.
So you were responding to imaginary posts?
It's pretty damn telling, that even tho you are personally able, that you don't want to do the math.
Maybe you need to try meditation or some shit.
Maybe "properly mounted" was not industry specific? How about "properly reinforced"? Lol
Anyway, they apparently have solutions for fly wheels etc to survive those forces and still function, which, IMHO, are more delicate than most electronics by their nature (spinning on a case to provide torque to spin vehicle). Maybe they are called reaction wheels? Fuck I can't remember.
Whatever
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BrutulTM
Good, bad, I'm the guy with the gun.
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You can survive a 4 foot fall onto tile. Could you survive a ride on that thing? All I'm saying is it's a lot more complicated than you're making it out to be and whatever payloads they are going to send on that thing surviving the initial acceleration is going to have to be a major design consideration.
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The acceleration on the path of travel is very slow; the payload is brought up to speed over a period of 90 minutes or so. The issue is centripetal acceleration, which is high but sustained
Phones break when dropped onto hard surfaces because of the concentration of stresses. As mentioned in the video, current commercial electronics can withstand thousands of G's if applied to the entire structure. This doesn't meant that it's not a consideration, just not one that's immediately fatal to the concept at the configuration they're targeting.
IMO, whether or not electronics will break under ~10,000 G's is much less important than what happens when they inevitably have a timing error on release and launch the thing into the walls of their ground facility.
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