Posted on 10/21/2024 11:52:29 AM PDT by TexasKamaAina
This technology aims to revolutionize the way satellites are sent into space, using a giant rotating arm to fling satellites into low Earth orbit.
(Excerpt) Read more at thebrighterside.news ...
The problem with the hypothetical space elevator isn’t materials science, it’s that it isn’t like dangling a plumb bob off an overpass.
“ I’m no physicist, but this concept seems to be lacking some basic calculations.”
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It would have to be at “escape velocity” (actually more because of huge immediate deceleration due to air resistance) upon exit from the slinger. There would be an extremely rapid build up of heat on/in the projectile because of this high speed in the LOWER ATMOSPHERE.
This might work on the moon but it would be very unlikely to be practical from the Earth.
Mirrors of optics and servo motors don't pass the Sampsonite test, let alone mil-spec 801.
Now launching heavies to stations that can then manufacture satellites while in orbit or on the moon makes a hell of a lot more sense.
Why lose 95% of energy and materials with each return to earth? You spent the resources to escape earth's gravity, why repeat the same thing a few thousand times for 5% of the yield?
Your knowledge could have saved 300 million taxpayers quite a fortune.
Railgun launching off the Earth’s Moon has a better chance of working, as long as it’s used to launch ores or processed materials rather than tech-laden vehicles. Some kind of catcher’s mitt would be needed, but the trajectory and the kinetic energy of the material to be caught would have to be matched with the motion, to avoid having the mitt careen away or plummet downward. It would be doable I think, to make the stuff tossed from the surface to basically rendezvous with the orbiting freighter, which would scoop it into its hold, and then break orbit to head to reentry in the Earth’s atmosphere, followed by a controlled landing.
Anyway, regarding launches from Earth:
Could a rail gun be used to launch a spacecraft?
https://www.quora.com/Could-a-rail-gun-be-used-to-launch-a-spacecraft
Blasphemer Physix naysayer!
Jeez… you’re on to me.
Between a penny and nickel each, yeah.
Almost all also know enough to defer to the other smartest guy in the room. By the end you have quite the accumulated gift of knowledge here.
“And he just needs $43 billion dollars in government handouts to make it work.”
Easy peasy. Claim you’re a minority owned business and you’re in like Flynn. Even better if you’re a big Democrat donor.
Even if the giant centrifuge spins up slowly and the internals are all in vacuum, it does seem the exit into air at escape velocity would be pretty spectacular. It wouldn’t be like a rocket gradually building velocity as air density is declining due to the change in altitude. Like another FReeper posted, it needs to exit the launcher at more than 25,000 MPH. Still, the concept is interesting.
The technical question is without any onboard means of propulsion whatsoever, how can the satellite guide itself to a designated orbit??? Are they operating on the mere supposition that an object of x weight thrown outward and upward and an angle of y degress, with a force of Z WILL UNDOUBTABLY, gliding on its own, reach a known stable orbiting height, pattern and route? Call me skeptical.
I expected this to be from BabylonBee.
I haven’t crunched the numbers but the gravitational force of the earth would be a constant acceleration of 1 g. The angular acceleration could be easily kept under 1 g. The centripetal force is F = mV^2/r. So the centrifuge would have to be pretty big and the object’s mass low to keep the centripetal force low. The biggest factor is velocity which is squared. Yeah, we are talking some pretty big numbers at 11000m/s escape velocities.
Very interesting short article on Bull and his space gun.
But then there’s this: “In March 1990, Bull was shot five times in the back of the neck while entering his apartment.”
They should have given him a Hunter S Thompson send-off.
I question your physics.
Remember the pictures of the early astronauts riding in the centrifuge with their faces all distorted? The max velocity was constant but the centrifugal (centripetal) force from the rapid change in direction was very high.
https://www.spinlaunch.com/orbital#p4
The problem with the sling launch is the package has to be launched (apparently) from sea level -- where the air is at its densest -- with enough velocity that it can coast through 60+ miles of atmosphere and still get to low earth orbit with a velocity of no less than 17,300 mph.
That means launch has to happen at, oh, I don't know, maybe Mach 60? That's hypersonic on steroids, several times faster than the heat barrier. Imagine the HEAT of anything going Mach 60 AT SEA LEVEL. And don't forget that the launcher arm has to going that fast, too. The heat from aerodynamic drag -- both on the launcher arm and the package -- would be tremendous. Parts of the SR-71 got to 1000°F at Mach 3-3.5, and aerodynamic drag increases at the square of the change in velocity, so skin temperature at those velocities must be tens of thousands of degrees. The highest melting point known to man is barely more than 7000°F.
Chemical propulsion rockets don't have this problem because they accelerate from zero at launch and get up into thinner air before they even go supersonic, much less hypersonic.
The math is beyond me (I don't have the presumed launch velocity or ballistic coefficient of their rockets) but my intuition is that the OP's headline is an out-and-out-lie, and that the launch only gets the package up to something like Burt Rutan used in winning the Ansari X-Prize competition, about 50,000 feet. Then the chemical rocket kicks in and takes it to LEO.
But launching it all the way to orbit from a catapult and without a chemical rocket boost? Color me skeptical.
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