Stochasty

I have seen a couple of papers on the arXiv discussing the mathematics behind Lorentz transformations between time-like and space-like observers. I don't remember the conclusions in detail (I only briefly skimmed the papers), but as I recall nothing in the transformations were ill-defined. That said, I otherwise agree with you; there are issues involved in defining reference frames for space-like observers which render such results unphysical even if they are mathematically well-defined.

In addition to possible migration suggested by the Nice model, and to density variations in the accretion disk during planet formation, it should be noted that Jupiter is just beyond the ice line. It has been suggested that this is no accident: volatiles boiled off from the inner solar system may have concentrated near Jupiter's orbit, allowing it to grow more quickly. Unfortunately, we only have indirect evidence of the formation of a single solar system at present, so there's very little data with which to use for comparison of various theories.

This isn't going to win any speed records, considering the trajectory used, but it is another chance to show off my Eeloo trip. Total score: 4831 days, -5 for rover, -25 for clean space, -10 for 1 flight, -30 for spaceplane, -15 for KSC, for a total of 4746 points. If only I'd added another seat, I could have had the "all at once" bonus. Not that it would matter. Any chance you'd consider adding an SSTO bonus? Perhaps one worth -4746 points? Edit: New score, with SSTO bonus, 4726 points.

Or block the doors so that EVA is impossible (to simulate an airlock malfunction).

Might I recommend that, rather than simply tell people what to do to set up this challenge (since it is rather detailed) you create a scenario file for it? For instance, put three Kerbals on a derelict craft headed for Kerbin, and ask people to mount a rescue mission. That gives a more well-defined goal, and would probably get more people interested in a challenge such as this.

The numbers shown in MechJeb for ihtoit's craft don't make sense for it to be an all LV-N craft; 320kN thrust and a TWR of 4.34? I only see that one engine, so either he's clipping parts (5 1/3 LV-Ns? That would put him over the 7.51t listed weight by itself, not to mention fractional engines being impossible. What else is in there for thrust?) or something else strange is going on. The Nukjet spaceplane I made back in 0.18 was around 22 tons and had a TWR of 0.57 at takeoff and could only barely make orbit. It might not have been the most efficient possible craft, but I have difficulty believing a working nuclear-powered craft could be shrunk to this extent. I would love to see the craft file if I'm wrong about this.

The Vethrfolnir: to Eeloo and back:

I blame Jeb. It was entirely his fault, and had nothing whatsoever to do with the sheer boredom of having to wait over an hour for the right geometry.

This should properly go in my gallery post up thread, but considering it's my magnum opus I wanted to make a new post to show it off. Behold, a single stage mission to Eeloo: This is in addition to the trips to Dres, Vall, and Laythe I linked in my gallery post. In all honesty, the mission to Dres was actually harder; I had something over 3km/s delta-v left in the tank when I began burning for home from Eeloo, and I could have made it using only a few hundred if I were willing to wait on a good geometry with Jool. Instead, I came home Jeb-style: a sundive, intercepting Kerbin at over 10km/s. With this mission, there are now only three places in the solar system I have not managed a single stage return from: Moho, Tylo, and Eve. Eve is impossible, and Tylo probably so. I have my sights set on Moho, though: I will find a way.

She flies pretty much like any other turbojet SSTO: ascend to ~30km, level off to gain speed, ascend slowly once you are near orbital velocity (don't ascend past about 32km before your surface velocity is ~1900m/s). Start throttling down as intake air drops below 0.10: 90% throttle at 0.09, 80% at 0.08, etc. You should be able to push apoapsis up to about 50km and periapsis above the surface using only jets. Once you hit about 0.02 intake air (or whenever your apoapsis stops rising from the jets and starts decaying from the air resistance) disable the jets, light the nuke, and push to orbit. Practice first with version A; she's a lot more forgiving regarding the ascent profile, and has jet fuel to spare. You should be able to make orbit spending no more than about 50 units of oxidizer total with version A; if it takes more than that you're not gaining enough speed with the jets. Version B is less forgiving, and I typically wind up having to spend between 100 and 150 units of oxidizer. The action groups are as follows: group 1 toggles the jets, group 2 toggles the LV-N, and group 5 toggles the intakes.

My newest SSTO craft, the Vethrfolnir: a two-seater interplanetary return spaceplane. She is the most versatile design I've built yet. There are two versions of the craft. Version A (craft file) is the more versatile design, with better handling and more jet fuel for in-atmosphere flight; Version B (craft file) is the extended range variant, designed for long trips. A few pictures: Here she is on the Mun, on Minmus, on Gilly, on Duna, on Ike, and on Dres (yes, Dres). These shots were spread out over the course of four trips (so, multiple destinations for some trips) and she returned (landed at KSC) for all of them. A gallery of the complete trips may be found here.

My newest SSTO craft, the Vethrfolnir: a two-seater interplanetary return spaceplane. She is the most versatile design I've built yet. There are two versions of the craft. Version A (craft file) is the more versatile design, with better handling and more jet fuel for in-atmosphere flight; Version B (craft file) is the extended range variant, designed for long trips. She has made return trips from the Mun, Minmus, Gilly, Duna, Ika, and Dres (yes, Dres), with future trips planned for Laythe, Vall, and Eeloo. Here she is on Dres. She returned safely to Kerbin (and landed at KSC) each time, including Dres. A gallery of the complete voyages may be found here.

When I first got the game (about six hours prior to the release of 0.18) I spent 40 consecutive hours crashing spaceplanes, with only restroom and food breaks (no sleep). (Granted, I was hopped up on flu medication at the time as well, so that may partially explain it, but KSP can still induce me into accidental all-nighters today.)

Huh. I learned something new. So forward mounted gimballing engines are counter productive; I'll have to remember to turn gimballing off for them in the future (not that it matters much with this particular craft).

Went canyon surfing on Dres!

Unless you move them far enough forward. My current craft has a rear-mounted LV-N counterbalanced by two forward-mounted turbojets, and the gimbal on the jets effectively acts as a second set of canards. (Well; unless KSP has gimballing messed up on forward mounted engines; I've got enough control authority, so I just assumed that they were working as intended.)

Yes. Check the first page of the K-Prize thread for a list, it should identify who went where. I've done it several times myself; see here for my most recent craft. That said, I do agree with you that the "two part" variant does add an interesting twist.

Two points: First, Ferram Aerospace Research makes certain things in the game harder, and certain things easier. Specifically, it shaves off roughly 1km/s delta-v from the cost of making Kerbin orbit for a well designed rocket, due to the realistic drag model that it implements. This means you can get to orbit with much smaller craft, as long as they are well-designed (the "well-designed" part being the "certain things harder" in my first sentence). Whether or not you consider this to be too performance enhancing is up to you; personally, I love FAR. Second, is having a second craft for the Mun lander required? What about doing everything as part of a reusable single stage? There are a number of people in the K-Prize thread that have done single stage return missions from the Mun, Minmus, Duna, Laythe, and others. The "two-part" portion of this challenge does make it unique and therefore interesting, but I don't think it's actually any harder than doing it as a single stage.

I posted a link to the Mun trip above, but I wanted to show off my new ship a little more, so I'm making a gallery of her exploits. Update: Added the third through sixth trips. First trip: Single Stage to the Mun, Twice! Second trip: Picking up Jeb in Eve orbit, then stopping by Gilly and Minmus on the way back to Kerbin. Trip three: To Duna and Ike with Jeb and Bill! Trip four: To Dres! Fifth trip: A simultaneous mission to Laythe and Vall. Sixth trip: To Eeloo1 Planned future trips: Moho! (What can I say; it's the only thing left I haven't gotten to, save Tylo and Eve which are impossible. Moho will be hard, though; I can save some delta-v using an Eve assist but it will take some serious planning to have a hope of getting there and coming home.)

I rarely use a parking orbit, but when I do I put it as low as I can manage; typically 70km. Anything above 75km was either a mistake or trying to orbit something awkward with poor handling. However, for almost all of my trips, I time my launch so that I can burn directly for transfer without orbiting. (I never go to LKO for the sake of going to LKO; if I'm there I'm either testing spacecraft or parking temporarily while I refuel.)

Linking this, since it also qualifies. By the way, tavert, in response to our discussion in the other thread: 13.5 tons bipropellant, 4 small jet fuel tanks, two turbojets, one nuke, and 30 intakes. She has too much jet fuel, actually; I wound up bleeding off 180 units of liquid fuel before the second Mun transfer.

Single stage to the Mun? I've done it before, but I've got a new ship I want to put through her paces, so why not! Behold the Vethrfolnir! Jeb designed this one to be his new runabout, but he was on Eve when KSC finally gave the go ahead to build it so Bob wound up taking the maiden flight. Hi Bob! You look unhappy. Don't care to fly something Jeb desgined? Hmmm... 47km; a little low to start my Hohmann transfer, but the geometry is right so why not! And inbound to the Mun; cutting it a little close here. No worries; Bob may not be Jeb, but he's still a Kerbmonaut! Landed safe and sound. And off again. The problem with horizontal takeoff vehicles is that the only way to get them off the Mun is to go crater jumping. Then again, that was probably what Jeb was planning on when he designed the thing in the first place. And back to Kerbin. Hmmm... you know... there's still an awful lot of fuel left in the tank. Why don't we go again? Straighten up and fly right! A little short on fuel; going to have to use a trick I came up with a while back. One gravity assist... Not your normal Mun intercept trajectory. And landed again; 1km/s delta-v left; just enough! Target acquired! Also, crater surfing! A familiar sight... Home sweet home.

The slower you're moving, the cheaper it is to change inclination. As for whether or not "higher is better" it depends on how steep the inclination change you need to make is; sometimes it's more efficient to do it where you stand, sometimes it's more efficient to boost yor orbit first and then make the change. This is obvious for the case of a 180 degree inclination change; it'd take about 4500 m/s to manage in LKO, but you can do it for under 2000 m/s by boosting your orbit to the edge of Kerbin's SoI, making the change, and then dropping your orbit back down. The math here is very similar to the math for bielliptic transfers. Sometimes they're efficient, sometimes they're not; it depends on how large a difference there is between your current orbit and yourtarget orbit, although I don't remember the exact formula off of the top of my head.

Thanks! It was a royal pain to design - balancing delta-v requirements, TWR, lift, and structural integrity was a nightmare. Even after I finally had a good design for takeoff, I had to completely tear it apart and redo the wings to manage a good landing. Also, I don't know what possessed me to try to put half the drop tanks above the wing, but I don't recommend it. I have to pitch up to >60 degrees for every staging event or the damned things crash into her tail. I think I'm done with Eve for the foreseeable future. Next project: SSTO Eeloo return.