1g Ships and Size:7 worlds...

[AnotherDilbert]

• Vector Movement prevents VERTICAL takeoff, but not HORIZONTAL. (try it)

I did:

So your solution is to accelerate to orbital speed on the ground, ignoring friction, and even passing through the planet?

What you described is:

Diving straight into the planet.

Gravity affects you even on turn 1.
Friction ("Atmospheric Braking") exists.

I would call that a fail to take off.

Your solution ignores gravity the first turn, directly against the rules.

 

[AnotherDilbert]

"Striker fills an important place in the Traveller universe - rules for ground combat with 15mm figures and vehicles."​

​

"The true value of Striker, however, lies with the advanced rules. A complete system for designing armored vehicles and aircraft at different tech levels is presented, along with air-to-air and air-to-ground combat rules. The package contains everything a Traveller adventurer needs for campaigning with miniatures."​

- Striker Book 1, pg 0

The section explicitly about starships, obviously doesn't apply to starships, right...

_ _ Starships and interplanetary vessels may occasionally be present to provide fire support. For the most part, even a moderate-sized military vessel will have sufficient firepower to seriously unbalance a game; nevertheless, rules for Traveller and High Guard ships are included for the sake of completeness.
_ _ A. Movement: The movement rate of a spaceship is determined in the same way as that for a grav vehicle; the ship's maneuver drive rating is used as its G value. A ship with a G rating equal to or less than the planetary gravity may not take part in combat actions except from orbit.

 

[Spinward Flow]

What is wrong with skimming across the ocean like a stone to build up velocity?

The problem with that is ... terrain context.
If you don't have a nice, cleared, suitable range within which to make that takeoff roll ... You Are Not Going To Space Today™.

Kind of like an airplane that doesn't have enough runway to get up past stall speed and start gaining altitude. With a VTOL, that's not a problem, because your stall speed is ZERO, so you don't need a runway ... you can just go straight up from anywhere you can land. Likewise, a VTOL can land almost anywhere there's a large enough space for the vehicle to park in ... unlike a CTOL plane that requires plenty of runway rollout for touchdown and braking. If you don't have the runway length, you probably shouldn't (try to) land there.

If there's plenty of ground support infrastructure, finding a place to make a rolling takeoff might not be a problem ... but if there isn't, because you're at an austere location (type E or X starport, for example) or you're just wanting to land somewhere OTHER THAN at the starport ... well, you might have a problem, especially if you needed to make an emergency landing (let alone an emergency take off).

Does it say that a 1G ship can fly from Surface to Orbit (10,000 km) in 2000 seconds or not?

{sigh}

10,000km is a generic distance, not a specific maneuver in a specific context, that is filling a slot on a table of sample distances in increasing increments. It just so happens to coincidentally be a relatively useful measure of distance that is often used for surface to orbit transfers (hint: there are other orbital altitudes besides 10,000km exclusively).

Next you'll be trying to tell me that the time to go up and the time to go down are exactly the same (never mind the gravity well) because a table says so. I'll tell you that it takes more time to climb up OUT of a gravity well (hence: High Guard ... hint hint) than it takes to fall down INTO one over the same distance with the same maneuver drive ... and you'll presumably say I'm "wrong" because you've got a table entry that you can point to and not have to worry about the broader context of what is going on in the situation so as to adjust your expectations accordingly.

In fact, I think you'll find that if you run the computation using the newtonian physics formula provided that the time to traverse 10,000km at 1G is suspiciously close to 2000 seconds while maneuvering in zero gravity once you do the math.

• T = 2 * sqrt (D / A)
• T = 2 * sqrt (10,000,000 / (10-0))
• T = 2000 seconds

What is the maneuver that the formula is computing for you?

• Accelerate > Flip > Decelerate

That's the interplanetary maneuver. You know ... this thing ...

If you only have to go 10,000km in microgravity it will take 2000 seconds to complete an accelerate, flip, decelerate maneuver over that distance.

So what happens at the bottom of a Size: 8 = 1G gravity well?
Um ...

• T = 2 * sqrt (D / A)
• T = 2 * sqrt (10,000,000 / (10-10))
• T = 2 * sqrt (10,000,000 / (0))
• T = You Are Not Going To Space Today™

As always ... Your Mileage May Vary ...

LBB 1-5 are clear that ships do fly to orbit and that Streamlining impacts which ships may enter which atmospheres. They say NOTHING about MANY ships being unable to land on MANY worlds (something important enough that it should have been mentioned).

You know why?
Because the authors of the LBBs expected Players and Referees to be SMART ENOUGH to fill in the gaps, rather than resorting to Rules Lawyering Fundamentalism that resists all attempts at context or common sense. They only had enough print space to provide the skeletal framework for us to work with to make our own worlds and Traveller universes to play in, leaving it up to us to fill in the details.

Medic: I can heal many things, but I can't heal-
Me: Don't say it. I already know.

 

[AnotherDilbert]

A half-truth. Striker does not deal with surface to Orbit travel ... it contains rules for MINIATURES and small unit combat. The comments about Spaceships refer to how to apply the STRIKER COMBAT RULES to them ... treat them like Grav Vehicles (Grav Tanks and Grav APCs are given extensive treatment in the Striker rules).

Of course, the rules covering starships in a planetary setting does not apply because they are in a rule book you don't like.

The rules in LBB2 that covers starship movement and goes into great detail with planetary templates, how far gravity extends, and how starships are affected, does not apply because it's in the combat chapter.

The rules in LBB1 that says smallcraft crashes on size 8+ worlds doesn't apply because it's just a character generation system, it can't have anything to say about spacecraft, now can it?

The short description of grav vehicles in LBB3 can't apply to grav vehicles, because ...?

But the LBB2 section about Interplanetary Travel, travel between planets, with a nice graphic of a ship travelling between two worlds, that obviously applies to landings and proves beyond a shadow of a doubt that gravity does not affect spacecraft, right?


After disqualifying LBB1, LBB2, LBB3, Striker book 1-3, and I assume LBB5 because that is just a wargame, there isn't much left of Traveller that you approve of, is there?

 

[AnotherDilbert]

• STRIKER is about MINIATURES COMBAT and the Starship rules govern which starships may participate by maneuvering like "Grav Tanks and Grav APCs ... Starships with 1G MD may not participate in Combat. [That is not the same as not being able to make a slow, clumsy climb to orbit with so little agility that a WW2 Fighter Plane with Korean War era missiles could shoot it down.]

Striker, B3, p11:
the vehicle cannot move

No ifs, no buts, and no unicorn farts.

 

[Condottiere]

Science/fictional solutions to realistic conditions.

I was thinking about this, and it's basically propulsion systems inside a gravity well, and more or less outside a gravity well.

A ship floats because it's designed/constructed to float, and won't sink because the engine is turned off, or isn't going fast enough, which could describe a spacecraft outside a gravity well.

A lighter than air craft would float in a gravity well, without needing a motor, unless it's a balloon which needs to be topped up with an occasional blast of hot air.

So a gravity based propulsion is an active interaction with the forces in a gravity well.

 

[mike wightman]

Guess we'll just have to leave it there.

I must be blind because I can not see a direct quote - all I can see are your rule interpretations.

In your Traveller universe only planes and generate aerodynamic lift, for some reason physics in YTU does not allow lifting bodies or even streamlined objects to generate lift. What happens to a car driven at 250kph with no down force spoilers in YTU?

 

[mike wightman]

Can a streamlined car fly? The Laws of Physics says no.

Yes, the trick is to control them once they are airborne - very fast cars must actually built with downforce in mind to prevent lift off.
Now add TL8 computer controlled flight surfaces.

And planes that stall drop like rocks too...

 

[mike wightman]

Your post actually proves atpollard's point.

World surface to orbit 10,000km
Time for 1g ship to travel this 2000s

Nowhere in LBB2 does it say you subtract the world's gravity from the m-drive rating to get effective acceleration

in point of fact I am still waiting for your direct quote rather than you interpretations.

 

[atpollard]

Yes, the obscure house rule called LBB3:

That can't possibly apply to grav vehicles, right? This must mean that grav vehicles fly using aerodynamic lift from their large wings, no doubt!


And the irrelevant book in Striker:

That just states "the vehicle cannot move", that obviously means the vehicle can move if we just apply enough unicorn farts.

The House Rule part is applying Striker RAW for miniatures combat participation to all aspects of Starship operations ... see post #418.
EXPLICIT: 2000 seconds at 1G from Surface to Orbit (10,000 km) [LBB2:77 pgs 10-11] ... is LBB2 wrong about EVERY Starship on EVERY world?

 

[atpollard]

Your solution ignores gravity the first turn, directly against the rules.

As previously stated:

• For the first turn it is no different than if the craft had WINGS and was traveling down a runway accelerating to takeoff speed ... the gravity vector is supported by the wheels. You are not claiming THAT is impossible under RAW, are you?
• It is no different than skipping over the water powered by grav thrust ... the gravity vector is supported by the hull on the water. You are not claiming THAT is impossible under RAW, are you?

Your criticisms have been addressed and Gravity was NOT ignored.

... So what happens in TURN 2 and TURN 3 under the Vector Movement RAW?
(You may as well ignore Atmospheric Drag ... the opponents of HTOL Starships are more concerned about those Giant Worlds with no Atmosphere to generate theoretical lift as it is.)

 

[atpollard]

The section explicitly about starships, obviously doesn't apply to starships, right...

What is so hard to comprehend about my position?

The section [in Striker] explicitly about starships applies to starships for:

• "ground combat with 15mm figures and vehicles." (which Starship Travel from Surface to Orbit is not).
• "for campaigning with miniatures." (which Starship Travel from Surface to Orbit is not).

The LBB Vector Movement prohibits a VERTICAL vector to orbit but not a HORIZONTAL vector to orbit.

Neither Striker nor Vector Movement abrogate the clear statements in LBB2:77 pg 10-11 that it requires 2000 seconds at 1G to travel from Surface to Orbit (10,000 km) or negate the obvious lack of any clear mention that MANY starships may not land on MANY worlds.

That is my position. You are welcome to disagree, but it is not unreasonable or illogical and it does not ignore the RAW.

 

[atpollard]

The problem with that is ... terrain context.
If you don't have a nice, cleared, suitable range within which to make that takeoff roll ... You Are Not Going To Space Today™.

You requested an evaluation of the Vector Movement because YOU CLAIMED that the Vector Movement RAW made Surface to Orbit travel impossible at size 8+. I obliged by examining the Vector Movement RAW (no small task given my dislike for the vector movement rules and their hyper-fiddly use in the real world.) The Vector Movement RAW do NOT prohibit HTO to orbit, they just yield some odd results (par for the course with the Vector Movement RAW). For every HTOL "what-if" criticism NOT COVERED by the Vector Movement RAW, I can come up with a VTOL "what-if" criticism NOT COVERED by the Vector Movement RAW. That only proves that the Vector Movement RAW are not "all inclusive" and may suggest that they are not intended to model Surface to Orbit travel.

If you don't want to go to space today, then don't go. Just don't pretend that the RAW are explicitly preventing you from going there:

LBB2:77 pg 10-11 permits 2000 seconds at 1G from Surface to Orbit (10,000 km) and all your angst does not change that.

• Vector Movement RAW suggest do not attempt VTOL on a size 8+world, use HTOL.
• Striker explicitly prohibits ground combat for 1G ships on a size 8+world, but does not change LBB2 for non-Striker situations.

 

[atpollard]

Of course, the rules covering starships in a planetary setting does not apply because they are in a rule book you don't like.

See post #418 ... it has nothing to do with "dislike" (I actually LIKE Striker) ... it has to do with what the Striker rules were created to DO (MINIATURES COMBAT) and that they were NOT created to DO (ROLEPLAYING TRAVELLER). Different horses for different courses.

TCS are not rules for Tramp Freighters to speculate in Cargo ... they just are not. So they apply where they are designed to apply (Fleet Combat) and not where they are not designed to apply (Speculative Trade). Same with Striker ... which ships operate like a Gtrav Tank in Ground Combat [YES] ... Starship Interplanetary Travel [NO].

Flipping it around, does Striker allow an Air Raft to operate like a Starship between worlds since Grav Vehicles and Starships are the same in Striker? (Does that help illustrate my point?)

 

[atpollard]

The rules in LBB2 that covers starship movement and goes into great detail with planetary templates, how far gravity extends, and how starships are affected, does not apply because it's in the combat chapter.

They apply.
They prohibit VERTICAL takeoff.
They do not prohibit HORIZONTAL takeoff. (you refuse to allow a planet's surface to support the weight of a starship in the Vector Movement ... You choose to interpret that as "no movement" or a "crash").

Your accusation is untrue.

 

[atpollard]

Striker, B3, p11:
the vehicle cannot move

... In MINIATURES COMBAT [the realm that Striker rules deal with].

No ifs, no buts, and no unicorn farts.

LBB 2:77 pg 10-11 states 2000 seconds from Surface to Orbit (10,000 km) at 1G.
No ifs, no buts, and "reactionless drives" are 100% unicorn farts.

 

[Spinward Flow]

I must be blind

That about sums it up.

In your Traveller universe only planes and generate aerodynamic lift, for some reason physics in YTU does not allow lifting bodies or even streamlined objects to generate lift.

{sigh}

Are all airframes designed to generate lifting force in atmosphere streamlined?
For the purposes of our conversation here ... yes.

So then, does it not follow that all streamlining of any and every variety must ipso facto generate lifting force in atmosphere?
No ... actually.

Where in the rules covering the movement of starships does the text explicitly say that starship streamlining generates lifting force in atmospheres?
Spoiler alert: IT DOESN'T ... you're just assuming that it does.

Do the rules state that streamlining allows ENTRY into atmosphere?
Yes, they do.

Do those same rules ALSO state that streamlining assists with EXIT out of atmosphere?
No ... they don't ... rather conspicuously ... and yet the argument that they do persists.

Don't believe me? Then quote the rule for starship movement that states unequivocably that streamlining assists with lifting force/acceleration "up" to escape atmospheres at the bottom of gravity wells.

Your post actually proves atpollard's point.

You CAN'T be serious.

I'm doing the mathematical equivalent of proving 1-1=0 ... and you're saying that I'm wrong (always have been, always will!).

Here, I'll do it again in a classical "show your work" presentation style.

1G - 1G = 0G net acceleration

That's 1G of maneuver drive power delivering 1G of force against a 1G gravity field, yielding a net acceleration of 0G.

You can hover with that.
You can "float" with that ... but You Are Not Going To Space Today™ with that kind of net performance.

You are not claiming THAT is impossible under RAW, are you?

@atpollard ... you're a Super Moderator ... and your desperation is showing.

It's not that the RAW forbids it ... it's that the RAW doesn't cover or address it in the terms that you're fixating upon.
Absence of evidence is NOT ipso facto evidence of absence.

Neither Striker nor Vector Movement abrogate the clear statements in LBB2:77 pg 10-11

What is the (simplified) net acceleration vector of 1G maneuver in a 1G gravity field in an up/down direction?

Me: 1G - 1G = 0G going "up" ... or 1G + 1G = 2G going "down"

You: 1G - 0G = 1G going "up" ... or 1G + 0G = 1G going "down"

I can't "dumb it down" any further than this.

And to be honest, I'm ashamed that I should be obliged to point out something so obviously basic.

The table you're referring to is a convenience showing pre-computed answers IN ZERO GRAVITY. Throw gravity acceleration vector addition into the mix (like you would have to do at the bottom of a gravity well on a planetary surface) and the answers CHANGE. That's just how vector math WORKS.

 

[atpollard]

It's not that the RAW forbids it ... it's that the RAW doesn't cover or address it in the terms that you're fixating upon.
Absence of evidence is NOT ipso facto evidence of absence.

Why does that argument not apply to a craft sliding along the surface of the imaginary surface of the planet until the Horizontal vector is greater than the Vertical vector in the Vector Movement rules?

That was MY question that has yet to be answered.

 

[mike wightman]

That about sums it up.

{sigh}

Are all airframes designed to generate lifting force in atmosphere streamlined?
For the purposes of our conversation here ... yes.

So then, does it not follow that all streamlining of any and every variety must ipso facto generate lifting force in atmosphere?
No ... actually.

Where in the rules covering the movement of starships does the text explicitly say that starship streamlining generates lifting force in atmospheres?
Spoiler alert: IT DOESN'T ... you're just assuming that it does.

Do the rules state that streamlining allows ENTRY into atmosphere?
Yes, they do.

Do those same rules ALSO state that streamlining assists with EXIT out of atmosphere?
No ... they don't ... rather conspicuously ... and yet the argument that they do persists.

Don't believe me? Then quote the rule for starship movement that states unequivocably that streamlining assists with lifting force/acceleration "up" to escape atmospheres at the bottom of gravity wells.

You CAN'T be serious.

I'm doing the mathematical equivalent of proving 1-1=0 ... and you're saying that I'm wrong (always have been, always will!).

Here, I'll do it again in a classical "show your work" presentation style.

1G - 1G = 0G net acceleration

That's 1G of maneuver drive power delivering 1G of force against a 1G gravity field, yielding a net acceleration of 0G.

You can hover with that.
You can "float" with that ... but You Are Not Going To Space Today™ with that kind of net performance.

@atpollard ... you're a Super Moderator ... and your desperation is showing.

It's not that the RAW forbids it ... it's that the RAW doesn't cover or address it in the terms that you're fixating upon.
Absence of evidence is NOT ipso facto evidence of absence.

What is the (simplified) net acceleration vector of 1G maneuver in a 1G gravity field in an up/down direction?

Me: 1G - 1G = 0G going "up" ... or 1G + 1G = 2G going "down"

You: 1G - 0G = 1G going "up" ... or 1G + 0G = 1G going "down"

I can't "dumb it down" any further than this.

And to be honest, I'm ashamed that I should be obliged to point out something so obviously basic.

The table you're referring to is a convenience showing pre-computed answers IN ZERO GRAVITY. Throw gravity acceleration vector addition into the mix (like you would have to do at the bottom of a gravity well on a planetary surface) and the answers CHANGE. That's just how vector math WORKS.

After such an eloquent post a few things to ponder.

First yes according to the laws of physics here in the real world a streamlined shape can generate lift.

Where do the rules as written directly say a 1g ship can not fly from a size 8 world - they don't, you are just assuming it.
I'm still waiting for your direct quote.

To quote you directly " It's not that the RAW forbids it ... it's that the RAW doesn't cover or address it in the terms that you're fixating upon. Absence of evidence is NOT ipso facto evidence of absence." And yet you are claiming that the absence of streamlining generating lift is. You are using this argument to claim your position is correct but the same argument is just as valid for streamlined lift.

Your maths is wrong because you are making incorrect assumptions. You keep assuming Traveller ships are rockets. Sow me an example of a Traveller ship that sits on its tail for take off?

How can you travel to orbit in zero gravity?

And as to how vector math works please answer this, what does the vector arrow in LBB2 represent?

To quote LBB3

obviously rules which could cover every aspect of every possible
action would be far larger than these three booklets

streamlined ships being able to fly to orbit are one such referee call.

You and a couple of others, say no, while a few of us say yes.

You are never going to convince me with your "rather unique posting style" and my arguments are not going to convince you.

 

[atpollard]

What is the (simplified) net acceleration vector of 1G maneuver in a 1G gravity field in an up/down direction?

Me: 1G - 1G = 0G going "up" ... or 1G + 1G = 2G going "down"

You: 1G - 0G = 1G going "up" ... or 1G + 0G = 1G going "down"

I can't "dumb it down" any further than this.

And to be honest, I'm ashamed that I should be obliged to point out something so obviously basic.

Apply the calculation to a Size 4 world and show me how 2000 seconds from surface to orbit works.
You refuse to see the OBVIOUS point:

• It works for NO WORLD SIZE if you subtract local gravity from the G-rating.
• It works for EVERY WORLD SIZE if local gravity is NOT subtracted from the G-rating.

You are so much smarter than me, so what does that tell you about the DESIGN INTENT of the game author?
Did he plan on subtracting Local Gravity from Performance or not?
Did he intend the TABLE to work for EVERY WORLD or for NO WORLD?

Let's go one step further:
LBB 2:77 Standard Ships Free Trader (Type A) & Subsidized Merchant (Type R) are both 1G, Streamlined and the most common ACS that Travellers are likely to own and use for Trade (as in the extensive rules on Cargo, Passengers and Speculation). Was it the design intent of the Game Creator that these ships and the players in them would be unable to land on 1/6 of the worlds they encountered [including EARTH] or was it their intent that the most common ships for trade would be suitable for trade by being capable of landing on any world and flying to orbit in 2000 seconds (33 minutes)? Which is more compatible with "Golden Age" Science Fiction [the stated inspiration for Traveller]?