FinalFan

That's an amazing story. Thank you for sharing it. I love that your first orbit was basically "boost straight up until you find geocentric stationary orbit"

That's true; I haven't been appreciating that its TWR has a slight edge over even the mighty Mammoth. That may possibly outweigh the extra weight in fuel burned on a short lived initial stage. (On the launchpad, three Mastodons have the same weight as a Mammoth and 4.4% more thrust, while the Mammoth has 5.4% better Isp.) And while the Isp gets much worse, it never entirely loses its edge in TWR. And the Mastodon's gimbal is a healthy 5°, while the Rhino (4°) is the only other engine in its weight class to beat 2°. In fact, the Vector (10.5°) is the only bottom-mounted engine that beats it on that score, and only the much smaller Bobcat matches it. So I have to take back what I said about the Mastodon not having any stand-out features. That leaves the glaringly obvious cost issue. At 22k a pop, the cost when clustering quickly becomes ridiculous. The Vector (18k) has a similar problem but obviously it, unlike the Mastodon, has the Mammoth. But I think pricing it the same as the Mainsail would go too far in the other direction. Given the engine's qualities and the inherent versatility that the Mammoth by its nature completely lacks, I think pricing them at exact parity (comparing one Mammoth to 3 Mastodons) would be selling the Mastodon at a significant discount. (Now that you've opened my eyes to seeing its virtues instead of fixating solely on its glaring performance flaw.) Just off the top of my head, 15,000 seems appropriate. It means you pay a premium versus the one trick pony Mammoth but the price isn't completely out of whack with everything else ... even the Vector.

You know, after all this is said and done, I love your mod @OhioBob but I just got [forum censored me lol] off and said "I'm going to make the Mastodon decent at something" and brute-forced the .cfg file to zero out at 19 atmospheres instead of 9. Now it still has 280 at sea level and 290 in vacuum but on Eve it starts at about 224.5. Oh and apparently the 2.5m-3.5m structural adapter no longer quite fits the 2.5m end. Don't ask me why.

Here's my answer to the OP's question: I concur with OhioBob that the Eve-sea-level Isp of the Mastadon is 152.5, but I recorded an Isp at approximately 7,000m of 238.7 instead of the 265 that he calculated. I didn't hit 265 Isp with the Mastodon until more like 11,000m. Oh, by the way, @OhioBob: is that graph slightly outdated? I was unable to experimentally confirm your graph's representation of the Vector and Aerospike Isp curves using the in-game item screen tool. My experience was that that your graph paints a relatively informative portrait, but the specific numbers are significantly off above sea level, as in the above example. As for where I differed from the graph, the Vector didn't catch up to the Aerospike's Isp for me until a little over 8 km (instead of under 4) and didn't fall behind again until right about 18 km (instead of 12.3). (Aerospike: 8km—266.1; 18km—303.3; Vector: 8km—265; 18km—303) As for the main point of my experiment, the Mastodon, after starting out a staggering 41 Isp behind the Vector as you pointed out, caught up to about 15 Isp behind the Vector at 12-15km (close to 15 behind in that whole range) before the Vector pulled away again. My experiments also suggest that Eve reaches 1 Kerbin atmosphere at around 14.6 km, which is substantially higher than the "about 10km" I've heard being traditionally quoted by other people. (I measured the Vector at 295.0 at 14,575m and this was consistent with my measurements from other engines.)

@Plusck thanks very much for the comprehensive answer! Fortunately it was Eve.

I've done this using the Mun, since it has a shorter orbit and thus can more conveniently set up such escape windows. In the end, though, I wasn't sure how much it helped versus just doing it from LKO. Assuming topped off fuel tanks from both locations (say 80km Kerbin/15km Mun), do you know the over/under on that one?

Whoa, 152 isn't even close to competitive with the Mammoth/Aerospike based on the pre-MH graph I'm looking at. Thanks for the info! Basically it's an expensive, less powerful Twin Boar.

Thank you for the info @Zhetaan although that's very disappointing if true. I haven't played with Making History yet but it seems like the Mastodon is pretty underwhelming for any purpose other than Apollo recreations. I was hoping that its lowest-in-game falloff of only 10 isp to 1 atmosphere from vacuum (because its vacuum isp is garbage) would at least translate to best-in-game isp at Eve sea level (because slower falloff). It's sad if that's not the case. I just bought MH due to the sale and I'll test your result experimentally when I finish a couple of things. [edit: Even according to your math, though, I suppose it's at least somwhat competitive with the Mammoth, so it can fill the gap between it and the Aerospike. I expect worse Isp but perhaps better TWR, but haven't tested yet or done math as good as Zhetaan.]

I guess I wasn't clear enough in articulating my question. In the current game, if you put a decoupler the wrong way and it sticks to the engine, you can fire the engine and it will overheat the decoupler and explode it, thereby solving your problem at the cost of a little fuel (assuming the explosion doesn't harm anything else). So my question to you is: Why couldn't you do this? Was it that the game worked differently at the time, or was it that the engine was too weak to overheat the decoupler, or what?

Thanks to this post, I'm thinking of Minecraft construction in terms of part count. Oh. My. Gosh.

I can't argue with your definitions. Usually only one thing turns on when I hit the SAS button, but of course the SAS also controls the RCS when they both happen to be on. I had thought that the reaction wheels on very large objects were prone to setting up a self-aggravating resonance in a way that the RCS thrusters by themselves were not prone to doing, but I can certainly believe that I was just wrong due to never leaving RCS on as long as I left reaction wheels on. You're sure about this?

You're right, and using RCS as fine control for interplanetary maneuvers is among the most satisfying things I've done, but we're still working on the basics here, and the context is primarily landing on a body—even docking is still on the horizon. It's good to avoid getting into bad habits, but on the other hand I want to avoid overwhelming with other tidbits. The basic thrust* is the same—SAS when it will do the job, RCS when SAS isn't enough. But I suspect you meant that SAS is the one more likely to tear apart stations, right? I don't have much experience there, but what little I do have suggests that SAS is the more dangerous one in that regard. *Ha ha.

You made perfect sense, and you're almost right. RCS is the one that uses special rocket fuel. Your Kerbal COULD use this, but the one with electricity (often called SAS) is a lot better ... you can refuel it RCS is usually saved for when you want to actually move around in space, not just twirl the ship around.

When you flew to the Mun, it had a probe, yes? Was there a little red or green circle to the left of the nav ball? Anyway, these little circles, if available, tell your probe and/or pilot to do certain maneuvers automatically: "keep it pointed prograde", etc. The most basic one is "keep it pointed in the direction it's in now; if something turns the ship try to turn it back to here" AKA "hold steady". Retrograde is what you do do slow down ... But if you are about to land and you go up a little then "retrograde" points your nose at the ground!! So, hold steady near the end.

Yes, let me explain what he means. You were losing control literally, due to going out of antenna range of home base. But a lot of people have trouble by burning retrograde to land ... if they stop moving down then suddenly retrograde could be the completely wrong direction! Once you are close to the surface make sure your SAS is set to "hold steady". Reaction wheels use electricity to point you in whatever direction you want. Very handy. Your command pod or probe has a weak version but you can unlock strong ones. RCS does a similar thing with tiny little rockets that spin your rocket, but can also move it side to side, up and down, etc. Weaker than regular engines obviously but good for docking and for keeping you upright when landing. Uses monopropellant fuel. You have a little in your lander can and command pod unless you empty the tiny little tank. Big tanks sold separately. If you use RCS make sure to space it out evenly.over your ship, e.g. 4x symmetry in the middle of a small lander.

For me the inclined orbit is annoying to hit. Not hard exactly but more of a hassle than the Mun's easy peasy dead level orbit. It's easy if you wait for KSC to cross the orbital path before launching, I suppose. Or maybe it's just me.

Yes, once you're at Minmus it's much easier to go from one biome spot to another compared to doing the same on the Mun. Getting there is trickier but doing multiple biomes is easier. If you're willing to fool around with docking then this is also a situation where having an orbiter and a tiny biome hopping lander that docks with it might come in handy. Plus it's very easy to tell the major types of Minmus biomes apart. Flats, slopes, highlands, easy!

Thanks for the heads up. I was waiting until I finished a certain mission milestone, but never mind!

Great job! I'd recommend looking on the bottom part of the tech tree for more science collecting instruments. I don't really remember where exactly they are but you probably don't have the atmospheric one, the seismometer, and the "gravioli" gravity detector.

Would you mind elaborating a bit on this one? If it was on backwards, I'd think it would still separate. The decoupler might be attached to the wrong rocket, but this can be solved by "engine induced explosive decoupling". However, if it was a Dawn engine, it might not have the power. Or did decouplers work differently in the past?

I think he was talking about the rescue craft that missed its target.

The most conservative place to put the materials bay on the disposable half of the lander. Collect the science result and put it in the command pod. Or you can try to bring it home with an extra copy of your landing zone data!

Good luck! Landing on a specific spot is a lot harder for me than landing just anywhere, but don't give up! Fortunately the Mun doesn't rotate very fast so you can mostly ignore that when planning your landing.

How about this: full parts access up to Mainsail level, and little or no nagging, but you get to make exactly one successful Mun/Minmus landing (defined as contacting the ground at less than 5 or 10m/s), then after five minutes or something the demo congratulates you and asks you to buy the game now that you've done enough to get an idea of what the full game will be like. If people want to exploit with fast landings or reinstalling the demo, let 'em. Pirates gonna pirate.

Oh, here is a good one for "tips and tricks": if you aren't using RCS, empty out the monopropellant in your pod or can. It's not much difference in weight, but it is a difference.