Orbital Fortress "Rubber Ball"

death-star.jpg

Could the Imperium build this? Setting aside its ability to destroy a planet. Lets just call this an orbital fortress, it has the ability to make a Jump, has fractional-G moving ability, and it about the size of the first Star Wars Death Star. I think it would be a very expensive ship to build.
https://en.wikipedia.org/wiki/Death_Star
The Death Star refers to any of several fictional mobile space stations and galactic superweapons appearing in the Star Wars science-fiction franchise created by George Lucas. The First Death Star was stated to be 87 mi (140 km) in diameter with a volume of 220,781 cubic miles, or (to give perspective) approx. 1/25 the size of our Moon.[1] It was crewed by an estimated 1.7 million military personnel and 400,000 droids.
 
-Daniel- said:
wbnc said:
Although I was successful in pulling off 'Hey they "shanghaied me off on a ship they attacked" defense. thanks to some clever tricks with the lock on my stateroom, and a crudely fashioned "explosive collar" hidden away from the other crewmemebers when I saw the writing on the wall, and hastily put on as the ship was boarded. :D
Sounds like some "fun" times around the old table, that one does. :D

Smart move with the collar too. :mrgreen:

It was fun....for me and the REF. the extra Kidnapping, slavery charges on the others didn't really add that much to their sentences.

But they learned two valuable lessons. Don't start fights that may lead to the Fleet noticing you....and if the fleet takes notice of you, it will not end well.
 
Tom Kalbfus said:
Could the Imperium build this?
70 km radius ⇒ 10¹⁴ dT = 100 trillion dT. That would be perhaps 1 million times the size of the entire Imperial Navy.

It would cost in the region of Cr 10²⁰, about 1000 times the entire Imperial GDP.

So, no the Third Imperium could not possibly build something like that.
 
AnotherDilbert said:
Tom Kalbfus said:
Could the Imperium build this?
70 km radius ⇒ 10¹⁴ dT = 100 trillion dT. That would be perhaps 1 million times the size of the entire Imperial Navy.

It would cost in the region of Cr 10²⁰, about 1000 times the entire Imperial GDP.

So, no the Third Imperium could not possibly build something like that.

Unless someone controls a huge portion of a galaxy and doesn't have to worry about little things like budgets and labor costs...no one can
 
One possible cheat is you could start with an asteroid that was 69 km in radius and round, then the Imperium could build the last kilometer of radius around the asteroid, such that it completely surrounds the asteroid with artificial hull, or it could be made in the form of a giant hollow sphere in the center of which is a giant liquid hydrogen tank. There are a number of power plants which feed off of that tank. it would probably need a pretty big jump drive, the usual rules would apply. Probably if something that big was built, it wouldn't jump, unless is was Ancient technology.
 
Hello Reynard,

Reynard said:
Maneuver one? Captain, it moves like a garbage scow. We can go around it. It has to sit outside the 100D or it can't jump.

Modifying the Rubber Ball to an advanced design would allow adding the early jump feature, but then instead of 100D they hull has to be about 90D.
 
Hello AnotherDilbert,

AnotherDilbert said:
phavoc said:
The problem is it can only be in one place at a time. Gas giants are BIG. It couldn't cover the whole gas giant, so it could be easily avoided.
Jupiter is about 150000 km in diameter, Traveller missiles have a powered envelope of 300000 km. With a few scouts, as carried by the fortress, we know when the intruders are coming. Manipulating an orbit takes a lot less thrust than moving into orbit from afar, as the intruders have to do.

Decelerating into an orbit from 300 000 km takes almost an hour at 6G. The fortress only has to be in the same hemisphere for some of that hour to be effective.

Unless we can launch the missiles over the horizon of the GG, which should be technically possible, since it is routinely done today, in which case we can launch on any foe anywhere close to the GG.

In order to launch ordnance over the horizon something has to be feeding information about the target's movement back to the launching platform. Satellites, aircraft, ocean going vessels, and boots on the ground can provide such information. However, each of them can be knocked out depriving the launching platform targeting information, which also happens routinely.
 
The real issue is if they can manufacture a super laser large enough to make constructing such a large weapon platform a worthwhile project.
 
Tom Kalbfus said:
One possible cheat is you could start with an asteroid that was 69 km in radius and round, then the Imperium could build the last kilometer of radius around the asteroid, ...
Still way too big.

70 km radius ⇒ 11,1 × 10¹³ dT
69 km radius ⇒ 9,8 × 10¹³ dT
Shell volume 1,3 × 10¹³ dT

So instead of a million times too big it is only 100000 times too big. Still way too big. (Any drives would still be based on the larger size.)
 
snrdg121408 said:
In order to launch ordnance over the horizon something has to be feeding information about the target's movement back to the launching platform. Satellites, aircraft, ocean going vessels, and boots on the ground can provide such information. However, each of them can be knocked out depriving the launching platform targeting information, which also happens routinely.
Absolutely. Note that the fortress carries 150 external sensor platforms (fighters and scouts).

I guess that finding something small and somewhat stealthy in the background noise provided by a GG is much more difficult than finding the same target in clear space. The intruder approaching a GG would be at a distinct disadvantage.
 
AnotherDilbert said:
snrdg121408 said:
In order to launch ordnance over the horizon something has to be feeding information about the target's movement back to the launching platform. Satellites, aircraft, ocean going vessels, and boots on the ground can provide such information. However, each of them can be knocked out depriving the launching platform targeting information, which also happens routinely.
Absolutely. Note that the fortress carries 150 external sensor platforms (fighters and scouts).

I guess that finding something small and somewhat stealthy in the background noise provided by a GG is much more difficult than finding the same target in clear space. The intruder approaching a GG would be at a distinct disadvantage.

Has anyone put limitations on the sensors of say small fighter craft as far as what they are capable of? A 30ton fighter is going to have more limited sensors than say a scoutship, so while a full 100 ton scout MIGHT have the necessary sensors, computers, and software to track and feed targeting data to another ship, do you feel that a small 30ton fighter should have those capabilities as well?

The rules put limits on small craft weaponry, so should the sensors be the same? If so it does open up having E2-C Hawkeye type craft to extend the range and capabilities of a fleets sensors and tracking.
 
phavoc said:
Has anyone put limitations on the sensors of say small fighter craft as far as what they are capable of?
No, but it is difficult to fit the best systems in a fighter. On the other hand even bad sensors will detect a battlefleet.
 
Hello AnotherDilbert and phavoc,

AnotherDilbert said:
snrdg121408 said:
In order to launch ordnance over the horizon something has to be feeding information about the target's movement back to the launching platform. Satellites, aircraft, ocean going vessels, and boots on the ground can provide such information. However, each of them can be knocked out depriving the launching platform targeting information, which also happens routinely.
Absolutely. Note that the fortress carries 150 external sensor platforms (fighters and scouts).

I guess that finding something small and somewhat stealthy in the background noise provided by a GG is much more difficult than finding the same target in clear space. The intruder approaching a GG would be at a distinct disadvantage.

The same GG background noise that makes the medium fighters and scouts difficult to detect is also messing up the communications between them and the Rubber Ball.

Then there is the need to maintain position against the GG gravitational field.

phavoc, sensors, active and passive, usually are able to detect contacts at greater than any weapon's range. Passive sensors usually out range active sensors but have the disadvantage of requiring time and maneuvering to determine the range which is not as accurate as bouncing an active sensor off the contact/target. The downside of using active sensors is that the contact/target knows your ship is there. Of course I have a quibble with the range limitations of the weapons since they are for the most part the same ones installed in hulls >= 100 d-tons.
 
Hello again AnotherDilbert and Tom Kalbfus,

AnotherDilbert said:
Tom Kalbfus said:
One possible cheat is you could start with an asteroid that was 69 km in radius and round, then the Imperium could build the last kilometer of radius around the asteroid, ...
Still way too big.

70 km radius ⇒ 11,1 × 10¹³ dT
69 km radius ⇒ 9,8 × 10¹³ dT
Shell volume 1,3 × 10¹³ dT

So instead of a million times too big it is only 100000 times too big. Still way too big. (Any drives would still be based on the larger size.)

Hopefully my math skills have not rusted on me and my calculations are on the right track.

The Rubber Ball has a volume 1,000,000 d-tons or 14,000,000 m^3. If the planetoid is roughly spherical the radius can be determined.

The formula for the volume of a sphere is (4/3) x PI x Radius^3

Using MS Excel goal seek 14,000,000 m^3 = (4/3) x 3.14 x Radius^3 returned a number of 149.5133 meters. If the number is the planetoid's radius the diameter is 299.0266 meters.

Cross checking using TNE FF&S Mk. I Mod 0 p. 11 the Hull Size table last column indicates that a hull rated at 1,000,000 d-tons has a L factor of 300 meters. For spherical hulls the L factor is the sphere's diameter. The math I used appears to agree with TNE FF&S if one rounds the L factor.

Cross checking using T$ FF&S the table on p. 102 has a 14,000,000 m^3 hull with a diameter of 299 m and Equation 67: Basic Hull Factors (a) of ((6 x Volume)/PI)^(1/3), I was not able to post using the actual formula shown, returned a value of 299.02659 meters.

Unfortunately, neither TNE or T4 have configurations of planetoid or buffered planetoid and I'll stick with the volume calculation for a sphere since they look closer to that shape on HG 2e p. 11.
 
snrdg121408"phavoc said:
Agreed. But detection vs. targeting are two different things. Or more precisely, you may know something is out there, but until you have better resolution you don't know what so you are potentially attacking it blind. Traveller doesn't really model the fog of war. ECM/ECCM are going to be working hard at obfuscating the target vs. identifying the target. Without a lock your weapons fire is going to cause very little damage (barrages overcome this, but there is a realistic limit), and missile/torpedoes will be far less effective. And nobody has inexhaustible magazines.

I was just asking to see if anyone had come up with some house rules around it.
 
snrdg121408 said:
The same GG background noise that makes the medium fighters and scouts difficult to detect is also messing up the communications between them and the Rubber Ball.
We'll need either a few crafts/satellites spread out in the same orbit to bounce a laser comm, or meson comms.

snrdg121408 said:
Then there is the need to maintain position against the GG gravitational field.
Orbit?

snrdg121408 said:
phavoc, sensors, active and passive, usually are able to detect contacts at greater than any weapon's range.
Yes, but we get only minimal detail, basically we know someone is there but not who. Not until Very Long range (with the proper equipment) do we get more detail so we can actually identify the sensor bogey, and then we are in combat range.
 
Condottiere said:
If it's directional, you can pump more power into it.

This should include sensors.

Active yes, passive, no.

And pumping more power into it won't always help with target acquisition. Not to mention the enemy can do the same with their ECCM.
 
Hello phavoc,

phavoc said:
snrdg121408"phavoc said:
Agreed. But detection vs. targeting are two different things. Or more precisely, you may know something is out there, but until you have better resolution you don't know what so you are potentially attacking it blind. Traveller doesn't really model the fog of war. ECM/ECCM are going to be working hard at obfuscating the target vs. identifying the target. Without a lock your weapons fire is going to cause very little damage (barrages overcome this, but there is a realistic limit), and missile/torpedoes will be far less effective. And nobody has inexhaustible magazines.

I was just asking to see if anyone had come up with some house rules around it.

Without bring in my experience as a submarine sonar technician, which has been dismissed since water is not the vacuum of space I can not provide adequate support to how passive sensing would work. For that matter, my limited knowledge gathered through research would also be dismissed as being a faulty analogy. Unfortunately, we do not have any real space borne experience how they would work.

So I'll hold any further comments on the subject and I hope what I have provided has been helpful.
 
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