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Timing of jumps with a fleet of ships

Drew

SOC-12
How does a fleet commander (regardless of tonnage or size) ensure that a fleet of ships jumps into a system at the same time? More importantly, is where do the ships arrive? This is more of a 3rd and 4th-dimensional warfare theoretical question. While our subsector maps are two-dimensional in nature do the systems represent; are there any notations in any of the literature that a system is "down" or "up" in a 3D universe? Do we use the approach of Ender - “The enemy’s gate is down” refers not to a breech or malfunction, but to the gate’s literal direction. While classic sci-fi shows (i.e., B5) the opening of the jump gates with multiple ships arriving in a near time, is it possible with the rules as written? Where do you position the arrival of an attacking fleet - behind the orbital defense grid (are they configured like the British defenses in Singapore) beyond the planetary gravity so a second jump can be made without refueling? Just curious
 
I believe MgT and perhaps T5 has synchronisation options, at least for small squadrons.

In CT the ships will arrive randomly over a day or so. Set the break out point quite a bit away from the target, wait for the ships to arrive, assemble the fleet, and then proceed to the target.

Or load the fleet on a large tender, jump the tender, launch the fleet.


Although our maps are 2D, Traveller uses normal 4D space-time. There is no natural up or down, Ender's Lesson is that any direction can be down, just consider it so.


At a guess, defensive fleets would be positioned inside a jump shadow, so as to preclude surprises, but that is up to the local admiral. Orbital fortresses would have to be at least somewhat mobile, lest they be destroyed by extreme range missiles.
 
I believe MgT and perhaps T5 has synchronisation options, at least for small squadrons.

In CT the ships will arrive randomly over a day or so. Set the break out point quite a bit away from the target, wait for the ships to arrive, assemble the fleet, and then proceed to the target.

Or load the fleet on a large tender, jump the tender, launch the fleet.


Although our maps are 2D, Traveller uses normal 4D space-time. There is no natural up or down, Ender's Lesson is that any direction can be down, just consider it so.


At a guess, defensive fleets would be positioned inside a jump shadow, so as to preclude surprises, but that is up to the local admiral. Orbital fortresses would have to be at least somewhat mobile, lest they be destroyed by extreme range missiles.
I am looking at the element of surprise as a deciding factor. Assembling a fleet (say in the Oort Cloud) is good for a head-to-head conflict, but it still may be detected at a long range (tech level dependent). Is there something that an advanced computer system could work out so that all forces appear near simultaneously at a location (might require a more complicated jump program that is measured in kilometers rather than in thousands of kilometers or AUs?
 
The Oort cloud is way too far away from the inner system, where most interesting things happen, it's weeks of acceleration away.

It's difficult to hide in empty space, but you can create the wrong impression. To paraphrase Honor Harrington, surprise is when what you see, isn't actually what you see. E.g. you see a battleship, but it's actually a freighter with ECM posing as a battleship.

To become less visible you can supposedly use black globe generators. Preposition your ship, accelerate to build a vector toward the target, turn the globe on completely; you are almost invisible but can also not see out. Let your vector take you to a preplanned position, hopefully undetected by the enemy, turn the globe off, you are now visible and can see out again.


You can hide on, in, or behind planets and gas giants, but that is probably more for defenders.
 
You can hide on, in, or behind planets and gas giants, but that is probably more for defenders.
Actually, with careful navigation plotting, a fleet could "aim" for a jump shadow point that would put an obstruction (such as a gas giant) between them and any presumed sensor net in the target system.

For example ... if the Terra system only had monitoring systems around Terra itself, a fleet jumping into the system on the far side of (say) Saturn would be able to use the large planetary radius and distance of the gas giant (orbit 6 vs orbit 3) to potentially hide the breakout jump flash from observers. Same holds true for jumping into the system at Neptune instead (although Neptune would be a smaller target in terms of planet size).

Yes, space is mostly empty ... but there are "large masses" scattered around, some of which are big enough to line up an obstruction to the line of sight.

Perhaps the biggest such "you wouldn't see that coming" jump shadow point would be at ... L3 ... on the far side of the star from the target planet. I'm thinking the local star ought to be "big enough" to conceal a group of incoming jump flashes ... assuming the defenders do not have sensors covering the "far side of the star" from their mainworld's orbital position.
Lagrangianpointsanimated.gif
 
Actually, with careful navigation plotting, a fleet could "aim" for a jump shadow point that would put an obstruction (such as a gas giant) between them and any presumed sensor net in the target system.

For example ... if the Terra system only had monitoring systems around Terra itself, a fleet jumping into the system on the far side of (say) Saturn would be able to use the large planetary radius and distance of the gas giant (orbit 6 vs orbit 3) to potentially hide the breakout jump flash from observers. Same holds true for jumping into the system at Neptune instead (although Neptune would be a smaller target in terms of planet size).

Yes, space is mostly empty ... but there are "large masses" scattered around, some of which are big enough to line up an obstruction to the line of sight.

Perhaps the biggest such "you wouldn't see that coming" jump shadow point would be at ... L3 ... on the far side of the star from the target planet. I'm thinking the local star ought to be "big enough" to conceal a group of incoming jump flashes ... assuming the defenders do not have sensors covering the "far side of the star" from their mainworld's orbital position.
Lagrangianpointsanimated.gif
If it’s important enough to attack and defend, it’s important enough to have the miserly cost of a sensor net.
 
If it’s important enough to attack and defend, it’s important enough to have the miserly cost of a sensor net.
Granted ... but not every system has a type A starport ... or a naval/scout base in system.
Point being that you can't just automatically assume "perfect blanket sensor coverage" of an entire star system, at all times, without failures of observation. That way lies madness HUBRIS.

There are going to be some star systems that are well patrolled and monitored (type A and B starports for starters) ... but then what about type C/D/E/X starports? Do they get the same assumption of blanket omniscience of EVERYTHING happening within a star system as far as jump flash arrivals and departures goes?

If not ... why not?
 
That's from MT Conoslidated errata (IIRC taken form the Q&A given in TD):

If double the jump preparation time is spent with all the affected ships in computer link via communication lines, use the following formula instead: 167 hrs + (2D×0.1 hr), yielding a result of from 167.2 - 168.2 hours. Most ships will arrive within minutes of each other, with the worst spread being up to an hour apart. Constant communication during the jump vector generate is essential for this to work, and double the normal jump vector generation time must be observed. But when getting there "on a dime" timewise is essential, then this technique is the key. Most civilian vessels don't bother.
 
Granted ... but not every system has a type A starport ... or a naval/scout base in system.
Point being that you can't just automatically assume "perfect blanket sensor coverage" of an entire star system, at all times, without failures of observation. That way lies madness HUBRIS.

There are going to be some star systems that are well patrolled and monitored (type A and B starports for starters) ... but then what about type C/D/E/X starports? Do they get the same assumption of blanket omniscience of EVERYTHING happening within a star system as far as jump flash arrivals and departures goes?

If not ... why not?
Then it’s not important enough to defend. The only common reason would be to deny refueling and transit, buy/delay time, and that presumes at least a big enough denial fleet with mobile sensor assets.
 
Perhaps the biggest such "you wouldn't see that coming" jump shadow point would be at ... L3 ... on the far side of the star from the target planet. I'm thinking the local star ought to be "big enough" to conceal a group of incoming jump flashes ... assuming the defenders do not have sensors covering the "far side of the star" from their mainworld's orbital position.
Yes, you could hide behind the local star (if the local system has no space presence), but it is several AU away from anything interesting. As soon as you move in to attack you will be detected, days in advance of arriving. It would be more surprising to break out of jump at the planets jump mask limit, in plain sight, and immediately accelerate toward the planet being only hours away.


A more careful admiral would not commit to win-or-die approach with empty fuel tanks. Jump in close to a gas giant, refuel, then proceed to the main objective. Or jump in using drop tanks, arriving with full tanks. Or jump in from a close deep space fuel depot. Both of those requires careful, lengthy preparations, probably giving up any semblance of surprise. Go into combat with full fuel tanks, so you can retreat if you have to. In a fluid situation, that means refuel before engaging enemy forces.

And since that is the rule, any deviation would be a real surprise...
 
I thought synchronized jumping was older, maybe Trillion Credits.

Detailed astrography is probably helpful, as well as the probable disposition of major fleet units and system defences.
 
I doubt if the original authors thought much about it - TCS, HG, FFW all assume you maneuver squadrons or fleets together as a unit.

It was only raised as an issue by annually retentive fanon questioning the meta game of the time spent in jump, which forced an unnecessary complication. A simple statement that all ships in a squadron or fleet coordinate their jump generate programs and thus all jump as a unit was all that was needed.
 
I am looking at the element of surprise as a deciding factor.
You mean "surprise" like being hit by a blimp? "Aah! Aah! It's coming...*checks watch"...*looks around*...Aah!!"

You're arriving 100D out from...whatever. The defender is going to have, at a minimum, hours of time to respond.

Anything defending has to be quite local (in space terms). It's not like they're going to scramble a response from the outer gas giants and be able to react "in time".

Plus, don't forget, while there may be mechanics on syncing the fleet, there's nothing that says you can determine when you'll arrive. It's still a 34 hour window, even if they do all arrive together.
 
Staging is typical of military movement, even in the van of the attack, or in a withdrawal, one picks rally points, for cohesion. I think it would be interesting if one fleet jumped into a system and the enemy fleet was there like an "oh crap!" moment. Even if not, help is at best two weeks away, the dogs can cause some real havoc in that time period.
 
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