A Tour Of The Lagrange Points. Part 3 - Trojans and Space Colonies at L4/L5

Excellent and informative video on Lagrange points. Great work!

No rail guns. Rail Guns are weapons. O'Neill proposed mass drivers to send bucket of stuff. With Good Engineering, it can arrive at the destination slowly and peaceful for capture.

Uhh... To state the obvious; if there's an asteroid at a Trojan point then why not use that for as much of the mass as possible. I can't thank you enough for this info. We now have a new destination for a manned landing that doesn't really need a lander. Are you listening NASA? We could build a space colony more easily than O'Neil could have imagined! If he'd only known...

I enjoyed that series a lot... I have heard the term before but never understood its true meaning, and now I know there are a couple of those Lagrange points! thanks for the videos :)))

I'm wondering that !!!
is there ever any space craft collided with any space stone or Asteroid or meteoroid (especially out of earth orbit) ????????
becuz there were many space craft launched but i have never heard of collision
like Voyager 1,2 . its probably floating in space around 40 years. how lucky it can be that not a single debris hit that craft
EVEN IF THE ANSWER IS NO.
But why IS IT SO!!!!!!

L3 is where the 👽 hide anyway the ones that aren't in the ocean.

Frasier, it's a somewhat easy concept for me to grasp orbiting around unstable LaGrange. How does this work with stable LaGrange points. If it's an automatic process being pulled into a well, how do you keep from hitting the other objects at, or coming in to the area?

How do the sizes of these regions compare with one another? Are they all about the same size relative to astronomical objects?

When the picture of the black hole was published I thought that it would have been better if we had had 3 of the ALMA telescopes in Earth-Moon L3, 4 and 5. Well, one could dream :-)

When gb00234 makes its closest approach to the sun, is there any chance that is could be a naked eye comet? Or even be visible with a telescope? I’ve seen people saying it might be quite large.

Any O'Neal cylinders will have to be built from material mined in space. We should never launch that much of our earth into space,

What about an Earth Moon Trojan Deep-space Gateway Station?

If asteroids are found in L-5 they could be used to build space colonies "onsite"

Looking towards Kardashev Type II megastructures are a bit demoralizing at our current tech level. I think humans should put away currently unreachable goals and non-sci fi fantasy tropes from years back like magical emitting artificial gravity fields and warp drives. True spaceships will not look like airplanes, submarines, naval ships, weird crescents, saucers, or other transient shuttles. They will be orbs. Orbs with radiation shielding, deflective curvature, and jack shaped skeleton trusses with suspended counter rotating compact pinion shafted O'neills inside them. A six configuration config is a gyro, a 14 config will fill up the diagonals. 14 centrifuges also means 7 trusses making the entire shell rigid. And each centrifuge should have a floor to pinion shaft height minimum of 25 meters. This is for anti-nausea. Plus you're gonna have comfort ceilings so you don't see any rotation. All in all we're talking a 150ish meter diameter spaceship. Bigger ships and you'll start seeing concentric multi-floored centrifuges. And the disparity of centripetal artificial gravity between the floors will be remedied by sliding topical surfaces.

I love your videos and this series on the L points is really helpful!

While watching a video by TMRO, I had an idea, and thought you might be able to make a video about it or include it in Q&A. I posted it there and I'll put the same post below.

The topic is space debris, with the context being the recent Starlink incident of not maneuvering to avoid ESA's satellite. Post starts here:

I have an idea for directing who needs to make corrective maneuvers in space: each satellite gets listed under a different classification (priority) depending on certain criteria. A cubesat or other immobile spacecraft would have right of way (they can't move). Then crewed spacecraft. Those certainly have to be first. Then we have the real classes (priorities): one-off, expensive satellites (like the science satellites from NASA, ESA, and other global space agencies) would pay to have a higher priority. That price could be determined by certain factors like how difficult it is to perform a maneuver (i.e. thrusters only meant for de-orbit). Few satellites on lower budgets would purchase lower priorities. Large constellations would get low priorities (or pay a higher premium). Ideally, in my humble opinion, large constellations like Starlink would make the majority of maneuvers themselves, regardless of which craft was there first. Especially for large, commercial constellations, purchasing a higher priority for each satellite wouldn't likely be worth it.

Ok, but to purchase something requires a seller. These funds would have to go to an international organization (we know we will need one eventually) which will use the funds to help with cleaning up space debris.

I know that the majority of debris is not from active satellites, but this is one way to address the active satellite part of the equation.

What do you guys think? Did anyone actually read this post?

One loophole I see is that non-mobile spacecraft have preferance, and therefore may be preferred by designers. Maybe all spacecraft above a certain mass would need to be able to do obstacle avoidance (with exception), or pay a higher fee. And of course, spacecraft should always have a way to deorbit, whether passive or active.

P.S. What about spacecraft with the same registered priority? Here we could refer to the spacecraft in orbit longest and/or consider the unique circumstances and/or ask the companies to figure it out (large fine if they choose to not move but collide? And/or heavily restricted access to space for those companies) Ideally, the decision of who maneuvers would be autonomous and indisputable.

What would happen to a plane or helicopter that tried to fly in the space colony? Would it lose control?

dont get me wrong, i love astronomy but the size of this project wont happen in the next 1000 years, by that time earth will be gone (doomsday)

What are the chances that the object that created the Chicxulub crater, was of extra Solar origins.
They seem to be looking like they are quite common and travel relatively fast, so can do a lot of damage.?

One of the first SF stories I read was Niven’s “Flatlander”. In it one of the characters remarks that a mistake was made in launching a spacecraft on a course that took it through one of the Earth’s Trojan points, the problem being that Trojan points are dust collectors and sending a spacecraft at speed though a concentrated dust field would not be good for it.

I haven’t seen this issue mentioned in any recent discussion on spacecraft at L4 or L5. Was Niven exaggerating the danger?

Question : How much gravity does have the lagrange points , like earth? 10g? more?

A stimulating three videos. But what about the Lagrange points of the other solar system planets? Wouldn't these be even MORE useful, particularly for astronomical purposes?

I'm surprised that lunar aluminium and titanium mining and smelting is not yet a technological priority.

Thanks Fraser.
How do you slow down the material shot by the rail gun when it arrives towards the O'neil cylinder?

Lagrange points make solar system sized telescopes realistic

If it is so easy fuel-wise to get to L4 or L5 then surely it is also easy to get back to Earth. And if there is a 220 km diameter asteroid at one of these points, what is to stop it too from ultimately coming our way? That is pretty frightening because a collision with such a beast would wipe out all life on Earth, boil the oceans, etc.

If we wanted to collect Mars rocks, would it be easier to get them from Mars' L4/5 than landing on Mars?

ASTROD sounds amazing! ASTROD II could use Jupiter's Lagrange points. We could, 'hear', kids jumping rope.

Great series,

🤓

I was a member of the L-5 Society in the late 70s. It seemed like O'Neill and others could start a colony then.

No, I don't want to her about the giant multi trillion dollar space habitats that will; never happen! The US is over $22 Trillion in debt and will be much more at the end of this administration! Even the initial Gateway Foundation's concept of Von Braun is way too grandiose, and will cost trillions, let along the full size one!
Instead of jumping to science fiction, how about we deal with science fact when it come to space habitats!instead of day dreaming of multi trillion dollar habitaes that will never happen?

Yay! Lagrange points for president!
Jokes aside. Great video.

We can take the old satellites shoot them in to L4 and L5

Does Saturn have trojians at its Lagrange points?

Thank you for this, I had just posted something like this somewhere else because I hadn't heard anyone mentioning uses of L4/L5: (You had similar ideas plus lots more!)

I think communication with Mars might be better in future if we have a relay station satellite near each of (or one of) Earth's Lagrangian points L4 and L5 so communication can continue when Mars is the wrong side of the sun. I've not heard anyone in the space industry discussing that idea. Perhaps it's too difficult (to build and set up such relay stations or to calculate the direction and wavelength of signal because of tadpole orbits around L4 and L5 and Doppler effect.
Space probes at such locations might be useful for other things like monitoring the sun or near earth objects or communication with other space probes at other planets that are on the far side of the sun.
Are such orbits around Earth's L4 and L5 stable enough for communication relay stations - or habitable space stations?

A good idea for using the L3 point is for watching the back side of the sun to get advanced warning of solar storms before that side rotates toward us.

Hi Fraser, very nice and inspiring series! There is one tiny point you may have explained not completely correct. The L4 and L5 points are stable not because of gravitations. On the contrary, on the potential contour map, they are at hill tops, although not quite steep ones. The reason they turned out to be stable anyway, is because of the rotation and the Coriolis force. I just learned this from Wikipedia today, hope this is correct info.

What would be the benefits of living in space though? I understand that it would be really cool, but what could we do there that we couldn't do on Earth?

Wouldn't it be awesome if we had a mineral rich astroid in any of these locations... We could do all kinds of cool projects for many generations. Just send up automatic robots that build a space station, communication devices, fusion and energy harvesting, even seeding other planets with what they need to support life.

please make a video on halo and lyapunov orbits.....

Sounds crazy but 450 Trillion is within human comprehension, so making progress...

I think Bezos should rather focus on fixing Earths degraded lands first, to make them habitable again.

question: can you discuss what some of the challenges would be "living in" L2?

Another question: The host planet would remain in the same relative position if one were to be looking out a "window" from a position within L4 or 5 ? there's lots of celestial mechanics in play.. are there any animations from the viewpoint of L4 or. 5? Any renderings? Seems the view and apparent motion, out the "window" would be static. thanks

Awesome 👌 👍

I developed a rough idea that L2 could be used to mitigate global warning by a large solar shield. You only need some technology to create a continent-sized shade from as little as tons of material in a reasonably controllable and safe way - but that does sound doable to me. Upkeeping it for years or decades sounds tougher. Figuring out a way how humanity could set up an international body to control it so that nobody feels threatened... and how do avoid that populist politicians of any country campaign against the project only to gain support -- now, THAT sounds dishearteningly difficult...