cubinator

Yep. And your boat will take a 0.00000001% reduction in propulsion efficiency from it, just like Jupiter's orbit is brought down slightly by slingshotting space probes.

That's fine. You can use the energy for whatever you want, including boat-mounted laser turrets. Your motion will take a hit while you're gathering energy, though.

Like if you were riding a wave and the wave was accelerating you? Then sure, you could maybe gather energy from that if the water was moving relative to the boat, but maybe your boat would hold its speed instead of accelerating. It definitely would not accelerate as much as if it were just gliding through the water. It's basically like regenerative braking in an electric car. That takes the kinetic energy of your car and stores some of it back in the battery for later use. It makes the car a bit more efficient, but the thing to note is that the act of storing the energy is what slows the car down: it's the brake! You might be able to do something similar with a boat, and if you could invent regenerative braking for a boat that would be a very cool invention indeed, but there's no way to do it without slowing the boat down.

It's because of what you're doing to get that energy back. You can think of the energy as a resource spread between two places: The kinetic energy of the boat moving through the water, and the electric energy in the battery inside the ship. When the boat is moving, the energy is like this: X X X X X X _ _ Kinetic energy Electric energy When you grab energy from the boat's motion to store it in the battery, the energy starts to go like this: X X X X X X _ _ Kinetic energy Electric energy With less energy in the Kinetic department, the boat will slow down, because its mass can't change from what we're doing (not at this fraction of the speed of light, anyway ). Eventually all the energy will be in the electric storage: X X X X X X _ _ Kinetic energy Electric energy Then the boat will be stopped. What you're proposing is that the boat keeps its kinetic energy while also gathering electric energy. That would look like this: X X X X X X _ _ Kinetic energy Electric energy X X X X X X X X _ _ Kinetic energy Electric energy X X X X X X X X X X X X _ _ Kinetic energy Electric energy See how that's impossible? There is more energy being created somewhere in the second case, and it is a law of the universe that that can't happen. If that is the case, then you will have a force on the boat against its direction of motion through the water, and it will slow down.

Well it's a boat, so I think we're covered in that department at least

It does add friction. That's where you're getting your energy from. To move energy from one system (water) to another (boat) you have to apply a force. If you're doing that with a turbine on the front of your boat, there is a mechanical force acting against the water which slows the boat down. If you're harnessing some kind of electrostatic energy through the hull, then there will be an electromagnetic force that slows the boat down. Think of how when you spin a motor with your hand, the coils exert a force back to your hand as they generate electricity. It is exactly the same that will happen if you try to grab electricity from the motion across the hull of the whole ship. It's like millions of infinitesimally small generators.

Absolutely. You're quite right: A ship moving through the water can pull energy from its motion and store it in a battery or what have you. Here's the part that makes absolutely any form of that ability totally useless, though: Doing so will slow the boat down. You'll gather a little bit of energy, at best equal to 1/2 * the mass of your boat * velocity of the boat ^2, in a perfect world with spherical cows and frictionless planes. Most likely quite a bit less than that, especially if you're using some roundabout method involving static or what have you. And then if you want more energy, you're going to have to spend your fuel to get the boat back up to speed. If you look at the big picture of all the things that are going on, the energy you gathered from motion is the same energy that came from your fuel reserve, be it diesel, uranium, a battery, or antimatter. You're better off using a small portion of that original source to run a generator on board, and I think that's essentially what you're talking about: using a small portion of the ship's power to run something other than propulsion. I think this is already done in most ships with electrical systems powered by the running engines - you can charge your phone on a cruise. The thing that most people have been pointing out as the most serious concern is that any energy you pull out of moving the boat through the water will cause it to slow down. The boat doesn't have an unlimited supply of energy in the moving water around it like a waterwheel on the shore of a river. The boat is spending a lot of energy to keep that speed, and if it pulls all of that energy out of drag or friction in any way, then it will immediately stop and not be able to keep going while it does that. You can absolutely take a small amount of energy from that motion using whatever system you'd like, but that's definitely going to slow the boat down and the engines will have to compensate by burning a little more fuel. There's no way to power the ship's motion with the ship's motion. (By the way, I seem to recall having the exact same conversation on this forum a long time ago, but the vehicle in question was an electric airplane instead.)

Unmanned probes to Eve can be quite fun. Maybe you can try to send a rover to one of the planets. The Jool system is easy enough to fly around as long as you've got a big enough antenna.

If it runs at more than .5 frames per second, I'm happy.

Peter Beck complained that they're messing with launch windows a few days ago.

Any good views of the launch pad post-hop? I'm curious as to what exactly went flying.

I've got it: NASATV is the most realistic space movie.

I suppose Apollo 13 is probably the most accurate space movie, being tightly based on real events. Or maybe it's Apollo 11, being composed entirely of historical footage.

Since when have KSP players been bothered by a little instability? Also: Donut planets?

No, actually Starship would be 150% reusable.

Various Jeb Kerman plushies and 3D printed models have been put in the hands of KSP fans, and some have even given those Kerbals a taste of flight, such as on high-altitude balloons. I am wondering if there is any known case of Kerbal merch being flown on a supersonic vehicle. Asking for a friend. This definitely isn't related to the 7-foot tall rocket propped against my desk right now.

The reason pandas are actually useful to conserve is that they act as an indicator species for the forests they live in - If pandas can survive there, the other, less humorous species which are harder to keep track of individually, like insects, are probably doing pretty well too.

Congratulations! As a fellow KSP Rubik's Cube engineer, I'd like to see what's inside. Does it use any mods? How many parts is it? Most importantly, did you manage to do it without using docking ports?

Live momentarily.

I think the launch pad is gonna need a new...pad...That engine tore a huge chunk of it out!

Well the 20 km one definitely will, so they'd better figure that out soon!

I think that next up is a 2 km hop.

Looks like it got just about to the target altitude, too. It doesn't look that high because the rocket is so huge.

HOP!

Looks like they're pressing up SN5 right now.