a fun-back-of the-napkin-calculation wrt interstellar space travel.
Suppose, you have the technology to accelerate a spacecraft to 0.5 lightspeed.
The distance to travel is 10 lightyears, which takes some 20years.
Now consider that:
You need a fairly large vehicle, which is not the size of your t
Robert Lynn wrote:
The energy costs for launching via a gun launch or a rocket won't be
> much different to a space elevator given the parasitic weight of the
> climber's laser receivers, motors, radiators, wheels etc
The payload of a lifter is 70% of the mass, with present technology. The
payl
The energy costs for launching via a gun launch or a rocket won't be
much different to a space elevator given the parasitic weight of the
climber's laser receivers, motors, radiators, wheels etc plus <25%
efficient electricity transmission to the elevator so need on the
order of 100kWh per kg paylo
Robert Lynn wrote:
A space-elevator must climb about 4km, even at 200km/hr that will
> take more than a week . . .
For freight, this is a non-issue. It takes a week or more to ship goods
from China to the U.S. but that does not bother anyone.
Note that after a few days of travel, the force
Space elevators for earth are probably unworkable, though they could
be pretty good for Mars (from Phobos) and maybe for the moon.
A space-elevator must climb about 4km, even at 200km/hr that will
take more than a week and requires a huge amount of power to be
supplied to the climber. That ma
The very first or "pilot" ribbon would be only 2 cm wide in the atmosphere
to reduce wind impact, 5 cm in space, and 10 cm in danger zone from space
junk. 1 micron thick throughout. So a 1 cm hole would be a serious problem.
The first 230 climbers would carry only additional ribbon, which is
attach
Vorl Bek wrote:
>
> How do you stop meteorites from hitting the ribbons?
>
You cannot stop them. See E&W section 10.2. You have to make the ribbon
survive the impact with a hole. In other words, you have to make it
stronger than needed for the weight of the climber, and shaped wide and
thin, so
ortex-l@eskimo.com
Subject: Re: [Vo]:In the foodsteps of Jules Verne
Jouni Valkonen wrote:
I think that the biggest problem with Space Elevator is that it is too
slow. I takes quite a lot of time to climb into geosynchronous orbit.
Edwards and Westling (p. 49) say the first gener
> That does not seem to be issue. E&W do not mention it. The only
> materials issue is space junk poking holes in the ribbons. Space
> junk has to be cleaned up, and it could be with a multi-ribbon
> space elevator. You would have to devote one ribbon to an
> interceptor craft for several months.
Jouni Valkonen wrote:
I think that the biggest problem with Space Elevator is that it is too
> slow. I takes quite a lot of time to climb into geosynchronous orbit.
Edwards and Westling (p. 49) say the first generation climbers should go
200 km/h. They have to go 100,000 km to reach the counter
I think that the biggest problem with Space Elevator is that it is too
slow. I takes quite a lot of time to climb into geosynchronous orbit. It is
better to get into LEO as fast as possible. I think that fast climbing is
too demanding for the materials and slow is just too slow in order to get
much
There would be hundreds of balloons along the rail. They also could work as
power collectors to the train, solar power.
As for the stability, I really doubt that fixed structures would be a
better solution. Something so long would accumulate vibrations from too
many sources and it would hardly be
Daniel Rocha wrote:
I think the best deal would be hold the rails by the use of balloons,
which would be anchored between high mountains.
I doubt this would work. Balloons are not stable. They get blown around.
They do not stay exactly in position. If the end of the tube moves
around even a
I think the best deal would be hold the rails by the use of balloons, which
would be anchored between high mountains.
2012/4/11 Jed Rothwell
> I did not know so many methods have been proposed.
>
> The Skylon reusable space plane seems like the most practical and low-cost
> method discussed here
I did not know so many methods have been proposed.
The Skylon reusable space plane seems like the most practical and low-cost
method discussed here. I think a space elevator would ultimately have the
lowest cost per ton, and it is the safest and most elegant solution. But it
calls for materials no
I think rail assisted launch is a lot more realistic right now than a space
elevator. However, an 80 mile $60 billion tube is too big of a project at this
point. A much more feasible approach would be to find a mountain over a mile
high with the right angle and build it so the g forces are rea
No chance. Requires massive budget, and technology that isn't yet
available. Electromagnetic catapults have never achieved the high
velocities required, not to mention the mega-engineering to create a
track 100's of km long that is levitated >20km above the earth by a
huge magnetic field, and yet
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