The Night's Dawn trilogy is one of my favourite novels. I took some inspiration from the concept of using autonomous combat drones for space combat. My drones are using a more conventional technology that is based on concepts you have presented on your website.
The Night's Dawn trilogy is one of my favourite novels. I took some inspiration from the concept of using autonomous combat drones for space combat. My drones are using a more conventional technology that is based on concepts you have presented on your website.
Thanks! I'm glad that my site was of assistance.
Your frigate will be quite an adversary, surrounded by its combat drones. Sort of like a space going hornet's nest.
very neat, i love the little utilitarian looking drone launchers, how they're clustered around the hull and the hinged caps. I think i've just noticed where you've hidden the RCS, they're absolutely tiny, looks like it would take a very long time to make a turn (and i realise its not meant for extreme manuvering), and translation performance would be very poor i'd imagine. Also visually they're not much bigger than some of the rivet/bolt holes or whatever in the panels. I think the nozzles should be at least twice the size, so they look more distinct from the other features, and have more of them.
... I think i've just noticed where you've hidden the RCS, they're absolutely tiny, looks like it would take a very long time to make a turn (and i realise its not meant for extreme manuvering), and translation performance would be very poor i'd imagine. Also visually they're not much bigger than some of the rivet/bolt holes or whatever in the panels. I think the nozzles should be at least twice the size, so they look more distinct from the other features, and have more of them.
I think i've just noticed where you've hidden the RCS, they're absolutely tiny, looks like it would take a very long time to make a turn (and i realise its not meant for extreme manuvering), and translation performance would be very poor i'd imagine. Also visually they're not much bigger than some of the rivet/bolt holes or whatever in the panels. I think the nozzles should be at least twice the size, so they look more distinct from the other features, and have more of them.
Of course from a physics standpoint, whether the RCS nozzles are too small or not depends upon the scale of the picture. If the drones are the size of, say, a school bus, then the nozzles might be big enough.
Of course from a physics standpoint, whether the RCS nozzles are too small or not depends upon the scale of the picture. If the drones are the size of, say, a school bus, then the nozzles might be big enough.
The diameter of the drone launcher tubes is about 2 m.
The diameter of the drone launcher tubes is about 2 m.
Well, measuring crudely my back-of-the-envelope says that if the drones are about 2 meters in diameter, then the RCS jets are at a minimum of about 0.4 meters in diameter, or about one and one-third feet. Which are pretty good sized jets.
I'm not sure how to relate jet diameter with thrust, but I will note that the Saturn V third stage had a single J-2 engine with a bell diameter of 6.8 feet. That was a thruster, not a RCS.
Well, measuring crudely my back-of-the-envelope says that if the drones are about 2 meters in diameter, then the RCS jets are at a minimum of about 0.4 meters in diameter, or about one and one-third feet. Which are pretty good sized jets.
I'm not sure how to relate jet diameter with thrust, but I will note that the Saturn V third stage had a single J-2 engine with a bell diameter of 6.8 feet. That was a thruster, not a RCS.
It's not the size of the thruster, but the force it is applying to to the ship. A large thruster that can apply a force of 1 newton is going to move the ship as fast as a smaller thruster that can apply the same force.
Well, measuring crudely my back-of-the-envelope says that if the drones are about 2 meters in diameter, then the RCS jets are at a minimum of about 0.4 meters in diameter, or about one and one-third feet. Which are pretty good sized jets.
I'm not sure how to relate jet diameter with thrust, but I will note that the Saturn V third stage had a single J-2 engine with a bell diameter of 6.8 feet. That was a thruster, not a RCS.
Whether the thrust of the RCS is sufficient or not depends on the ships total mass. I still haven't decided that detail. But even with a sophisticated technology that allows advanced light construction the ship will certainly have a mass exceeding 10.000 tons (that includes the reaction mass for the engines). As a military vessel the frigate should have an adequate maneuverability. I think I will try a design with a few more RCS systems just for comparison.
I'm pretty sure salsa is right. As long as the materials of the system are sufficiently durable I don't see why you couldn't pump out as much thrust as is needed. It will only be limited by how much pressure the system can take before it starts getting damaged. So I would imagine the rcs wouldn't need to be very large in the future where very dense materials would be available.
i'm sure they could be small yet extremely powerful, not seeking to get into a technical debate (though i'd still say too small) my point mainly is that it would be nice to be able to see them;)
i'm sure they could be small yet extremely powerful, not seeking to get into a technical debate (though i'd still say too small) my point mainly is that it would be nice to be able to see them;)
I agree that a few more thruster would improve the visual appearance of the RCS systems. Redundancy would be the other aspect...
After going through the topic for first-to-last page progress comparison, I suddenly realized I hadn't commented on it yet.
Anyway I can only repeat has been said - very nice and believable design!
I particularly like subtlety of the panel style and the drone launch tubes. Almost can't wait for textures
It's not the size of the thruster, but the force it is applying to to the ship. A large thruster that can apply a force of 1 newton is going to move the ship as fast as a smaller thruster that can apply the same force.
I'm aware of that, thank you. If the thrusters are chemical (i.e., non-nuclear), that puts a (pretty pathetic) upper limit on the exhaust velocity of about 4,500 meters per second. Now, thrust is:
F = mDot * Ve
where:
F = thrust in newtons
mDot = mass flow of propellant in kilgrams per second
Ve = exhaust velocity in meters per second
So the only way to increase the thrust of a chemical rocket is by increasing the propellant mass flow. Which means increasing the size of the exhaust nozzle.
Since there was a question of whether the thrusters were large enough, I was trying to determine if the size of the exhaust nozzle was large enough to provide an adequate amount of thrust.
I'm pretty sure salsa is right. As long as the materials of the system are sufficiently durable I don't see why you couldn't pump out as much thrust as is needed. It will only be limited by how much pressure the system can take before it starts getting damaged. So I would imagine the rcs wouldn't need to be very large in the future where very dense materials would be available.
Well, sort of.
The trouble is that there is a limit on the thrust, if you are using chemical thrusters.
There is a much higher limit if you are using nuclear thrusters, but I'm not sure Alnair wants his attitude jets spouting radioactive atomic fire.
A real rocket man would. Nay, a real MAN would! Project Pluto
:devil:
Oh, lordy, not the infamous Project Pluto. Blasted thing didn't need a warhead, all it had to do was travel to the target city and fly around it for a while.
You see, it was a nuclear powered cruise missile, with no radiation shielding. The problem was disposing of the accursed thing after it had finished its mission, I understand that ditching it into the Marianas Trench was discussed.
The problem was disposing of the accursed thing after it had finished its mission, I understand that ditching it into the Marianas Trench was discussed.
Oh ya because that's just what we need tossing some radiation into an area that might hold some of the biggest and meanest creatures on the planet. GODZILLA MUCH?!?
Posts
The Night's Dawn trilogy is one of my favourite novels. I took some inspiration from the concept of using autonomous combat drones for space combat.
The drones are currently under heavy development but close ups will follow soon...
Your frigate will be quite an adversary, surrounded by its combat drones. Sort of like a space going hornet's nest.
That was the idea.
Good point! Will think about that!
The diameter of the drone launcher tubes is about 2 m.
I'm not sure how to relate jet diameter with thrust, but I will note that the Saturn V third stage had a single J-2 engine with a bell diameter of 6.8 feet. That was a thruster, not a RCS.
It's not the size of the thruster, but the force it is applying to to the ship. A large thruster that can apply a force of 1 newton is going to move the ship as fast as a smaller thruster that can apply the same force.
Whether the thrust of the RCS is sufficient or not depends on the ships total mass. I still haven't decided that detail. But even with a sophisticated technology that allows advanced light construction the ship will certainly have a mass exceeding 10.000 tons (that includes the reaction mass for the engines). As a military vessel the frigate should have an adequate maneuverability. I think I will try a design with a few more RCS systems just for comparison.
I agree that a few more thruster would improve the visual appearance of the RCS systems. Redundancy would be the other aspect...
Anyway I can only repeat has been said - very nice and believable design!
I particularly like subtlety of the panel style and the drone launch tubes. Almost can't wait for textures
F = mDot * Ve
where:
F = thrust in newtons
mDot = mass flow of propellant in kilgrams per second
Ve = exhaust velocity in meters per second
So the only way to increase the thrust of a chemical rocket is by increasing the propellant mass flow. Which means increasing the size of the exhaust nozzle.
Since there was a question of whether the thrusters were large enough, I was trying to determine if the size of the exhaust nozzle was large enough to provide an adequate amount of thrust.
The trouble is that there is a limit on the thrust, if you are using chemical thrusters.
There is a much higher limit if you are using nuclear thrusters, but I'm not sure Alnair wants his attitude jets spouting radioactive atomic fire.
Awww. but it's so much cooler when they do that.
Project Pluto
:devil:
Nuclear maneuvering thrusters, Project Orion style! How about that?
You see, it was a nuclear powered cruise missile, with no radiation shielding. The problem was disposing of the accursed thing after it had finished its mission, I understand that ditching it into the Marianas Trench was discussed.
Oh no, There goes TOKYO!
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