Only if low enough in a preset, decaying orbit. (why would you set that up?)
Certainly. But why would you be aiming your damaged ship directly on a vector to crash into a planet? (discounting battle scenarios close to a planet)
Commercial starship lifeboat requirements
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Only if low enough in a preset, decaying orbit. (why would you set that up?)
Certainly. But why would you be aiming your damaged ship directly on a vector to crash into a planet? (discounting battle scenarios close to a planet)
If you're on an inbound full-duration thrust course, it's entirely possible your vector prior to the final maneuver might bring you into contact, especially if "chasing" the planet in its orbit.
Again, tho', this is only solvable with a powered, thrust capable self-rescue or by external rescue, but external rescue may not have the needed time to match vectors.
Oh, and every edition has allowed for redundant drives.
You would have to be VERY close to the planet when you drive suddenly and without warning "failed". Since you would probably be aiming for an orbit rather than hitting the planet, the odds of both happening would be less than me winning the lotto a couple of times. Not high enough to require ships be equipped with lifeboats. Airliners fall out of the sky more frequently and escape systems for passengers aren't required.
:rofl::rofl::rofl:Umm, no. You don't understand fusion pp's. So, no radioactive plasma running amok through the ship.o:
Or reactionless drives.
Or faster-than-light travel.
Or violating conservation of momentum.
Or violating the laws of thermodynamics.
Or generating artificial gravity fields.
If you have achieved multi-megawatt fusion without producing Alpha or Gamma or thermal radiation, then I yield to your expertise, otherwise I stand by the claim that it is no less of a magic black box than the MD and JD.
Fusion reactions and theoretical PP'ss ARE pretty well understood in the present. Your post simply shows that YOU don't understand...
Hi,
As I've noted before, I believe that weak, aged and/or damaged components may be more likely to fail when stressed more than normal. Hence, if you are trying to reverse thrust and/or start your thrusters to either 'break' to enter orbit or 'boost' to exit orbit after a period of inactivity or constant G operation then to me this seems like the type of situations where an aged, damaged or deteriorated component might fail.
Beyond this I think(?) that there is the potential that if you are inbound toward an inner planet and your power plant or drives fail you may end up in a deteriorating orbit in toward the main mass/star in the center of the system.
For a reactionless drive (that Trav uses) they are either on (producing accel, such as during ANY maneuver) or they aren't. There is no special "stress" from "reversing" direction. 1G accel (Free Trader) is just that. Doesn't matter what else is going on...
Which the Traveller PP does not match.Fusion reactions and theoretical PP'ss ARE pretty well understood in the present. Your post simply shows that YOU don't understand...
In which way exactly?
This comes under the "space is very, very big" category. If you are very close to something, an "undesirable" course can be deadly rather quickly: a bad thing happening in the middle of a re-entry or as you're starting your fuel-skimming run will likely spell the end of your ship and everyone aboard - and then we can argue whether bailing out offers any hope or not. However, a bad thing happening in the middle of nowhere, say 60 diameters out from the planet as you're traveling from jump to orbit, usually means you're going to be drifting deeper into nowhere: you'll hit your orbital insertion point with too much velocity and zip past the planet and outward (or inward toward the local sun). Any pilot with half a brain will make sure his course does not court disaster if something breaks, especially given the very generous fuel and power resources at his disposal.
In the case heading out to the Jovian, you become locked into a fixed vector rather than running the planned acceleration-turnaround-deceleration course, and you'll hit the planet's orbit either before the planet gets there or after, again continuing outward.
Think of it like this: you're heading out toward the Jovian. The planet orbits counterclockwise from your point of view. You plan to arrive at the planet in time to meet its leading edge so you can make orbit. To do that, you must arrive there in X hours, Y minutes, and so forth. Arrive early, you miss your appointment (unless you alter course). Arrive late, again you miss your appointment, the planet moves on without you. There's a very, very narrow window where, if you coast from that point, you'll hit the planet, and that actually occurs in the middle of the acceleration leg - plenty of time for someone to head out and tow you into a safer course. From that window forward, if your drive fails you'll get there before the planet does. You will not impact the planet, and even if you're very, very close when it happens you won't be pulled in - you'll be in the middle of slowing to an orbital velocity, so you'll have too much speed to do more than fly past and see your vector bent.
Yes, that's a very good point. However, it's really only a problem for warships ('cause they have high-G drives), and they tend to be very well maintained, and they tend both to travel with support and to have their own lifeboats. Civilian ships don't tend to do more than 1-2Gs, maybe 3, and any world with a 6G ship's boat or two ought to be able to head out there and intercept them in a reasonable time. The only thing the civilian needs to do at that point is manage to keep people alive for a few days.
In other words, your damaged ship is a warship or exploratory ship or maybe a miner, since merchants have no interest in such a system. If they did - if for example it was a pass-through point on the way to another system - it'd have a starport with fueling capacity, and it would also therefore have some boats available to help rescue you.
Additionally, on the topic of system redundancy on Traveller Starships and Spaceships, there seems to occasionally be some discussion about how the systems onboard a ship are likely redundant and potentially even segregated to allow undamaged sections to not be affected by the possibility that systems in a damaged section of the ship may not be working due to damage in that section.
You CAN in fact fit backup systems under High Guard and MegaTrav rules. There are rules for how to deal with that in Trillion Credit Squadron and the MegaTrav Referee's Manual. Combat damage rules may imply redundancy in some other systems, in that it's not possible to damage them (no damage roll for the life support, inertial dampers and so forth). Those either have sufficient built-in redundancy or sufficient dispersal that battle damage is not likely to significantly degrade their function. It could be something like lightbulbs: you might knock out a few lightbulbs, but there are so many and they're so easily replaced that it doen't affect much.
At any rate, whatever it's "like", it's clear that systems like life support systems are resilient, at least in combat situations. Whether they're resilient in other situations is up to the gamemaster.
With a few exceptions, that's almost entirely up to the gamemaster. There are no rules, for example, on how often you need to get into the guts of the life support machinery; there's just a general annual maintenance rule and rules about life support costs, implying use of some consumables or wear items. Ergo, any application of the task system to the life support machinery would be something cooked up by a specific gamemaster for a particular game, rather than something one would expect to see in anyone's game universe.
O Lordy, the fusion plant debate rears its head again.:rofl:
Okay, here goes:
Take a 400 dT Subsidized Merchant. That's a nice round 4 EP one-thousand-megawatt power plant. Consumes 4 dT of fuel each month. 4dT of hydrogen happens to be 4 metric tons of hydrogen - 4 million grams. A month is about 30 days, give or take - 2,592,000 seconds at 30 days, 2,419,200 seconds at 28 days. Let's use 2.5 million seconds just to make the math easy. Okay, so the fusion reactor consumes 4 million grams in 2.5 million seconds - 1.6 grams to produce 1 billion joules. That's AFTER the reactor uses whatever energy's needed to produce the force required to bring that hydrogen to fusion - hypothetically, there's more than a thousand times more energy available in that gram, but we don't know how much hydrogen escapes without being fused and we don't know how much of the energy is needing to be fed back into the plant to sustain the reaction; we only know output.
A billion joules - that's like roughly 500 pounds of TNT. Nasty, but most of it's energy: like 4 1/2 MeV per reaction, plus some gamma, plus some oddbits like neutrinos, plus that gram-and-a-half of plasma at 10 to 14 million kelvin, assuming a proton-proton reaction. The reactor is already designed to grab and use that energy and it's already dealing with the gamma, or else you couldn't mount it in a ship. That pretty much applies whether we're debating a billion joules or ten billion or a hundred billion - the plant's already designed to deal with that level of energy and that gamma production. The only wildcard left in the equation is that gram-and-a-half of plasma at 10 to 14 million kelvin - what does it do when it slips its restraints?
And remember, once it slips its constraints, there isn't any more gamma or energy production - fusion stops dead.
This is where my very limited physics gets weak. Just how many joules is in 1.6 grams of plasma at 10 to 14 million degrees? I don't recall how to figure that, might be something simple but it escapes me at the moment. I vaguely recall that we were dealing with something that could turn several kilograms of the plant's fusion chamber into a molten mess - but the Subsidized Merchant power plant's several dTons - maybe 5 to 10 times that many metric tons in mass. Turning a few kilos at its core molten puts the plant out of commision pretty much for good - unless they're used to that kind of thing and design the core to contain that kind of event and to be pulled out and replaced when that kind of thing happens. What a few kilos of molten stuff at the core of several thousand times as much mass does not do is create a danger to the ship. Except of course in that the ship now has no power.:devil:
These:
And the Waste Heat that doesn't exist in Traveller.
And the possiblity that all of the fuel consumed may be needed for fusion increasing the energy of the plasma in the chamber by a factor of 1000.
These all make it a magic black box with the same name as a real theoretical technology.
So comparing the fusion reactor (that we know little about) to fission reactors that we know a great deal about and ignoring any risks directly associated with the actual fissile material in the reactor ...
... what is the cooling system made of? Is it toxic? Is is superheated? Is it irradiated from exposure to all those high energy particles and Gamma rays that it absorbs? How much of those tons of PP are dangerous coolant? On a fission reactor, the answer is YES and A LOT. On a fusion reactor - who knows?
We know even less about the JD and MD, so why are they assumed to be largely harmless and inert boxes that pose no danger to the ship or crew under any circumstances? I remind you of the CT ship design rule that a hull was constructed with two distinct compartments - engineering and everything else. No people could be quartered in Engineering and no MD/PP/JD could be located outside of Engineering. That suggests to me at least a possibility that the equipment in engineering may not be completely benign ... and it may pose a potential risk to the ship and crew.
This is not a crusade on my part to rewrite the game rules to make the Engineering section of a starship more dangerous than the personal combat system ...
... it is just an attempt to suggest that there could be situations other than unimaginable coincidences that might justify a ship having the capability to evacuate the crew from the ship.I find it curious that I need to defend the concept that Fusion power produces radiation and could pose a health hazard if the Power Plant was suddenly destroyed.
I also mentioned that the cryogenic fuel stored in metal tanks posed a greater threat to the living compartment than the PP, making it another source of trouble that could warrant either vacc suits or escape pods or both.
[PS. Thanks Carlobrand for doing the heavy lifting.]
Hi,
Although I have misplaced my copy of the Ship Operators Manual, if I am recalling correctly in MT the maneuver thruster plates are said to be able to generate thrust in any direction, regardless of orientation. As such, its my understanding that when you get to the point in mid journey where you stop accelerating in one direction and start accelerating in the opposite direction you'll have to alter something such as either changing the polarity of the charge to the plates or some other similar type operation.
On the other hand, if you are instead assuming that at mid journey you flip the ship then that would imply the use of some sort of attitude control thruster etc which likely not have been in use up to that point.
Either way this kind of seems to imply to me that in order to change from accelerating in one direction to accelerate in the opposite direction (or in other words to decelerate) something will change relating in a load on the components of the device in question (be it the maneuver thruster plates or the orientation control machinery) that hadn't been present previously.
Hi,
To me my biggest concern about interaction with planets would be when trying to enter or leave an orbit where either thrusting too long or too short, or on a vector a bit off from what you had planned may result in your ship missing its orbital insertion requirements which could either result in the ship skipping off the atmosphere or coming in too steep or fast, etc.
My concern here would probably be that if you were heading from say a planet like Earth to a planet like Jupiter and something goes wrong at the midpoint switchover from accelerating to increase your velocity to accelerating in the opposite direction to decrease your velocity, such that the maneuver drive or power plant fails preventing a change to your acceleration (ie, you are now no longer accelerating in any direction and instead just continuing along your current velocity vector) this can lead to your heading outbound from the system at a fairly high speed.
As I understand it not all milieu assume that warships will always necessarily be highly maintained, especially since for these warships may have legacy systems of a higher tech level than what the current governments can support.
For adventuring ship's and/or ship's under charter by a Patron etc such a situation seems fairly possible to me.
That's my concern. If stuff like bridges and basic controls, computers, power plants, maneuver drives, jump drives and some defensive stuff like screens do not have an intrinsic redundancy to them unless you specifically specify that the design is carrying either a backup system or an oversized system to allow the system to still meet requirements if damaged, then I'm left wondering whether other systems like basic life support, air handling, water handling, grav plates and such would have any more redundancy than the other systems.
Yeah I agree. But since MT specifically notes that spectacular failures can result in damage to or destruction of the system in question it would seem to me that there could well be situations where an attempt to do something challenging (such as trying to enter orbit with a damaged or aged ship etc) could potentially result in damage to or destruction of some part of that system, as the game master seems fit etc.
According to that book, the plates can go in reverse at only 10% thrust. So, you do flip your ship 180 degrees to "reverse thrust" when traveling.
Interesting questions. I understand some U.S. Navy subs were using sodium as a reactor coolant. I haven't the foggiest idea how that worked, but it does point to some interesting possibilities.
Because nothing happens when you break 'em?
Issue is, canon doesn't really give us anything warranting an evacuation other than that "vaporized" result, and that one is of unknown origin. Something in the ship carries the potential to "vaporize" it; we don't know what it is. The jump capacitors are notoriously touchy about being overloaded, but that presupposes they're charged; this "vaporized" bit can happen at any time irrespective of the charge status of the capacitors. Meanwhile, damage to the jump drives themselves doesn't do anything but deprive you of jump. Maneuver drive hits just make you lose maneuver. Power plant hits just make you lose power. Game treats them like you have several discrete units and damage stops one of them. However, even a critical result that takes out the entire jump/maneuver/power plant doesn't do more than that.
Still, something deep in the ship, something that can only be reached by criticals, harbors enough power to "vaporize" the ship. And, that potential exists even if the power plant and maneuver drive have been reduced to scrap and the jump drive is cold. Could be the maneuver drive - that's mystery tech, we don't know what might be involved in it or whether it might harbor some ability to suddenly release mega-energy when broken in just the right way. I don't tend to think it's the power plant for the reasons I've already given.
...This is not a crusade on my part to rewrite the game rules to make the Engineering section of a starship more dangerous than the personal combat system ...
Again, problem is that CT canon doesn't hint at them beyond that mysterious "vaporized" result.
MegaTrav offers that task system, but that leaves outcome in the hands of the gamemaster. A mishap when you're late with annual maintenance means a 3d mishap roll instead of a 2d roll - but mishap only occurs on fateful or hazardous tasks or on fumble (natural 2) results. The Starship Operating Procedure in the Imperial Encyclopedia offers no fateful or hazardous tasks related to ship operation other than jumping in a gravity well.
Even for a fumble, the consequence is entirely up to the imagination of the game master except in the case of misjump. It could be anything from damage to or destruction of the component to damage to or death of the person making the task roll, or both. Whether it went beyond that to create a situation requiring evacuation - doesn't actually say yes, doesn't actually say no.
So, the gamemaster can choose to create a circumstance warranting a need for evacuation, by interpreting the mishap rules on a fumble to allow it - but the MegaTrav rules neither explicitly offer nor explicitly foreclose such a circumstance.
Therein lies the rub.
Engineering must be kept separate from the rest of he ship, even though combat says nothing happens when you break it.
The rules give almost no reason for a lifeboat, while several small craft are specifically touted for their utility as a lifeboat.
Another Traveller paradox.
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