A Solar Brigantine?

jedion357's picture
jedion357
October 4, 2013 - 7:55am
Brigantines were brought up in another thread discussing new classes of ships for the game. They were a ship with a large crew and sails and oars and could both sail or row in the calm. It got me thinking about how you would adapt that to SF since the stand out feature was two methods of propulsion: what about a solar sail combined with one of the other methods in KHs. With chemical engines it would be a lot of free propulsion in the inner system and could make a system ship just that much more economical. With atomic (even ion) you 'd have interstellar capability but would be able to shut down the engine and maneuver by sail, presumably for the purpose of stealth I guess.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!
Comments:

Jaxon's picture
Jaxon
October 4, 2013 - 8:26am
solar sail in space...like a solar panel on a satelite?

jedion357's picture
jedion357
October 4, 2013 - 8:32am
No, its a method of propulsion using solar wind (light and or radiation) which pushes on the sail and provides propulsion for a craft. It works best in the inner system.google it, id provide a link but im driving.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

TerlObar's picture
TerlObar
October 4, 2013 - 9:14am
Basically you use radiation pressure from the start against very thin light-weight but strong sails, hundreds to thousands of square kilometers in size.  The physics is pretty simple, it's the materials science of making the sails that makes it tough.  And you can only go outware (and possibly quarter against the "wind").  Going in toward the star is basically not possible.
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My blog - Expanding Frontier
Webmaster - The Star Frontiers Network & this site
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iggy's picture
iggy
October 4, 2013 - 9:36am
Is it really true that you can only solar sail away from a star?  Or is there a lack of experience here and we may learn that just like sailing in wind, a sail could be angled to adjust the pressures of the solar radiation on either side of the sail creating a differential thus creating thrust in toward the star.
-iggy

jedion357's picture
jedion357
October 4, 2013 - 10:04am
There is more than one theorized method of using the solar wind for propulsion and perhaps this area could use some looking into.

Solar Sails are slow and not something you'd use in combat- even a near miss by something exploding would shred the sail.

for game purposes it would be something that you would use on a campaign level- for instance a stealth ship uses a solar sail to decel into the inner system because the risk of detection via energy sensors is to great. It gets into the inner system and does its passive scouting and flies out the other side on the sail. When its far enough out it folds the sail and ignites the atomic drive and reports home.

For a low budget freight hauler the savings in chemical fuel may make a family owned ship economical and even prosperous in the early days of the Frontier.

Also in a binary or even trinary system you might have situation where a solar sail might be highly effective being able to use more than one source of solar wind.

The downside is that should combat be neccessary you'd have to jettison or fold the sail and rely on the other engine which pretty much means you wont bother with combat.

I can see two uses- short haul inner system- system ships and specialized military version designed for  specific missions ie stealth scouting of an enemy held system or insertion of a special forces team into the enemy's back field.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

TerlObar's picture
TerlObar
October 4, 2013 - 2:56pm
There's definitely a lack of experience Smile

The basic principle of the sail is that you bounce the light of the star off it and the momentum of the photons is imparted to the object.  Since the photons only move radially outward from the star you can't move directly "upstream".  It should be able to tack and quarter the "wind" and move in most directions, just not directly in.  It's probably possible to move "inward" at some angle to the star but with less propulsion.

I'm not sure the stealth mode would really work.  To have any effect on a ship sized object, the sails have to be huge, comparable to the size of moons in some cases.  That's going to make a very bright object.  It might go unnoticed but maybe not.
Ad Astra Per Ardua!
My blog - Expanding Frontier
Webmaster - The Star Frontiers Network & this site
Founding Editor - The Frontier Explorer Magazine
Managing Editor - The Star Frontiersman Magazine

jedion357's picture
jedion357
October 4, 2013 - 4:11pm
Magnetic Sail working with solar plasma
http://en.wikipedia.org/wiki/Magnetic_sail

Solar Sail with a actual sail:
http://en.wikipedia.org/wiki/Solar_sail

We should consider spit balling an article together as there is a possible launch of a solar sail craft in 2014 to deliver a payload to the L1 point (Sunjammer) it would be timely to get it together for early 2014 publication IMO.

I think we can hand wave the materials science advances like the ion and atomic engines and work up some stats/descriptions- for example it would be plausible that solar sail craft are more fragile then std. star ship hulls so minus X number of HP per hull size when making a solar sail ship.

combat rule that the first weapon hit or near miss of certain weapons trashes the sail.

and other details we consider vallid as guess work for this.

EDIT
Electric Sail
http://en.wikipedia.org/wiki/Electric_sail
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

Malcadon's picture
Malcadon
October 4, 2013 - 4:45pm
Did someone say sails... IN SPACE!!!


iggy's picture
iggy
October 4, 2013 - 6:01pm
Tacking and quartering is what I was anticipating.  Age old sailing techniques with an SF twist.  I would expect they would also take advantage of gravity assist when available.  However we should think of this as the slow boat version of teavel and freight where the engine craft are likened to air travel and freight. 
-iggy

jedion357's picture
jedion357
October 5, 2013 - 2:30am
The magnetic solar sail could potentially lift off from the magnetic pole of a planet and use the magnetic field of a planet with some loss of maeuverability. There is some real materials science to over come with this method of propulsion be we can assume that one of the mythical alloys from Crash on Volturnus or Federanium from Zebs Guilde is key in this.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

Jaxon's picture
Jaxon
October 5, 2013 - 9:22am
This may contribute:

It reminds me of BattleTech. The Jimpships used Fuchida-Kearny drives to warp up to 30 light years away. When they arrived at a Zenith or Nadir jump point, they unfurled the sails and started to recharge. The time to recharge depended on the star - yellow, orange, etc. The time was measure in hours from 60 or 100 hours up to...I think something like 400. When it was recharged, the sail was rolled up and put in the Jumpship - next planet. The was the Ares Convention that, due to the rarity of Jumpships and lost technology, made it illegal to fire on a Jumpship.

This type of craft may also be good for exploration.

just food for thought.