I like Rudy's suggestion.
gravities with a research mass driver two decades ago, and if modern
maglev trains can accelerate many tons of hardware and people to
hundreds of miles per hour, I wonder what a team of hobbyist/amateurs
could do with some second-hand electronic parts and the right piece of
property today.
Come to think of it, a "launch ramp" up the side of a suitable slope
might not be necessary. Dig a hole. Point the maglauncher near to
vertical. That might even make recovery from failed vehicle engine
ignition safer to recover from.
Of course, if a magnetic catapult provides the "first stage" for
launching a bean can-sized satellite, how does one shield the mission
electronics from EMP damage?
Hmmm...maybe work on development of the launch catapult and vehicles for
a few years while waiting for the mission package to run on photonics
rather than electronics.
Colin Keizer
I've been fascinated with the concept of mass drivers for years.
1. heat shielded payload to avoid having to operate in a vacuum.
2. de-energized electronics that booted off optical memory once started up.
3. Have one end of the driver underground with the other at ground level.
This gives you the tilt you need, and you could capture energy from lowering the payload from ground level to the loading pad and use it to help support operations.
4. Build the driver in modular sections on steel rails, like train cars. You'd have three sets of tracks, one in the center for the launch tube, one to each side to support an over head crane for placing or removing launcher segments. You could then also use the rails as power and data busses for launcher ops.
5. As soon as you had a minimum number of launcher segments in place, you'd start launching scramjet-assisted payloads. After you had enough more, you'd start launching payloads that didn't need assist.
Dan Stafford
I like Rudy's suggestion.
If Dr. O'Neill, Dr. Kolm and some graduate students could achieve 500
gravities with a research mass driver two decades ago, and if modern
maglev trains can accelerate many tons of hardware and people to
hundreds of miles per hour, I wonder what a team of hobbyist/amateurs
could do with some second-hand electronic parts and the right piece of
property today.
Come to think of it, a "launch ramp" up the side of a suitable slope
might not be necessary. Dig a hole. Point the maglauncher near to
vertical. That might even make recovery from failed vehicle engine
ignition safer to recover from.
Of course, if a magnetic catapult provides the "first stage" for
launching a bean can-sized satellite, how does one shield the mission
electronics from EMP damage?
Hmmm...maybe work on development of the launch catapult and vehicles for
a few years while waiting for the mission package to run on photonics
rather than electronics.
Colin Keizer
.
> Of course, if a magnetic catapult provides the "first stage" for
> launching a bean can-sized satellite, how does one shield the mission
> electronics from EMP damage?
>
catapult" - a cannon? As far as I remember, technology for launching small
payloads from cannons to a distance of tens of kilometers exists since WWII
(or maybe WWI). It is very brute-force, kind of antique, but it is also far
easier/simpler and probably cheaper to build. And it would avoid EMP damage.
> Colin Keizer
Lucio Coelho
Hello
I had devised a air impulse design that used a column of water faling from a considerable distance, like down a mountain, in a pipe of course, and using that to pressure a smaller tube which propelled the payload.
It is simple, safe, fool proof and re-loading involves no more than pumping the water back up the mountain. I think as a general rule, we should try to avoid explosives, chemicals, etc. as much as possible. They add complexity to what is a hobbyist venture.
Electricity, parabolic mirrors, whatever, all seem in the spirit of my suggestion. as I said, it is just an idea. No formal design exists, but creating such a design and fabricating it is probably doable by skilled amateurs.
> I had devised a air impulse design that used a column of water faling from
a
> considerable distance, like down a mountain, in a pipe of course, and
using
> that to pressure a smaller tube which propelled the payload.
>
> It is simple, safe, fool proof and re-loading involves no more than
pumping
> the water back up the mountain. I think as a general rule, we should try
to
> avoid explosives, chemicals, etc. as much as possible. They add complexity
to
> what is a hobbyist venture.
simply let the water filling the launch tube flow out, and then you don't
even need pumps. But I don't have any idea of how much acceleration/speed
such a mechanism could provide.
Lucio Coelho
The column of water , if falling from 1000 feet in a 12 foot diameter pipe, can accelerate air in a 2 foot diameter pipe to Mach 1.
> The column of water , if falling from 1000 feet in a 12 foot diameter
pipe,
> can accelerate air in a 2 foot diameter pipe to Mach 1.
places you can find much higher mountains stepping down to near-sea-level.
So you can pipe a high lake/water course to your tube (which would have the
lower end at sea level and the upper end at 300 m) and, after launch, just
flush out the water into the sea.
I know at least one place in my country with those characteristics, the
coastline where the Brazilian Highlands (see
http://www.peakware.com/encyclopedia/ranges/brazil.htm) "fall" steeply into
the Atlantic. Plenty of rainfall at the top, with abundance of water
courses. I guess that there is some place like that in the US - along the
Rockies?
Lucio Coelho
I think I'm just jumping in here not knowing much about the whole
propulsion and launch subject but I thought I'd try a little. Haven't
really posted to this list before either, hope it's okay.
a site for the launcher do you not also have to worry about how low in
altitude it starts at. For example, say you can have a 300 meter track
starting at sea level, and then you can have a 200 meter track starting at
an elevation of 500 or 1000 meters already, then it is probably still
advantagous to create the 200 meter track instead of the 300 meter one. A
simple trade study on this could be done once you have candidate sites for
a system like you are proposing. It all depends on where you want it to go
I guess.
Or so it seems to me.
Joshua.
Hello
thought. If the water column falls 3200 feet, you can accelerate the pulse to
escape velocity.
I have also hypothesized a lower cost nav system for launch. You use GPS to
create an invisible tunnel into orbit defined as a series of rectangles the
payload aims for. As it pierces each 'box'" it looks for the next one, and so
on.
what would be the acceleration curve? A shot like a canon or a gradual
increase like todays rockets?
You may consider Marshall Savage idea of using a gentle sloping mountain as
a guide for a tunnel to use maglevs to impulse a vehicle to escape
velocity. I believe he went so far as to suggest the evacuation of air from
the tube using a kind of seal at the upper end so that air resistence would
be elimnated until the escape into the atmosphere at the higher elevations
of the mountain. I beleive he had suggested mount Kilamanjaro in Africa;
power for the enterprise to be generated by sea OTEC's.
(OTEC- a kind of temperature engine utilizing differences between tropical
warm waters and deep cold ocean)
The aceleration was the key, as was the large OTEC generator.
It would seem easier to have a dedicated lake to use force of dropping water
for power. Of course you would need to calculate the amount of oomph needed
depending on the mass of the vehicle, yes? A bigger vehicle requiring more
water volume to produce push....yes?
very interesting concept still.
bob
SLF
> Hello
>
> This is what I hoped for, people discussing how to do it. More food for
> thought. If the water column falls 3200 feet, you can accelerate the pulse
to
> escape velocity.
>
> I have also hypothesized a lower cost nav system for launch. You use GPS
to
> create an invisible tunnel into orbit defined as a series of rectangles
the
> payload aims for. As it pierces each 'box'" it looks for the next one, and
so
> This is what I hoped for, people discussing how to do it.
> More food for thought. If the water column falls 3200 feet,
> you can accelerate the pulse to escape velocity.
foot diameter pipe still seems like an excessive engineering hurtle
to me.
What if the launch tube was only six inches diameter instead of the
two feet originally mentioned? This group recently discussed micro
payloads. I'm thinking of soup/soda can sized payloads.
Biggest problem I see is "cooking the soup" on the way up. ;) If
you're launching at escape velocity, would it just be a matter of
putting an ablative heat shield on the payload?
Chris.
The panama canal has culverts in that size category, designed and built at
turn of the century, so is definetly doable today.
Read this:
10 Years and $387 million in 1903-1913 dollars. Not to mention the
number of lives lost during the project.
Sure, doable. The panama canal was and still is an excessive
engineering hurtle. I thought this idea was supposed to lower launch
costs.
Chris.
Two notes relevant to this discussion line:
Perhaps a year ago this group discussed launching up an equatorial
mountain in South America. As I recall, the mountain was Chimborazo, which
is in Ecuador, 6267 m tall, almost on the equator (already going East at ~
1000 + miles per hour), and on top of the "equatorial bulge," making it the
best place to launch from solid Earth. SeaLaunch already does business from
the equator (see http://www.sea-launch.com/) using the Earth's rotation and
low cost water transport to the launch site. Orbital speed in mach 25 or
so. The idea was to use electromagnetic propulsion up the west slope to the
top, and then rockets after that. Perhaps someone has files on this, which
may be indexed under Chimborazo. This could work if construction costs for
the ramp and other needed infrastructure are either not too costly or the
cost can be spread over lots of launches. These are problems any new launch
venue will have to solve.
A second idea being considered is amateur rockets to orbit, I presume to
lower the cost, which I think is unlikely. A space news letter I get
(spaceupdate@... from http://www.space.com/) posted the following
this morning; "* Amateurs to Make a Stab at Space With Rocket
http://www.space.com/missionlaunches/launches/amateur_rocket_020618.html
A group of rocketeers hope the next two weeks will put them in the
history books with a vehicle that, if successful, would be the first amateur
rocket shot into space."
Sincerely, Jay Huebner
Cannons don't achieve speeds any where near the mach 25 needed for orbit. A
"Army 45" fires at less than mach 1, as does any gun that can be silenced,
else the sonic boom would make the silencer useless. Guns are ultimately
limited by the speed of the gas particles, which must bounce off the back of
the projectile to give it momentum. Powder burning at 3000 K, considering
(1/2) m v (squared) equals (3/2)k T (which is kinetic theory of gases),
gives its gas (or plasma) particles only a few thousand miles per hour
(perhaps mach 4 or 5). So there is no hope for a gun to shoot from Earth to
space.
> launching a bean can-sized satellite, how does one shield the mission
> electronics from EMP damage?
>
Since you're planning to launch can-sized satellites, why not use a "gas
catapult" - a cannon? As far as I remember, technology for launching small
payloads from cannons to a distance of tens of kilometers exists since WWII
(or maybe WWI). It is very brute-force, kind of antique, but it is also far
easier/simpler and probably cheaper to build. And it would avoid EMP damage.
> Colin Keizer
Lucio Coelho
Hellol
governed by the mass of the water. Other considerations are whether the
payload had a booster attached.
Manned payloads sounds a bit ambitious for a first try. I am not advocating
that right now. Ask me after some unmanned payloads are launched
successfully. ;)
Where the electricity comes from is irrelevant for a pumping operation.
Windmills might be adequate.
The Savage design was in an evacuated tube, as i understand. I don't think
they ever worked out how to get the payload out of it and into the thinner,
but still present, air over MT. Kilamonjaro. OTEC is a great idea but is it
necessary to transmit power over 3000 miles.
I think the Andes would be a great location. High and on the equator with
lots of water nearby.
I concede this would be a massive civil engineering project but it is all
low-tech so it becomes just a matter of time and money.
Hello
I think its greatest value would be as a cheap 'first stage' with a more
conventional rocket carrying the payload to orbit.
As to comparisons to the Panama Canal, perhaps a more direct comparison is
the aqueduct from the Colorado River to Los Angeles. It goes up and over the
Rockies.
Electromagnetic propulsion was reported in articles to commonly achieve acceleration in the range of 1K G's. I recall an article in the late 1980's that a university test model accelerated an aluminum bicycle rim to over 230mph in the space of 31 inches. I'd bet you could lengthen the tube and lower the power and achieve a 3-5 G launcher.
I still think simple ablative heat shielding on the leading edges of the payload containers would enable overcoming atmospheric heating issues, and avoiding using vacuum woud reduce costs, as well as unnecessary shock on the payload when the craft transitioned from an evacuated tube to the open atmosphere on launch.
Also, an electromagnetic system would only have one moving part, basically. The payload.
Dan
Cannons don't achieve speeds any where near the mach 25 needed for orbit. A
"Army 45" fires at less than mach 1, as does any gun that can be silenced,
else the sonic boom would make the silencer useless. Guns are ultimately
limited by the speed of the gas particles, which must bounce off the back of
the projectile to give it momentum. Powder burning at 3000 K, considering
(1/2) m v (squared) equals (3/2)k T (which is kinetic theory of gases),
gives its gas (or plasma) particles only a few thousand miles per hour
(perhaps mach 4 or 5). So there is no hope for a gun to shoot from Earth to
space.
> Of course, if a magnetic catapult provides the "first stage" for
> launching a bean can-sized satellite, how does one shield the mission
> electronics from EMP damage?
>
Since you're planning to launch can-sized satellites, why not use a "gas
catapult" - a cannon? As far as I remember, technology for launching small
payloads from cannons to a distance of tens of kilometers exists since WWII
(or maybe WWI). It is very brute-force, kind of antique, but it is also far
easier/simpler and probably cheaper to build. And it would avoid EMP damage.
> Colin Keizer
Lucio Coelho
.
Whoa Chris,
rights from France, solving health challenges, etc.
I is from there, third generation, born and raised so I'm privy to more than
most about canal :-) hence PANAMA bob hehe
What essentially you are considering is creating tunnel or culvert 3,200 ft
long and 3 meters in diameter or there abouts and the feasibilty of such a
thing regarding engineering.
The center wall of one of the locks sets is around a mile long and in the
center of it and in the bottom of the 1000 ft long 110 ft wide chambers are
culvert to direct water from lock chamber to chamber. All gravity fed, no
pumps. What was once the largest manmade lake in the world was the
reservoir providing the waters for the movement of ships. Kind of like the
launch thing in reverse....huge volumes of water but moving relatively
slowly and lifting great ships.
If you were to eliminate the actual ditch digging part, and the construction
/ creation of support infrastructure, the $400 mil would be considerably
less.
Volume of concrete for all 3 lock mass is akin to 10 Cheop pyramids. Since
you would only be building one, not three, and the mass wouldnt be so much
as to house ocean going 900 ft long ships, you can see the costs would be
more reasonable and cost effective. There would be the building of a dam /
reservoir to accumulate the waters, but it may be possible to pump the
water back up and reuse most of it , less what evaporates or leaks.
Lets just take common cost for a cubic yard of concrete with labor and add a
little more and peg it at $100 yd\3
lets say its 4000 ft long to include loading area and what ever. Thats
1,333 yds long. assume 15 feet thick "walls' to withstand pressures thats 5-
yards . and assume an inside diamention of the tunnel of 20 ft.
Forsimple math sake, lets consider it a 50 ft square cross section witha 20
ft square hollow inside then at 4000 ft long
so that puts it around 210 sq yds x 1333 = 280,000 cubic yards or round it
to 300,000 cubic yards of concrete ...again at $100 per cubic yd that would
be roughly $30 million (ok ok quickie math, see any glaring mistakes?)
Of course you would need to add some engineering costs, some support costs
to build, other infrastructure at the actual launch site, the launch
vehicles, etc etc.
Common estimates for a shuttle are at least $300-$500 million. Jumbo Jet 747
around $240 million.
Hmmm this looks more and more attractive. Russia estimate for a
Buran/Energia booster launch cost are around $130-$150 million.
Intersting concept this hydrolic ram booster. Very Interesting.
bob
SLF
[snikt]
> Biggest problem I see is "cooking the soup" on the way up. ;) If
> you're launching at escape velocity, would it just be a matter of
> putting an ablative heat shield on the payload?
>
are perfectly doable. However, he was writing about larger payloads, and I
don't know what would be the behavior of "soda cans" in the same conditions.
I'm specially concerned about stability and air drag (considering the low
mass-to-surface ratio of a "soda can" payload) while passing through the
atmosphere. But, again, that is just my intuition speaking, I'm a nullity in
aerodynamics.
> Chris.
[snikt]
Lucio.
> Cannons don't achieve speeds any where near the mach 25 needed for orbit.
A
> "Army 45" fires at less than mach 1, as does any gun that can be silenced,
> else the sonic boom would make the silencer useless. Guns are ultimately
> limited by the speed of the gas particles, which must bounce off the back
of
> the projectile to give it momentum. Powder burning at 3000 K, considering
> (1/2) m v (squared) equals (3/2)k T (which is kinetic theory of gases),
> gives its gas (or plasma) particles only a few thousand miles per hour
> (perhaps mach 4 or 5). So there is no hope for a gun to shoot from Earth
to
> space.
replied suggesting a canon-like launcher not as a "SSTO", but also as a
first stage. I'm sorry that I did not make that clear in my post.
[snikt]
Lucio Coelho
> the $400 million price tag includes the whole sha bang, and also
> purchasing rights from France, solving health challenges, etc.
>
> I is from there, third generation, born and raised so I'm privy to
> more than most about canal :-) hence PANAMA bob hehe
> What essentially you are considering is creating
> tunnel or culvert 3,200 ft long and 3 meters in
> diameter or there abouts and the feasibilty of
> such a thing regarding engineering.
Wasn't it the case that this tunnel had to be vertical?
[snip very interesting canal stats]
> Lets just take common cost for a cubic yard of
> concrete with labor and add a little more and
> peg it at $100 yd\3
>
> lets say its 4000 ft long to include loading
> area and what ever. Thats 1,333 yds long.
> assume 15 feet thick "walls' to withstand pressures
> thats 5-yards . and assume an inside diamention
> of the tunnel of 20 ft.
>
> Forsimple math sake, lets consider it a 50 ft
> square cross section with a 20 ft square hollow
> inside then at 4000 ft long so that puts it around
> 210 sq yds x 1333 = 280,000 cubic yards or round it
> to 300,000 cubic yards of concrete ...again at
> $100 per cubic yd that would be roughly $30 million
> (ok ok quickie math, see any glaring mistakes?)
I get 233 sq. yds. but no problem. Still rounds the same.
> Of course you would need to add some engineering costs, some
> support costs to build, other infrastructure at the actual
> launch site, the launch vehicles, etc etc.
I don't believe these costs are insignificant enough for you to pass
them off. I'll bet they double or triple the cost of materials.
And, don't forget the cost of the launch tube and the man-made lake
at one end. And, if I'm right about the vertical challenge, might
this not increase the cost by an order of magnitude?
Still, if the cost is $1 billion (US), that's a one time construction
cost. In the long run, it's probably insignificant (in today's
dollars).
The next question is what does it cost every time you activate and
replenish the ram. And what does it cost to maintain the structure?
I'll bet that's small compared to these number below.
> Common estimates for a shuttle are at least
> $300-$500 million. Jumbo Jet 747 around
> $240 million.
>
> Hmmm this looks more and more attractive. Russia
> estimate for a Buran/Energia booster launch cost
> are around $130-$150 million.
What percentage of this cost would be eliminated by the HRB?
> Intersting concept this hydrolic ram booster.
> Very Interesting.
Indeed.
Chris.
hello
surface. It does not have to be vertical. only the total fall matters.
I am gratified I have started such a lively discussion. Just to keep things
focussed, I proposed a ramp of some kind as a cheap first stage. Perhaps
direct to orbit could be possible for micro payloads.
private companies, clubs, universities, perhaps as a consortium, could
reasonably expect to fund and build.
Even if the price is comparable to a shuttle, it is a reusable structure that
will last for years and doesn't cost a lot to operate.
Personally, I think the cost can be very low. Comparable to pipeline
construction.
More imprtantly, it is rebuildable and repairable. Even if the initial design
shows flaws, they can be corrected failry easily.
I.e. Comparable to pipeline construction.
If you use the water to compress gas to push on the back of a satellite,
like pushing a bullet out a barrel, in order to get the required particle
velocity, assuming the gas is air, its temperature must be on the order of
200,000 K. This follows from the gas laws, one-half mass times velocity
squared equals three half Boltzmann's constant times temperature. Just plug
in orbital velocity and the other constants. Such temperatures are only
generated in a volumes of more than a few liters by nuclear devices.
To review, think of a bullet going down a barrel. It will collide with
any gas particles in front of it, and loose momentum (slow down) as a
result. It can only go faster if there were more gas particles bouncing off
the back of the bullet. But how fast (hot?) must the propellant gas be in
order for its particles to catch up with the bullet, if it is going mach 25?
That is the 200,000 K value. This is the reason rockets will work to orbit
satellites, but guns won't. No matter how colorful it may be to imagine
running water down the sides of mountains, you will not generate these
temperatures with falling water.
Electromagnetic mass drivers, however, can do the job of accelerating
masses up ramps, as they accelerate atomic particles to approach the speed
of light. The technology was developed by physicists in the last century,
and applied by O'Neill in the 70's to space applications in devices called
mass drivers.
Sincerely, Jay Huebner
Some relivant pages on ramps/guns are:
http://www.astronautix.com/lvfam/gunnched.htm
http://world.std.com/~jlr/doom/bull.htm
In 1990 Iraq had "Project Babylon", led byGerald Bull, which was actively constucting a gun based launcher.
http://www.vectorsite.net/tarokt3.html
my website: WWW.SOPHONT.COM
Sign-up for Video Highlights of 2002 FIFA World Cup
Hello
RB
Thanks for the URL's on big guns.None have come close to orbit, and if they have put projectiles in space or not depends on one's definition. Most folks don't say 40 km up is space. Still that is impressive, but hardly in orbit sincethe maximum altitude which occurs with the minimum velocity. Newton's work was done before, and in fact made, the kinetic theory of gases possible, so one can not claim he was really thinking about (or in a position to understand the issues of) putting a satellite in orbit about Earth with a cannon, which one of the sites acknowledges. One can get higher gas velocity by going to lower mass molecules. Hydrogen, a diatomic molecule with a mass of 2 atomic mass units, being the fastest. Compared to air, with an average molecular mass of about 29, hydrogen would have velocities of about 4 times faster at the same temperature. Helium is the next fastest, and the faster velocity of Helium at room temperature (which gives a higher speed of sound in it)is what makes voices high pitched with helium in the voice box. So for highprojectile velocity, I suppose electrically heated hydrogen would be the best bet. I am sure some folks have worked on this, but I don't have any leads. Sincerely, Jay Huebner
http://www.astronautix.com/lvfam/gunnched.htm
http://world.std.com/~jlr/doom/bull.htm
In 1990 Iraq had "Project Babylon", led byGerald Bull, which was actively constucting a gun based launcher.http://www.vectorsite.net/tarokt3.html