Reaction Control Systems?

[Giovanni Blasini]

Refresh my memory, have we ever gotten clear descriptions of the reaction control systems on fighters, DropShips and WarShips?

[Weirdo]

I believe the newer/better maintained DropShips use a system of conduits and magnetics to reroute exhaust from the main drives to various thrusters around the ship. I remember reading this, but not where I found it. I'll bet WarShips work the same way.

DropShips that aren't in as good condition have to make do with chemical rocket thrusters, though I imagine still far more powerful than what we have today.

No clue for fighters, though I'm leaning towards a mixture of chemical thrusters and vectoring the main drives.

[Chinless]

Refresh my memory, have we ever gotten clear descriptions of the reaction control systems on fighters, DropShips and WarShips?

Hmm, lets see. TechManual p176 has the following for DropShips - "While the main engines work by expelling the byproduct of the fusion reaction through the ship’s aft or underside to produce thrust, dozens of much smaller exhaust nozzles over the outer hull also expel superheated plasma so the pilot can adjust the heading and altitude."

"Civvie Droppers and less sophisticated Succession War-era ships—which dropped these expensive and maintenance-intensive plasma nozzles—have learned this lesson the hard way. This is why so many to date have been retrofitted with a series of chemical propellant-based thrust motors to make up for their lack of foresight.

Looking back further, AeroTech 2 Revised p99 adds to this a little - "On the best-designed DropShips, numerous small exhaust nozzles also dot the crafts’ hull. The pilot uses these to alter the vessel’s heading and altitude, though many craft use hardier but inefficient chemical thrusters in place of the fragile and expensive fusion jets. A magnetic containment system channels the main plasma exhaust to the drives and out the exhaust nozzles, allowing the pilot to steer the vessel and protecting the crew from harmful radiation."

AT2R p105 has the following for fighters - "Clusters of small chemical thrusters enable the fighter to maneuver in a vacuum."

There doesn't appear to be anything mentioned separately for WarShips though.

Chris

[idea weenie]

For just spinning around their center of mass, flywheels would work nicely to let Dropships maneuver.  Not sure how effective it would be for fighters or small craft. 

[Empyrus]

Flywheels work only as long as they got spin. They're fine for adjusting space station direction or spinning grav-decks up or down, but not really good for something that may need to maneuver a lot and in unpredictable manner.

[idea weenie]

Flywheels work only as long as they got spin. They're fine for adjusting space station direction or spinning grav-decks up or down, but not really good for something that may need to maneuver a lot and in unpredictable manner.

???  Thought that was what I meant?

Flywheels would be spun up and down as needed, rotating the craft around its center of mass.  After that the main engine is pointing in a new direction, and you thrust to give yourself a new vector.  This allows you to have a single 4G engine in one location (and build the ship skyscraper style), instead of trying to put four 1G engines at optimal points around the hull, and having to blare acceleration warnings whenever you need to dodge.

The nice part about flywheels is that you don't use reaction mass to change heading; so depending on the reaction speed of flywheels vs thrusters, you may prefer one over the other.  The lack of reaction mass might be useful for merchants, as one less bill to worry about.

[Giovanni Blasini]

But will SAS systems work with reaction wheels alone, or will you need to use moar boosters...er, RCS thrusters, too?

(Why yes, I have been playing a lot of Kerbal Space Program)

[idea weenie]

But will SAS systems work with reaction wheels alone, or will you need to use moar boosters...er, RCS thrusters, too?

(Why yes, I have been playing a lot of Kerbal Space Program)

Assuming you mean Space Activity System, and not any of the other possible abbreviations for SAS, it will work.  You spin the wheel in one direction, and you rotate the other direction.  The rate of your rotation is proportional to the speed that the flywheel turns, and the ratio of the flywheel's mass to yours.  For example, if you have a flywheel that is 10% your mass, and you spin it at 5 rpm, you will spin in the other direction by .5 rpm.

As to how massive the flywheel needs to be and the power needed to spin it up, that needs more math.

Cray?