Jump Flares

[Gadrin]

this would be the flash and such produced by a starship entering/Exiting jumpspace.

is this described anywhere in canon ?

I can only find "jump flare" in the fluff inside the Milieu-Zero book (doing a PDF search thru the CT/JTAS roms).

Even if it isn't how do you work it in YTU ?

 

[BlackBat242]

Well,I only have/play CT, so:
1. no jump flare
2. I don't know what is in other rules-sets.

 

[far-trader]

The description I'm most familiar with, at least as far as completeness of a description, is from the DGP (semi was once canon) MT "Starship Operators Manual Vol. 1"* Paraphrased and summarized:

Going into jump the grid slowly comes to life glowing as the pattern is built. As the energy builds the area around the ship starts glowing then becoming suddenly so bright that it is painful to look at with the naked eye. Then "blink" and the ship is gone and the glow rapidly fades to a point and disappears.

Coming out of jump is the reverse. First there's a glowly haze then a point source that rapidly expands to a blindingly bright area glow and that fades revealing the ship with the grid glowing that slowly fades as lines dim in order.

Personally I dislike that description for a lot of reasons.

In MTU going into jump is a big display of raw energy as the jump drive tears a hole into jump space. The ship tumbles in as the jump drive pours energy in to hold the hole open. Then it's all black again. No warm up grid glowy effect or other stuff. Just a short lived mini-sun effect "ahead" of the ship. What you can tell from this, from quite a ways off, is how much fuel is used. So if you know the size of the ship you can guess how long a jump was attempted. But knowing where it is going is another matter.

Coming out of jump is dictated in part because of how I see it working and part because I want, nay, DEMAND, stealth by any handwave required

So in MTU coming out of jump is a very "quiet" affair. Jumpspace is a very cold place and it takes a lot of energy during the trip just to keep the ship from freezing solid at absolute zero. When the ship drops out of jump there is no flash and it carries a residual cloud of that cold jumpspace so for a brief time the ship is all but invisible to all sensors and can run dark for a time if the desire is to remain unspotted for as long as possible.

* I still curse the fates for taunting me with that implied promise of more

 

[Ishmael]

I say that entry and exit into j-space causes spacetime to ripple like a diver entering water. These ripples make for localized and possibly steep gravity gradients which can cause stray hydrogen atoms/molecules to emit energies proportional to the gradient through some subatomic piezo-like process. The greater the jump involved, the greater the emissions... the less smooth the transition, the greater the emissions. The ripples dampen out fairly quickly.

impressive sounding BS, but it works for me.

 

[Gadrin]

< smacks head, remembers has MT Imperial Encyclopedia >

unfortunately the Starship Operating Procedures don't mention anything...

I was trying to determine if Doppler effects would/could be used to determine the type of jump.

Far Trader you mention yours being...

[FONT=arial,helvetica]As the energy builds the area around the ship starts glowing then becoming suddenly so bright that it is painful to look at with the naked eye. [/FONT]

Hmmm, I wonder if in YTU those points could be studied at interstellar distances (with TL9+ optics) ? The reason being after reading Jack McDevitt they use the ability to receive normal light speed radio , then jump ahead to pick it up again.

It seems in a TU (any with light effects for the Jump) they could observe the jump on this end, then the ship could return before the light reached the original starting point, and be observed at a precise time (assuming it's bright enough to reach). But no doppler

...although GURPS makes use of "running & standing jumps" where a vector is assumed during the jump so that you come out of jump moving towards a world (and hope you're on course).

Sorry, just weird-ness/rambling on my part. Sometimes I like to introduce things that could play the part of clues for adventures

Guess I'll need Orion Drives after all o: :rofl:

...or setoff atomics... < searches for the bwhahaha smiley >


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[Supplement Four]

There is a light flash described in MT's Starship Operator's Manual.

IIRC, MWM mentions it in his JTAS artcle on jumpspace. It's been so long since I read it, though, I may not recall that one correctly.

 

[far-trader]

Far Trader you mention yours being...

As the energy builds the area around the ship starts glowing then becoming suddenly so bright that it is painful to look at with the naked eye.

Nope, that bit's not mine but from the MT SSOM

But I'll wade in with my opinions...

Hmmm, I wonder if in YTU those points could be studied at interstellar distances (with TL9+ optics)?

Possibly, but at what resolution? And with the likely possibility of it being lost against the background light of the system's star (unless a deep space jump) and/or simply obscured by interstellar dust (in either case). And of course it'll take years for the light to cross the distance, if it can be seen.

But I think you lost me on the rest

I think there's a limited amount of information available (how much fuel was used, in MTU) but it could be possibly useful. In a scenario where perhaps a ship enters a system and is told by someone there that the ship they're looking for jumped out just hours earlier. The pursuers could jump a light-week and some hours (maybe plus a day to be sure) out from the system (not very far) and a week later they return to normal space and wait to observe the jump flash for a clue as to how far the other ship went. Though of course the info is now a week old and the other ship will have arrived at it's destination and have at least a week's lead on the pursuers. That the kind of situation you're thinking about?

 

[jfetters]

I don't do the grid thing - never really liked it. I've always been inspired by the Keith illustration in the Traveller Book showing the Type S going into jump similar to how it works in Star Wars.

But that is more the perception of those on board. From the outside, an observer would see a flash and then nothing.

Note that someone using their sensors would be able to detect a large energy emission as the jump drives spin up.

Coming out of jump is just another flash.

 

[Gadrin]

But I think you lost me on the rest

I think there's a limited amount of information available (how much fuel was used, in MTU) but it could be possibly useful. In a scenario where perhaps a ship enters a system and is told by someone there that the ship they're looking for jumped out just hours earlier. The pursuers could jump a light-week and some hours (maybe plus a day to be sure) out from the system (not very far) and a week later they return to normal space and wait to observe the jump flash for a clue as to how far the other ship went. Though of course the info is now a week old and the other ship will have arrived at it's destination and have at least a week's lead on the pursuers. That the kind of situation you're thinking about?

Yeah, just going over the possibilities. It probaby won't help much other than determining that a ship actually jumped, unless it can be tracked at a much later date.

Light-minutes away in the same system seems reasonable enough, say by an SDB on it's way in to the 100-D point, but it would have to know ahead of time (eg, radio/meson call went out waaaaay before that to be on the lookout. etc).

Otherwise, I think the logical assumption is that it jumped, and to piece together likely destinations.


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[Moose]

I have no problems with the concept of jump flash, although I too prefer to think of it as a phenomenon of J-space entry, with re-entry into normal space being a much less showy affair. Leaving is easily seen, arrival can be accomplished by stealth.

My biggest reservation with hull grids is a selfish one. Although I have very little time for Virus and the collapse, Hard Times led me to ponder the possibilities of retro-fitting non-jump vessels with "jump cradles" - externally mounted assemblies housing J-drives, fuel and as little else as could be managed. (I've long ago lost the designs, but might be tempted to re-create a few). It wouldn't be too difficult to salvage some drives and tankage, lash them onto a 95t shuttle or a 50t cutter, and hey presto cheap starships, perfect for Hard Times! (And staying above the 100t displacement for canonical obedience).

 

[rancke]

I have no problems with the concept of jump flash, although I too prefer to think of it as a phenomenon of J-space entry, with re-entry into normal space being a much less showy affair. Leaving is easily seen, arrival can be accomplished by stealth.

Unless the locals are cheating by having infrared detectors. Your arriving ship is a beacon of infrared radiation no matter what it does in the vbisible spectrum. The gravity waves it makes upon arrival may or may not be detectable; I forget what canonical gravity detection ranges are like.


Hans

 

[Gadrin]

The "bazooka" part is accurate, but not the "hiding" part. If the
spacecraft are torchships, their thrust power is several terawatts. This
means the exhaust is so intense that it could be detected from Alpha
Centauri. By a passive sensor.


 The Space Shuttle's much weaker main engines could be detected past the
 orbit of Pluto. The Space Shuttle's manoeuvering thrusters could be seen as
 far as the asteroid belt. And even a puny ship using ion drive to thrust at
 a measly 1/1000 of a g could be spotted at one astronomical unit.

From http://www.projectrho.com/rocket/rocket3w.html#nostealth

So, I doubt a jump-bubble/rift/hole/whatchamacallit is in the terawatt range however it could be spotted by ships elsewhere in the system.

It might be detectable at interstellar ranges by sophisticated active sensors, after the commensurate amount of time.

Interesting...could be a Jack McDevitt-type of archeological/forensic way to look for a jump via a historical back-look/weirdness. Sorta reminds me of the time-scanner from GURPS Ultra Tech. Just need to figure out a way to make it practical for a single adventure.




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[Trent]

You could always do it like on babylon 5, or battlestar galactica.

As fpr me, in Ad Astra I use a "jump portal" that forms in front of the ship and it flies into, something like B5, but I made mine resemble a 3I sunburst to reflect that the imperium is based on the abilities and limits of jump drive, and possibly the symbol of it was inspired in part by the jump opening.

 

[Renaissance Man]

Jump IMTU

I would say yes to jump flash. Energy is being used (equal to the hydrogen being used,) and it has to go somewhere. However, there is very little flash on departure, since this matter and energy is being vented almost immediately into jumpspace. The ship pretty much just disappears, with a very light after image of a few stray hydrogen nucleii being shot out as alpha particles. Instead, the bulk of the energy emission occurs when the ship reappears, at which point the hydrogen used in the jump spills into realspace as electromagnetic radiation, primarily x rays and gamma rays. It's a pretty exotic signature. If there's anybody there who has sensors looking in the right place, they'll pick you up right quick. This is why the IISS monitors new systems from light years away before deciding if, when and how to go in.

No jump portal either, at least not in the conventional sense... IMTU jumpspace doesn't have much in common with three dimensional space. If there's a portal, it doesn't appear in "front" of the ship like an object in normal space. Nor would the ship need to move through normal space to enter it. As far as normal space is concerned the portal is located at the exact point as the ship.

The less motion your ship is involved in, the easier and more precise the calculations will be for the jump. Inertia is as confounding to astrogation as gravity. The closer you come to C, the greater the likelihood of misjump. Velocity is conserved when you return to NS from JS, but direction of motion will be completely unpredictable... another consideration.

 

[mmbutter]

Velocity is conserved when you return to NS from JS, but direction of motion will be completely unpredictable... another consideration.

This makes "running jumps" - mentioned several times in OTU products - impossible.

 

[Renaissance Man]

Yeah, I never claim to be a canonista. I like to think of the standard jump as a big deal that requires all your ducks lined up in order to do safe and proper. And PC's almost never do things safe and proper, which allows good astrogators to shine.

 

[mmbutter]

Yeah, but running jumps are cool - you come out of jumpspace with a vector and speed that puts you at the starport quicker. Players like it because it saves time, the GM likes it because occasionally they'll misjump (where the exit vector puts them in a situation of the GM's choosing, like headed high speed towards the star or some such) or they'll enter a system where running jumps into the system are illegal and basically show up with a black mark already...

 

[Renaissance Man]

That's a good point.

Maybe I could just make accurate running jumps harder to do, giving the astrogator some time in the spotlight while still allowing crews with a bit of skill and daring to grab cargos and refuel that much faster.

Seeing as I'm waiting for T5 and some players, "MTU" is at best a working theory.

 

[mmbutter]

Yeah, I already play them as "harder to do" because you have to match velocities with the destination port when leaving the origin star system. In GURPS terms, I apply a DRM of -6 (on three dice).

 

[Magnus von Thornwood]

Since the title of the thread is Jump Flares...

I have been nosing around and reading various threads which there seems to be this whole argument about jump flares and how some folks hate them, which mostly seems to be because they want to have stealthy precipitation out of J-Space and have no one notice them.

Not to get an infraction, but this seems to be a crap @ss cheat so that those folks can have all sorts of cool 'no one sees us arrive' stuff happen.

Now, my question is this why can't you do both, i.e. have jump flares but use ye old masking when exiting J-Space, like say plotting your jump to put you on the dark side of say for example Jupiter which has a surplus of radiation and thus be hidden from Terran sensors. That way the only way someone might notice you is if they keep a real tight watch on the baseline and random noise of Jupiter's radiation and maybe they go 'Hey, Bill is it just me or is there an abnormal spike in the Jupiter rad profile? Should we get some SBDs out there and see what's up?'

Of course I must admit here for the policy of full disclosure that we here in Magnusland are all for things like Jump dimming, Jump Grids and of course Flashes. So I am kinda biased, but really why can't both be possible, jump flares and clever use of the local system to conceal your arrival?

Because, I am after all a royal PITA.