What Would It Take to Shoot a Cannonball Into Orbit?

[rangerrebew]

    Author: Rhett AllainRhett Allain
 

What Would It Take to Shoot a Cannonball Into Orbit?
 

Gravity is pretty complicated if you think about it. The motion of a ball falling on the surface of the Earth is caused by the same interaction as the moon orbiting the Earth. That's crazy. It's even crazier to realize that humans figured out that these two motions (falling ball and moon) are from the same gravitational force. It sure doesn't look the same.

Now imagine that you are around during the time of Isaac Newton (let's say early 1700s). How do you make this model of universal gravity? I don't know how he did it, but Newton finally made the connection between the motion of planets (and moons) and the motion of objects on the surface of the Earth. He explains this connection with his famous thought experiment of a cannon firing a ball from a tall mountain. Here is his diagram from A Treatise of the System of the World.

https://www.wired.com/story/what-would-it-take-to-shoot-a-cannonball-into-orbit/

[Oceander]

A heck of a lot of gunpowder, and a very big, long cannon. 

[Joe Wooten]

https://en.wikipedia.org/wiki/Gerald_Bull

Interesting character.

[Elderberry]

A space gun(cannon) by itself is not capable of placing objects into stable orbit around the object (planet or otherwise) from which it launches them. The orbit is a parabolic orbit, a hyperbolic orbit, or part of an elliptic orbit which ends at the planet's surface at the point of launch or another point. This means that an uncorrected ballistic payload will always strike the planet within its first orbit unless the velocity was so high as to reach or exceed escape velocity. As a result, all payloads intended to reach a closed orbit need at least to perform some sort of course correction to create another orbit that does not intersect the planet's surface.

[Joe Wooten]

A space gun(cannon) by itself is not capable of placing objects into stable orbit around the object (planet or otherwise) from which it launches them. The orbit is a parabolic orbit, a hyperbolic orbit, or part of an elliptic orbit which ends at the planet's surface at the point of launch or another point. This means that an uncorrected ballistic payload will always strike the planet within its first orbit unless the velocity was so high as to reach or exceed escape velocity. As a result, all payloads intended to reach a closed orbit need at least to perform some sort of course correction to create another orbit that does not intersect the planet's surface.

That's what was interesting about Dr. Bull's HARP proposal. He wanted to use a lengthened 16" gun to shoot a projectile that was a 2 or 3 stage solid fuel rocket

[Smokin Joe]

https://en.wikipedia.org/wiki/Space_gun

HARP was one such attempt, the Gerald Bull 'supergun' developed for the Iraqis was another, and the Germans had the V3 in WWII (bombed out of existence by the RAF).

Since Bull, SHARP has been the main project.

I wonder if railguns could be used in that fashion, and the concept for launching materials from the Moon has been proposed, at least in science fiction.

[Joe Wooten]

https://en.wikipedia.org/wiki/Space_gun

HARP was one such attempt, the Gerald Bull 'supergun' developed for the Iraqis was another, and the Germans had the V3 in WWII (bombed out of existence by the RAF).

Since Bull, SHARP has been the main project.

I wonder if railguns could be used in that fashion, and the concept for launching materials from the Moon has been proposed, at least in science fiction.

I have not seen anything about it in several years, but there were proposals about 20 years ago for using electromagnetic rails as a first stage for launching rockets. It will not work too well at sea level, but the proposal I saw was to use a mountain in a geologically stable are, like the Davis Mountains in West Texas. Even there, current materials technology will be tested to the limit

[thackney]

I have not seen anything about it in several years, but there were proposals about 20 years ago for using electromagnetic rails as a first stage for launching rockets. It will not work too well at sea level, but the proposal I saw was to use a mountain in a geologically stable are, like the Davis Mountains in West Texas. Even there, current materials technology will be tested to the limit

Once we start mining the moon, it will be a usable method for sending material to earth.  Until the "Loonies" rise up and use it to bomb our cities with kinetic weapons.

[Smokin Joe]

Once we start mining the moon, it will be a usable method for sending material to earth.  Until the "Loonies" rise up and use it to bomb our cities with kinetic weapons.

Or, for that matter, a means to launch payloads just about anywhere in the solar system.