Ort Cloud/Keiper Belt Refueling

[RandyT0001]

Just watching Discovery Channel "3 Minutes to Impact" and had a thought. (I can hear those 'Oh no, not again!' comments.) In Traveller the potential use of Ort Cloud-Keiper Belt objects for refueling is accepted but watching the show there was a comment by Levy about the tiny amount of gravity influence needed to change the orbit of these objects and change them into comets falling into a system. It is a very small amount of gravitational influence (the thump of a finger). How much gravity influence will a starship exert on the nearby bodies as a ship refuels in an Ort cloud? I know the ship has a very small mass and gravity inherent to it compared to a star but it's close proximity to the bodies might create enough of a disturbance to the orbits of these bodies to transform them into a cometary path plunging into a system. Maybe one the forums more physics educated members could do some rough calculations to determine the changes and it's potential to create comets. If the odds are greatly increased (especially in systems without GG that normally 'cleanse' a system of comets) then there might be Imperial restrictions outlawing Ort Cloud-Keiper Belt refueling.

Thoughts, comments?

 

[Malenfant]

Well, a 100 metre radius sphere of ice will have a mass of about 4.2 million tons (assuming a density of 1000 kg/m3). A 1 km radius sphere will have a mass of 4.2 BILLION tons (and a 10 metre radius sphere will have a mass of 4200 tons).

To qualify as a comet, we're usually talking about things that are a few kilometres across - i.e. with billions of tons of mass.

Now one problem might be that all the general pushing and shoving of smaller bodies involved in the refueling (especially if you're using tractor beams or other gravitic tech) will nudge the body out of orbit a bit. But it's still unlikely that it would suddenly push it into the inner system.

It would be very unlikely that refueling in the Oort CLoud or Kuiper belt would be a hazard to the inner system. Particularly since it would most likely take hundreds of years for the object to get to the inner system anyway, and then there's a minimal chance that it would even hit a planet anyway, and then you could have it diverted by a close encounter with giant planet...

 

[The Oz]

I agree with Malenfant, also anything in the Oort Cloud small enough to be affected by refueling will also be small enough to be easily rediverted by a visiting warship, even a small one.

I could see the Imperium banning/restricting Oort Cloud refueling, but that's because of who would most likely be doing it (smugglers, spy ships, pirates) rather than any "ecological" risk from the practice. There's not any real reason for honest traders to be out there in the Long Dark refueling, when all the money to be made is usually in the inner system.

 

[flykiller]

There's not any real reason for honest traders to be out there in the Long Dark refueling, when all the money to be made is usually in the inner system.

if the system has only one world that is interdicted, or the system is only a way-point and the worlds are all well within the star's 100d limit, then such refueling might be common.

 

[The Oz]

Originally posted by flykiller:
if the system has only one world that is interdicted, or the system is only a way-point and the worlds are all well within the star's 100d limit, then such refueling might be common.

I imagine the Imperial Navy would argue that if the system is interdicted you shouldn't be there anyway, and if it's a waypoint system where the Oort Cloud is the only source of fuel then someone would set up a refueling point for traders, since merchies don't have the time to waste mining their own ice for fuel.

And if there isn't enough traffic through that waypoint system to make a refueling station viable, then there's no real reason for you to be going through there, now is there?

The Navy can be so stuffy about these things....

 

[far-trader]

The Oort Cloud and Kuiper Belt is going to be a lot, a whole lot, a huge almost unimaginable lot, of space for the Navy to monitor and patrol. I doubt they'd bother. If the system is interdicted by the Navy for security reasons they'd just set up a broadcast system to let you know you are in violation and they are not responsible for damages or loss of life. Then they'd mention that the whole of the system is heavily mined and unless you want to be blown up you had better go to station keeping and squawk your ident so they can come and "escort" you to the port for questioning.

 

[flykiller]

Then they'd mention that the whole of the system is heavily mined

hoo, that'd be a lot of frozen mines. could all the industry of palique build enough? be easier and cheaper to monitor and patrol the area.

 

[Whipsnade]

I see the Oort cloud and Kuiper Belt more as jump navigation hazards and not as fuel sources. Mucking about on and around a billion ton ice/snow 'berg' and trying somehow to gather fuel you'll still have to refine will be something most folks - scouts and military included - will be loathe to do. Look at a belter's life expectency in CT for instance.

Of course, this doens't mean that folks won't do it and PCs being PCs will definitely try it, but refueling in the Deep Dark isn't an everyday, every week, or every month evolution.

Question for the boffins: Other systems will have Oort clouds, but what about Kuiper Belts? Will they be found in all systems? Or just a few?


Have fun,
Bill

 

[far-trader]

Originally posted by flykiller:
</font><blockquote>quote:</font><hr />Then they'd mention that the whole of the system is heavily mined

hoo, that'd be a lot of frozen mines. could all the industry of palique build enough? be easier and cheaper to monitor and patrol the area. </font>[/QUOTE]Well I guess it would depend on the cost of effective patrols vs one time seeding and minimal monitoring. Besides I never said they actually did mine the system

You tell me if you're going to take the chance and call the Imperial Navy on that bluff

My vision of space mines tends to change over time and systems. At the moment I'm thinking (T20) a pop-up triple missile turret for the modelling. That is it masses 2 tons, costs MCr5.0 (unarmed), with an effective USP 3. The extra ton of volume and MCr4.0 is for a Model/2 computer and sensor package with a Model/1 communications sub-system. Arming will depend on the degree to which the IN feels the system warrants. Conventional warheads if its just a low level interdiction, like maybe some for your own good or a trade blockade. Nuclear warheads if it's a biiiiig secret that no one can be allowed to know.

The IFF-AI of the mines just float doing pulsed scans. Few and far between for any single mine since they work together. If one detects a craft it goes active and broadcasts the warning which also alerts all it's sibling mines in range with the target data. If you do as it orders (zero your vector and broadcast your ident, immediately) it will hold fire unless otherwise ordered by the monitor station. If you do not obey or the Navy deems you a threat you will be under fire from multiple mines

Now of course we don't need to literally salt the volume with mines. As long as the threat is there most sane traffic will steer clear. That doesn't mean you won't get a few spy craft testing the defenses or pirates taking the risk to refuel out of need, or the odd misjumped PC It does mean that for a low cost we can influence the already small likelyhood of visitors to the area. At least I think it's gotta be cheaper than an equally effective manned patrol mission. We'd be talking a lot of ships, and men, and supplies on the off chance of a trespasser, as opposed to a lot of mines, a few monitor stations and some maintenance craft, after the massive mining operation of course. But that would be one action. I'd probably have one mine layer group on station to make more effective of the mines by moving them around. The mine layers would probably even be the monitor stations and include maintenance craft so we don't need more ships or personnel for that.

Anyway that's my take, YMMV of course

 

[Malenfant]

You're going to need a heck of a lot of mines (probably about as many as there are Oort Cloud objects) to cover the whole cloud... (or even just the Kuiper belt)

 

[Malenfant]

Originally posted by Larsen E. Whipsnade:
[QB] I see the Oort cloud and Kuiper Belt more as jump navigation hazards and not as fuel sources.

Except they're not. Oort Clouds and KBs are very thinly populated - you have pretty much no chance of intersecting the 100D limit of one (tiny as they are) if you pass through it.

(in the mid-70s the Voyager spacecraft flew right through the asteroid belt and didn't hit anything, and didn't have to avoid anything either, and that is much more densely populated than the Oort Cloud).

but refueling in the Deep Dark isn't an everyday, every week, or every month evolution.

For starters, you have to FIND something to refuel from. Given that everything is frozen solid out there they'd barely show up on long range IR scans.

Question for the boffins: Other systems will have Oort clouds, but what about Kuiper Belts? Will they be found in all systems? Or just a few?

For now, I think we assume that they all have them because they're a natural side-effect of stellar and planetary formation. But it depends on the situation really. Multiple star systems with Far companions may have clouds that are disrupted - maybe one or both stars would have a remnant Kuiper belt though.

 

[far-trader]

OK, reality test, let's see if I did the math right and pass

Sample problem: Defend Earth's Kuiper Belt from unwanted visitors:

KB radius approximately 50AU gives us a circumferance of some 300AU (in round figures), about 45,000,000,000km.

Let's be very generous and say the thickness is within our mine's maximum strike range or 900,000km for the missiles, but the sensor is only 450,000km. So we want to overlap coverage (yes it's a bit thin but I'm still afraid the number of mines is going to be huge). We place two mines 900,000km apart every 450,000km around the perimeter. We need 100,000 mines for minimal coverage. At a cost of Cr500,000,000,000 plus whatever the monitoring and tending ships will require.

For the same coverage with 200ton SDBs let's allow one SDB going each way (so two per unit) spaced at the maximum range of the missiles of 900,000km to allow for quick attack. So we only need 50,000 SDBs on patrol. Cost for just the ships is Cr10,000,000,000,000. That's 20 times the cost, but does not factor salary for some 300,000 crew, and life support, and maintenance and a whole host of other minor issues.

Certainly the SBDs are more versatile and perhaps you could get away with fewer but I still think the mines are the cheaper way if all you want to do is keep snoopers out by threat and force.

Please check my math and propose other plans if you feel inclined. I for one welcome more ideas.

I am NOT going to try to figure out how to protect the area of a sphere some 3 light years out. For that matter, at that range I'm not inclined to protect or even worry about it in the least under the guise of system defense

 

[Malenfant]

Don't forget that you need to factor in the time it'd take to even lay the mines around the perimeter. And also, IIRC the belt thickens with distance from the star too til it joins the oort cloud.

If they are to be undetectable, they need to be thermally shielded so that IR can't pick them up, which may make the mines more expensive. (and one other problem - it means NOBODY can get into the KB. Friends and enemies are shut out, and it would be exceedingly difficult to remove the mines unless you had some remote detonation signal you could use, because you're not going to find them again).

Frankly, it's probably more worthwhile to just not mine it. Like I said, the chances that a ship would jump out into the Belt or Cloud and even find an object close enough to refuel from are quite low...

 

[Whipsnade]

Dr. Thomas,

Thanks for the info on Kuiper belts.


Bill

 

[Pickles]

It wouldn't even make much of a hiding place for nefarious activities, with low object densities like that.

 

[The Oz]

With the low density of objects in the Oort Cloud there really isn't any honest reason for someone to be out there, which is why I think the Imperial Navy would like to make it illegal to be out there in the first place. Not that the Navy will waste much time patrolling all that space, but if they do catch you doing something they don't like but can't prove and they =can= prove you were out in the Oort Cloud they can always charge you with that.

 

[Jeff M. Hopper]

I can think of many different social groups that would populate Oort Clouds and Kuiper Belts simply because they would appeal to isolationists. Also, out of the way places are good for placing things out of the way - like prisons or research installations or religious retreats or "punishment" military posts or hermitages.

 

[Ran Targas]

The outer reaches of any system (especially off-disk) would definitely be so far out of the way that you could pretty much do whatever you want without much chance of being seen. With the huge volume of space available (as previously calculated), the low level of ambient light (to reflect off your hull), and the low level of interest in objects floating there, it's a great place to hide.

You could even park something very conspicuous (i.e. pirate enclave, secret research station, clandestine military outpost, etc.) out there with little concern of being accidentally stumbled upon. And think of all the things that may be just sitting out there waiting to be found, hmmmm?

I think this is an area that most Trav GM's and players never really think about as they jump between 100d limits. It's kind of like only thinking about cities and never the interstates that connect them or the countryside you pass through between them. I had to literally teach my players by example and scenario to use deep space and the outer reaches of the systems they visited. Now when they are planning covert activities, they jump in as far from the system center as they can and still reach their target within the time constraints of the mission. Lots of running silent and drifting.

This goes back to my points on the differences between commercial and military/scout navigation. Big shippers would never bother training anyone to jump into the wilds of an outer system when their insurers wouldn't cover them for it. Only the military or pseudo-military would see this skill as a necessity.

 

[Whipsnade]

This is slightly off topic, but I have Yet Another Question For The Boffins.

It goes without saying that spotting Oort and Kuiper objects is extremely hard and that they are scattered from hell to breakfast as it were, so...

- How does the Third Imperium map 'em?
- Does the Imperium even bother to map 'em?
- Does the Imperium usually wait until said objects enter a system 'deep' enough to get 'lit up' by the system's star(s)? (Being deeper in the system makes them slightly more dangerous and those are the ones you'd want to keep a sensor on.)


Bill

 

[Malenfant]

Originally posted by Larsen E. Whipsnade:
[QB] - How does the Third Imperium map 'em?
- Does the Imperium even bother to map 'em?

Given that they don't in themselves cause much of a threat just by being out there, they probably wouldn't care to map them at all. If they did, they'd probably have telescopes in the inner system looking for them, or the odd specialised survey ships out there in the cloud. But there wouldn't be much purpose in it beyond scientific exploration and data gathering.

of course, the Imperium's astronomy TL appears to be much lower than our own, given that they don't seem to know that brown dwarfs and planets exist between stars .

Does the Imperium usually wait until said objects enter a system 'deep' enough to get 'lit up' by the system's star(s)? (Being deeper in the system makes them slightly more dangerous and those are the ones you'd want to keep a sensor on.)

Well, it'd make it a lot easier to detect them in that case. Then you'd just plot out the orbit and call it a comet - if it's a potential threat (which is unlikely. Look at how many comets (as opposed to asteroids) are a current threat to us today - ie none) then they'll try to do something about it.