Bunsen

I just started on a project along these lines, in true Kerbal fashion. By that I mean lots of "found lying by the side of the road" parts -- the only parts of this that weren't salvaged from the garbage are the Stellaris Launchpad microcontroller, the breadboard, and the LED. It's in its infancy; last night I just managed to get the Launchpad talked into speaking USB HID, rigged a launch abort switch, and spent the rest of the evening aborting launches. That solid, satisfying CLUNK of the toggle switch is addictive. I'm up to abort (switch on the left, duh) and two action groups (with the center-off SPDT on the right) now, which I've standardized as jettisoning the launch escape tower and deploying parachutes. Those banana plugs at the upper right are only there because their threads seem to be mangled and I couldn't get them out easily. In the end, I decided they're appropriately Kerbal and gave up.

They've gone to plaid! Awesome work.

I'm curious about the practical results of those schemes. As usual, the Wikipedia articles are a near-impenetrable quagmire of abstract math and precise but opaque jargon. I might be able to work through them in a week or so, but I'd rather just bother you instead. How deep into control theory would you have to go to find an algorithm that mimics nhnifong's approach? It looks to me like that involves some prediction of the system's behavior -- the first RCS burn places the system on a trajectory through state space that intersects the desired trajectory, then you wait for the intersection and burn again to stay on the desired path. But maybe you can approximate that with something really simple if you parameterize the problem the right way... Dammit, I think I've just been nerd-sniped.

Quite. That's exactly what my probe was doing in that first picture. I burned off the last few drops of propellant also, but it didn't make a lot of difference compared to the slingshot.

I guess that's a common thing for us space geeks; this is the first thing I ever sent outside Kerbin orbit [edit: Well, intentionally anyways. They were brave souls all, and let us never speak of them again.]: It was last seen hauling ass into interstellar space. I don't know exactly when it forgot how to gravity, but it was a while ago: The accelerometer simply reads 00.00 m/s^2

Yeah, those are called "maneuver nodes" and they aren't an autopilot so much as a "what if?" and planning system -- it shows you where you'd go if you burned for a certain amount of delta-v at a certain time. It will also tell you (on and next to the nav ball, as long as you're not in cockpit view) the direction and magnitude of the delta-v, so you can accurately perform a planned burn. Pointing your ship the right way, firing the engines at the right time, and shutting them off at the right time are still up to you.

Once you're in a proper orbit the game will do exactly what you want, no piloting (auto- or otherwise) involved. If you're finding that the ship crashes into Kerbin, either you weren't in orbit (or were orbiting within the atmosphere), or you were orbiting so far out that an encounter with Mun or Minmus threw you into a reentry trajectory (unlikely). Hit http://wiki.kerbalspaceprogram.com/wiki/Tutorial:_How_to_Get_into_Orbit and pay particular attention to the bit about getting your whole orbit above 70km.

Only if you use a very strange definition of "possible." The Alcubierre drive requires craptons of stuff with negative mass, and that doesn't exist (you'll find a few authors who downplay this by calling it "exotic matter" instead of "negative-mass magical unicorn farts," but it's still pure fantasy). Creating fundamental particles that don't exist, nor have even been plausibly hypothesized, is more than a technological problem.

That first IVA Mun landing was pretty exciting, but I felt a much greater sense of accomplishment when I pulled off a reasonably efficient (i.e. launch, circularize, one transfer burn, brake within a few hundred meters of the target and RCS the rest of the way) LKO rendezvous with no external mathematical assistance. I used the map view to see inclinations and phase angles, but the rest was done with standard HUD instrumentation, a notepad, and my grandfather's slide rule. Turns out that degree in physics is good for something, but it took a couple tries before I could crank through the math fast enough to keep up without pausing the game. The amusing part came when I started that little project by looking for information on quick-and-dirty rendezvous techniques. Google quickly led me to a 1963 Ph.D. thesis by some guy named Edwin Aldrin Jr., with a dedication that reads I'd say Dr. Aldrin got his wish.

You can change staging behavior in the VAB -- look at the column at the lower right. You can add steps in the staging process with the little "+" buttons, drag elements between stages, and reorder stage groups, all without messing with action groups. Click one of those "+" buttons to create a new staging step, drag the parachute icon into it, and drag it to the top of the column. If you want to fire the 'chute before other things, then create an action group for it and you can activate it either way.

If you want to change the inclination of your orbit, lower velocity is always better. Less total v means less delta-v for a given change in angle. If you want to change your total energy, then higher velocity is better, as Herr Oberth tells us. I think it's easier to see how it works by focusing on the energy of your rocket, though: Kinetic energy goes as the square of speed, so a small change in speed produces a change in energy that's proportional to your initial speed. If you're familiar with calculus this is obvious; if not then take a look at the graph on http://www.wolframalpha.com/input/?i=x^2 and notice that the slope (i.e. change in y per unit change in x) gets steeper when x gets bigger. So if you're coming in hot as hell from an interplanetary transfer and trying to make a capture burn without wasting precious fuel, your goal is to reduce your total energy enough that you don't escape the planet's SOI again. You can do that most efficiently with a course that takes you as close as possible to the planet, so your limited delta-v buys you as much delta-E as possible. Edit: Um, yeah, what Frederf said while I was typing.

The man speaks truth. Mine would have to be immediately after my very first Mun landing, actually. I landed with slightly more than the lander manufacturer's specified maximum lateral velocity... and then thought "Well, falling over didn't break any of the important parts off, and it's pointed toward a hill. Time to take this baby off some sweet jumps." Turns out that doesn't work so great above about 15 or 20 m/s.

First unmanned landing was a rover to Duna, which was the low hanging fruit delta-v-wise. For a manned mission, I ended up hitting Ike first. I had a handy, compact lander design worked up, but it didn't have enough gas to both land on and ascend from anything bigger than the Mun (and only barely that -- hope you like doing circularization and rendezvous burns with just RCS!), so it went to a nice, shallow gravity well.

I got hooked around 0.8.mumble. As essential as time warp is to doing much of anything, flying whole missions in 1x brings a sense of verisimilitude that's hard to match otherwise. Having to manually calculate the necessary delta-v for your transfer burn, do something else for 15 minutes, then come back and fire a circularization burn -- and having to wait another half hour if you screw it up -- motivates one to put a bit of thought into the process. I also remember being excited as hell when RCS showed up. Not because it made huge rockets controllable, but because we finally had a passable orbital maneuvering system. First thing I did, and I'm sure I'm not alone in this, was get into orbit with a small RCS-equipped pod and play tag with the spent upper stage. I didn't even realize at the time that I was basically imitating Gemini 4. Never did have the same problems as McDivitt, though; that only happens if you're patient and cautious about your maneuvering. That sort of thing was, uhm, not an issue. And that first time watching Kerbin rise over the gray, desolate limb of the Mun, after days of crashing Munar Lander Training Vehicles all around KSC in anticipation of 0.12's release and a couple flubbed transfer orbits... Well, I couldn't help but hear Frank Borman reading Genesis in my head. Can't recall any other game that could produce moments like that. But the important thing was that I had an onion tied to my space suit, which was the style at the time...

Made Kerbal orbit, with maybe slight cheating -- I realized I was reentering the atmosphere when it dropped to 2x time warp, so I burned hard (and very nearly followed DonLorenzo into Kerbol orbit). Given that, I\'m not sure if this one counts. Somewhere near perikerb; it\'s high enough that it stays in 10x time warp: And my best guess for apokerb; Kerbin stopped getting smaller about here. I think I must have been out near munar orbit by this point.