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The Tyranny of the Rocket Equation (2012)

nasa.gov

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Re: The Tyranny of the Rocket Equation (2012)

#72
post #56

"If our planet was 50% larger in diameter, we would not be able to venture into space, at least using rockets for transport." I thought this was quite though-provoking from a Drake Equation standpoint. From what I've gleaned, the earth-like planets we know of seem to be a big bigger than Earth. Perhaps if there's civilization out there, they are hampered by the misfortune of being on a planet that's practically impos…

We're still very early in the development of spaceflight. If you compare with the car industry, we're at the early industrialized phase, where large companies carefully start to develop the necessary technology. Now, 100 years later, a lot is standardized and the knowledge is so common that everybody has the basics, and people can build cars in their back yards. It's the same development that happened with airplanes.…

You might be interested in Copenhagen Suborbitals (copsub.com): A danish group trying to reach space in a DIY fashion financed by donations. It's quite impressive what they've already achieved with not that much more than duct tape!

Re: The Tyranny of the Rocket Equation (2012)

#73

"If our planet was 50% larger in diameter, we would not be able to venture into space, at least using rockets for transport." I thought this was quite though-provoking from a Drake Equation standpoint. From what I've gleaned, the earth-like planets we know of seem to be a big bigger than Earth. Perhaps if there's civilization out there, they are hampered by the misfortune of being on a planet that's practically impos…

You could still do it with nuclear propulsion. Orion, if you absolutely have to go into space today and don't mind riding a string of atomic explosions.

Re: The Tyranny of the Rocket Equation (2012)

#74
post #72
post #56

Earlier quoted context omitted.

We're still very early in the development of spaceflight. If you compare with the car industry, we're at the early industrialized phase, where large companies carefully start to develop the necessary technology. Now, 100 years later, a lot is standardized and the knowledge is so common that everybody has the basics, and people can build cars in their back yards. It's the same development that happened with airplanes.…

You might be interested in Copenhagen Suborbitals (copsub.com): A danish group trying to reach space in a DIY fashion financed by donations. It's quite impressive what they've already achieved with not that much more than duct tape!

That is amazing, thank you so much for linking it. I did not know about them, and it does indeed seem like they have made a lot of progress. I'll be following them from now :)

Re: The Tyranny of the Rocket Equation (2012)

#75
People that have played different versions of Civilization will remember the Triremes.

They couldn't end a term in the ocean, only the coast. However, you could take a punt and travel over the ocean - with only the hope there was land on the other side.

Horribly expensive, but discovering new land or another civilization early could be transformative for the same.

Re: The Tyranny of the Rocket Equation (2012)

#77
post #76
post #70

Earlier quoted context omitted.

eer...yes? https://en.wikipedia.org/wiki/John_Carmack#Armadillo_Aerospa...

Oh. I stand corrected, should have researched that before commenting.

This exchange made me grin :)

To add some value to my comment, here's a cool video from one of armadillo's test rockets: https://www.youtube.com/watch?v=9u0qlIoSSkQ

Re: The Tyranny of the Rocket Equation (2012)

#78

Earlier quoted context omitted.

If you were in a vacuum, that could be a wonderfully efficient way of converting mechanical movement into kinetic energy. We have to deal with atmospheric friction, though, and the places where the cannon would launch from (the surface) has the thickest part of the atmosphere, so the most friction.

what about vacuuming the cannon? like those ping pong ball cannons?

What happens when you leave the cannon? Either the cannon exit is near ground level, in which case you still have the air resistance problems; or it's not, in which case you have the problems of building very a tall cannon.

Re: The Tyranny of the Rocket Equation (2012)

#79
So this is something I've always wondered about.

Can anyone explain the equation for getting to an earth sun Lagrange point?

Since were already on earth orbiting the sun it would seem we already have the correct orbital velocity to hang out at a Lagrange point. So we could really approach these points at any speed no? Is there potential to use less fuel than you'd need to reach an earth orbit?

Re: The Tyranny of the Rocket Equation (2012)

#80
post #72
post #56

Earlier quoted context omitted.

We're still very early in the development of spaceflight. If you compare with the car industry, we're at the early industrialized phase, where large companies carefully start to develop the necessary technology. Now, 100 years later, a lot is standardized and the knowledge is so common that everybody has the basics, and people can build cars in their back yards. It's the same development that happened with airplanes.…

You might be interested in Copenhagen Suborbitals (copsub.com): A danish group trying to reach space in a DIY fashion financed by donations. It's quite impressive what they've already achieved with not that much more than duct tape!

as the article says, space != orbit. i don't see how you can get 8 km/s delta-v in a garage.

edit: doesn't mean it's not interesting, but orbit is so much more challenging than just space it's not funny.

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