So you've misjumped. Now what?

[Proneutron]

For the record, this is why I favor making running Jumps -- they save time, and you can still calculate the route so you arrive at the destination world with (nearly) zero relative velocity.

IMTU there is no inertia in Jump space so you exit motionless relative to the nearest huge mass. No matter your speed when entering. In a star system that is the star. In an empty hex it is the average vector for the nearest stars.

 

[Enoki]

IMTU there is no inertia in Jump space so you exit motionless relative to the nearest huge mass. No matter your speed when entering. In a star system that is the star. In an empty hex it is the average vector for the nearest stars.

Whereas I have always played it that inertia is maintained, but the problem is if you are moving when you jump the location of the 'exit' is imprecise so you end up with a less--far less--accurate jump than if you do it stationary.

 

[Proneutron]

Whereas I have always played it that inertia is maintained, but the problem is if you are moving when you jump the location of the 'exit' is imprecise so you end up with a less--far less--accurate jump than if you do it stationary.

nice!

 

[Condottiere]

One issue would be you don't see the traffic at the destination before exit, so it probably is more of a regulatory thing.

 

[Proneutron]

One issue would be you don't see the traffic at the destination before exit, so it probably is more of a regulatory thing.

Space is FAR too big and any ship FAR too small to worry about that. You'll win the lotto a few times before you will hit another ship coming out of jump.

 

[Condottiere]

Six sided dice tend to shrink the universe quite a bit.

 

[whartung]

The ships vector being maintained through jump is Canon. Even if you jump while "stationary", when you arrive, you will likely will not be stationary, as when you jumped you were stationary to the local star. The local and destination stars are moving relative to each other, so when you jump "stationary", you effectively inherit that relative motion between the two stars.

A proper navigator could set your vector in your current system to make it zero out when you arrive in the destination system.

All of this is a pedantic nit. The relative motion of the starts system is not dramatic enough to really be noticed, especially on ships with 1G+ drives. If you jump in with no fuel (or a dead M drive), however, then that can be an adventure seed for the local space patrol having to match vectors and dock to slow you down so you don't hit the orbital children's orphanage.

 

[Grav_Moped]

Bearing in mind that a Jump's destination is fixed at the time it is initiated, I think the idea that a mass "pulls" a ship out of Jumpspace is misleading, and even confusing.

Jump drives are not hyperdrives or warp drives; a trip through Jumpspace is essentially an ideal ballistic curve of sorts: a Jump's endpoints are both fixed from the get-go, hence the need for all the number-crunching by a Big Iron computer mainframe to plot a course for Jumping. As such, the mass at the destination would anchor the precipitation end of the Jump's arc from the moment the Jump is initiated at the origin end.

The conceptual problem has always existed: a starship's position is fixed relative to what, exactly? All reference frames in space are relative to the speed of light, but not to any privileged mass. The idea that starships typically reduce their velocity to "zero" before jumping is nonsensical inasmuch as object's velocity is always velocity relative to something else.

Like, for example the nearest stellar mass a starship is operating in the vicinity of, or (my preferred interpretation) the inertial frame of the entire honkin' galaxy...

For the record, this is why I favor making running Jumps -- they save time, and you can still calculate the route so you arrive at the destination world with (nearly) zero relative velocity.

I was looking for a discussion of running jumps vs. 0-velocity jumps, so I had somewhere to hang this observation:

I've figured out why the rules want 0-velocity jumps: Jump Cassettes.

The tapes are valid for a particular trip, jumping from a specific point at a specific time. (They might include a fallback option of jumping a day or a week later from that point.) It's a lot easier to get to that exact point (or recover from missing it due to evasive maneuvers or pilot error) if you arrive a little early and are at rest when you get near it. If you hit the 100D limit running hot but miss, you have to slow to a stop, accelerate toward the correct point, then come to a stop again. By then, the calculation on the tape will have expired (though you may just have to wait until the next time-window supported by the tape).

Navigation skill allows calculating how to correct for the location/vector deviation in real time, so even if you miss the window you can still use the jump tape.

It shouldn't apply if the ship's using the Generate program, but maybe it does.

Basically, this explains both the "come to a stop at 100D before the jump" and the "pilot can do navigation under routine circumstances, but you need a navigator on all but the smallest starships nonetheless" issues.
It's not entirely satisfactory, but it's an explanation.

 

[boomslang]

I've figured out why the rules want 0-velocity jumps: Jump Cassettes.

[snippage]

Basically, this explains both the "come to a stop at 100D before the jump" and the "pilot can do navigation under routine circumstances, but you need a navigator on all but the smallest starships nonetheless" issues.
It's not entirely satisfactory, but it's an explanation.

This seems both plausible and playable to me.

 

[Condottiere]

That always seemed obvious to me, and in theory, you should get a bonus on the misjump possibility, and a penalty when trying to do a running jump.

 

[kilemall]

I view the navigator as being something like a bombardier in a WWII heavy bomber- not critical until the most important instance of the trip, entry into jump, and I suppose defining where they are at the conclusion of a misjump.


As such I usually have the navigator working up a plot to jump, including the velocity and point at which the jump takes place. The point is ahead of the ship giving time for the Generate program to complete, presumably the ship's velocity would be a factor to handle as well. Also, a bit of drama as the navigator takes over the helm of the ship to finely control it's vee and course and initiating the jump.


I wouldn't stipulate that a jump tape would require zero velocity per se, that would be very wasteful of transit time in many instances. What I would expect is that the jump tape has few precalculated jump points and that the ship needs to go to them.


This would have positive effects for piracy as any foreknowledge or even observation of where these jump points are would allow the pirates to be in a very advantageous for coverage, rapid capture and egress. OTOH that could work well for protective SDBs to cover a small bit of space that counts for jump transit rather then react to wherever a captain's whim chooses where to jump.

 

[Grav_Moped]

It's not that it requires zero velocity, it's just that it requires the ship to be at a specific point at an exact time. Best to get there early with not much of a vector, so you can correct minor position errors before the window closes. (Yeah, frame of reference issues make this a little bit sketchy as an explanation.)

And I agree they ought to have several departure windows programmed both for OPSEC (it's hard to wait at all the possible spots) and redundancy (the cassettes don't seem to expire, so maybe they have multiple solutions stored but only at one-week intervals since normally ships travel on alternate weeks?)

 

[kilemall]

The CT jump tape business is a dirty thing.


But only cause of the software pricing.

 

[Condottiere]

No, just that a deadstop would make the astrogational calculations rather more precise.

 

[whartung]

The CT jump tape business is a dirty thing.
.

I dunno, I kind of like the jump tape idea.

It goes well with the "no empty hex jump" universe.

And the idea that there are systems out there that are "unreachable". Makes Red Zone enforceable.

For routine merchant traffic, it's a nothing burger. Buy the tape when you file the flight plan. And it's One More Thing adventurers have to deal with to go off the reservation.

It's a neat little mechanic that can add a bit to a campaign.

It can also be a mechanic to time gate things.

"Here's the Jump tape to get to Sauron Epsilon 9, and here's the one to get back -- but it's only valid for 10 days, so keep that in mind."

 

[mike wightman]

In CT it's jump cassette not jump tape.

But this application is a nice idea

 

[Condottiere]

So how much does a jump tape cost nowadays, ten thousand credits?

Compare that to the care and feeding of an onboard astrogator.

I would suppose you could take a course in astrogation at your neighbourhood junior college.

 

[boomslang]

"Here's the Jump tape to get to Sauron Epsilon 9, and here's the one to get back -- but it's only valid for 10 days, so keep that in mind."

I have long thought that the use of Jump Cassettes is probably mandatory on any vessel that is subsidized -- for insurance and security purposes if nothing else. Installing the Generate program on a subsidized starship might be a contractual violation, and may well be prohibited by default by an annoyingly-unremovable version of the Anti-hijack program (requiring some Computer-skill-based effort on the part of would-be hijackers or skipping owners to work around, or else they will need bring their own cassette, possibly leaving a trail of evidence depending on how it was sourced).

Then the navigator/astrogator, if required, becomes the person responsible for getting the starship into the designated time-and-place envelope to make the cassette useful. A good post for a captain to hold, perhaps. If the ship tries a running jump (because there was an unexpected delay in liftoff, for example) the navi needs to make sure the speeding vessel makes the pre-calculated window without over- or under-shooting, and triggering a (perhaps) sub-100D-Misjump chance.

Missing that window would then require thrice the already-spent time to subsequently decelerate, accelerate back toward the planet, decelerate for landing, and buy another blasted cassette in order to have another go at it. Presumably, this would be financed by docking the navi's paycheck for the cost of the second cassette plus any additional overhead (another berthing fee and an extra day's life support for the entire crew and passengers, again for example).

 

[boomslang]

So how much does a jump tape cost nowadays, ten thousand credits?

Compare that to the care and feeding of an onboard astrogator.

Or, conversely, compare the competitively-low cost of a forged cassette acquired by a Steward or Gunner with Streetwise skill from a Black Market contact in a regular port-of-call. Especially useful for getting to (and, with a second, bundled purchase, back from) one of those oh-so-potentially-lucrative Red Zone worlds when the Port Authority flatly declines to sell you an official one.

I would suppose you could take a course in astrogation at your neighbourhood junior college.

Except that such a sabbatical would typically take four years. (Perhaps one could combine it with a "crop-dusting" minor. )

 

[Grav_Moped]

The CT jump tape business is a dirty thing.


But only cause of the software pricing.

I dunno, I kind of like the jump tape idea.

It goes well with the "no empty hex jump" universe.

And the idea that there are systems out there that are "unreachable". Makes Red Zone enforceable.

For routine merchant traffic, it's a nothing burger. Buy the tape when you file the flight plan. And it's One More Thing adventurers have to deal with to go off the reservation.

It's a neat little mechanic that can add a bit to a campaign.

It can also be a mechanic to time gate things.

"Here's the Jump tape to get to Sauron Epsilon 9, and here's the one to get back -- but it's only valid for 10 days, so keep that in mind."

Useful as a mechanic for the reasons you mention, but also including a recurring expense that can be bought off by getting Generate. As a simulation? "The return solution is only valid on 1107-102 at 1853:00hrs Imperial Sidereal Time. You'll have to stay at SE9 for exactly two days (whether you like it or not)."

So how much does a jump tape cost nowadays, ten thousand credits?

Compare that to the care and feeding of an onboard astrogator.

I would suppose you could take a course in astrogation at your neighbourhood junior college.

Close. 10 kilostarbux per jump number. Navigator costs Cr5000(salary) plus Cr4000(life support) plus Cr8000(foregone cargo revenue of 4Td/one stateroom) per month. KCr17 per month. Tapes or Generate can't replace a navigator except on ships 200Td or smaller. Basically, only a Scout/Courier or an A2 Far Trader saves money by using jump cassettes instead of a navigator (and that only on Jump-2 runs).

I have long thought that the use of Jump Cassettes is probably mandatory on any vessel that is subsidized -- for insurance and security purposes if nothing else. Installing the Generate program on a subsidized starship might be a contractual violation, and may well be prohibited by default by an annoyingly-unremovable version of the Anti-hijack program (requiring some Computer-skill-based effort on the part of would-be hijackers or skipping owners to work around, or else they will need bring their own cassette, possibly leaving a trail of evidence depending on how it was sourced).

Then the navigator/astrogator, if required, becomes the person responsible for getting the starship into the designated time-and-place envelope to make the cassette useful. A good post for a captain to hold, perhaps. If the ship tries a running jump (because there was an unexpected delay in liftoff, for example) the navi needs to make sure the speeding vessel makes the pre-calculated window without over- or under-shooting, and triggering a (perhaps) sub-100D-Misjump chance.

Missing that window would then require thrice the already-spent time to subsequently decelerate, accelerate back toward the planet, decelerate for landing, and buy another blasted cassette in order to have another go at it. Presumably, this would be financed by docking the navi's paycheck for the cost of the second cassette plus any additional overhead (another berthing fee and an extra day's life support for the entire crew and passengers, again for example).

This suggests that there could be a restricted version of Generate that only computes courses between authorized origin-destination pairs. It might be discounted. It probably has an emergency override to let you get back to an authorized world if you misjump... (It might also be set to automatically force you back toward a designated world regardless of where you planned to go...)

Can you record your own tapes from the Generate program? Saves a CPU slot you might need if you're jumping under fire...

The pilot is responsible for positioning the ship inside the jump tape's launch window (it's just normal-space maneuvering, clearly within the purview of the Pilot skill). The navigator is responsible for adjusting the tape's output to compensate if it's outside that window when the jump drive lights up.

Speaking of misjump... using jump tapes turns a misjump into a total party kill even if you come out close to a fuel source. You can't get back.