EVA While in Jump - Feasable?

[Mithras]

My young players are on a ship for the first time as passengers, and the ship's computer will be sabotaged in order to blow up the ship and kill the PCs.

Will this work? The captain of the Far TRader tries to come out of jump. It fails, alarms ring, the ship shakes violently KO-ing the engineer. The pilot wrestles with the controls and the captain gets the three passengers (PCs) to help him get to the drive room where the computer interface can be overriden. Otherwise the warpfield runs out of fuel in 15 minutes and implodes killing everyone.

BUT.

The cargo hold is being flooded with liquid hydrogen. Effects on PCs in vacc-suits? The captain suits up and tries to move down the side corridor, but the computer has switched the grav plates to -3G he is stuck. Only the PCs can now EVA, while in jump, hug the hull to get to the aft dorsal harch of the drive room, without scraping the inside of the warp-bubble. What a sight! This sounds dangerous, but I don't want it to be an instant killer...thoughts?

It should prove extremely exciting and make for a memorable first passenger flight

EDIT: MMmm, I'm using a deckplan I picked up on the web. The MGT deckplan does not feature the drive room's dorsal hatch, and includes a little access corridor that crosses the bow of the ship. My deckplan does not.

So. Effects of liquid hydrogen?????

BTW: My players are my sons, 11 and 14. They will love this.

 

[lastbesthope]

Liquid hydrogen can exist at temperatures higher than that of the background temperature of space, but it will conduct heat away from the player in their vac suit better than a vaccum would, so the risk of overexposure to cold would be a scientific issue.

LBH

 

[rust]

So. Effects of liquid hydrogen?????

This could be interesting for you:

http://en.wikipedia.org/wiki/Hydrogen_safety

 

[Mithras]

"You guys can't enter the cargo hold in your suits, they give out tiny electrical charges, but that will be enough to ignite the dTons of hydrogen leaking into the cargo hold. We have to go around!!"

Wiki Quote:
"Hydrogen-air mixtures can ignite with very low energy input, 1/10th that required igniting a gasoline-air mixture. For reference, an invisible spark or a static spark from a person can cause ignition."
"Although the autoignition temperature of hydrogen is higher than those for most hydrocarbons, hydrogen's lower ignition energy makes the ignition of hydrogen–air mixtures more likely. The minimum energy for spark ignition at atmospheric pressure is about 0.02 millijoules."

 

[Annic Nova]

Umm..Its liquid hydrogen......much more stable, and should not have any oxygen present to mix with and cause ignition.

I like your scenario!!

 

[rust]

Umm..Its liquid hydrogen......much more stable, and should not have any oxygen present to mix with and cause ignition.

If hydrogen from the fuel tanks flows into the cargo hold, it will not re-
main liquid, and unless the cargo hold is depressurized, there will be
sufficient oxygen for an explosion. In fact, I am almost certain that an
event like this would have a high probability to destroy the ship.

 

[Duroon]

Perhaps you haven't seen the core book errata in which they talk about someone going outside during jump.

And I quote, "I Go Outside!
Player characters being player characters, it is entirely likely that they will somehow end up outside a starship during a Jump. They die.
Horribly. A merciful Referee might rule that a character standing on the outside of a ship as it Jumps is stranded in normal space but
otherwise healthy. Opening the airlocks while in a Jump bubble is suicidal."

 

[rust]

And I quote, "I Go Outside!
Player characters being player characters, it is entirely likely that they will somehow end up outside a starship during a Jump. They die.
Horribly. A merciful Referee might rule that a character standing on the outside of a ship as it Jumps is stranded in normal space but
otherwise healthy. Opening the airlocks while in a Jump bubble is suicidal."

Ah, well, they only have to wear a Probability Transducer, which is easy
to make with a bit of aluminum sheet, a cord and a geranium leaf (or a
laurel leaf, if geranium should be unavailable). Each ship's library has a
description of how to make one within a couple of minutes. 8)

 

[Vile]

Ah, well, they only have to wear a Probability Transducer.

I've always wondered about the Traveller reluctance to have anything to do with Jump Space. Perhaps it's because of a desire to avoid adding too much information to a handwave, but in both written and visual science fiction FTL space is often an interesting addition to the setting.

 

[phavoc]

Couple of things.

1) Jump bubbles don't have a specific time frame when you jump. When you activate your jump drive it dumps the fuel outside of the ship to generate a bubble. This bubble slowly collapses over time and when you reach your destination it collapses completely and out you pop from jump space.

2) Jumping has a timeframe built into it, but that timeframe is somewhat random. I guess potentially you would know approximately when your bubble drops, but as far as I can tell the rulebook isn't clear on that. I think you are supposed to estimate the timeframe in jumpspace at the time of jump. But there is probably some margin of error too.

Space suits probably could handle the liquid hydrogen, but then again maybe not. since they are designed for vacum they would not leak... however they aren't necessarily designed for a liquid environment, which could short out circuits or the like.

 

[BP]

I've always wondered about the Traveller reluctance to have anything to do with Jump Space. Perhaps it's because of a desire to avoid adding too much information to a handwave, but in both written and visual science fiction FTL space s often an interesting addition to the setting.

Its better if such an awesome handwavium is kept vague and up to individual discretion - too much information just snaps the suspenders of disbelief

Case in point - EVA during jump leading to unavoidable death is just plain inconsistent with the idea of a 'jump bubble' - and since few ships are absolutely smooth and void of indentations, grooves, creaveses and protrusions - just makes no rational sense. Even allowing for possibility it would need to be uncommon if EVA stays attached to hull - otherwise the hull and sensors and weapons would likewise be frequently damaged during jump.

As to your senario Mithras - it sounds like your boys are in for fun.

Some thoughts -
What happens if they attempt to disable Power Plant or at least cut computer power?

If vacc suits are Hostile Environment then you can have a nice fire - the vaporized liquid H2 breaching the 'flooded' cargo hold should ignite a pressure explosion upto sealed bulkheads - quickly using up all the oxygen and possibly damaging life support (burning hydrogen is hard to see and produces water and would probably be out fast enough not to do major system damage - and should trigger automatic fire suppression assuming that is not under computer control).

UV and infrared detectors in suits should show hydrogen fire along with temperature sensors - but they should have a hard time seeing it themselves.

 

[The Chef]

This sounds brilliant, and sets the imagination flaring.... crawling the outside of the hull mere inches away from a swiriling boiling bubble of ignited gas, inching their way across the ship to a distant tiny hatch.

as for the hydrogen, could they not vent the cargo bay... by say opening the doors to space?? or am i really in the realms of fiction here? is there a manual override to the doors, crack them open and let the loose gas flood into space... ah but what happens if the jump bubble ignites it.. oh i think i see why greater minds didnt suggest this. note to self, if i ever make it to space, always do what i'm told and do not under any circumstance result to creative thinking.

 

[Mithras]

Yes, I think liquid hydrogen in the hold will be a bit drastic actually. Maybe some other cargo leak - see, I need the cargo hold out of bounds, I need to force the PCs to go outside the ship ....

As to jump procedures/physics, its MTU, so I can have specific, timed jumps, size of jump bubble etc, to suit the story. Then they'll remain in place for the rest of the campaign.

 

[rust]

I need the cargo hold out of bounds, I need to force the PCs to go outside the ship ....

There could be those giant cargo handling robots in the cargo hold, each
with a weight of several tons, and all of them now controlled by the mad
computer. They moved that cargo so that it now blocks all doors, and they
will attack anyone who attempts to enter the cargo hold ... :wink:

As for jump space, it is your universe, you can handle it any way you like.
Go with whatever makes the most fun and is compatible with future ad-
ventures, too. Unless you create some kind of obvious contradiction, it
will be fine.

 

[iainjcoleman]

So. Effects of liquid hydrogen?????

 

[Mithras]

Neat!

One of the PCs is a computer whizz, so the problem needs to be computer based, having the sabotaged program operate cargo robots is neat. They can't vent that out into space ...

I need the cargo hold out of bounds, I need to force the PCs to go outside the ship ....

There could be those giant cargo handling robots in the cargo hold, each
with a weight of several tons, and all of them now controlled by the mad
computer. They moved that cargo so that it now blocks all doors, and they
will attack anyone who attempts to enter the cargo hold ... :wink:

 

[PrinceYyrkoon]

Once the hydrogen begins to leak, it will disrupt the internal pressure, causing a malfunction in the jump drives. The ship will disintegrate after being forced back into realspace and all of its atoms will be distributed over a number of randomly generated parsecs.

Poof. Roll up another character.

 

[rust]

I just remembered that I did read a very interesting description of an EVA
in hyperspace a while ago. I am almost certain that it was in a novel by
Elizabeth Moon, something from her Familias Regnant series - Once A He-
ro, most probably.

 

[Annic Nova]

Handwavium to fix previous handwavium...I like it.

The "jump Bubble" was a hand wave to explain the huge use of hydrogen fuel.....

The original explanation of Jump was a grid in the hull....th ebubble was a later Mongoose addition.

All to explain a hand waved jump theory...

whatever.......

 

[BP]

Yep - and it makes oh so much sense :roll:

Consider that jump fuel requirements increase linearly with jump number. Volumes don't unless they are 1 dimensional. Given the quality of the explanations (i.e. numermous holes in the logic) - I seriously doubt an appropriate non-linear rate of collapse was considered...

At any rate - I do like the simple game mechanics of Jump - they work.

In MGT the EVA during jump is covered in a footer gray box that is missing in my Pocket Rulebook edition - which is good since I wouldn't use it. Logically it makes no sense - consider open bay modular transports and added turrets and sensors. But, mainly because it ruins a great roleplay opportunity. As mentioned in the footnote - players will invariably attempt it - why pass on a great opportunity?

In MTU EVAs are possible during Jump as long as contact is maintained with the ship: Dexterity, Average (+0). In the event of failure, saving checks may be made each second to regain contact within 6 seconds: add DM -1 per atttempt, Difficult (-2). After 6 failed attempts they can say goodbye. (But, of course, this does not neccessarily mean they are dead - think reappearing next to, inside ship during jump or upon re-entry of this or some future jump - maybe as a child or geriatric!)

My presumption here is that the suit sensors and human senses of direction and motion become useless very quickly over short distances - light and gravity doing very unusual things in uncontrolled jump space. Hence the contact check is Average rather than Routine or Simple and the re-contact check is instantly Difficult and gets worse quickly with no positive DMs.

Visually I describe Jump Space as mostly black. Wisps of blobby color are percieved like ghost images - but nothing a human or computer can pin down. As one looses contact with a jumping ship's hull, the ship will dissappear in a splotchy 'black fog' almost instantly - and within seconds is not disternable in any way (though it may be just mere meters away). The crux is that manuever control does not work consistently - thus a systematic manuever pattern cannot be used to re-obtain contact with the ship. If contact is re-establish it will not neccessarily be facing the ship - maybe they moved forward (in their point of view) and will come in contact from behind. Basically reconnecting is a matter of luck - and regardless of Irish heritage, if ya don't make it in 6 seconds - ya don't make it!