aerodynamic streamlining

[flykiller]

most traveller ship depictions look like very sleek fighter aircraft. most traveller ship deckplans' attempts at aerodynamism look like fat pigs with wings, or like blocks stuck in the middle of dramatic aerodynamic silhouettes. block and close-structure vessels seem unpopular, though space vaccuum and vtol maneuver drive make them quite acceptable operationally. how important is atmospheric/dramatic streamlining in your traveller ship depictions/deckplans?

(for an "other" response, please explain)

 

[atpollard]

Personally, l am less concerned about streamlined vs unstreamlined and more bothered when the deck plan and exterior image are not even close to depicting the same ship.

 

[Patron Zero]

Streamlining, IMTU in particular, has been more function than fashion as a 'tool' for fuel-skimming or performing other maneuvers in atmospheres.

 

[sabredog]

IMTU I require streamlining (partial or full) with some kind of control surfaces for in atmosphere flight and maneuvering, and for skimming.

A lot of designs are lifting bodies that can land and take-off fine, but like the Space Shuttle, really have maneuvering qualities of pretty much zero. Those are the "partial streamlined" hulls of HG, and can skim, maneuvering while doing so with limited control surfaces. To land they really just come in in a controlled fall, then a straight glide like the shuttles. They rely far more on drives than the fully streamlined designs for take-offs and landings. If a ship with a lower G rating is trying to lift from a world with a higher gravity it needs an assist from boosters rented from the port. Partially streamlined ships cannot enter any atmosphere denser than Standard IMTU.

If they are on combat in atmosphere they are pretty much just a falling target. Pilot skill does not factor into maneuvering in atmosphere since they can't do much more than make slight pitch and yaw adjustments to their glide path and, like the shuttles, the computer pretty much does the work.



Fully streamlined ships can land and take-off in any atmosphere and can maneuver as can any aircraft within it. They can use a runway to assist a take-off and so lift from a world with a higher gravity than the ship's M-drive is rated for. The Pilot's skill can be used for in-atmosphere maneuvering in combat, and landings/take-offs are generally easier to perform. The ship can land and maneuver with some damage to the control surfaces but it is a lot riskier than with a partially streamlined ship because this design requires them for lift. Accordingly, hull damage might knock a hole through your wing that causes your ship to roll over into a turning stall once you hit atmosphere. Very bad.

But, IMTU fully streamlined ships are prettier than the rest so they are built more often if you can afford it. They also can land in water if designed for it, so that tends to be the popular shape for yachts and survey craft.

Of course, this is IMTU, and your mileage may vary.

 

[warwizard]

I produce many designs with realistic reaction mass requiring maneuver drives (HEPLAR, Fusion Rocket, Daedalaus) for a Terran dawn campaign, full streamlining is a requirement for any of these that need to enter atmosphere, however generally these are scout ships that are making one time visits to worse than hell worlds, they do not bother landing just fly into the atmosphere collect samples looking for life traces and then boost back out, perhaps picking up reaction mass while doing it.

If the ships have antigravity I have them slow to the same speed as the upper atmosphere then slowly lower themselves through the atmosphere, conduct any fuel scooping/refining while hovering motionless or proceeding to the low port. (4 hours) This requires only a basic simi streamlined shape for stability, and a robust thruster based attitude control system in absence of control systems. (See Larry Niven's Drunkard's Walk for an example of a thruster based attitude control system used for atmospheric maneuvering.)
Even the lowly Air Raft can go to orbit and de orbit in this method, not requiring any streamlining beyond the windshield, just a lot of time. (Did you bring extra air bottles for your PLESS? No, then better turn around now.)

Only if you are entering atmosphere and are planning on retaining a large vector do I need the hypersonic level streamlining, typically this is a requirement for ships that lack modern creature comfort things like the artificial gravity and g compensation fields with all that entails. Many published adventures have a crippled starship heading into a planet with assurance of doom if the repairs are not made in time to advert the looming disaster. This railroading is not needed most rookie players are quite able to provide their own doom scenarios.

 

[kilemall]

I should mention my IMTU deflectors in this context.

Deflectors are essentially mini-repulsors that are considered part of the M-drive tonnage, and are mounted on the hull to deflect micrometeorites and at higher TLs, small rocks.

But at medium TLs the deflectors get strong enough to act as atmospheric shielding, and eventually they progress to acting as conformal lift and maneuver 'virtual surfaces'.

As such they can give streamlined bodies more lift and agility, and allow more reentry ability to partially streamlined hulls.

 

[aramis]

I should mention my IMTU deflectors in this context.

Deflectors are essentially mini-repulsors that are considered part of the M-drive tonnage, and are mounted on the hull to deflect micrometeorites and at higher TLs, small rocks.

That much is actually canonical. See Beltstrike, folder 1, page 2....

(Ships under power are not affected-part of the M-drive generates a low-power screen against radiation and meteorite impact- but a power faiiure during approach within about a million kilometers of the gas giant would be fatal.)​

 

[kilemall]

That much is actually canonical. See Beltstrike, folder 1, page 2....

(Ships under power are not affected-part of the M-drive generates a low-power screen against radiation and meteorite impact- but a power faiiure during approach within about a million kilometers of the gas giant would be fatal.)​

Ya, I didn't bring up the other part of deflectors which is low power deflection of charged particles (solar flares essentially), wasn't relevant to atmospheric reeentry, although on second thought could be used to create a plasma shield, turning that to account and being part of the conformal lift surface. Hmmm.

I'm a bit lost on the term canonical as applied to Traveller. I was under the no doubt self-induced impression that editions published under Miller's guidance were canonical and things like JG, FASA, GURPS and MgT were licensed but alternative.

Is MgT canonical? What constitutes canon vs. non-canon?

 

[aramis]

Ya, I didn't bring up the other part of deflectors which is low power deflection of charged particles (solar flares essentially), wasn't relevant to atmospheric reeentry, although on second thought could be used to create a plasma shield, turning that to account and being part of the conformal lift surface. Hmmm.

I'm a bit lost on the term canonical as applied to Traveller. I was under the no doubt self-induced impression that editions published under Miller's guidance were canonical and things like JG, FASA, GURPS and MgT were licensed but alternative.

Is MgT canonical? What constitutes canon vs. non-canon?

There are about 4 different kinds of canon...
1) OTU canon - this is generally "most recent edition" - except that MGT is NOT canon for the OTU, except for those products marked as for the Third Imperium. GT is canon for events prior to 1115, last I heard, but nothing from then on is.
2) Rules Canon for edition - each edition has a separate rules canon. The errata Don accumulates is the most current for each edition.
3) Technology Canon - Traveller is, at its most fundamental level, about technologies. The Jump Drive and the Maneuver Drive canon is "most Current FFE edition", and supersedes all prior as to what can and cannot be done with a specific drive in the context of the Traveller universe. This relates to OTU canon... but isn't quite the same. Many people's games use the technology but back port it to other editions and/or their own ATUs.
4) Canon for a specific ATU - there are several ATUs, and what is canon for them varies by their authors.

Note that Marc considers the "apochyrpha" materials to be informative, but not of need canonical; much of it was adopted as canon in part, and later published in canonical materials.

In general, newest edition trumps. T5.09 is the most current edition for the tech base, and explains a few things in new ways that illuminate other editions rules - all the way back to CT, in a few cases.

 

[SanDragon]

Lookit the pretties!

And I just put this here because I hate going to these polls expecting something new and all that happened was a voting.

 

[kilemall]

There are about 4 different kinds of canon...
1) OTU canon - this is generally "most recent edition" - except that MGT is NOT canon for the OTU, except for those products marked as for the Third Imperium. GT is canon for events prior to 1115, last I heard, but nothing from then on is.
2) Rules Canon for edition - each edition has a separate rules canon. The errata Don accumulates is the most current for each edition.
3) Technology Canon - Traveller is, at its most fundamental level, about technologies. The Jump Drive and the Maneuver Drive canon is "most Current FFE edition", and supersedes all prior as to what can and cannot be done with a specific drive in the context of the Traveller universe. This relates to OTU canon... but isn't quite the same. Many people's games use the technology but back port it to other editions and/or their own ATUs.
4) Canon for a specific ATU - there are several ATUs, and what is canon for them varies by their authors.

Note that Marc considers the "apochyrpha" materials to be informative, but not of need canonical; much of it was adopted as canon in part, and later published in canonical materials.

In general, newest edition trumps. T5.09 is the most current edition for the tech base, and explains a few things in new ways that illuminate other editions rules - all the way back to CT, in a few cases.

Thanks for the clarifications.

 

[aramis]

Thanks for the clarifications.

No problem.

Just beware history grogs like me - who tend to look at the oldest sources as original, and the intermediate ones as others' take upon the original...

 

[flykiller]

for those who answered "other", an explication might be helpful.

 

[atpollard]

for those who answered "other", an explication might be helpful.

yeah, what he said.

... inquiring minds want to know.

 

[mike wightman]

I've just voted other so I suppose I must explain why.

Many of the ships IMTU are space only, so don't need to be streamlined at all.

Streamlining is for atmospheric performance - partial streamlining, lifting body, airframe in that order.

Null grav modules mean even unstreamlined ships can descend to a planets surface if needs must.

 

[whartung]

Null grav modules mean even unstreamlined ships can descend to a planets surface if needs must.

Even with null grav modules, the ship may well need to be able to sustain winds of up to 100 MPH, or even more depending on the atmosphere of the planet you're landing on. (Or if you happened to have had it parked in the Caribbean this year...)

 

[ShawnDriscoll]

In my sessions, streamlined ships burn up in atmospheres just as much as non-streamlined ships will.

 

[nobby-w]

So I did a historical (i.e. pre-3I 'verse) some time ago and did some 'ships of the 1st and 2nd Imperium.' - really common designs to fit the niches of common small ships adventurers might use or encounter. I also put my geek hat on (OK all my hats are geek hats, although I don't own a fedora) and designed the look and feel with a bit of thought to the engineering and practicalities of the design. Some of the designs I came up with included:

• Small transport and merchant ships using a lifting body design. These included a courier/transport (i.e. something to use in the same sort of roles as a Type-S), a couple of classes of 200-600t streamlined merchants and a large-ish streamlined tailstander merchant.
• There were spaceplane shaped pinnaces and shuttles between 50-200 tons, and some smaller streamlined craft. I re-imagined something equivalent to a cutter as something like the Aliens dropship but with a more lifting body shape.
• I also did some unstreamlined designs. I never really took fighters down to something as small as an X-wing. Something more like 60-80 tons and capable of carrying a decent weapons payload was more my scene.

 

[Timerover51]

I use a small ship universe and with my background in wet naval architecture, I lean towards enlarged submarine designs and flattened cylinders that I know will handle pressure differentials. Streamlining is pretty much automatic, as the ships are accelerating while lifting from a planet. For very large ships, I tend towards somewhat streamlined, but maybe not enough for Standard and Dense atmospheres. The problem is the unsupported length to bean to hull depth ratio.

 

[Carlobrand]

In my sessions, streamlined ships burn up in atmospheres just as much as non-streamlined ships will.

Why? With a lower coefficient of friction, they ought to have a higher chance of making impact than the blocks - which is admittedly no better as a way to end a session than burning up, but still.

... The problem is the unsupported length to bean to hull depth ratio.

What he said.

I go with "other" because the factors that make a ship able to land don't really have a lot to do with streamlining. Ultimately what makes the difference is 1) can the ship handle ~1G along the axis on which it intends to rest without breaking its back, and 2) can the ship get from ground to orbit on that axis without toppling over and presenting an axis that can't handle the load.

I liked the SOM view of the drive for the way it allowed for application of G lateral to the drive. You could fly in, presumably gain some lift by "kiting" - angling so the air hit your belly at an angle - and transfer thrust to the lateral as you decelerate until you come to a brief hovering halt to land your scout or free trader, then take off by applying Gs to bring you to a vertical launch position and launch straight up. However, it effectively means all the stress centers at the drive: it's like a giant hand holding the ship from its tail end when it hovers laterally. Nautical ships don't handle being held up by only one end well (reference Titanic) and Traveller spacecraft might have the same issue if, as Timerover mentions, they are not of dimensions that permit it and/or not reinforced for it.

Streamlined ships by design are capable of landing, therefore capable of taking stress perpendicular to the axis of flight and, presumably, with a frame and landing gear that distribute stress in a way the hull can handle. MT was nice for that 'cause you could "streamline" a rectangular solid if you wanted to, which meant you could assume it had a frame and landing gear up to the job. The "partially streamlined" Azhanti High Lightning handles thrust along its axis and can handle flight through at least the thin levels of atmosphere traveled for fuel skimming. It does not appear to be able to handle the buffeting associated with flight through a standard atmosphere, or perhaps it can but is likely to break at a weak point if it tries to suspend itself in a lateral hover using the drives. A Lightning class cruiser might try to land tail first, but a stiff wind could shove it off axis and cause a disaster. You'd need tugs to help guide it down so it could preserve its axis against horizontal forces, and probably some sort of slip designed to receive and support it while it was on the ground.

Shapes like spheres could come down on their tails. Other ships would need something like a mobile drydock - flydock? - that could go up, dock with them, then bring them down while giving them the support they needed to keep from falling apart.