Escape Velocity

[Supplement Four]

Here's a question...

I know it's been debated over and over in the past, but, can a ship with a 1G M-Drive launch from a Size 8 (Earth) world with a 1G gravity field?

DGP's Starship Operator's Manual says "yes". It states that starships have "overdrive" capability for short periods of time, allowing a ship with a 1G M-Drive to reach escape velocity from a 1G world.

Another popular opinion among Traveller players is that, "no", a 1G M-Drive cannot reach escape velocity using it's M-Drive alone, but that starships have anti-grav drives (along with their jump drives, maneuver drives, and attitude adjustment systems) that can be used inside a planet's gravity well. This "grav assist" allows 1G M-Drive ships to reach escape velocity from 1G worlds.

Tonight, I'm reading White Dwarf (and posting a lot of stuff! Because I'm intrigued by all these things, dammit!), and I see yet a third opinon on the matter. According to this WD article, 1G M-Drive ships cannot escape from 1G worlds without "boosters" that can be hired from the local starport to give the ship more thrust.

These boosters cost 10Cr per ton of the vessel (which can add up for the thin margins of some trader craft). Of course, the trader captain can always make orbit and use a shuttle service to get his cargo on the planet.

I kinda like the second option above (grav assist) for MTU.

How do you tackle this idea in your game?

 

[Supplement Four]

Here's a question...

I know it's been debated over and over in the past, but, can a ship with a 1G M-Drive launch from a Size 8 (Earth) world with a 1G gravity field?

DGP's Starship Operator's Manual says "yes". It states that starships have "overdrive" capability for short periods of time, allowing a ship with a 1G M-Drive to reach escape velocity from a 1G world.

Another popular opinion among Traveller players is that, "no", a 1G M-Drive cannot reach escape velocity using it's M-Drive alone, but that starships have anti-grav drives (along with their jump drives, maneuver drives, and attitude adjustment systems) that can be used inside a planet's gravity well. This "grav assist" allows 1G M-Drive ships to reach escape velocity from 1G worlds.

Tonight, I'm reading White Dwarf (and posting a lot of stuff! Because I'm intrigued by all these things, dammit!), and I see yet a third opinon on the matter. According to this WD article, 1G M-Drive ships cannot escape from 1G worlds without "boosters" that can be hired from the local starport to give the ship more thrust.

These boosters cost 10Cr per ton of the vessel (which can add up for the thin margins of some trader craft). Of course, the trader captain can always make orbit and use a shuttle service to get his cargo on the planet.

I kinda like the second option above (grav assist) for MTU.

How do you tackle this idea in your game?

 

[Supplement Four]

Originally posted by Supplement Four:
Tonight, I'm reading White Dwarf (and posting a lot of stuff! Because I'm intrigued by all these things, dammit!), and I see yet a third opinon on the matter. According to this WD article, 1G M-Drive ships cannot escape from 1G worlds without "boosters" that can be hired from the local starport to give the ship more thrust.

These boosters cost 10Cr per ton of the vessel (which can add up for the thin margins of some trader craft). Of course, the trader captain can always make orbit and use a shuttle service to get his cargo on the planet.

But, one of the side effects to playing M-Drives this way in your Traveller game is listed in the article as well. I think it's pretty cool.




Acceleration Damage

It is assumed that there is no mystical "inertial compensator" as is stated in the SOM (and much of SciFi). If you've ever read the first few pages of Peter Hamilton's The Night's Dawn Trilogy, you've read that excitng section where the crew of a space vessel suddenly comes under attack. The klaxon sounds. And, crew runs for their acceleration couches as the ship begins to make combat high-G maneuvers.

Or, remember reading Haldeman's The Forever War and his description of what it was like zipping out to Jupiter at High G for months and months at a time?

If you like the way that makes your game feel (maybe a bit more "realistic"?), then you might want to scrap your inertial compensators and give this idea a try.

What is says is: Characters will take damage during high G maneuvers (anything over 1G) to the tune of 1D of damage per G rating over 1G.

In other words--

--Ships will move at a max of 1G of speed during normal conditions, regardless of the ship's M-Drive rating. Higher G maneuvers are reserved for combat (because of how uncomfortable it is for the crew moving at higher than 1G velocity).

--Ships with M-Drives rated at higher than 1G are considered military - or combat capabable.

--A ship with a 4G M-Drive will use power equal to 3Gs around a dense world with a 2G gravity field. Inside the ship, it is equalized at 1G (3G - 2G = 1G).

--Characters strapped into acceleration couches and the like will receive a bonus against damage applied to them due to high G manuevers. (+2 damage if not in a couch.)




I think this is an interesting concept to add to a Traveller game.

Thoughts?

 

[Supplement Four]

Originally posted by Supplement Four:
Tonight, I'm reading White Dwarf (and posting a lot of stuff! Because I'm intrigued by all these things, dammit!), and I see yet a third opinon on the matter. According to this WD article, 1G M-Drive ships cannot escape from 1G worlds without "boosters" that can be hired from the local starport to give the ship more thrust.

These boosters cost 10Cr per ton of the vessel (which can add up for the thin margins of some trader craft). Of course, the trader captain can always make orbit and use a shuttle service to get his cargo on the planet.

But, one of the side effects to playing M-Drives this way in your Traveller game is listed in the article as well. I think it's pretty cool.




Acceleration Damage

It is assumed that there is no mystical "inertial compensator" as is stated in the SOM (and much of SciFi). If you've ever read the first few pages of Peter Hamilton's The Night's Dawn Trilogy, you've read that excitng section where the crew of a space vessel suddenly comes under attack. The klaxon sounds. And, crew runs for their acceleration couches as the ship begins to make combat high-G maneuvers.

Or, remember reading Haldeman's The Forever War and his description of what it was like zipping out to Jupiter at High G for months and months at a time?

If you like the way that makes your game feel (maybe a bit more "realistic"?), then you might want to scrap your inertial compensators and give this idea a try.

What is says is: Characters will take damage during high G maneuvers (anything over 1G) to the tune of 1D of damage per G rating over 1G.

In other words--

--Ships will move at a max of 1G of speed during normal conditions, regardless of the ship's M-Drive rating. Higher G maneuvers are reserved for combat (because of how uncomfortable it is for the crew moving at higher than 1G velocity).

--Ships with M-Drives rated at higher than 1G are considered military - or combat capabable.

--A ship with a 4G M-Drive will use power equal to 3Gs around a dense world with a 2G gravity field. Inside the ship, it is equalized at 1G (3G - 2G = 1G).

--Characters strapped into acceleration couches and the like will receive a bonus against damage applied to them due to high G manuevers. (+2 damage if not in a couch.)




I think this is an interesting concept to add to a Traveller game.

Thoughts?

 

[RandyT0001]

IMTU, the MD rating divided by two, round up, is the ship's capability to negating planetary gravity. A MD of 3 can negate up to 2g's of a planet's gravity. This means high MD 6 SBD's can lurk deep in a GG (to the planet's 3g zone) and still fly out to attack at 6g's.
YMMV

 

[RandyT0001]

IMTU, the MD rating divided by two, round up, is the ship's capability to negating planetary gravity. A MD of 3 can negate up to 2g's of a planet's gravity. This means high MD 6 SBD's can lurk deep in a GG (to the planet's 3g zone) and still fly out to attack at 6g's.
YMMV

 

[far-trader]

Well a few points leap out at me...

If you have no inertial compensation then your ships are likely to be tail sitters. And without inertial compensation, and contragrav lifters how likely is it that we'd have artificial gravity? Pretty unlikely since all three are just varients of the same technology. So now we have ships with no AG which are tail sitters. What else is related to this? Bingo! Traveller maneuver drives. So they are no longer a magic Grav Thruster but some kind of reaction drive, which is gonna mean a lot more fuel as reaction mass.

Can you see how this "simple cool" WD idea is snowballing unintended consequences that don't seem to have been thought out by the original author? There may even be more but already it's very unTraveller. Maybe good for some obscure (ie Ref designed) aliens but not for Charted Space.

 

[far-trader]

Well a few points leap out at me...

If you have no inertial compensation then your ships are likely to be tail sitters. And without inertial compensation, and contragrav lifters how likely is it that we'd have artificial gravity? Pretty unlikely since all three are just varients of the same technology. So now we have ships with no AG which are tail sitters. What else is related to this? Bingo! Traveller maneuver drives. So they are no longer a magic Grav Thruster but some kind of reaction drive, which is gonna mean a lot more fuel as reaction mass.

Can you see how this "simple cool" WD idea is snowballing unintended consequences that don't seem to have been thought out by the original author? There may even be more but already it's very unTraveller. Maybe good for some obscure (ie Ref designed) aliens but not for Charted Space.

 

[far-trader]

Next let's address the title of this thread, Escape Velocity*

What you actually seem to be talking about is a straight shot up requirement for escape velocity. But we don't really need that, even with just 1G. As long as the craft has a form of lift, say wings in atmo, 1G of thrust is more than enough to make orbit. The thing is you trade time and distance in climbing to altitude.

This is how I see Traveller's contra-grav working, as virtual wings that don't need atmo, just a gravity field to work against. Any depicted actual airframe is more for control in atmo than lift. This nicely gets us back to the Traveller norm of lateral decks perpendicular to thrust and 1G is more than enough to fly to orbit.

* which btw lured me with the promise of being about one of my favorite games

 

[far-trader]

Next let's address the title of this thread, Escape Velocity*

What you actually seem to be talking about is a straight shot up requirement for escape velocity. But we don't really need that, even with just 1G. As long as the craft has a form of lift, say wings in atmo, 1G of thrust is more than enough to make orbit. The thing is you trade time and distance in climbing to altitude.

This is how I see Traveller's contra-grav working, as virtual wings that don't need atmo, just a gravity field to work against. Any depicted actual airframe is more for control in atmo than lift. This nicely gets us back to the Traveller norm of lateral decks perpendicular to thrust and 1G is more than enough to fly to orbit.

* which btw lured me with the promise of being about one of my favorite games

 

[far-trader]

OK, another issue just struck me. These boosters, they attach where exactly? And are controlled how exactly?

What I mean is they will need to be balanced on the craft, one size will not fit all, and Traveller has a mulitude of different ships.

And there is nothing in the standard design package about stress points to attach extra thrust to. Sounds a lot like a hardpoint definition in fact. So these boosters would probably mean your ship has to dedicate hardpoints to booster mounts. Probably all of them.

And the control issue. Are they simple JATO rockets? So once I light them up, however I light them up, I'm committed and there's no turning back. And probably limited maneuvering. Let's hope ground control has cleared my flight path and no idiot ignores them and crosses in front of me.

And what about those backwater ports? Surely these boosters come under the category of reasonable facilities, like class C and better. But would I find them at a class D? Unlikely I'd say. So do I have to pack my own?

Nope, I don't like this alternate idea much at all. It requires far too many changes for too little benefit in coolness.

 

[far-trader]

OK, another issue just struck me. These boosters, they attach where exactly? And are controlled how exactly?

What I mean is they will need to be balanced on the craft, one size will not fit all, and Traveller has a mulitude of different ships.

And there is nothing in the standard design package about stress points to attach extra thrust to. Sounds a lot like a hardpoint definition in fact. So these boosters would probably mean your ship has to dedicate hardpoints to booster mounts. Probably all of them.

And the control issue. Are they simple JATO rockets? So once I light them up, however I light them up, I'm committed and there's no turning back. And probably limited maneuvering. Let's hope ground control has cleared my flight path and no idiot ignores them and crosses in front of me.

And what about those backwater ports? Surely these boosters come under the category of reasonable facilities, like class C and better. But would I find them at a class D? Unlikely I'd say. So do I have to pack my own?

Nope, I don't like this alternate idea much at all. It requires far too many changes for too little benefit in coolness.

 

[far-trader]

Lastly the acceleration damage idea. While I agree and like the idea of felt acceleration the damage seems rather arbitrary and extreme.

Damage from what exactly? And why only over 1G?

I think 1G of lateral acceleration will be felt more than 2G of linear acceleration. What's more the lateral acceleration is more likely to lead to injury than the linear acceleration. What I mean is changes in orientation are going to be more problematic than simple addition to the vector. If you wanted to add coolness and some reality to the equation rather than introduce a questionable mechanic for acceleration effects apply it to agility instead.

Personally I've always figured Traveller ships had inertial compensation (about*) equal to the current maneuver drive rating. It's part of the package of thrusters/contra-grav/artigrav (the whole gravity manipulation thing). This way when a ship hits something (or something hit's it) it's felt (being outside the operating field effect).

* Not exactly equal. There is a small margin built in so you know what the ship is actually doing without reference to instruments. When you hit the go button the drives wind-up to full acceleration in a couple minutes, with the IC lagging perceptibly but not significantly. So you feel maybe 1/10th the acceleration you're doing at any time.

But I don't include agility in this. Agility to me is a rapid orientation change (or changes) in an attempt to avoid terminal weapons locks, and the IC can't compensate for it so you'd better be strapped in if you don't want to go bouncing off the plates. THIS is where I'd apply damage, and 1D per point of agility seems generous to those not secured. I wouldn't apply any damage to anyone in a couch.

 

[far-trader]

Lastly the acceleration damage idea. While I agree and like the idea of felt acceleration the damage seems rather arbitrary and extreme.

Damage from what exactly? And why only over 1G?

I think 1G of lateral acceleration will be felt more than 2G of linear acceleration. What's more the lateral acceleration is more likely to lead to injury than the linear acceleration. What I mean is changes in orientation are going to be more problematic than simple addition to the vector. If you wanted to add coolness and some reality to the equation rather than introduce a questionable mechanic for acceleration effects apply it to agility instead.

Personally I've always figured Traveller ships had inertial compensation (about*) equal to the current maneuver drive rating. It's part of the package of thrusters/contra-grav/artigrav (the whole gravity manipulation thing). This way when a ship hits something (or something hit's it) it's felt (being outside the operating field effect).

* Not exactly equal. There is a small margin built in so you know what the ship is actually doing without reference to instruments. When you hit the go button the drives wind-up to full acceleration in a couple minutes, with the IC lagging perceptibly but not significantly. So you feel maybe 1/10th the acceleration you're doing at any time.

But I don't include agility in this. Agility to me is a rapid orientation change (or changes) in an attempt to avoid terminal weapons locks, and the IC can't compensate for it so you'd better be strapped in if you don't want to go bouncing off the plates. THIS is where I'd apply damage, and 1D per point of agility seems generous to those not secured. I wouldn't apply any damage to anyone in a couch.

 

[Supplement Four]

Originally posted by far-trader:
OK, another issue just struck me. These boosters, they attach where exactly? And are controlled how exactly?

The article actually goes into some depth about them. They're kinda cool. I don't think I'll use them in my game, but I do like reading speculative stuff like this. I can tell the author put a lot of time into thinking about how these things work. You can tell, from his writing in the article, that he was actually playing a campaign (it seems to me that rules written by those who play tend to be better than those who just speculate and don't "play test").

Also, remember that this article was written when all Traveller was...was the first three books and B4 Mercenary.

Much of what you call "Traveller" today (in your posts here) is based on all that has been developed for Traveller.

This guy, writing this article, had four little books to work with--books that are quite sparse on some details.

It makes the article that much more interesting coming from that perspective.

What I mean is they will need to be balanced on the craft, one size will not fit all, and Traveller has a mulitude of different ships.

There are different types. Some are reuseable. Some are one-time-use and then throw away.

The boosters are designed specifically for a certain type of craft (they're not interchangeable between all ships with 400 ton hulls, for example).

Basically, what they are is an extra little space ship--a tug--that is connected to the ship's hull. The reusable ones can be somewhat permanent. The throw-away ones are used one time and then disgarded, not unlike drop tanks.

What's really cool and interesting is that the writer of the article even speculates that the boosters can even be used for creative uses during play: as a unmanned exploration vessel, or as a message torpedo.

Neat thinking, I'd say.

As for control, they're controled from the ship's bridge--as you would a remote spacecraft.

The boosters are basically a combination of: Hull; Fuel; M-Drive; Computer. They're small space ships, really, used to provide extra thrust to a vessel to help it make escape velocity (when the ship's main M-Drive won't do the trick).

The author of the article gets into chances for breakdown and the need for repair, special-use boosters; disposable vs. resuable...etc.

Neat stuff.

 

[Supplement Four]

Originally posted by far-trader:
OK, another issue just struck me. These boosters, they attach where exactly? And are controlled how exactly?

The article actually goes into some depth about them. They're kinda cool. I don't think I'll use them in my game, but I do like reading speculative stuff like this. I can tell the author put a lot of time into thinking about how these things work. You can tell, from his writing in the article, that he was actually playing a campaign (it seems to me that rules written by those who play tend to be better than those who just speculate and don't "play test").

Also, remember that this article was written when all Traveller was...was the first three books and B4 Mercenary.

Much of what you call "Traveller" today (in your posts here) is based on all that has been developed for Traveller.

This guy, writing this article, had four little books to work with--books that are quite sparse on some details.

It makes the article that much more interesting coming from that perspective.

What I mean is they will need to be balanced on the craft, one size will not fit all, and Traveller has a mulitude of different ships.

There are different types. Some are reuseable. Some are one-time-use and then throw away.

The boosters are designed specifically for a certain type of craft (they're not interchangeable between all ships with 400 ton hulls, for example).

Basically, what they are is an extra little space ship--a tug--that is connected to the ship's hull. The reusable ones can be somewhat permanent. The throw-away ones are used one time and then disgarded, not unlike drop tanks.

What's really cool and interesting is that the writer of the article even speculates that the boosters can even be used for creative uses during play: as a unmanned exploration vessel, or as a message torpedo.

Neat thinking, I'd say.

As for control, they're controled from the ship's bridge--as you would a remote spacecraft.

The boosters are basically a combination of: Hull; Fuel; M-Drive; Computer. They're small space ships, really, used to provide extra thrust to a vessel to help it make escape velocity (when the ship's main M-Drive won't do the trick).

The author of the article gets into chances for breakdown and the need for repair, special-use boosters; disposable vs. resuable...etc.

Neat stuff.

 

[Pickles]

Originally posted by Supplement Four:
The boosters are designed specifically for a certain type of craft (they're not interchangeable between all ships with 400 ton hulls, for example).

That would make them pretty impractical from a stock control point of view. How do the starport management chose which and how many boosters to stock? Visiting ships would have to check ahead whether a particular starport had their kind of boosters in stock, so they would only work for regular shipping lines, not for independent traders.

So, in the very limited case of subsidised merchants, they might work. Except they would have to be designed from the start to take these boosters, for all the reasons Far Trader mentioned above.

 

[Pickles]

Originally posted by Supplement Four:
The boosters are designed specifically for a certain type of craft (they're not interchangeable between all ships with 400 ton hulls, for example).

That would make them pretty impractical from a stock control point of view. How do the starport management chose which and how many boosters to stock? Visiting ships would have to check ahead whether a particular starport had their kind of boosters in stock, so they would only work for regular shipping lines, not for independent traders.

So, in the very limited case of subsidised merchants, they might work. Except they would have to be designed from the start to take these boosters, for all the reasons Far Trader mentioned above.

 

[Supplement Four]

Originally posted by the Bromgrev:
That would make them pretty impractical from a stock control point of view. How do the starport management chose which and how many boosters to stock?

They're not really "off the shelf" items, according to the article. A ship captain needs to plan ahead.

A Type A or B startport might have a few of them around, for sale, for standard design starships, but typically, the boosters are built to spec. They're small spaceships, after all, that attach to the hull.

The article reasons if a starport is on a busy starlane, it might have some. If it isn't, then the ship captain of the 1G vessel will probably only make orbit around the world and use shuttles to ferry his cargo dirtside (or dock with the highport, if there is one).

Basically, the article infers that 1G starships have a hard time out there in the big beyond. They're made cheap (as cheap as a starship can get), and typically, they don't land dirtside unless a ship travels to a low G world (or the boosters are put into use).

I think it's an interesting alternate Traveller idea.

But, I wouldn't use it in my campaign.

I just post it here because I thought it was an interesting read.

-S4

 

[Supplement Four]

Originally posted by the Bromgrev:
That would make them pretty impractical from a stock control point of view. How do the starport management chose which and how many boosters to stock?

They're not really "off the shelf" items, according to the article. A ship captain needs to plan ahead.

A Type A or B startport might have a few of them around, for sale, for standard design starships, but typically, the boosters are built to spec. They're small spaceships, after all, that attach to the hull.

The article reasons if a starport is on a busy starlane, it might have some. If it isn't, then the ship captain of the 1G vessel will probably only make orbit around the world and use shuttles to ferry his cargo dirtside (or dock with the highport, if there is one).

Basically, the article infers that 1G starships have a hard time out there in the big beyond. They're made cheap (as cheap as a starship can get), and typically, they don't land dirtside unless a ship travels to a low G world (or the boosters are put into use).

I think it's an interesting alternate Traveller idea.

But, I wouldn't use it in my campaign.

I just post it here because I thought it was an interesting read.

-S4