Buddy431

When I use the RCS configs, my RCS block only thrusts in one direction ("backwards", or "down"). I can change this direction by rotating the rcs block, but it doesn't thrust in 4 directions like the stock rcs does. Is this intended behavior?

Launching into a escape trajectory may be easier, but if you actually want to hit a planet, you want to launch into a specific escape trajectory, which is harder. Curiosity did enter a parking orbit. The Mars exploration rovers did too. In fact, most of the interplanetary probes I can see seem to use one. Use of a parking orbit increases the launch window time for interplanetary probes, which otherwise would essentially need an instantaneous launch window. In practice, the spacecraft tend to spend less than a full orbit in their parking orbit, but they are true orbits with perigee above the atmosphere. This book has a little bit of information about the parking orbit used by the New Horizons probe: it's impressive how accurate their injection into an interplanetary trajectory was. They had to make only 3 course corrections on the way to Jupiter, or magnitudes 5, 5, and 1.6 m/s (this was much less than they budgeted for). The New Horizons craft used its Centaur liquid fuel upper stage for part of the burn, and then a solid fuel engine for the rest of the interstellar injection burn. I suppose the benefits of being able to evaluate your trajectory and extend your launch window far outweigh the small amount of inefficiency you incur. I do know that many geostationary satellites are sent directly into their geostationary transfer orbit. It is mandatory for the Ariane 5, where the upper stage engine doesn't have the restart ability. The Ariane 5 launches essentially from the equator, meaning no inclination change for a geostationary transfer orbit. The recent falcon 9 launch from the U.S. did require an inclination change, so it did use a parking orbit before going into its geostationary orbit. But with geostationary satellites you're mostly going for some orbit of approximately the right dimensions, and the timing is a lot less important. Does anyone know of any interplanetary spacecraft that didn't first enter a parking orbit before heading into their escape trajectory?

One more for you: The LV-N Atomic Rocket Motor, trimodal: when I go to the action group editor, it doesn't come up with any information or options. Sorry about all this.

The masses appear to work now. One thing I did notice is that the 2.5 m nuclear engine from Nova Punch doesn't seem to like to load. It's not a huge deal to me so I just deleted the part, but something either in real fuels of the engine config file probably isn't right for that engine. Thanks a lot for the update. That was a quick turnaround.

1) The proton rocket was originally built as an ICBM. So was the Titan II rocket that the US launched for a while, so it also used a storable fuel (as did the Titan III and Titan IV that were derived from it). When you want a rocket that can be stored in a missile silo for years at a time with minimal maintenance, but be ready to launch in minutes, liquid oxygen isn't going to cut it. I'm not sure why the early Ariane rockets used it. They weren't, as far as I know, ever intended to be missiles. It does make a simpler engine (no igniter needed). The Ariane 5 upper stage used to deliver the ATVs to the space station uses hypergolic fuel because the cryogenic upper stage (which is more powerful, and used to launch satellites into a geostationary transfer orbit) cannot be restarted, while the storable upper stage can be. 2) LH2/LOX still does have the highest specific impulse of any fuel, so it's not unreasonable to use it as a first stage, even if it does require larger tanks. The space shuttle and Ariane 5 both have solid boosters to help provide additional thrust in the early stages of flight. The delta IV can (though doesn't necessarily) also use solid rockets to help it out. And anyway, LH2/LOX engines don't necessarily do too poorly in the thrust to weight department. The Vulcain on the Ariane 5 and the Space Shuttle Main engine are pretty comparable to the RD-180 used on the Atlas V. 3) While it's true that solid rocket motors have a fixed burn time and cannot be shut off, that's also more-or-less true for liquid fuel motors too, in that the burn profile is pre-programmed into them before launch. Real motors used on launchers are not, for the most part, like KSP motors: they generally do not have throttle ability, and are not used to fine-tune the orbit. The booster delivers the spacecraft into an approximate orbit (which is generally pretty good: they can get within a few dozen m/s of the desired velocity), and then the spacecraft itself will do the fine-tuning with much smaller motors, making course corrections as needed. Most launchers will not put a satellite into a geostationary orbit: They will put the satellite into a highly elliptical geostationary transfer orbit and let the spacecraft maneuver itself into the final orbit. This is true of interplanetary launches as well: The launcher will get the spacecraft headed in approximately the right direction, but multiple course corrections will be needed during the cruise phase.

OK, I have a clean install with just real fuels v4.2 (from the first post), and the stock engine configs from post 2 from 2 days ago. If useRealisticMass = true in RealSettings.cfg (the default), the engines weigh the stock amounts at the first tech level, and then decrease in mass as the tech level rises (i.e. the LV-T30 has a mass of 1.25 at tech level 1, and decreases to 1.020 at tech level 7. The action group menu displays that it "was 1.250" If I set useRealisticMass - false, the engines still weigh the same (i.e. the Lv-T30 weighs 1.25 at tech level 1, down to 1.020 at tech level 5). However, the Action group panel now says "was 4.000". Obviously the game is taking into account the 3.2 multiplier, but not in the correct way, I think.

I'm having trouble with the new Stock Engines configuration file, where the masses of the engines isn't changed when the UseRealisticMass setting is changed from true to false (or vice-versa). They always have the heavier stock masses.

Ferram, I don't think it's stretchy tanks. I had the same problem with a Mun lander using (I think) only stock parts + mechjeb. It's interesting, because I'd already landed the Mun lander once and taken off again to a new site, and done this with the same design before with no problem. Happens exactly as you describe: get a certain distance from where I was parked (about 3 km I think?), and I get the three symmetry attached tanks teleporting back, and fuel lines stretching. I'm landed near the south pole of the Mun, and the flags I try to plant are also showing weird behavior: I can plant them, and they look fine, but if I quickload the flag isn't visible (it is in the map view), and it claims it's under acceleration if I try to switch away. It's happened every time I've tried it with this specific craft, but I've used identical craft before in different areas with no problem.

When I'm using just modular fuels (even with no other mods), the base masses of the fuel tanks are too high by a factor of about 4.079. Looking in the Tank Types.cfg appears to give the appropriate mass (0.000625*volume), but in game they are not this value.

Maybe I'm just missing something, but with the latest install of real fuels, I can change the fuel type in the tank, but all of the engines (just stock engines used) look like they just want to use liquid fuel/oxidizer. Did the way of changing engine fuel type change?