Alternative to Rockets

Are there any way for rockets to fly in space , other then throwing mass
out in one direction and moving in other

"George Kinley" wrote in message ...
Are there any way for rockets to fly in space , other then throwing mass
out in one direction and moving in other

All methods of getting into orbit involve action-reaction in one way
or another, though some can (mostly) avoid rocket engines.

Methods of (mostly) avoiding rocket engines:

1) Space elevator. A long cable to geosynchronous orbit.
2) Mass drivers/railguns/coilgun launchers. Unfortunately, the big
electromagnetic launchers that can fling a spaceship into orbit
without turning passengers to goo is really, really long, like 600-700
miles for a 3G launch.

Mike Miller, Materials Engineer

"Mike Miller" wrote in message
om...
"George Kinley" wrote in message
...

2) Mass drivers/railguns/coilgun launchers. Unfortunately, the big
electromagnetic launchers that can fling a spaceship into orbit
without turning passengers to goo is really, really long, like 600-700
miles for a 3G launch.

As was pointed out in an earlier post to this web site, well designed and
packed "cargo" can withstand hundreds to thousands of gees acceleration. A
1000G electromagnetic launcher would only
be about 3 miles long. Also I seem to recall talk of a "supergun". The
astronauts could go by a small cheap rocket - I think 5 astronauts plus
short-term life support mass about one ton.

"Roger Stokes" wrote in message ...

As was pointed out in an earlier post to this web site, well designed and
packed "cargo" can withstand hundreds to thousands of gees acceleration. A
1000G electromagnetic launcher would only

I'm well aware of the ability for cargo to survive 1000G (and higher)
launches. I was specifically addressing passengers in cannon-type
launch systems.

Mike Miller, Materials Engineer

Mike Miller wrote:
2) Mass drivers/railguns/coilgun launchers. Unfortunately, the big
electromagnetic launchers that can fling a spaceship into orbit
without turning passengers to goo is really, really long, like 600-700
miles for a 3G launch.

Not that it would be a "make or break" factor, but they did centrifuge
tests way back where the subjects were immersed in water, then spun up.
The water pressure outside the body opposed the internal pressures, and
the subjects/victims were able to carry on conversations at 12+ G's.

I've thought that if you need to carry water on missions, for shielding
and all of the other reasons, might as well put it to work for you.

Just did a quick google...the Swiss have a suit called the Libelle that
is based on the principle, lets you chit chat at 12 G's sustained. It
would be higher laying back in a couch.

In article ,
nafod40 wrote:
Mike Miller wrote:
2) Mass drivers/railguns/coilgun launchers. Unfortunately, the big
electromagnetic launchers that can fling a spaceship into orbit
without turning passengers to goo is really, really long, like 600-700
miles for a 3G launch.

Not that it would be a "make or break" factor, but they did centrifuge
tests way back where the subjects were immersed in water, then spun up.
The water pressure outside the body opposed the internal pressures, and
the subjects/victims were able to carry on conversations at 12+ G's.

I've thought that if you need to carry water on missions, for shielding
and all of the other reasons, might as well put it to work for you.

Just did a quick google...the Swiss have a suit called the Libelle that
is based on the principle, lets you chit chat at 12 G's sustained. It
would be higher laying back in a couch.



Cool! If they're chit chatting and, well, breathing, I assume the head
doesn't need additional protection at 12 G's?

I think the standard flight suit applies regular pressure on the legs and
torso, but as I recall a pilot can only go to about 8 G's before blacking
out in a turn. What's different about that?


--
"Things should be made as simple as possible -- but no simpler."
-- Albert Einstein

Gregory L. Hansen wrote:
In article ,
nafod40 wrote:

Mike Miller wrote:

2) Mass drivers/railguns/coilgun launchers. Unfortunately, the big
electromagnetic launchers that can fling a spaceship into orbit
without turning passengers to goo is really, really long, like 600-700
miles for a 3G launch.

Not that it would be a "make or break" factor, but they did centrifuge
tests way back where the subjects were immersed in water, then spun up.
The water pressure outside the body opposed the internal pressures, and
the subjects/victims were able to carry on conversations at 12+ G's.

I've thought that if you need to carry water on missions, for shielding
and all of the other reasons, might as well put it to work for you.

Just did a quick google...the Swiss have a suit called the Libelle that
is based on the principle, lets you chit chat at 12 G's sustained. It
would be higher laying back in a couch.


Cool! If they're chit chatting and, well, breathing, I assume the head
doesn't need additional protection at 12 G's?

I think the standard flight suit applies regular pressure on the legs and
torso, but as I recall a pilot can only go to about 8 G's before blacking
out in a turn. What's different about that?

The big diff was that with the water suits, it was as if they weren't
even at 12 Gs. Just a day at the office. Using standard G-suits, you
have to really strain to keep the blood in the noggin. The G-suit only
provides 1-2 G improvement alone, but it also lets you push against it
to raise the tolerance. Very exhausting.

One interesting alternative might be what could be called a "recursive
trebuchet": essentially, a highly damped and well-controlled whip. On the
surface of a planet, anchor a catapult with a very short moment (swing),
perhaps less than one degree. On top of that, put a smaller catapult, and
another on that, and so on.

If kept static, such a structure could not exceed 10-12 km in height because
of limitations of structural strength, but if it were kept in continuous
motion, the sum of centrifugal forces balanced against the pull of gravity
might allow something of considerable length and enormous flexibility and
strength. If it could be made long enough to allow its tip to describe an
arc of, say, 1000 km, acceleration of the tip to orbital velocity might be
kept down to the vicinity of three gravities.

This would be a very large structure, and its mass would probably allow the
launching of enormous projectiles. Think of capsules the size of cruise
ships being plucked from the ocean and flung into space; that will give you
a notion of the scale.


Jim McCauley

2) Mass drivers/railguns/coilgun launchers. Unfortunately, the big
electromagnetic launchers that can fling a spaceship into orbit
without turning passengers to goo is really, really long, like 600-700
miles for a 3G launch.

Mike Miller, Materials Engineer

AFAIK, if a human being is suspended in a fluid (easily deformable
medium) which has the same specific gravity as the mean specific
gravity of human tissue, then g-loadings on face down prone
individuals can be very high for periods of several seconds and even
minutes before significant short term ill effects are seen. I cannot
recall the source, but believe the Air Force looked at "wet" cockpits
to permit pilots to sustain maneuvers of many tens of g's, and
determined that while the costs outweighed the benefits, no plane
could be built which would overstress the pilot during the duration of
the ACM that might be required.

Perhaps 100g's for very short times would be tolerable. Certainly
blood pooling of short durations is an acceptable risk for many when
the destination is considered.

Can anyone say how seconds a human being so supported can tolerate
being accelerated at 10, 100, and (doubtfully at all) 1000gs.

If I remember it ok, 10 seconds is little trouble indefinitely, 100 is
barely doable for tens of seconds, and 1000 is out of the question
(bones falling through soft tissue, etc.).

Thank you, Tom Perkins

"George Kinley" writes:

Are there any way for rockets to fly in space , other then throwing mass
out in one direction and moving in other

1.) The _definition_ of a "rocket" is "something that throws mass
(or more precisely, _momentum_) out in one direction in order to
accelerate in the opposite direction." If it _doesn't_ "throw mass
out the back," it _ISN'T A ROCKET_.

2.) Anything that does _not_ "throw mass out the back" (or more precisely,
_momentum_) in order to accelerate would violate Newton's 3rd Law of Motion
(AKA, the conservation of Momentum). In 300 years, _NO ONE_ has observed
a replicatable violation of Conservation of Momentum.


-- Gordon D. Pusch

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