jamis

(Alternate title: "Discovered: Greasing your ship with kerbals vastly reduces atmospheric drag") This story begins with a massively (for my hardware) overbuilt space station, which I called the "Hotel Galactica". By the time I gave up on it (because it was more slide-show than game, at that point) there were 18 kerbals living in it (with room for up to 64). (Sadly, I can't seem to find any of the pictures I took of this station in its hey-day...) And there it sat, in a 250km Kerbin orbit, for the next 12 game-years. I considered just terminating it, but the thought of those 18 kerbals dying for nothing didn't sit well with me. Finally, I decided it was time. I bit the bullet, reduced the physics delta to 0.03, and began a rescue. I wanted to minimize visits to the station (understandably), so I build this simple solution for returning 18 kerbals in a single flight: I then spent a bit of time tidying up the station--transferring kerbals to shared spaces and discarding unused sections of the craft, to bring the part count down to a more manageable number. Then, it was show time. The rescue ship flew great, and made orbit without difficulty. Even docking with the station went off without a hitch. (The base, as you can see, is in a sad state of disassembly, only a shadow of its former glory.) Then the fun began: 18 EVA's, moving each Kerbal out of his apartment and into one of the seats. At last, it was time to bring these kerbonauts home. All went as planned--the retro burn, the descent, reentry: But, wow, we really seem to be burning brighter than expected: And look, here we are at about 11km, having JUST STOPPED BURNING RED. (Do notice the atmospheric shock-wave around the ship--it was still moving at over 800m/s.) The kerbonauts were getting nervous at this point. Terrain detail was visible, and we were STILL descending at over 300 m/s. I burned the last of my fuel in an attempt to kill velocity, bringing our speed to under 100 m/s. Surely that would be slow enough for the parachutes to take over, right? Wrong. Observe the last known shot of this brave crew, 400m above the surface, as they watch their docking port, power generator, RCS fuel, and--yes--parachutes, fly rapidly away from their ship. The inevitable result: Let us pause and honor this brave crew of 18 kerbals with a moment of silence... ... But, hey, did you notice how aerodynamic those kerbals made the ship? I wonder if that would work to optimize an ascent...

Were you wanting to make a manned, or unmanned trip? For your first visit, I'd recommend a probe, myself. It simplifies so many things. For a probe, you don't need a very big rocket. In fact, one of the tiny Rockomax 48-7s engines, and a fl-t400 fuel tank, should be more than sufficient for the probe itself. Make sure you've got enough power, too--more than once I've got a probe on approach to another planet, only to discover it's batteries were dead. Once there, the simplest (though not the most efficient) way to do it is to just get your probe into orbit around the sun. To do so, just get in a low Kerbin orbit, and burn prograde until your orbit escapes Kerbin's SOI. For our purposes, it is best to do this when you are "behind" kerbin relative to it's own path around the sun--in other words, you'll want to burn when the sun is behind you. This way, you can use Kerbin's own orbital momentum to push you into a higher orbit (closer to Duna). Once you've escaped Kerbin's SOI, set Duna as your target, and use the maneuver nodes to experiment with a trajectory to Duna. Pick a spot own your orbit and pull the prograde marker until the orbit reaches Duna's. Slide the maneuver node around your orbit until you get an intercept (or reasonably close). You may need to make a full orbit around the sun before you find a good intercept. From there, it's very much like visiting Minmus from Kerbin. You follow your maneuver node to change your orbit to intercept, and then make any necessary course corrections mid-flight to get the best intercept you can. And once you're in Duna's SOI, you should be in familiar (technical) territory again--adjust your periapsis, circularize your orbit, etc. Duna's a great place to visit! Good luck! Let us know how it goes.

I set myself a challenge last night to build the smallest rocket I could, capable of carrying two Kerbals on a round-trip to Minmus and back--including a landing. The result, "Waterskipper on Heaven's Eternal Pond"! A 5.2t craft that uses less than 135 units of fuel for the round-trip. Next steps -- I'm going to try a Duna landing and return with this same rocket, taking advantage of some Kethane-based refueling stations I've got orbiting Minmus and Ike. We'll see how it goes...tonight!

That Laythe mission thread is inspiring! My idea isn't nearly as ambitious as that, but it certainly sets a kind of precedent for lander seeding. Also, excellent point about making sure the crew capsule ends up orbiting in the same direction as the landers. That's going on my checklist, for sure. I'll report back!

I've set myself a goal to plant a flag on every body for which it is possible. (I'm sure most of us go through this stage, yeah?) As of this morning, I've accomplished that for Moho, Eve, Gilly, Kerbin, Mun, Minmus, Duna, and Ike (and Dres will be done by this evening, hopefully). But as I eye the Joolian system, I'm trying to think of the best way to go about it, especially since Tylo will be so demanding. So I had a thought--what if I sent multiple unmanned missions ahead, which simply carried landers sufficient to land and return to orbit, and put one such lander around each moon of Jool? Then I could send a single manned mission through the Joolian system, rendezvousing with each lander in turn, landing, planting a flag, and returning to the orbiter. Has anyone tried this, who could maybe offer some advice for such a mission? Even if you haven't tried it, does it sound feasible?

Moho was much, much harder to visit than I expected. It took me about three or four tries, but I finally got it--a round-trip with three kerbals, with a brief (and nearly tragic) landing to plant a flag and appreciate the scorched scenery. The expeditionary ship was a core engine (with command module and nano-lander), capable of about 12k delta-v. I launched it first, then docked two tugs to it, bumping the final vessel to over 17k delta-v. When all was said and done, the ship returned home with just about 2k delta-v remaining. In all, my Moho adventures have been a sad and often-tragic tale of underestimation. Even my lander, with its 2500 delta-v, was just barely adequate for the landing, orbit, and subsequent rendezvous. But it all came together! Photo proof of my adventure: http://imgur.com/a/kROyp So, now I'm curious: what's the minimum delta-v you've spent on a round-trip to Moho, including landing? I feel like 15k is steep, but maybe that's just the price you pay to visit a rock so deep inside a gravity well.

I'm working on my first mod--a sci-fi teleportation device that is less magic and more science (meaning, it's got lots of constraints, and isn't a panacea for lifting things into orbit). I've got the basics of it working (thanks to HyperEdit for showing me how to drop a vessel into an orbit), but there are a few things that I've not been able to figure out. Specifically: I need to take one vessel and position it adjacent to another vessel, and then orient it so that the docking ports on the two vessels can be safely coupled. Using the HyperEdit method, I can drop a vessel into the same orbit as another vessel. But even though their positions are identical (vessel.GetWorldPos3D() reports identical coordinates for both ships) they are not overlapping as I would expect. (Obviously, I don't want them to overlap, but I'd like to understand why they don't, even with identical coordinates.) From there, I then need to figure out how to determine the relative coordinates of two parts on two different ships, orient the two vessels appropriately, and then move them together. I think I've got the orientation bit figured out (reverse the direction of the orientation of the part's topNode, and then use Quaternion.LookRotation to find a transform to apply to the vessel), but the positioning bit is baffling me. Any tips?