WIP Discussion (Part 1!)

[Karst45]

Would you really lose atmosphere if you were to pump all the air, with compressor, into air tank?

[javcs]

Would you really lose atmosphere if you were to pump all the air, with compressor, into air tank?

If you could actually pump everything out and behind adequate seals, no.
However, you can't do so effectively. One can get most of the atmosphere out, but not everything.

[fredgiblet]

Would you really lose atmosphere if you were to pump all the air, with compressor, into air tank?

You could, theoretically, suck almost all of the air out. However it would be difficult to suck out ALL of it, meaning there would always be a loss. Additionally doing so would require a fair amount of time, not a problem when you're just out on a pleasure cruise but in combat operations the time it would take to cycle a hangar of any significant size would be crippling.

[Absalom]

How can having "only" three types be "excessive?" Excessive means "more than is necessary."

Especially when it comes to small craft, I'm sure there are hundreds of varieties in use. I've listed the major types that make sense to me, which is already overkill in terms of the needs of the story.

By being excessively minimalist (the "excessive" applies to the "only", not to the "3": having that strong of a constraint on the variety of small vessels is excessive, even if you apply the constraint to basic designs instead of design variants), I was depending on context. I was arguing that 3 types of small craft is far too few (at one point, I even mentioned the possibility of having 3 types of standard utility shuttles if you're in the middle of replacing a design).

[discord]

actually, you want some kind of 'launch system' it does not however need to be very powerful but you want the small craft well away from carrier before it lights up the drives, anything that can accelerate probably a few dozen metric tons or so at 40g is a high energy event, read explosive.

i do not want that exhaust ruining MY paintjob.

[GeoModder]

Has anyone thought of the effects on a shuttle/fighter craft when it clears the hangar hatch while the Tempest is under acceleration?
I have the impression that a "scratched paintjob" is the least of the craft's concerns under those circumstances.

[Karst45]

Would you really lose atmosphere if you were to pump all the air, with compressor, into air tank?

You could, theoretically, suck almost all of the air out. However it would be difficult to suck out ALL of it, meaning there would always be a loss. Additionally doing so would require a fair amount of time, not a problem when you're just out on a pleasure cruise but in combat operations the time it would take to cycle a hangar of any significant size would be crippling.

well considering that a combustion engine (let say 2 Liter engine) can "consume" about 18l per rotation (average atmospheric compression ratio 9:1 x liter) and can run at average of 2500 RPM (for ease of calculation normally is around 2750)

So it consume 45000 liter per minute of air. Surely to empty a room it would be quite fast. And it a normal engine under normal use. Vacuum pump of that technology erra could be that efficient or even more.

As Florence once said: in space if there one thing you dont want to loose it atmosphere!

[fredgiblet]

That's...not what the compression ratio is. The compression ratio is how compressed the air is after the piston goes up. So that engine would take roughly 2l worth of fuel-air mixture and compress it to .22l.

Also as the pressure drops in the hangar the vacuum pumps would get less and less efficient.

[bunnyboy]

Little math. 3 m x 3 m x 5 m room has ordinary athmospere.
You have pump, which take 20l air per rotation with 3000 RPM.

So in each rotation, it takes 1/1500 of air. Then, after 1 minute there is left (1-1/1500)^3000 of air, which is 13,5%. That means you lose over 6000 liter of air, if you open the hatch now.

Also, the pressure will push the door on 135 kg/m^2, so it may not be the easy or safe to open it.

[Arioch]

Has anyone thought of the effects on a shuttle/fighter craft when it clears the hangar hatch while the Tempest is under acceleration? I have the impression that a "scratched paintjob" is the least of the craft's concerns under those circumstances.

Right, which is why launching or recovering small craft is something that should be done only under minimal (or, ideally zero) acceleration.

[Absalom]

I'm imagining coordinated micro-second burns for a short period of time.

For launches:
1) The bay's inertial control & gravity are turned off (may happen as part of 2),
2) The fighter/whatever uses maneuvering thrusters (or whatever other option) to leave the bay (probably the launching ship will make a quick burn at this point to accelerate the process),
3) The fighter orients it's thrust axis ~90 degrees to the launching ship's thrust axis (so that the thrust won't approach the launching ship),
4) Both fighter & launching ship make brief burns of their main engines (timed such that neither will encounter exhaust),
5) After a sufficient (and for the fighter, presumably brief) coasting period both reorient themselves so that they can restart their main engines unimpeded.

For retrievals:
1) Bay inertial control & gravity are turned off,
2) Both fighter & retrieval ship accelerate towards roughly the same point for a collision course (this is presumably a low-velocity operation, performed by vessels already flying in tight formation),
3) At predetermined points, both start decelerating,
4) The retrieval ship stops it's deceleration early, so that it 'overshoots',
5) The fighter stops it's decelerating burn,
6) Fighter passes close enough to the retrieval ship's engines that they are no longer in it's exhaust cone, it completes it's deceleration, afterwards passing into the retrieval ship's bay,
7) The retrieval ship completes it's deceleration, the fighter is automatically restrained (probably by restoring inertial control, but maybe something else).

Both would have very delicate timing & thus be completely automated, but I expect that they'll be standard during combat operations to minimize vulnerability to enemy fire. Personally, if I were designing a combat ship I'd try using either elevators or a small 'ring bay' (ala BSG's launch nacelles) for launches & retrievals (both allow wave-offs & some limited maneuvering for both vessels during both operations).

[Michael]

If im understanding what Arioch has said right, then the hanger is an extremely haphazard place, i don't think it would be safe, or possible, to do what you're saying for the retrievals, especially if you need to get out of the combat zone quickly, i would imagine the equivalent of a....(screw it im gonna say it) Tractor beam, would be employed once the fighter is close enough and then dragged into the hanger bay its self, since the two vessels were moving at the same speed (or is it velocity? i can never remember) reactionary thrusters can be used to land in an available space of the hangar....would that work?

[junk]

My idea can be used something akin to that, in that the fighter dock could easily be left zero atmosphere when maintenance is not required, but the issue that really applies is offloading transports.
Do you do so without atmosphere and be forced to wear comparitively immobile spacesuits for bodily protection, having to be careful not to damage the suit and such, or do you go for a plan B: Full atmosphere with less than 10% losses of gas thanks to evacuating as much as you could, and then utilising two chambers of similar size (extract 80-90%, open section two (halving the pressure), move through the door, close door, open access to space (losing half of your remaining 10-5% of the original)

After all, storing tons of air is not difficult, many gas cylinders hold a few hundred times their own volume. The main issue is the energy and time cost required to evacuate the gasses, as pumping gasses is never particularly fast nor efficient.

Keep in mind, that loroi pressure suits seem to take up a lot less space. Plus the pilots are always going to wear them anyway. So depressurisation (and lower risk of explosion) is usefull.

[Michael]

My idea can be used something akin to that, in that the fighter dock could easily be left zero atmosphere when maintenance is not required, but the issue that really applies is offloading transports.
Do you do so without atmosphere and be forced to wear comparitively immobile spacesuits for bodily protection, having to be careful not to damage the suit and such, or do you go for a plan B: Full atmosphere with less than 10% losses of gas thanks to evacuating as much as you could, and then utilising two chambers of similar size (extract 80-90%, open section two (halving the pressure), move through the door, close door, open access to space (losing half of your remaining 10-5% of the original)

After all, storing tons of air is not difficult, many gas cylinders hold a few hundred times their own volume. The main issue is the energy and time cost required to evacuate the gasses, as pumping gasses is never particularly fast nor efficient.

Keep in mind, that loroi pressure suits seem to take up a lot less space. Plus the pilots are always going to wear them anyway. So depressurisation (and lower risk of explosion) is usefull.

forgot about that

[junk]

My idea can be used something akin to that, in that the fighter dock could easily be left zero atmosphere when maintenance is not required, but the issue that really applies is offloading transports.
Do you do so without atmosphere and be forced to wear comparitively immobile spacesuits for bodily protection, having to be careful not to damage the suit and such, or do you go for a plan B: Full atmosphere with less than 10% losses of gas thanks to evacuating as much as you could, and then utilising two chambers of similar size (extract 80-90%, open section two (halving the pressure), move through the door, close door, open access to space (losing half of your remaining 10-5% of the original)

After all, storing tons of air is not difficult, many gas cylinders hold a few hundred times their own volume. The main issue is the energy and time cost required to evacuate the gasses, as pumping gasses is never particularly fast nor efficient.

Keep in mind, that loroi pressure suits seem to take up a lot less space. Plus the pilots are always going to wear them anyway. So depressurisation (and lower risk of explosion) is usefull.

forgot about that

It's not only that. Keep in mind that a hangar will be usually a fairly large area. So harder to cordon off with bulkheads to create smaller compartments. So by having no atmosphere in there reduces a risk of decompression changing pressure in a fairly large segment of the ship. It also keeps the crewmembers safer.

Means explosions overall have less of an effect inside of this larger area. Denies fires, keeps toxic fumes at bay and last but not least makes it a lot easier to manage and keep the ships clean. Also air tends to be fairly corrosive. So if you can keep it away from your machines, you have no reason not to do it.

[Fotiadis_110]

Three things:
First: the ability for ANYTHING to pump gas is limited by the pressure of the gas it is trying to draw in, thus if you start at 1 atm, the cylinder you are drawing the gas into (say an engine) can at best have 1 atm of gas within it, the next cycle it will have less gas available to draw out and thus the efficency drops.
Getting a 'perfect vacuum' is an ideal environment for physics experiments, however it is also said that nature abhors a vacuum, and I should point out that EVERYTHING has a partial pressure.
If you live in a skyscraper made of steel, you are breathing in iron vapours, live in a wooden house? you are breathing wood vapour.

Second:
Magnetic clamps are less an idea regarding catapults, than a versatile and adaptable means for recovering and deploying small craft without such ships bouncing around in their bays/deployment tunnels like beans in an empty tin can. Think the aircraft carriers elevators with the landing wires incorporated into the same design.

Third:
When loading and unloading various materials, it is typically easier and safer to work inside a pressurised environment, which was the basis of my idea for the pressurised hanger system.
I'll admit having your fighters in vacuum environment for normal combat deployment would be beneficial, and Arioch's suggestion would provide a sensible means to maintain those craft without needing to enter a pressurised hanger space, so I applaud it!
Still I am not a big fan of 'adaptable tunnel' connections between starships, you really need seriously strong connections to make an easy to use system, and even then, orientation would have to be matched to prevent awkward bits where the emperor might have to crawl through a down/up tunnel between two starships to get off her personal yacht onto her primary warship!

[bunnyboy]

if it works, it is not stupid.
If it is practical, it is not awkward.

[Fotiadis_110]

There are devices created to clean the inside of bottles, called bottle brushes.
For the life of me I consider them one of the most practical but most awkward to actually use items I have ever had to utilise, in particular I find them unbelievably cumbersome when trying to clean bottles with narrow mouths, so much so in fact, I typically dispose of unwanted water bottles rather than go through the difficult effort to clean out the inside properly.

Spending a good half hour trying to get the space shuttle to line up with the connector to the international space station is awkward, yet the link itself is based around being the most practical design that can be adapted to suit a wide variety of other space craft, with the same overall frustration.

I also know of some gate designs which are very easy to use, in no way are the awkward, however the hours you would spend trying to make one of these things work properly makes them at best horribly impractical in terms of making and design, but they are somewhat elegant when you actually utilise them.

Incidentally I have seen a better bottle cleaning product, but I doubt I know anyone willing to fork out 120 dollars for a high pressure bottle cleaning system. (for domestic use anyway)

[Absalom]

Connecting the ramps shouldn't be all that difficult. You have your robotic ramp and a small shuttle, which are both fastened to the same object. The ramp is told to connect to the standard connection point on the shuttle, which it does. At worst, when the end of the ramp nears it's target, the action might transfer to a second stage that handles detailed movements. We're talking about (at the worst) car factory positioning technology here, WE could do this with the proper equipment. It doesn't require a new connector technology, the trick is entirely in the 'corridor' that connects the lock with the main body of the host ship. If this is too complex to work, then so are things like the Canadarm. The only passingly difficult thing to deal with is maintaining the air-tightness of the joints, which is a challenge, but probably something that WE have the materials for. Connecting ramps are easy, efficient, and quick, look at the average airplane passenger ramp for a low-tech prototype.

[HanEmpire]

The new character is cuuuuute.