Supraluminal

Oh, heh. Never mind then! I must have erroneously imagined the bit about the mass being the same. Pretty sure I read that it's 1 Earth gravity at the surface, though, yes?

Not sure which thread I saw it in, but apparently Kearth's radius is indeed 600km, and its mass (and hence surface gravity) is the same as Earth's. Density is obviously much higher because of that.

Right, but once your fuel has been liquified, I don't think you can compress it much further (if at all, practically speaking). I'm not a physicist or chemist so I could be wrong about this, but I really don't think compressing/cooling rocket fuels beyond the point of liquefaction is a feasible means of increasing fuel capacity on a spacecraft.

OK, I made it out to 10,000km and started my return flight last night, but I had to give up and go to bed at about 8,500km out. Trying again right now. I'm on my way out with a bit more fuel than last time, so it's off to a good start!

Liquids are actually relatively incompressible. They might be delivered by pressurized gas, but that's not the same as compressing a bunch of fuel so you can fit more in a tank. That much is definitely outside the realm of 'realism.'

I'm giving this a shot right now, and I think I can pull it off. However, the 10,000km distance stipulation feels needlessly and arbitrarily far off - as long as you can orbit, then achieve escape velocity, you can get to any distance you want. It's just a matter of patience. Same goes for getting back; as long as you can slow yourself to below escape velocity, you'll drop back to the planet eventually. There may be some challenge in managing your return trajectory at that distance so that you aren't headed straight for the ground at high speed, I guess. I don't think it's as much a physics issue as an instrumentation/control one, though, if I've correctly understood the crash course (pun intended) in orbital mechanics that this game has sent me through.

If your mods/addons are strictly new parts and not edits to the stock ones then no, I don't see how they could affect it. I think limiting your thrust was the key. I've been meaning to play around with that - obviously air resistance is killer, so if it's more efficient to plod steadily out of the atmosphere at 100m/s than it is to blast full speed ahead the whole way up, you'd end up with more fuel once you hit vacuum... which could make a huge difference. Definitely gonna have to try that with some of my rockets the next chance I get!

Are you using modded parts...? How did you make it to 20km/s with that?

I've created the Honda Civic of rockets. It's simple, reliable, effective, and boring. You can hit T, peg the throttle, press space a couple of times, and be on your way out into the reaches of space at 5500m/s. Or, if you prefer, you can end up in a stable orbit with about 2.5 tanks of fuel to maneuver with. It even comes with a parachute as part of our commitment to safety! Here's one on the launch pad: And a bit later, starting to keel over for a horizontal burn: Like I said, boring, but it gets the job done! It's also a good base to slap more bits on to, if you're careful.

Nice landing! Looks like they'll be home in time for lunch after a five-minute walk. As for 'doing better,' you could certainly get into orbit with more fuel to maneuver. Though I guess part of the fun sometimes lies in making every last drop count!

That makes sense! I wish component weights and stuff were displayed in the in-game UI. I'd rather not have to dig around in the config files and wiki for that kind of info when I'm building a rocket.

I also tend to use them only as a first stage. They seem to put out lots of thrust very quickly, which is great for getting off the ground but not so hot for maintaining stability once you're on the move. They're also just kinda difficult to get integrated into subsequent stages very smoothly (lots of mucking around in the stage editor required for anything like good results). That's my take on them as part of a utilitarian craft intended to actually get into (and back out of) space, anyway. For creating cobbled-together deathtraps, they're indispensable!

I've been using a very similar base design, but with up to four liquid fuel tanks per stack with good success. In straight-up escape-velocity testing, 3-tank stages outperform 2 tanks, and 4 tanks are even better still by a small margin. I haven't tried 5-tank stages yet, but I suspect that's pushing the fuel-to-engine ratio too high. Stability might become a problem as well; it's already slightly wobbly at 4 tanks. I do find that an initial solid booster stage is helpful for getting off the ground with this design - I have a ring of 9 of them right around the top of the bottom liquid stage and 3 attached to the bottom engine nozzles. Each booster gets its own SAS module on top. That's enough to gain a couple kilometers of altitude and about 100m/s of initial speed, and it's pretty stable to boot. I've been twiddling with attaching more boosters, but without much success. I'll probably try to stick some more liquid engines onto the sides just for kicks, but in general I haven't found that approach to work very well either.