We would only build a space elevator if it made economic sense. Given the reality of construction costs, even if we had the materials, it would like cost many trillions of dollars (at least) so whatever we used it for would have to produce much more value than that.
Even more importantly, if we had access to the materials necessary to build space elevators, there are other, much more pressing terrestrial needs that would use up all those materials long before somebody tried to build an elevator.
No matter how much fun it is to contemplate their existence, nobody has come up with a justification for the necessary investment required to build and operate one.
Some technologies are developed by the free market before they are economically viable too. LEO constellations for instance (both the original - iridium, and starlink).
Starlink is totally different beast, as it is magnitudes faster than GSM and literally belongs to broadband Internet, when have virtually global coverage (yes, exists 4G and even 5G, but they don't have global coverage now).
These are somewhere similar to cryptocurrencies, which lose 1st world (and most important market), because created by scientists of 1st world, to solve problems which are not important for first world, and 2nd/3rd worlds are not capable to maintain sustainable development/support of crypto-technologies.
So from first look could appear as cryptocurrencies are not economically viable at all, but I think, their real problem, that 2nd/3rd worlds are too fragmented to gather resources need to develop solution of their problems, not just be involved in works of 1st world developers.
>iridium
For some reason I was skeptical of this (suspiciously tidy) myth-making, and the more I look into it the more I'm convinced I was right to be skeptical.
Turns out the relevant engineers -- Ken Peterson and Ray Leopold -- both worked on military and government communications systems immediately prior to being hired at Motorola and starting the Iridium project. Peterson's bio is rather vague on timelines[0], but available information on Leopold indicates he joined Motorola in 1987[1] (directly from the Air Force Electronic Systems Division,[2] which develops communication systems), which is the same year he and Peterson started work on Iridium.[3]
This has all the hallmarks of one of those nice neat (and of course plausibly deniable) tech transfers from military/taxpayer dollars, complete with the cute official origin story featuring a C-suite executive's wife.
[0] https://www.tributearchive.com/obituaries/25954530/ken-peter...
[1] https://ocw.mit.edu/courses/16-886-air-transportation-system...
[2] https://en.wikipedia.org/wiki/Electronic_Systems_Center
[3] https://www.laits.utexas.edu/~anorman/long.extra/Student.F98...
This doesn't seem that difficult given the potential value of mining. I suspect terrestrial politics would dominate this conversation—access to said elevator is far more interesting than any collective concern, and humans as they stand are not capable of resolving collective concerns on any level.
25 years later, it seems just as far fetched.
Maybe you could have a HALO of THORNS (Telemetry homogeneous orbital restrainer nano-lattice stabilizer) - that have 13 satellite thrusters that can maintain the alignment of the nano-pillars... and have them sectionaly distributed as rings on the Z -- with tethered lattice of tubes tying it all together like a Chinese finger trap.
https://www.youtube.com/watch?v=RnofCyaWhI0 <-- These things... https://i.imgur.com/O9eWZnH.jpeg
and the carbon lattice is also a fuel-capillary system - that feed like a live thing...
I’m probably overestimating the size of the anchor.
In the first episode, a space elevator is bombed. It’s pretty catastrophic! I think a lot of people underestimate the forces involved in something of this scale collapsing.
“ The tether wrapped around the planet like a garrote.
It cut 50 levels down.”
This is obviously fiction, but so is this research and the general concept of space elevators.
I wouldn't be surprised it the ambient electrostatic field from the atmosphere were sufficient to power station keeping, or at least some of the instrumentation.
If that works, I'm sure they could extend it to twice as long, almost into space.
Always love that concept with how it's actually engineer-able with current materials and sounds like it shouldn't work until you look closely.
https://en.wikipedia.org/wiki/Skyhook_(structure)
Interesting idea, but if I'm understanding correctly, how do you stop the thing you hooked from swinging around and back down? Would you need to reel in 50 miles or whatever of cable?
The car starts out on the ground at 465m/s. It has to accelerate to 11,068 km/h.
What makes it accelerate? The cable, without any force applied to it anywhere? Or is there a rocket on that car?
To put mass into orbit, you have to accelerate that mass. And do it without decelerating the elevator.
There are no free lunches.
Momentum transfer from the cable, which is attached to an orbiting counterweight.
In this design, some of that momentum would be borrowed from the Earth’s rotation via the cable’s coupling to its magnetic field. In general one boosts the counterweight directly or, more practically, by sending things down [1].
[1] https://space.stackexchange.com/questions/22447/how-will-the...
A launch loop can harvest energy and momentum from the rotor to accelerate payloads, but I don't see any such mechanism here.
In terms specifically of mass/energy conservation, as the other reply said, energy is borrowed from either the earth's rotation and/or kinetic energy from a counterweight at the end of the elevator up in orbit.
On a conventional space elevator this is true. You just go up to 35,786 km altitude (AKA geostationary orbit) and let go.
However the structure described in this paper only goes up to 200 km altitude, so it still needs a horizontal acceleration system.
Neat idea but not particularly possible given current material science as always seems to be the case with space elevators.
Once you have the elevator operated some of the transportation could be used for refueling coolant.
And you start it from space and gradually lower it down to earth.
If we could build this at all, we could build it on the ground, then just switch it on (gradually) and it would float, and if we needed to get consumables up, they can be pulled up on a winch like any other payload to space.
But also, I don't know why you think Starship is the right category for a solution; the structure in this paper is 200 kilometers in size (it says altitude, but for magnetic repulsion the best separation distance is a constant factor of the size before your get performance issues), whereas a fully stacked Starship is about 0.12 - 0.15. It would be like trying to refuel a 747 in flight with an personal selfie drone.
No way to passively reach cryogenic temperatures—let alone the deep-cryogenic ones demanded by high current-density superconductors.
A launch loop could be short-range magnetic or electric pressure between the cable and the sheath, Earth's field is not important and it would also work on a body with no magnetic field, and it mostly functions by being a very big moving part surrounded by a vacuum chamber.
It's like a gyroscopic force versus an electromagnet: they're both forces, but one is caused by mechanical movement versus the other which is caused by magnet fields.
Wikipedia has a listing, if that helps: <https://en.wikipedia.org/wiki/Space_tether_missions>
The gap between current material science and the required advancements for constructing a magnetically levitated space elevator is significant. Let's break down the key areas where advancements are needed and assess the current state compared to the required state:
1. Superconducting Materials Current State:
NbTi Superconductors: NbTi (Niobium-Titanium) superconductors are among the most common, with critical temperatures around 9-10 K. They are widely used in MRI machines and particle accelerators. NbTi can sustain high current densities and generate substantial magnetic fields, but only at very low temperatures maintained by complex and costly cryogenic systems. Required State:
Higher Temperature Superconductors: For a space elevator, superconductors that can operate at higher temperatures would reduce the need for extensive cryogenic cooling, thus making the system more practical and less costly. Currently, high-temperature superconductors (HTS) exist (like YBCO - Yttrium Barium Copper Oxide), which can operate above 77 K (the boiling point of liquid nitrogen), but they are not yet produced in long, high-quality, and affordable lengths suitable for large-scale engineering projects. Gap Analysis:
The primary challenge is to develop superconductors that can operate at higher temperatures with sufficient current densities and stability. The current material science has not yet achieved a commercially viable production of long-length HTS with consistent quality and performance required for such applications. 2. Carbon Nanotubes and Advanced Fibers Current State:
Carbon Nanotubes (CNTs): CNTs are known for their extraordinary tensile strength and low density, making them ideal candidates for space elevator cables. However, the production of long, defect-free CNTs with consistent properties remains a significant challenge. Current production techniques yield short lengths with varying qualities, and scaling up these methods while maintaining material integrity is difficult. Required State:
Mass Production of High-Quality CNTs: For a space elevator, extremely long CNTs or similarly strong materials are required to construct a cable that can withstand the enormous stresses involved. These materials must be lightweight yet possess ultra-high tensile strength and stability over long periods. Gap Analysis:
The major hurdle is the ability to produce continuous lengths of high-quality CNTs or alternative advanced fibers at a commercial scale. The technology for producing and manipulating these materials at the necessary scale is still in its infancy. 3. Structural Materials and Stability Current State:
Composite Materials: Current composite materials, including carbon fiber composites, offer high strength-to-weight ratios. However, they are not yet capable of withstanding the specific stress and environmental conditions required for a space elevator, particularly in terms of radiation resistance and thermal stability. Required State:
Advanced Composites and Alloys: Materials need to be developed that can endure the harsh conditions of space, including temperature extremes, radiation, and micrometeorite impacts, while maintaining structural integrity over potentially very long periods. Gap Analysis:
Development is needed in creating materials that not only provide the necessary strength and durability but also can be manufactured and maintained at a reasonable cost. Improvements in radiation shielding and thermal management materials are also required. 4. Cooling and Power Systems Current State:
Cryogenic Cooling: Current cryogenic systems can maintain superconductors at low temperatures, but they are heavy, complex, and energy-intensive. They are impractical for continuous, large-scale applications like a space elevator. Required State:
Efficient Cooling Solutions: More efficient and lightweight cooling systems are required to maintain superconductors at operational temperatures without prohibitive power consumption. Alternatively, development of superconductors that operate at higher temperatures, requiring less intensive cooling, would be beneficial. Gap Analysis:
Significant innovation is needed in both cooling technology and power systems to make a space elevator feasible. The challenge is to achieve efficient, reliable, and cost-effective solutions that can be integrated into the elevator structure. Summary The gap between current capabilities and the required advancements is substantial. While we have foundational materials and technologies, such as NbTi superconductors and carbon nanotubes, they are not yet developed to the extent necessary for practical use in a space elevator. Advances in high-temperature superconductors, scalable production of high-quality carbon nanotubes, and the development of lightweight yet strong structural materials are critical.
Material science must progress significantly in these areas to move closer to realizing the concept of a magnetically levitated space elevator. This will require substantial research, development, and potentially novel breakthroughs in materials engineering and related technologies. The timeline for achieving these advancements is uncertain, and it could span several decades.
What is an intermediate market for medium-length high-quality CNTs?
* quotes because all things are relative, by "medium" in the context of a space elevator you may have meant "continent sized"?
Could CeOFeAs permit cooling with hydrogen [2][3]?
[1] https://en.m.wikipedia.org/wiki/Niobium%E2%80%93titanium
[2] https://www.sciencedirect.com/science/article/abs/pii/S09214...
[3] https://en.m.wikipedia.org/wiki/High-temperature_superconduc...
(H2 leaks are not just inevitable,large scale deployments of LN2 cooling already exist)
Coming up with some way that lets us waste more mass will push aerospace away from such an exotic set of technologies towards more mainstream use. It is only the fact that space flight is barely possible that makes it so hard.
The original MCKESR concept had a ring-shaped conductor orbiting in a magnetic field, but a later concept had a chain of ferromagnetic objects being attracted magnetically. The latter was kept passively stable by alternating segments of magnets, one segment where the attraction was stable radially and unstable vertically, the next the opposite. If the ring was moving in the right speed range this would cause dynamic stability in both directions. This Alternating Gradient principle is used (via magnetic forces on moving charged particles) to focus beams in most modern particle accelerators.
(2024) Why physics favor Mass Drivers over heavy lift rockets
guy's voice similar to Bret Victor, (R&Deployment) economics slightly better than space elevator-- you can also use SC magnets but in easier config, repurpose Hyperloop research etc
