shynung

Go one step better: have the drones instead carry a nuclear warhead designed to work as bomb-pumped lasers.

Most if it, yes. There's bound to be a few sensor sats overseeing important areas that happen to have some sort of CIWS installed.

People of the past centuries used to speculate about travelling to the Moon and Mars using rockets, something we can do today with some effort. It's not a stretch for us to speculate high-tech futuristic sensors that can see what we can't see today, using mechanisms we haven't figured out yet.

Yep. Disguising a warship as an asteroid is too risky. As a freighter ship, on the other hand... Though, hiding weapon systems might be a rather complicated task by itself. A freighter ship carrying a particle cannon would be pretty suspicious.

I think a space warship would have two sets of engines; one for regular orbit-to-orbit travel, and another for evading projectiles, similar to afterburners on atmospheric fighter jets.

Surely you're not working on all of them at once?

Alright, then. What's your next planned topic, if I may ask?

I can't do video edits, sorry. Maybe SRG is still around? I'd ask him.

I could help with research and data gathering, maybe grab a few fancy pics or diagrams, but not much else.

I'd say accompany the speech with more pics. Relevant ones, not just random gameplay, kind of like how Scott Manley does his science videos.

Being a Canadian. K^2.

Yes, I'd need to. What I'm saying is that the engine needs to generate enough energy to offset the combined drag from stopping the particles relative to the ship, and collecting the particles toward the ship. Assuming that the only propellant comes from the collected particles, mass flow is essentially constant; the energy spent by the reactor goes toward boosting engine exhaust velocity. That is 3,000 kilometer/second. Dividing by 9.81 (standard gravity, which is what I assume you wanted me to do) will get me 306 kiloseconds, which is equal to 306,000 seconds. I don't see where I'm wrong. For comparison, SpaceX Merlin engine have a 3.05 km/s (3050 m/s) exhaust velocity. This isn't about the ion engine yet. This is the amount of power being fed to said ion engine. Basically, the ion engine needs to be fed more than 22.5 terawatts/second of electrical energy in order to impart enough thrust to offset the drag from the scoop.

A bit. High thrust is more of a handy capability than a needed feature; it's useful in certain circumstances. You didn't tell me we're using a shuttle for that, so I assume the the ship simply lands on it tail-down. It's not that much of a stretch, though; Phobos and Deimos surface gravity is very small.

Military purposes. Dodging missiles would require a lot of thrust. Also, moderately high thrust enable landing on low-gravity moons. Phobos and Deimos looks like nice places to visit. Ayup. At least Zubrin's rocket doesn't need finicky reactors, like these nuclear thermals and nuclear VASIMR. Most of the reaction happens just outside the nozzle. Much easier to control, too; just fuel input valves, and no such things as control rods. It works almost like a hypergolic rocket. So are 1 kW/kg nuclear reactors. We shouldn't talk about them too.

But the thrust is... close to negligible. Gas-core nuclear thermal rockets can get 1500 secs, with decent thrust. Also, nuclear pulse rocket. And nuclear salt water rocket. They can get big specific impulses too, but with much more thrust to bear. One must. Because without radiators, reactors are useless. Nuclear thermal rockets happen to not need a radiator because it doesn't convert thermal energy into electricity first; it dumps the heat straight into propellant instead. By comparison, nuclear electric rockets need radiators, because they feed on electricity rather than straight thermal energy. To generate electricity from heat, a cold spot is required, because the heat engines (be it Brayton turbines, Stirling engine, or thermocouples) that drives the electric generator work on temperature differences. This is the radiators' role, radiating heat from itself to act as a cold spot for the heat engines to dump heat onto. In short, reactors meant for straight thermal energy (thermal rockets, or nuclear smelters) need no radiators by default. Reactors meant for electrical energy will require radiators. So, for nuclear electric rocket, radiator mass must be taken into account.

Thanks for the input. Implementing.

That's the ticket.

So what you say is, Forget VASIMR. We go there by nuclear thermal rocket.

Surface tension, and by extension fluid cohesion. In the vacuum of space, that's the only thing that can keep a liquid from boiling.

Nice work! That looks really cool. I'd say keep the tankbutt. It seemed like almost every other engine has it.

Mass of gasoline and oxygen needed to feed those Chevy big blocks. Jokes aside, if chemical generator is what's needed, an array of fuel cells could do the job much more efficiently.

Indeed. Though, simply braking isn't the only thing a ramscoop could do. In order for the scoop to collect anything at all, the particles have to be ionized. This is assumed to be done by a laser/microwave contraption on the ship's nose. An ion engine can use these ionized particles as propellant. For the ship's engines to generate any useful thrust, all it has to do is to throw the collected particles out the nozzle at a higher velocity than the particles incoming towards the scoop, while maintaining the mass flow. Example: ramscoop is picking up 50 kg of particles per second. Relative velocity of incoming particles in relation to the ship is observed to be 3,000 km/s (1% c). In order to generate thrust, engine exhaust velocity must be more than 3,000 km/s, implying a specific impulse higher than 306,000 seconds. Since mass flow must be constant, the engine must transfer more than ( 50 * ( 3,000,000 ^ 2 ) ) / 2 = 22,500,000,000,000 W/s = 22.5 TW/s of energy to the collected particles as kinetic energy.

It's not trivial, but possible, to construct a cylindrical pipe-bundle tank which uses a much simpler construction method: arranging the pipes into a sheet (think of radiator plates), then rolling the sheet-of-pipes into a cylinder. Cover it with a corrugated plate that do double duty as radiator and debris shield, and you have a pipe-bundle tank that looks similar to typical KSP propellant tanks.

Doesn't have to be that complicated. Textured cylinders are enough. Besides, why would anyone store uranium-salted water in a bundle of pipes exposed to the elements? One MMOD strike, and there goes the rest of the deltaV. Though, I think having tanks in multiple sizes, say half-length, quarter-length, and one-eighth-length would be useful.