Well, even with a space elevator, the amount of energy required is still the same, but you can now use earth-bound energy sources.
You don't need to carry the energy source with you on your trip.
Must be a lot more efficient.
Jan
You don't need to carry the energy source with you on your trip.
Must be a lot more efficient.
Jan
With a space elevator you'd also use it like a funicular - one "pod" up as one comes down, to maximise efficiency.
Yes, von Braun's merits in those bad WWII days were the introduction of a fuel pump instead of just pressurized reservoirs to enhance fuel and oxidizer flow, hence dramatically increase thrust.
I encountered the NACA acronym the first time when I developed some interest in radial aircraft engines: The NACA cowling to gain additional thrust from the hot cylinders and heads.
Best regards!
I get the feeling NASA are making it up as they go along... 🤔
But here's what I know about Artemis III landing in 2025:
https://en.wikipedia.org/wiki/Artemis_3
Young Elon Musk supplies a huge, fully fueled up version of Starship called Starship HLS for the Moon landing after some refueling complications involving a specialist Space Tanker and the SpaceX Starship:
https://en.wikipedia.org/wiki/SpaceX_Starship
Starship HLS doesn't need heat shields or fins on the Moon:
https://en.wikipedia.org/wiki/Starship_HLS
Everybody following so far? 😕
By about 2030, all the bits of the Lunar Gateway should be in place for even more complicated things:
https://en.wikipedia.org/wiki/Lunar_Gateway
And here is what the modules all do:
This is all most interesting. There's all sorts of other stuff going on later. Lighter landers. The permanent Moonbase and all that.
I suppose the idea is technology is moving so fast, that most problems can be solved down the line.
WE ARE GOING!!! 😀
But here's what I know about Artemis III landing in 2025:
https://en.wikipedia.org/wiki/Artemis_3
Young Elon Musk supplies a huge, fully fueled up version of Starship called Starship HLS for the Moon landing after some refueling complications involving a specialist Space Tanker and the SpaceX Starship:
https://en.wikipedia.org/wiki/SpaceX_Starship
Starship HLS doesn't need heat shields or fins on the Moon:
https://en.wikipedia.org/wiki/Starship_HLS
Everybody following so far? 😕
By about 2030, all the bits of the Lunar Gateway should be in place for even more complicated things:
https://en.wikipedia.org/wiki/Lunar_Gateway
And here is what the modules all do:
This is all most interesting. There's all sorts of other stuff going on later. Lighter landers. The permanent Moonbase and all that.
I suppose the idea is technology is moving so fast, that most problems can be solved down the line.
WE ARE GOING!!! 😀
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Indeed, as Sir Arthur C. Clarke wrote:
"The net energy requirements would be almost zero, as in principle all the energy of returning payloads could be recaptured; indeed, by continuing the structure beyond the geostationary point (necessary in any event for reasons of stability) payloads could be given escape velocity merely by utilising the ‘sling’ effect of the Earth’s rotation."
https://spaceref.com/newspace-and-t...r-key-to-the-universe-by-sir-arthur-c-clarke/
Sir Arthur was not the first person to come up with the idea of a "space elevator" or "cosmic funicular". However, he was responsible for introducing the concept to a far larger audience in his book 'The Fountains of Paradise'.
Member @benb once alerted me to a "ludicrous-but-true bizarre thing" called Spinlaunch: https://www.syfy.com/syfy-wire/spinlaunch-centrifuge-slingshots-rockets-into-space
... forget the lunar lander/ascent vehicle, been there done that. Instead go for elevator proof-of-concept, eventually Mars deployment. No air & thin air.
Raise castles in the sky, out of local rock.
Raise castles in the sky, out of local rock.
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Could a lunar space elevator actually be doable? https://www.universetoday.com/10049/space-elevator-build-it-on-the-moon-first/
One could be attached to a space station at a Lagrange Point where the Moon and Earth’s gravity cancel out, so the station can remain stationary.
Since the Moon’s gravity is 1/6th that of Earth’s, the cable could be built using high-strength materials that are currently available instead of exotic materials with extreme tensile strengths.
Attachments
Thanks. Ancient article though. Sure the moon rotates slowly, but couldn't synchronous orbits be placed much lower/closer-to-surface than L1? Or are they all intrinsically unstable due to the Earth's pull? (Including at L1 according to the article.)
I could probably spend many years pondering Space Elevators, with so many things to consider, as with any new technology.
https://en.wikipedia.org/wiki/Effective_potential
I would observe that L1, L2 and L3 (unlike L4 and L5) need station keeping, which might cause problems with Space Elevators,
I think these things could go HORRIBLY HORRIBLY wrong at many levels. And so does NASA currently.
They are just modestly extending stuff that works, rather than wandering off into speculation.
I would like to better understand the elliptical orbit of the Gateway Lunar Station and its orientation, and why NASA have chosen it.
Latest picture from Artemis 1:
https://www.nasa.gov/artemis-1
Stay on-topic, folks! 🙂
Best Regards from Steve in Portsmouth, UK.
https://en.wikipedia.org/wiki/Effective_potential
I would observe that L1, L2 and L3 (unlike L4 and L5) need station keeping, which might cause problems with Space Elevators,
I think these things could go HORRIBLY HORRIBLY wrong at many levels. And so does NASA currently.
They are just modestly extending stuff that works, rather than wandering off into speculation.
I would like to better understand the elliptical orbit of the Gateway Lunar Station and its orientation, and why NASA have chosen it.
Latest picture from Artemis 1:
https://www.nasa.gov/artemis-1
Stay on-topic, folks! 🙂
Best Regards from Steve in Portsmouth, UK.
I love that bit in the middle "Loiter" ... sounds really technical ... gonna think of this diagram next time I'm hanging out on a street corner
You are correct about the "intrinsically unstable".
Given how slowly the Moon rotates, a lunar synchronous orbit would be so far away from the Moon that the Earth's gravity would disrupt that orbit.
I read that the Gateway is planned to be deployed in a highly elliptical seven-day near-rectilinear halo orbit (NRHO) around the Moon.
A description of the NRHO is given here (but it's complicated!): https://en.wikipedia.org/wiki/Near-rectilinear_halo_orbit
I've found this simple explanation for this choice of orbit: "An NRHO would enable a cislunar* space station to save propellant for orbital corrections and avoid the blocking of sunlight by the Moon from reaching the station’s solar panels, while always keeping the spacecraft within a line of sight to ground controllers on Earth."
*Cislunar space is the area around the Earth extending out to just beyond the Moon’s orbit, and including all of the five Lagrangian points.
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So sad. What can we hope to "learn" then, this second time around? I was actually too young (six) for Apollo 11, only "second-hand" lunar landing. For some folks here, it will be quite interesting re-living their childhood -- 1969 and 2029 sixty years apart symmetric about the midlife "40". Remember the popular joke about diapers etc.? I generalized it: At age 80-X a man rekindles his interest/obsession from age X.
40 & 40
Only a man astride midlife looks / both ways
— his Book of Life unfolded / open and mirrored sewn,
its first leaf and last / conjoin one and same,
its second and next to last, and so on —
knowing his final act shall continue / and fulfill / that his beginning.
40 & 40
Only a man astride midlife looks / both ways
— his Book of Life unfolded / open and mirrored sewn,
its first leaf and last / conjoin one and same,
its second and next to last, and so on —
knowing his final act shall continue / and fulfill / that his beginning.
Like the original space race, there is now a race to control cislunar space. Cislunar space represents an opportunity, but also poses a threat.
China has leapfrogged the U.S. in cislunar ventures by recently showing it could launch an object from the Moon and accurately land it back on Earth, something that has clear military applications. https://www.planetary.org/space-missions/change-5
Hence NASA's interest in cislunar orbits.
P.S. The sketch of Gateway's orbit shown above looks like a drawing made by someone who hasn’t quite gotten the hang of their Spirograph set!
China has leapfrogged the U.S. in cislunar ventures by recently showing it could launch an object from the Moon and accurately land it back on Earth, something that has clear military applications. https://www.planetary.org/space-missions/change-5
Hence NASA's interest in cislunar orbits.
P.S. The sketch of Gateway's orbit shown above looks like a drawing made by someone who hasn’t quite gotten the hang of their Spirograph set!
Space exploration was without a doubt the focus of the USA when I was in grammar school. In 1969 I was old enough to feel great pride and awe when the first lunar walk occurred. I followed the space program for virtually my whole childhood. It was part of the reason I became so interested in science and technology.
It is, but a space elecator will be able to generate energy with traffic coming down the elevator (unlike turning it intoheat by trying to burn up whatever is coming in for re-entry) dramatically reducing the net amount of energy the elevator consumes.
Important to keep the amount going up about the same as that coming down to avoid changing the length of a day.
dave
Charles Sheffield’s Web of the World came out the same month as Clark’s book, i read them both within 30 days, and it really left an impression. Sheffield’s use of nanobots to grown the elevator in space and then fly it into place was more dramatic, but Clark extending the elevator out beyond geosynchronous orbit to allow for a slingshot start for anything being launched into deeper space.
dave
It's interesting that these two novels, which were the first popularisations of the space elevator, came out so close together - so I decided to do some research:
Clarke writes in an open letter which is reprinted at the end of Sheffield's book:
"Early in 1979 I published a novel, The Fountains of Paradise, in which an engineer named Morgan, builder of the longest bridge in the world, tackles a far more ambitious project - an 'orbital tower'. The construction material is a crystalline carbon fibre, and a key device in the plot is a machine named 'Spider'.
A few months later another novel appeared in which an engineer named Merlin, builder of the longest bridge in the world, tackles a far more ambitious project - an 'orbital tower'. The construction material is a crystalline silicon fibre, and a key device in the plot is a machine named 'Spider'."
Clarke made it quite clear that no plagiarism was involved - it was just one of those coincidences that occur in science fiction writing from time to time. Suddenly, authors decide to write about building space elevators, or about solar sails, or about black holes etc. etc.
https://www.tor.com/2017/11/28/did-...unate-coincidences-happen-in-science-fiction/
I will have a go at Near-Rectilnear Halo orbits when I have digested a bit more of the lterature. This being what the Gateway Staion will be using. It's a very surprising solution to calculations of orbits. And very unintuitive like that old game of Lunar Lander which the older members may remember, where you had to land on the Moon with limited fuel.
For today I have been following the biggest problem on the Moon. It is LUNAR DUST! Gets everywhere. Breaks spacesuits, breaks electrical switches, scratches visors and lenses. Gets up your nose and irritates your lungs.
I have read far too much science fiction myself. I liked Asimov's stuff, even if it lacks emotional content and does not read so well now. Dust?
Humans hate it, Stars love it... 😀
For today I have been following the biggest problem on the Moon. It is LUNAR DUST! Gets everywhere. Breaks spacesuits, breaks electrical switches, scratches visors and lenses. Gets up your nose and irritates your lungs.
I have read far too much science fiction myself. I liked Asimov's stuff, even if it lacks emotional content and does not read so well now. Dust?
Humans hate it, Stars love it... 😀