Physics question: Catapult objects into orbit

[The Last Conformist]

It think the problem is you'd need to achieve an escape velocity from launch, since there is no propulsion but the imediate velocity of take off, and this means achieving 11.2 km/s at release and that requires explosives, I fail to see how a catapult could store the potential energy required which would not destroy it's structure, even with space age alloys.

What sort of catapults are we allowing? A trebuchet would indeed seem infeasible with present materials science.

 

[Sidhe]

It wouldn't work, aerobraking would simply slow it's descent not throw it into a new orbit, to do that would require a sgnificant antigravitational boost. best you could achieve is a bump to a slightly higher orbit but that would soon decay as it slowed down again, it'd be like skipping a stone off a pond albeit a stone with temporary wings.

 

[The Last Conformist]

It wouldn't work, aerobraking would simply slow it's descent not throw it into a new orbit, to do that would require a sgnificant antigravitational boost. best you could achieve is a bump to a slightly higher orbit but that would soon decay as it slowed down again, it'd be like skipping a stone off a pond albeit a stone with temporary wings.

Kindly read my post again.

 

[Sidhe]

I see what your saying but it would be very ineficient and you would require a method of pointing the projectile in just the right direction to keep skipping it efficiently(gyroscopes and small thrusters perhaps?) Or am I misreading your post?

Oh of course a Trebuchet is fine but it would not have the strength to hold up under the huge pressures exerted to achieve a lift off of such high velocity, imagine the counterbalance weight to throw something that fast, were talking: I think it's about 25,000 mph here. You'd need a shell and explosives and even then the gun may well need repair after launch. Incidently there are guns that can do this.

 

[The Last Conformist]

I see what your saying but it would be very ineficient and you would require a method of pointing the projectile in just the right direction to keep skipping it efficiently(gyroscopes and small thrusters perhaps?) Or am I misreading your post?

I don't know if you are.

You're right it's a kinda silly idea, however. It's got no pragmatic interest.

As for building the actual catapult, I doubt any materials known today are strong and lightweight enough to make a counterweight (still less torsion!) catapult of the prerequisite power. An interesting idea might be an EM catault, but I'm really not into the physics of that.

 

[ybbor]

Oh of course a Trebuchet is fine but it would not have the strength to hold up under the huge pressures exerted to achieve a lift off of such high velocity, imagine the counterbalance weight to throw something that fast, were talking: I think it's about 25,000 mph here. You'd need a shell and explosives and even then the gun may well need repair after launch. Incidently there are guns that can do this.

you know, in you don't need flight to build the Apollo program. Most people think that this is the "alternative" way the devolpers let us send men to the moon.

lots and lots of gunpowder + really big cannon + man = moon

 

[The Last Conformist]

you know, in you don't need flight to build the Apollo program. Most people think that this is the "alternative" way the devolpers let us send men to the moon.

lots and lots of gunpowder + really big cannon + man = moon

Considering the prereq for the Apollo Project is Rocketry, this seems unlikely.

 

[Sidhe]

you know, in you don't need flight to build the Apollo program. Most people think that this is the "alternative" way the devolpers let us send men to the moon.

lots and lots of gunpowder + really big cannon + man = moon

I agree.

Aw cmon TLC, he'd get there he'd just leave a big man shaped whole on the surface, that is getting man to the moon though

 

[ybbor]

Considering the prereq for the Apollo Project is Rocketry, this seems unlikely.

rocketry can still be accesed w/o flight if you have both artillery and rifiling

here, I took a screenshot:



EDIT: looks like you don't need electricity either. you can light candels for your view

 

[The Last Conformist]

rocketry can still be accesed w/o flight if you have both artillery and rifiling

I'm perfecly aware of that. My point is, if a civ has access to rocketry, there's no reason to assume they use cannons instead of rockets to reach the Moon. Whether they have developed airplanes would seem irrelevant.

 

[Cheezy the Wiz]

just remember that an object in orbit is really just falling at the same rate that the Earth recedes from it

 

[Zwelgje]

Some people think a technique like this can be viable:

Sled Could Be Launcher of the Future
Developers at the private space technology firm, LaunchPoint Technologies of Goleta, California, have begun the design of a new system that could launch microsatellites into orbit without the help of launchers and at a fraction of the cost. According to Launchpoint, the system design is one that utilizes a levitating sled that whirls around a giant magnetic ring at increasing speeds. Once it reaches it desired speed, the circular accelerator apparatus would release a small satellite onto a ramp at 10 kilometers per second. The program, being funded by the US Air Force, uses much less energy than conventional linear accelerators, such as rockets. Launchpoint thinks they could eventually fire hundreds of miscrosatellites into space each day.
(New Scientist, http://www.newscientistspace.com/ar...etic-sled-could-hurl-objects-into-orbit-.html, 5/22/06).

 

[Leifmk]

just remember that an object in orbit is really just falling at the same rate that the Earth recedes from it

In what frame of reference?

 

[AL_DA_GREAT]

Try using more force

 

[Souron]

You could make a game like Spaced Penguin. It's a slingshot, not a catapult, but otherwise it seems to fit the assignment.

 

[Perfection]

What would happen if you stuck the moon into your program?

I suspect you might get some actually interesting orbits if you fire crap at the moon.

 

[Mise]

What would happen if you stuck the moon into your program?

I suspect you might get some actually interesting orbits if you fire crap at the moon.

If you fired something at the moon just right, it would orbit at the point where the gravitational force of the earth equals the gravitational force of the moon. (Actually it would crash into the satellite that's already there, IIRC.)

 

[IglooDame]

Try using more force

Ah yes, the Marine Corps method.

 

[mdwh]

you know, in you don't need flight to build the Apollo program. Most people think that this is the "alternative" way the devolpers let us send men to the moon.

lots and lots of gunpowder + really big cannon + man = moon

Actually this makes sense, though not because of using an alternative method with a big cannon.

The point is that the normal method of using a rocket doesn't involve "flight", in the sense of using a wing to generate lift. Okay yes, technically if you fire a rocket up, you've achieved "flight" in some sense, but this is not going to be useful for building planes (i.e., general heavier than air vehicles for travelling within our atmosphere). It's perhaps conceivable that a civilization might develop rocketry and even space flight, before they developed flight?

 

[Perfection]

Actually this makes sense, though not because of using an alternative method with a big cannon.

The point is that the normal method of using a rocket doesn't involve "flight", in the sense of using a wing to generate lift. Okay yes, technically if you fire a rocket up, you've achieved "flight" in some sense, but this is not going to be useful for building planes (i.e., general heavier than air vehicles for travelling within our atmosphere). It's perhaps conceivable that a civilization might develop rocketry and even space flight, before they developed flight?

Perhaps so, especially in the instance of a smaller world with a thinner atmophere.