Hi all,

I was having a converstation with my wife last night, and I remembered
hearing about this guy who was working on launching things into orbit by
firing them from a large cannon. He was funding it by selling his expertise
in artillery to other countries, and ended up being killed while working for
Iraq (back before they invaded Kuwait). He was supposedly fairly close to
his objective before he was killed.

A. Does anyone know the name of the person I'm talking about or at least
heard of him? It's been a few years since I've heard anything about him or
his research.

B. What would the minimum initial velocity be for an object be to reach
orbit from sea level without any other thrust being applied after the initial
force (I know the force required to achieve the velocity depends on the
weight of the object).

C. How much would this change if the original force was applied at say
40,000 feet.

You may be able to tell from B and C that math isn't my strong point.

"He turns not back who is bound to a star."
Leonardo da Vinci

Uh, as far as I know an objetc shot by a cannon *can't* achieve a sustainable
orbit - you could launch it in an elliptical orbit, but then it would sink
and burn in the atmosphere after just one orbit around Earth. The solution
would be using (relatively) small rockets to circularize the orbit when the
object reaches the highest point of its originally elliptical trajectory.

However, I've heard someone saying that the gas exhaust speed of no known
chemical explosive could shot something to orbit. But I have no idea about
the math behind that...

Lucio Coelho

Sounds like a bunch of Bull

Canadian astrophysicist Gerald Bull is the one youre thinking off.

One of the concepts was to launch anti satellite payload that would disable
spy satellites passing ovr head.

One of the many cannons is supposedly able to reach 2000 miles.

Bragging was that a rocketlaunches once, cannon can be used multiple times.

> Hi all,
>
> I was having a converstation with my wife last night, and I remembered
> hearing about this guy who was working on launching things into orbit by
> firing them from a large cannon. He was funding it by selling his
expertise
> in artillery to other countries, and ended up being killed while working
for
> Iraq (back before they invaded Kuwait). He was supposedly fairly close to
> his objective before he was killed.
>
> A. Does anyone know the name of the person I'm talking about or at least
> heard of him? It's been a few years since I've heard anything about him
or
> his research.
>
> B. What would the minimum initial velocity be for an object be to reach
> orbit from sea level without any other thrust being applied after the
initial

>
> C. How much would this change if the original force was
> applied at say 40,000 feet.

Less that you would think. There have been some proposals for launching
rockets from high-altitude balloons, but the problem with getting into orbit
is chiefly one of achieving the needed velocity. The potential energy
aspect of it is a relatively minor thing.

That said, ballistic launch from high altitude would help to reduce one
serious problem: air drag (and its attendant heating). O'Neill thought that
the ultimate space launcher might be something like a giant mass-driver
suspended in the upper atmosphere by solar-powered hot air balloons. I even
wrote a SF novella about such a thing named "The Bridge to Space":

http://members.aol.com/howiecombs/bridge.htm

But I warn you that I'm not sure how seriously I take even my own
speculations in this area.

Another important point is that one could not achieve orbit on a ballistic
launch alone. One would need an (admittedly modest) rocket engine for an
orbit circularization burn at apogee.

Regards,

Mike Combs

--- In ssi_list@... Donald Brewer >
> A. Does anyone know the name of the person I'm talking about or
at least
> heard of him? It's been a few years since I've heard anything
about him or
> his research.

You're thinking of Gerald Bull, and you haven't heard much about him
because he was assassinated in Brussels, with five bullets to the
back of the head, in March of 1990.

Here's a link to a summary of his research and a mini-bio

http://world.std.com/~jlr/doom/bull.htm

TangoMan

>Hi all,
>
>I was having a converstation with my wife last night, and I remembered
>hearing about this guy who was working on launching things into orbit by
>firing them from a large cannon. He was funding it by selling his expertise
>in artillery to other countries, and ended up being killed while working for
>Iraq (back before they invaded Kuwait). He was supposedly fairly close to
>his objective before he was killed.
>

>A. Does anyone know the name of the person I'm talking about or at least
>heard of him? It's been a few years since I've heard anything about him or
>his research.
>
Gerard Bull; almost certainly killed by the Israeli secret police. Those
guys don't mess around.

>B. What would the minimum initial velocity be for an object be to reach
>orbit from sea level without any other thrust being applied after the initial
>force (I know the force required to achieve the velocity depends on the
>weight of the object).
>
You can't easily get to orbit from ground level like that for several
reasons:

- cannons to achieve that, whilst in principle possible, have some
practical issues, such as being very large, and suffering from erosion
of their barrel each time they are fired.
- an orbit that was created from a shot from the ground still intersects
the ground
- they're really very noisy indeed (not so much annoy the neighbours,
more sort of kill ;-) )!
- the projectile would see orbital velocity at ground height and tend to
burn up.

Still, speeds of 2-5 km/s seem possible; orbital velocity is 7.8 km/s,
so an extra 'second stage' kick motor can be used to add the extra speed
and circularise the orbit; this was what Bull proposed. The acceleration
is ferocious; 1000g or more, so no stowaways.

>C. How much would this change if the original force was applied at say
>40,000 feet.
>
Yeah it would help a bit. The atmospheric pressure halves every 18000ft
or so. But the velocity needed is still almost the same, so you'd have
less atmospheric losses; maybe 300 ft/second less out of ~25000 ft/sec.