Trojan Points

[Timerover51]

I am working on setting up a sector well to the rimward of the Solomani area. I have settlements in the Megin-giord Asteroid Belt (Megin-giord is Thor's Belt of Strength), located in the Sword Sub-sector of the Piper-Norton Out Rim Sector.

The settlements are in the Belt proper, but I also have settlements in the large Gas Giant, Ragnarok, Trojan Points, The leading group is Hugin, with the trailing group named Munin. (These are the names of Odin's two ravens, that fly the earth searching out news for him.) The two groups of asteroids are the system's primary refueling and trading stations, as all of the asteroids in the main belt sweep past them on a regular basis in the Belt's orbital period. Better prices and deals can be made by contacting the various Belt settlements directly, but the main shipping lines use the Trojans for their transshipment point.

What I was wondering if anyone has used the existence of the Trojan Point groups in their universe? I assume that any system with a large gas giant is likely to have Trojan Point asteroid groups, with systems having several gas giants having more than one such pair of groupings.

 

[nobby-w]

I am not an astronaut I do play one in Kerbal Space Program.

Trojan points would be a perfectly good place to put a space station build structures on an asteroid occupying it. On a solar system scale they would be quite a long distance from the gas giant, though, some 60^O leading and trailing it.

One point of using a Trojan point (as opposed to something in orbit around the primary) would be if Delta-V was expensive enough that it was worth not having to go into the gas giant's gravity well. However, in this situation the orbital rendezvous between the gas giant and L4 or L5 points would also be very long winded.

Another point might be the substantial radiation from the gas giant, although if you have folks living in its system then you have to really assume that shielding has been solved.

Otherwise it might be better just to have your station in orbit around the gas giant itself or one of its moons. You could also have a space station in the L4 or L5 point of one of the moons.

 

[agorski]

In the Jovian Chronicles RPG setting, the Jovian Federation has settlements on asteroids at the Jupiter trojan points, with a regular transport system between there and the primary orbital colonies around Jupiter.

 

[Timerover51]

I am not an astronaut I do play one in Kerbal Space Program.

Trojan points would be a perfectly good place to put a space station build structures on an asteroid occupying it. On a solar system scale they would be quite a long distance from the gas giant, though, some 60^O leading and trailing it.

One point of using a Trojan point (as opposed to something in orbit around the primary) would be if Delta-V was expensive enough that it was worth not having to go into the gas giant's gravity well. However, in this situation the orbital rendezvous between the gas giant and L4 or L5 points would also be very long winded.

The two groups, Hugin and Munin have a fair number of ice asteroids to supply fuel for ships, along with shipments of additional fuel from the Belt itself. There would be no need to use the gas giant for refueling. The Belt settlements also have plenty of fuel for refueling. Both groups also have plenty of oxygen for life-support replenishment, if needed.

Another point might be the substantial radiation from the gas giant, although if you have folks living in its system then you have to really assume that shielding has been solved.

The approximate equation for the circumference of the orbit of Ragnarok is 2 times the distance from the Megin-giord star time pi (or circa 3.14). At a point 60 degrees leading or trailing Ragnarok, one-sixth of the circumference of the orbit, the Trojan Points are as far away from Ragnarok as they are from the star. There is not going to be any problem of radiation from the gas giant.

Otherwise it might be better just to have your station in orbit around the gas giant itself or one of its moons. You could also have a space station in the L4 or L5 point of one of the moons.

At the Trojan Points, you do not have to deal with the gravity well of Ragnarok, about the size of Jupiter, nor the radiation belts around it. There you would have a problem with radiation as a result of the gas giant. Besides, there is plenty of material at the Trojan Points to work with.

Hugin and Munin, along with several Belt settlements, have Class B or C starports, with the difference being that refined fuel is also available at all of them. That is needed for the intra-systen transports.

 

[mike wightman]

Trojan points have another useful property, they are part of the 'interplanetary transport network' which is basically the pathways taken for very low energy/delta V transit around a system relying on gravitational interactions. It takes a long time to get anywhere, but it is very low energy so it may have uses.
https://en.wikipedia.org/wiki/Interplanetary_Transport_Network

 

[Winged Cat]

In the campaign I am currently playing in, for the maiden voyage (under our command, anyway) of our ship, we prospected to raise funds. We specifically went to the trojans of our system's main gas giant, as they were less mined out.

I know of someone else who runs a TL 10 Sol system campaign, wherein Neptune's trojans host two observatory ships forming a long baseline array (at least in one dimension) telescope.

 

[JimMarn]

Are Jupiter's Trojan points stable enough to have such ships and telescopes placed there ?

My read in astronomy books, albeit decades ago, was that those locations changed over time as to what was there and what moved in/out due to fluctuations caused by Jupiter moving past Saturn.

 

[jcrocker]

Yes.

To qualify that, down in the last paragraph of this site:

https://en.wikipedia.org/wiki/Jupiter_trojan

It had the line, "Simulations show that the orbits of up to 17% of Jupiter trojans are unstable over the age of the Solar System". Which suggests that up to 83% of the Jupiter trojans *are* stable over the age of the Solar System. That truly is long-term parking.

There was a diagram at the start of the article, the trojans seem to cover a lot of space. I'm sure if you went to the edge of the 'safe' region, yes, you'd get pulled out of a trojan orbit quicker than if you were at its heart.

Of course, even if you do get nudged out of a trojan point, it's not like you fall off a cliff, or get sucked into a black hole. Any ship, any space telescope would have something to maneuver a bit, they should be able to get back on course soon.

 

[mike wightman]

Being nudged out of the trojan or L point is what makes the interplanetary network possible, a small perturbation or minimal delta V spend will send you on your way. It may take you tans, hundreds or even thousands of years to get to another 'useful' orbit but it will happen.

 

[Timerover51]

Thank you, Jcrocker, for the link. It looks like there will be a lot more material in the Ragnarok Trojan Points than I thought. A cubic kilometer of water ice will run around 916 million tons. With hydrogen being one-ninth of that, you have 100 million tons or so of hydrogen to use. There is going to a lot of cubic kilometers of water ice out there.

Yes.

To qualify that, down in the last paragraph of this site:

https://en.wikipedia.org/wiki/Jupiter_trojan

It had the line, "Simulations show that the orbits of up to 17% of Jupiter trojans are unstable over the age of the Solar System". Which suggests that up to 83% of the Jupiter trojans *are* stable over the age of the Solar System. That truly is long-term parking.

There was a diagram at the start of the article, the trojans seem to cover a lot of space. I'm sure if you went to the edge of the 'safe' region, yes, you'd get pulled out of a trojan orbit quicker than if you were at its heart.

Of course, even if you do get nudged out of a trojan point, it's not like you fall off a cliff, or get sucked into a black hole. Any ship, any space telescope would have something to maneuver a bit, they should be able to get back on course soon.

 

[mike wightman]

You will also find plenty of carbon and nitrogen too. Setting up a refinery at the equivalent of the Trojans in your system will net you lots of resources - enough to construct habitable asteroid stations inside some of the larger lumps of rock, spin the insides to simulate gravity if you don't have grav plates in your setting, or just build O'Neill cylinders.

 

[Whipsnade]

I read several years ago that Neptune's trojan points may have many more larger bodies than Jupiter's points. Not more bodies in total, more bodies over a certain size.