Author Topic: Space Elevator Development  (Read 23781 times)

Offline Kansan52

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Re: Space Elevator Development
« Reply #20 on: 06/06/2018 11:03 pm »
Relying on memory but it says that each trip on the elevator would be days. That strikes me as very limiting.

Offline A_M_Swallow

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Re: Space Elevator Development
« Reply #21 on: 06/07/2018 03:26 am »
Relying on memory but it says that each trip on the elevator would be days. That strikes me as very limiting.

The elevator is thousands of miles long and you are basically in a car. This limits you to the speeds of fast car. So the journey takes several days.

Offline CameronD

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Re: Space Elevator Development
« Reply #22 on: 06/07/2018 04:28 am »
Relying on memory but it says that each trip on the elevator would be days. That strikes me as very limiting.

The elevator is thousands of miles long and you are basically in a car. This limits you to the speeds of fast car. So the journey takes several days.

So... even if Space Elevator technology was feasible (and it isn't), it'd be a bit like saying:  "Let's not fly from one side of America to the other - that's sooo routine. There's this great new tech called a car.. let's drive instead!!!"  ???

Really?!? Wow!
« Last Edit: 06/07/2018 04:31 am by CameronD »
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline aceshigh

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Re: Space Elevator Development
« Reply #23 on: 06/12/2018 02:09 am »
aceshigh,

To begin with, the height of the FLOATING DOCKS will now be more around the 60-80 km mark. I've added
that as a comment on the video after feedback I've received.
I have failed to mention in video 003 that the FLOATING DOCKS will actually be supported by blimps.
They are meant to be floating balloons, hence the name. I will definitely address that in the new video to make sure there is no confusion, thank you.

The 'space elevator' name is more to stay in line with the existing concept of 'not using rockets' essentially.
I've labelled this a 'multi-stage approach elevator' for now as the ultimate goal is to get to space as efficiently as possible.

and FYI regarding where space begins:
https://www.popsci.com/where-does-space-begin?con=TrueAnthem&dom=tw&lnk=TATW&src=SOC&utm_campaign=&utm_content=5b1278c200bd4700073e9461&utm_medium=&utm_source=


I know where space begins. The question is if you know the difference between space and orbit.

Tell me... what happens if you go up and reach space at an altitude of 300 km at a speed of 5000 km/h and turn off your engines?

Offline colbourne

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Re: Space Elevator Development
« Reply #24 on: 06/13/2018 03:32 am »
If you combine a high altitude base, with an orbital "bolo" type rotating elevator there is potential possibilities of putting something into a high orbit with minimal energy expenditure.

I see no future of the standard bean stalk space elevator on Earth because it is too slow , has too little mass transfer capability and requires the use of unobtainium to be feasible. The mass of the elevator with current materials is so high, all of which needs to be launched with rockets, that it makes no sense.

If we do find an indestructible material so a light weight elevator is possible, there may be potential.

Offline aceshigh

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Re: Space Elevator Development
« Reply #25 on: 06/13/2018 03:52 am »
I see no future of the standard bean stalk space elevator on Earth because it is too slow

for passengers, yes. For bulk cargo? No.

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has too little mass transfer capability

source? 5 store tall elevator... several of them per cable... it all depends on the thickness of the cable, which in theory can be expanded by robot weavers going up and down the cables and adding new threads...

Quote
and requires the use of unobtainium to be feasible.

or just a breakthrough in carbon nanotubes or graphene?

Quote
The mass of the elevator with current materials is so high, all of which needs to be launched with rockets, that it makes no sense.

needs to be launched with rockets?

Offline hkultala

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Re: Space Elevator Development
« Reply #26 on: 06/13/2018 06:16 am »

has too little mass transfer capability

source? 5 store tall elevator... several of them per cable... it all depends on the thickness of the cable, which in theory can be expanded by robot weavers going up and down the cables and adding new threads...

Not very easy ;)

And, always when anything is lifted from the ground to the terminal station, the system loses angular velocity. (which it cannot afford to lose). Need to have (very high isp) thrusters in the terminal station to offset this.

Quote
Quote
and requires the use of unobtainium to be feasible.

or just a breakthrough in carbon nanotubes or graphene?

Mass-manufacturing these in the required scale can be considered unobtainium.

Quote
Quote
The mass of the elevator with current materials is so high, all of which needs to be launched with rockets, that it makes no sense.

needs to be launched with rockets?

It cannot be built ground-up like tower. Most of it has to be built from from up to down. So most of the mass has to be first lifted to GEO.

« Last Edit: 06/13/2018 06:17 am by hkultala »

Offline colbourne

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Re: Space Elevator Development
« Reply #27 on: 06/18/2018 07:08 am »
I dont think many people realise how high a space elevator has to be. GEO is at approximately 35,786 km (22,236 mi) above mean sea level, and this is the minimum height for a space elevator, using a large counterweight. Most designs use extra cable above  GEO height requiring a total length around 70,000km (43,750 mi).
Traveling at train speeds a shuttle is still going to take weeks to get to orbital height. Using current materials a tapered cable is required which will be probably miles thick at the GEO point as it has to support the mass of cable, plus shuttle.

Offline J2m1s

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Re: Space Elevator Development
« Reply #28 on: 06/24/2018 03:51 pm »
I figured out a indirect way to make a smaller space elevator, doesen't need to be 36000km, but a few hundreds, I am really happy to explain my method so others would develop it based on it, but I am afraid of plagiarism, so please tell me how to protect and publish my method.

Offline alexterrell

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Re: Space Elevator Development
« Reply #29 on: 06/24/2018 04:16 pm »

It cannot be built ground-up like tower. Most of it has to be built from from up to down. So most of the mass has to be first lifted to GEO.
Many proposals have the first strand lowered from GEO. Once that is anchored, climbers take ever more strands up from the surface.

Offline meberbs

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Re: Space Elevator Development
« Reply #30 on: 06/25/2018 06:18 am »
I figured out a indirect way to make a smaller space elevator, doesen't need to be 36000km, but a few hundreds, I am really happy to explain my method so others would develop it based on it, but I am afraid of plagiarism, so please tell me how to protect and publish my method.
Patents are designed for exactly this situation, though in theory you won't get one unless the idea actually could work and hasn't been thought of before.

If you just want attribution and aren't trying to make money off of it, then there is no need for a patent. Posting online creates an effectively permanent record, so depending on your preferences you can just post a paper, including just on this forum, with however much identifying information you want to share, at least your name, and maybe a picture or basic biographical information such as where you went to school. (Up to you to balance how much detail vs. your own privacy)

You most likely have not thought of a novel working idea here. Wikipedia has a summary of many of the alternative launch concepts that could theoretically work. https://en.wikipedia.org/wiki/Non-rocket_spacelaunch There are probably some others out there, but generally just variations on things from that article. If your idea is not already on that page, it is likely that your idea couldn't work and you are missing something.

Offline alexterrell

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Re: Space Elevator Development
« Reply #31 on: 06/25/2018 09:24 am »
Now that we have boosters that are smart enough to land and perform sub orbital manouvres, is it time to revist the rotovator, or momentum exchange tether concept?

This was described by Zubrin in
Hypersonic Airplane Space Tether
Orbital Launch (HASTOL) System

It relied on a suborbital Mach 12 place to transfer the payload to a tether, which would then whip it up to a Geostationary or Lunar transfer orbit.

According to the abstract:
Quote
The tethers can be built today using presently available commercial fibers. The tethers are long, typically 400 to 1600 km (1300 to 5300 kft) in length. The total mass of the space tether plus the Tether Central Station typically will be 30-200 times the payloads being handled.

That probably doesn't make it suitable for a BFR - too big. But it would be ideal for smaller payloads like a Dragon capsule.

Could the Falcon 9 booster reach Mach 12?

Offline aceshigh

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Re: Space Elevator Development
« Reply #32 on: 06/28/2018 01:06 am »
Relying on memory but it says that each trip on the elevator would be days. That strikes me as very limiting.

The elevator is thousands of miles long and you are basically in a car. This limits you to the speeds of fast car. So the journey takes several days.

So... even if Space Elevator technology was feasible (and it isn't), it'd be a bit like saying:  "Let's not fly from one side of America to the other - that's sooo routine. There's this great new tech called a car.. let's drive instead!!!"  ???

Really?!? Wow!

Really? So you never heard of SHIPS travelling from the west to the east coast much slower than a car and having to go south to go through the Panama Canal?

Or about ships transporting cargo from US to China, China to South America, etc, etc?

Why not do all of that by AIRPLANE?


When you need to transport LOTS and LOTS of cargo, you canīt pay the price of an airplane. Too expensive. And even a BFR would be tooooo expensive to transport for example 100 thousand tons of Earth food and tech in exchange for Asteroid metals.


Space Elevators have that in mind. Expensive to build (like the Panama canal) but once it's built, objetive is the cost of transport to be in the order of a few cents of a dollar per kilogram (cargo itself, even food, must be more expensive per it's weight than the transport of the same weight)

Offline CameronD

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Re: Space Elevator Development
« Reply #33 on: 06/28/2018 03:07 am »
When you need to transport LOTS and LOTS of cargo, you canīt pay the price of an airplane. Too expensive. And even a BFR would be tooooo expensive to transport for example 100 thousand tons of Earth food and tech in exchange for Asteroid metals.


Space Elevators have that in mind. Expensive to build (like the Panama canal) but once it's built, objetive is the cost of transport to be in the order of a few cents of a dollar per kilogram (cargo itself, even food, must be more expensive per it's weight than the transport of the same weight)

You describe a system that not only requires large amounts of unobtainium to build but defies all known laws of nature to be "expensive" to build (I admire your optimism) but then say that, once built, the objective is the cost to "be in the order of a few cents of a dollar per kilogram"??  ???

If you could perhaps kindly explain how something impossible to construct at any time in the foreseeable future could possibly be cheaper to operate than tech that already exists, then I'll reconsider my point of view.
« Last Edit: 06/28/2018 03:09 am by CameronD »
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline TrevorMonty

Re: Space Elevator Development
« Reply #34 on: 06/28/2018 03:28 am »
Issac Arthur has excellent Youtube channel with video on Space Elevators plus whole lot more grand ideas on lowering cost of space access.

NB He's added a lot new videos over last few months.

Offline gbpfan12

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Re: Space Elevator Development
« Reply #35 on: 06/28/2018 03:28 am »
How about Issac Arthurs favorite Orbital Rings. Their much better then space elevators.



Edit: lol just posted then saw the above post.
« Last Edit: 06/28/2018 03:30 am by gbpfan12 »

Offline A_M_Swallow

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Re: Space Elevator Development
« Reply #36 on: 06/28/2018 08:25 am »
When you need to transport LOTS and LOTS of cargo, you canīt pay the price of an airplane. Too expensive. And even a BFR would be tooooo expensive to transport for example 100 thousand tons of Earth food and tech in exchange for Asteroid metals.


Space Elevators have that in mind. Expensive to build (like the Panama canal) but once it's built, objetive is the cost of transport to be in the order of a few cents of a dollar per kilogram (cargo itself, even food, must be more expensive per it's weight than the transport of the same weight)

You describe a system that not only requires large amounts of unobtainium to build but defies all known laws of nature to be "expensive" to build (I admire your optimism) but then say that, once built, the objective is the cost to "be in the order of a few cents of a dollar per kilogram"??  ???

If you could perhaps kindly explain how something impossible to construct at any time in the foreseeable future could possibly be cheaper to operate than tech that already exists, then I'll reconsider my point of view.


Using current materials space elevators can be built on the Moon, Mars and large asteroids. It is Earth that has the material strength problem.

Offline aceshigh

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Re: Space Elevator Development
« Reply #37 on: 06/29/2018 02:31 am »
When you need to transport LOTS and LOTS of cargo, you canīt pay the price of an airplane. Too expensive. And even a BFR would be tooooo expensive to transport for example 100 thousand tons of Earth food and tech in exchange for Asteroid metals.


Space Elevators have that in mind. Expensive to build (like the Panama canal) but once it's built, objetive is the cost of transport to be in the order of a few cents of a dollar per kilogram (cargo itself, even food, must be more expensive per it's weight than the transport of the same weight)

You describe a system that not only requires large amounts of unobtainium to build but defies all known laws of nature to be "expensive" to build (I admire your optimism) but then say that, once built, the objective is the cost to "be in the order of a few cents of a dollar per kilogram"??  ???


even the strenght needed to build it on Earth is FAR from being unobtainium. No need to be as strong as scrith (Ringworld fantasy material, tensile strenght similar to strong nuclear force).

Carbon nanutubes, graphene and diamond nanothreads are all candidates. Making them of good quality at macroscopic level is an ENGINEERING problem, not a physics problem.

If it's not a physics problem, it's not unobtainium.


Quote
If you could perhaps kindly explain how something impossible to construct at any time in the foreseeable future could possibly be cheaper to operate than tech that already exists, then I'll reconsider my point of view.

expensive infrastructure. Once in place, not much energy should be needed to move very large amounts of cargo.

Just like ships and the panama canal are expensive, but end up being cheaper for bulk transportation than the much faster airplanes.

On the other hand, moving a huge cargo ship to transport a few people would be very expensive.

ships become cheap because of the sheer amount of cargo they can transport.


that is the vision for the space elevator. As you thicken the cable and as you use same infrastructure (including counter weight) you can get more and more cargo into space. Slowly but cheaply. Rockets still being used for moving people and urgent cargo.

Offline LMT

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Re: Space Elevator Development
« Reply #38 on: 07/09/2018 04:02 am »
When you need to transport LOTS and LOTS of cargo, you canīt pay the price of an airplane. Too expensive. And even a BFR would be tooooo expensive to transport for example 100 thousand tons of Earth food and tech in exchange for Asteroid metals.


Space Elevators have that in mind. Expensive to build (like the Panama canal) but once it's built, objetive is the cost of transport to be in the order of a few cents of a dollar per kilogram (cargo itself, even food, must be more expensive per it's weight than the transport of the same weight)

You describe a system that not only requires large amounts of unobtainium to build but defies all known laws of nature to be "expensive" to build (I admire your optimism) but then say that, once built, the objective is the cost to "be in the order of a few cents of a dollar per kilogram"??  ???

If you could perhaps kindly explain how something impossible to construct at any time in the foreseeable future could possibly be cheaper to operate than tech that already exists, then I'll reconsider my point of view.


Using current materials space elevators can be built on the Moon, Mars and large asteroids. It is Earth that has the material strength problem.

We found the martian case quite approachable.  A "Mars Lift" could be the first proof-of-concept, and a first commercially viable space elevator. 

Notably:

The martian tether is much shorter than a lunar tether (20,000 km vs. perhaps 80,000-200,000 km). 

Short length and low gravity allow for construction with materials having specific strength in the same order-of-magnitude as existing CNT film. 

The need for one-way cargo delivery to Mars justifies an unpowered elevator system, a simplified "rappeller" delivering cargo to the surface, only. 

Also Dr. Lades successfully demonstrated that an off-equator tether avoids Phobos, passively and always; as illustrated at left.

« Last Edit: 07/09/2018 06:00 pm by LMT »

Offline JonathanD

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Re: Space Elevator Development
« Reply #39 on: 09/10/2018 03:04 pm »

Dunno if they've been brought up, but Liftport has some interesting stuff on their site: http://www.liftport.com/lunar-elevator.html

If NASA is determined to build the Deep Space Gateway, which in its current incarnation is pretty useless, why not scale it up and use it as a counterweight for a lunar space elevator?  The lunar case makes the most sense to me for a number of reasons:

1) dV requirements for conventional lunar landing really suck, a lunar space elevator would make delivering tonnage to the lunar surface way more realistic (either to an equatorial region or to an alternative polar tether as per this graphic https://upload.wikimedia.org/wikipedia/commons/thumb/a/a5/Lunar_space_elevator.svg/760px-Lunar_space_elevator.svg.png)

2) And obviously gets resources from the lunar surface back up to an easy-to-get-to orbit (He3, water, or LH2/LOX).

3) If the counterweight stored LH2 and LOX, you would have a legit refueling station for interplanetary travel.  This would be an enabler for a lot of different cycler-type spacecraft that would make regular trips to Mars and back, for instance.  This would reduce fuel requirements for something like BFS, or give greater fuel margin to allow BFS to slow down upon Mars approach and save the wear & tear on the thermal protection system.

4) While the moon's slow rotation would mean either a pretty long cable or a pretty big counterweight, from the materials side it's very much something that is within manufacturing capabilities of today thanks to low gravity and lack of atmosphere. 

5) Because of the relatively small gravity well, the lunar space elevator tether would not need to be tapered at all, either in terms of size or strength - that means you could have a dramatically simpler system in terms of repair and maintenance, and even a large "pulley" system which would allow cargo to move in both directions simultaneously.

This seems like a no-brainer for a permanent presence on the moon.  Yes it would be expensive, but over the long run would more than pay for itself compared to making direct conventional landings on the moon and other planetary bodies on an ongoing basis.

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