Talk:Orbital ring

This article is surely an ideal candidate for deletion, or at least a massive curtailment of waffle?

It links to one website and one author's thoughts on an arbitrary and fantastical idea. Thousands of people have dreams, that is no reason to give each one a wikipedia entry just because they are written up on a personal site on the net or in a book or whatever. In fact, just the sort of rubbish one would expect to find on wikipedia! 86.143.73.37 (talk) 12:43, 23 December 2009 (UTC)

It's been published in detail in a reputable journal as well as covered in a non-fiction book called Indistinguishable from magic by a well-regarded physicist (Robert L. Forward). And papers are still being published on one from of this ring.- Wolfkeeper 15:20, 23 December 2009 (UTC)

So, it seems to be a notable topic.- Wolfkeeper 15:20, 23 December 2009 (UTC)

The text does not mention that the ring needs to be almost 26,000 miles in circumference, so this is indeed mega engineering. Ccpoodle (talk) 14:38, 5 January 2008 (UTC)

I find Yunitskiy's video misleading. It's more a promotion of some kind of elevated light rail technology (which it hardly explains, except for saying that it uses less materials for the support), using orbital rings as a teaser. — Preceding unsigned comment added by Votsalo (talk • contribs) 06:12, 26 March 2018 (UTC)

1963 mention

This conception seems to be first(?) proposed in 1963 novel "Черный столб" (The Black Column) by Евгений Войскунский and Исай Лукодьянов, where it was called "Кольцо Кравцова". In this novel the orbital ring appeared because of giant magma column erected itself from drilling hole, twisted around the Earth, and was cut out by a bomb. Alone Coder (talk) 06:26, 30 March 2008 (UTC)

Unless it has the spokes, while it would be a ring around the Earth, it wouldn't be an orbital ring intended for orbital launch. It's also science fiction, whereas the article is about an actual engineering study.- (User) WolfKeeper (Talk) 17:43, 30 March 2008 (UTC)

I can't comment on the technical aspects, but sci-fi conceptions are well worth mentioning in an encyclopedia article, as they often precede the more scientific version and can even inspire it... just look at Arthur C Clarke and the geostationary orbit. Just my two cents. 65.96.201.130 (talk) 02:45, 5 February 2009 (UTC)

Costs

The $15 billion cost that's quoted in the article is based on the assumption that a "space manufacturing facility" exists that can provide most of the initial materials at a very low cost. Since no such facility exists and the price of constructing one would be astronomical, the quoted $15 billion price is very misleading. The estimated cost of actually launching the materials was about $31 trillion. —Preceding unsigned comment added by 128.227.87.245 (talk) 22:59, 10 December 2008 (UTC)

And once again, someone has edited out the fact that the low-ball $15 billion price estimate assumes the existence of a space manufacturing facility that can provide thousands of tons on materials for construction at very low prices. I don't know if someone keeps editing that out because they're confused and haven't actually read Birch's paper, or if they're trying to obfuscate the cost for some reason. Either way, as written the article gives the erroneous impression that it could actually be built at the present time for around $15 billion, which is not at all true.

This is a wildly incorrect reading of the source. The second paper [1] actually discusses multiple possible strategies, including bootstrapping from space materials and bootstrapping with a smaller initial system. The 31 trillion dollar scenario doesn't actually serve a purpose, and should probably have been edited out of the paper. The 15 billion dollar estimate is based entirely on sending materials from earth to space using a smaller initial system referred to as a "bootstrap ORS" in the paper and estimated to mass 1.8 x 10^8 kg. The cost to create it is estimated in 3.4.12 to be 1.3 billion dollars (1982). Section 3.4 concludes with a cost that includes putting twenty ladders in orbit along with a ring massing 1.8x10^11 kg. This is NOT a minimal system, but the same full fledged system described as needing 31 trillion dollars to launch without bootstrapping. The system utilizing space manufacturing facilities (section 3.3, "SMF-produced ORS") is said to cost 77 billion dollars, not 15 billion. Lsparrish (talk) 16:25, 26 October 2016 (UTC)

Orbital Velocity

Orbital Velocity - as I understand orbital mechanics, every orbit (altitude, apogee and perigee) have specific velocities, i.e., there is no such thing as "slightly faster than orbital speed. Faster than orbital speed for a given orbit results in a new and higher orbit, or at least a different apogee or perigee. I think this invalidates this approach to placing objects in LEO. comment added by karen12398, 17 January 2009. —Preceding unsigned comment added by Karen12398 (talk • contribs) 20:37, 17 January 2009 (UTC)

There's no problem with that aspect; the ring isn't actually in orbit (think of a Niven ring), but being flexible cable, it must be above orbital speed (for an actual orbit at its altitude) to maintain tension. --24.7.241.89 (talk) 06:27, 30 January 2009 (UTC)

• Read Paul Birch's "ORBITAL RING SYSTEMS AND JACOB'S LADDERS--II" at least until you come to the statement describing his massive orbital ring concept as being in Low Earth Orbit. He claims the ring is in free fall every except where magnetic skyhooks ride on it. This would mean that the ring is actually in several orbits, magnetically receiving impulse from the skyhooks to change from one elliptical orbit to another. In an actual working orbital ring system there would probably need to be under some tension in the orbital ring so that the ring does not miss the second skyhook after being sent on somewhat inaccurately by the first. The ring is above circular orbital velocity but never reaches apogee because of the impulse it receives from the skyhooks.FARTHERRED--98.240.152.101 (talk) 07:13, 30 June 2009 (UTC)

Cost estimate removal and reverting of same

Reliable sources do not need to be absolutely trustworthy. This whole article is based upon a rather shaky idea, but one can find where the cost estimate came from when there is a reference. I do not trust the estimate so much that I would invest money based upon it, far from that. Still I am happy to have an estimate.--Fartherred (talk) 04:06, 19 November 2009 (UTC)

Different articles have different standards for references. One must take this article and its references with a grain of salt.--Fartherred (talk) 04:10, 19 November 2009 (UTC)

The cost estimate of $31 billion for an orbital ring around Earth seems unrealistic given that the space station has cost $100 billion. Why did we build a space station using rockets when we could have built an orbital ring for a third of the cost, which would then lower the cost of putting things in orbit by several (4) orders of magnitude?

If you were trying to get a realistic number in today's dollars it would be about 270 billion for the launch costs. The main issue is that the paper (which is from 1982 and specifies the 1975 dollar) was assuming that space shuttle derived heavy launch would cost only 173 USD/kg (79 USD/lb). This prediction was thought to be realistic in 1980's, but turned out to be not at all correct because of design flaws in the shuttle -- the shuttle was "reusable" on paper, but required very expensive repairs every time it was flown, which ended up making it even more expensive than expendable rockets. Better approaches to reusable vehicles currently being explored by SpaceX could get the price to something comparable though, which is a key point in Elon Musk's plans for Mars colonization featuring the BFR. Note that the major cost savings will be from reusable vehicles and economies of scale with larger vehicles -- currently, the vehicle cost is what predominates, not fuel or energy cost. In any case, a translation to current day launch costs using the Falcon Heavy (90 million USD = 60 tons, which is about 7000 USD/kg) would be 270 billion USD for the given mass of structure (180,000 tons = 3000 FH launches worth). The space station didn't have the benefit of the Falcon Heavy's economies of scale (and technical advances) so its cost to launch was quite a bit higher than that per kilogram. It would cost less than 1 billion (~720 million) to launch the space station's mass (400 tons) with a series of 8 Falcon Heavy launches. Lsparrish (talk) 16:10, 14 September 2018 (UTC)

Static and Active Orbital Rings

This article only describes active rings, supported by a rotating cable or mass pellets. It has no mention of static rings, as described here, which are effectively built by linking together the lower parts of a series of skyhooks. Even if static rings are unviable due to stability issues, they should probably be described. Thoughts? DrHacky (talk) 17:27, 9 February 2016 (UTC)

Orbital ring <> space elevator

The opening statement "An orbital ring is a concept for a space elevator" seems highly dubious. Although these are related concepts, an orbital ring is *not* a space elevator. — Preceding unsigned comment added by 124.157.73.108 (talk) 19:52, 21 February 2019 (UTC)

I disagree. The cables (referred to by Birch as Jacob's Ladders) are in fact space elevator cables. Tsiolkovsky's tower is a different kind of space elevator that goes to geosynchronous orbit (and is not plausible with existing materials, unlike the Orbital Ring). LEO is in space, and the altitude of LEO is also space, therefore it's a space elevator. Lsparrish (talk) 20:09, 18 June 2020 (UTC)

Yunitskiy's SkyWay film is unverifiable, self-promoting nonsense for a different technology

Currently a self-published piece of Yunitskiy SkyWay promotion is being used to illustrate theories he published in 1995 (view it here [2]) that do not appear to have generated any scientific interest. If they had, it would be secondary sources that need to be cited specifically in relation to his ideas and not a single self-promoting resource as is the case here. And an illustration of his ideas has to specifically reference these ideas and not be self-promoting propaganda for another technology. This film actually concerns (until the last few seconds) the EcoTechnoPark, a test site for Yunitskiy's SkyWay technology situated in Belarus which is very much based on earth and is further unconnected to space. In discussing his work, Yunitskiy is explicit in stating that his projects should be realized on earth and not in space and that all space research is worthless. Read about an interview with him on this subject here: [3]. He states emphatically that Elon Musk and his SpaceX programs are utter nonsense. This Belarusian inventor has made dubious claims about his scientific credentials, associating himself with the RAEN which is noted by Wikipedia as being supported by unqualified scientists who peddle pseudoscience. His SkyWay project on earth is to say the least controversial. If you want to include his space theories here you should at least quote a secondary source who found this aspect of his work sufficiently interesting to mention in a published article. Currently. This film should certainly be removed as it is self-published promotion concerning an entirely different technology that has not received independent testing let alone scientific consensus. The text about his theories, if it is mentioned at all, should be in relative length to the interest that has been shown in it by the scientific community and the original self-published manuscript cannot be used as the basis for such a lengthy discussion. –Zachar (talk) 18:43, 16 April 2019 (UTC)

Please help improve 'Yunitsky's model' text

The work by Yunitskiy which refers to this theory is called Струнные транспортные системы: на Земле и в космосе (1995) [String Transport: on earth and in space]. This work is cited in the references but not in this over-technical explanation which contrasts to the rest of the article. It doesn't really make a lot of sense, and because no actual work is cited it is difficult to verify. Help improve the English and reduce it technical complexity so it makes sense. Is there anyone who is actually familiar with the original who can verify it? How much of this information is actually necessary? Please help by making your own improvements to the text below:

Anatoly Yunitskiy's theory concerns a General Planetary Vehicle (GPV) for the transferal of the ring to a low planetary orbit. This ring would be located parallel to the equator and would consist of individual segments connected by hydraulic cylinders. Inside the ring segments there are cells for placing the payload and necessary equipment. The heart of the GPV consists of two circular channels passing through all the segments of the ring. High vacuum is kept up in the channels and they are completely isolated from the environment. Inside these channels there are two magnetically levitated flywheel rotors assembled from small metal and flexible (e.g., polymer) segments. The flywheel rotors would be held by an electromagnetic system mounted inside the GPV shell, according to the principle of magnetic levitation, and act as the rotors of the giant motor. The GPV ring would be located on a specially equipped overpass, encircling the Earth. In the initial condition it is fixed on the overpass. With the help of an external energy source one of the rotors would spin up to a speed higher than the orbital speed at sea level. Due to the centrifugal force, the rotor would balances itself and then fly upwards; after releasing a clamp the GPV ring would begin to rise up, increasing in diameter. Thus, the hydraulic cylinders and gaps between the segments allow the formation to increase in length. The belt rotor would stretch by 2-5% due to its elasticity. Having achieved the required height the rotor transfers to the generator mode, and the electricity generated would be used to boost the second rotor in the opposite direction. As a result, the GPV would accelerate to achieve the First Cosmic Velocity on a low planetary orbit. The height reached by the GPV is determined by the rotor's initial kinetic energy and the capability of its body structure and rotors to stretch. On the equatorial orbit the GPV would be unloaded into stationary orbit the cells located at the same orbital altitude as the plane of the equator. Landing would be carried out similarly in reverse order.

Information about the edit -

[1] 'circumplanet' doesn't seem to be a word although 'circumplanetary' does return a single mention in Wikipedia. I think they just mean a low planetary orbit.

[2] The text was in the present tense as if it is describing it, not a theory; I tried to change the text so it sounds like a theory. Note the language in Birch's model "it can be..." ; "it would..." ; "Birch calculated that..." etc.

• Please note that this extended article includes a lot of information about Orbital Rings and theories that exist around it, both fictional presentations and actual theories, and also the advantages it could play in the future and so forth. It doesn't mention Yunitskiy or his theory: [4].

The following Russian article mentions this Orbital Ring theory by Yunitskiy: "The inventor designed an electromagnetic ring around the Earth, which, under the influence of centrifugal forces, was to be lifted into space." You can read the original article cited here: [5]. –Zachar (talk) 20:47, 23 April 2019 (UTC)

Please don't use self-published sources

Facts have been added to the article concerning Yunitskiy's Orbital Ring theory and a verified reference to a Russian source has been replaced with Yunitskiy's personal website. References that are self-published by the writer can not be used as the basis to add facts to a Wikipedia article. The reason given for this change were that this was a better reference. Unfortunately, it links not to a verified source at all but to Yunitskiy's personal website. Because these facts may well be true, I haven't reverted it yet back to how it was before. But someone will have to find these facts in a source which is not self-published by Yunitskiy. –Zachar (talk) 10:46, 13 July 2019 (UTC)

I replaced the reference with a link to Yuznitskiy's original article in the Russian popular-science magazine Tekhnika Molodezhi, and linked to a scan of the issue from the Tekhnika Molodezhi archive site. Skepticalgiraffe (talk) 15:03, 25 July 2019 (UTC)

Dates

It would be useful to add years to the "Orbital rings in fiction" section and put it into chronological order. Skepticalgiraffe (talk) 16:33, 19 February 2020 (UTC)

Astroengineering proportions

I deleted the claim that Orbital rings are "astroengineering proportions". In the Astroengineering article, the smallest example is a Dyson sphere. Whereas an orbital loop is a couple of hundred thousand tons of half-inch steel cable. The hard part is getting it up there. -- PaulxSA (talk) 08:22, 10 May 2020 (UTC)

Internal tension

I just made a change where I removed some references to internal tension. In my view it's not a central aspect of a likely design for this, as it's not necessarily a contiguous cable (a swarm of small masses may make more sense) and not necessarily fully encased (only near the elevators/stations does it need to be accelerated).

That doesn't mean there can't be systems which do have internal tension, it's just that it doesn't necessarily make sense to focus on that aspect. Lsparrish (talk) 17:24, 1 December 2021 (UTC)