Srpadget

My personal "limit", if you want to call it that, seems to be somewhere around 250-300 parts on the pad prior to launch. Usually much less. I just haven't ever needed more than that. Mind you, I've barely ever left Kerbin's SOI. If I ever do anything really ambitious like an Eve-return mission or Jool-5, I expect the part count will go way up. I have no idea what my COMPUTER's limit is--I am blessed with a brand-new (I've had it maybe 2-3 months?) upper-midrange gaming rig, purchased specifically because my old machine whimpered and cried at the very thought of running KSP. At particularly busy times around one of my refueling/transfer space stations, I may have had as much as 400-500 parts in physics range at once with no perceptible lag at max graphics settings. (But don't quote me on that number; I don't actually count them up.)

As others have said, rescue missions are essentially exactly like rendezvous/dock except the last step is "kerbal jetpacks to pod hatch" rather than "ram the docking port at low speed". There are two important differences, though, which cannot be stressed too much: 1) Do not thrust with your main engines while they are pointed directly at the kerbal you are trying to rescue. The rocket exhaust is capable of flinging the poor guy away from your rescue vehicle at high velocity. RCS maneuvering thrusters are much safer. 2) Someone else already said to shift focus/control to the recued kerbal for the final approach/grab/board using [ or ]. But I must stress that it MUST be done using those keys. The usual obvious methods used bymost beginning players (clicking in map view or select in tarcking station) will not work. [ and ] at short range is the ONLY way to gain control of the stranded kerbal.

I'm a terrible cynic. Near as I can tell, pretty much everybody's real working definition of airhogging is "something other people do which is more extreme than what I do, and makes airbreather SSTO's too easy/ugly. It's cheaty. What *I* do, on the other hand, is just making use of the physics of the Kerbal universe and isn't cheaty airhogging at all."

::snort:: Yeah, right, like THAT'S a danger. My "precision re-entry/landings" when returning rockets to Kerbin are now getting good enough that I *usually* don't hit the mountains to the west, or end up too awfully many kilometers out to sea in the east. Thank goodness funds are so easy to come by (flag spam! *ka-ching!* orbital science spam *ka-ching!*) that it's just gilding the lily to try to extract every possible Kredit of recovery costs, or I'd never fly anything I couldn't launch in a spaceplane...

D'oh! "Launch clamps: they're not just for stability any more!"

So I finally had my first experience with "destructible buildings". It happened when I took a vehicle I've successfully used a couple times in V0.24 and put it on the launch pad. And the launch pad promptly blew up. Near as I can tell, from the stress of setting the rocket on it...? Now, this was NOT a Humongo-Booster[tm], certainly not by the standards I've seen tossed around here. Most of the mass was in 9 Kerbodyne SRBs that get it most of the way to orbit; those add up to around 200 tons, so the whole thing on the pad is probably 250 tons or thereabouts. I'm sure that there are plenty of people out there who have successfully launched vastly heavier lifters than that, in V0.25 with destructible buildings turned on. I have also seen complaints here that the runway is too fragile (though I haven't experienced that yet, myself). So how have others worked around this? Is the era of Heavy Lift over? (And for that matter, do we know if the devs have any plans to toughen up the runway and launch pad?)

I was curious about how the behavior of parts change with distance/SOIs (solar panels and antennas, mostly). So I fired up a "goofing around" save and slapped together a poorly-thought-out probe (as one does for missions with really loos parameters). Paid almost zero attention to angles during execution, because my immediate goal was just "head outsystem while avoiding Mun" with no particular destination. Stopped burning when apo was out a bit beyond Eeloo orbit. Grabbed data at several points along the way out, then figured "Hey, I have a bunch of dV left, maybe I can turn this into a high-lob trajectory to actually fly by Eeloo". Eeloo was in a crappy location relative to my (essentially random) orbit, so I wasn't optimistic--but while setting up the maneuver node I thought I noticed a telltale flicker just as pe passed Duna's orbital radius. Yup. So...I went to Duna. Via trans-Eeloo space. Pretty much by ACCIDENT. And even hit the timing such that Ike was on the far side of its orbit when I reached Duna SOI, so it couldn't play space-billiards with my approach and aerobrake. (Dang it, that last part NEVER happens on a "serious" mission! Why NOW?)

Egg-zactly yes. Parts-testing contracts got SO MUCH EASIER for me when I (finally) figured that out. FUEL is not required, just the ability to stuff the part into the next stage and hit the space bar.

The way jets and rockets create thrust is to fling reaction mass out the back end at high speed. The primary difference is that the reaction mass that gets flung out the back end of a rocket is ENTIRELY the fuel/oxidizer mix. So the contents of the tank are both energy source and reaction mass. Whereas in a jet engine, the reaction mass is basically composed entirely of intake air. The fuel is ONLY there as a way of making the intake air really hot so that it shoots out the back end at high pressure/speed. Using what we in engineering refer to as "rough order of magnitude estimation", about half (ish) of what shoots out the back end of a rocket is fuel--rocket exhaust is a noxious brew of chemical combustion products. About 1/100 (ish) of what shoots out the back end of a jet engine is fuel -- jet engine exhaust is essentially just really hot air with a teensy bit of combustion products as more-or-less minor impurities.

Well dang. The amount of time I've spent in orbit around Minmus, and I *never noticed* that its equator didn't line up with its orbital plane... I feel stupid...

I had One Of Those Hours. When everything happens at once, despite my intentions. I got distracted by a launch window for a probe. That window came up shortly before my imminent Mun Orbital Station needed to make its Munar orbit-insertion burn. It was close, but there seemed to be enough time between them that it would be okay. Once the probe was on its way, I took a look at the progress of the Munar-Station-to-be, which had about 15-20 minutes until its burn. (Heh. Well timed!) And then, while I was in map view centered on Mun, I realized ... OMG I NEED TO DO A RENDEZVOUS BURN REALLY SOON NOW (to dock a tug to a Mun lander with near-empty tanks, so it can get to the aforementioned Mun Orbital Station for refueling). Or else wait around, burning doughnuts in the sky, until the lander gained a full lap on the tug...with Bob and Jeb getting impatient and bored in the lander. (And possibly running out of snacks.) So, RUSHRUSHRUSH set up the rendezvous burn. Fire. Note that the resulting closest approach, while not ideal (0.3km rather than my preferred 0.1-0.0) should do, and I have no flippin' TIME to fine-tune it! RUSHRUSHRUSH over to the Munar Station and its long, barely-stable Nukes-towing-flexible-structure orbital capture. Resulting orbit isn't as circular as I'd like (about a km difference between peri and apo), but NO TIME TO FINE TUNE NOW! RUSHRUSHRUSH back over to the tug and lander and their imminent docking! OMG well in physics range already! NO TIME TO SET UP A NODE JUST MATCH VELOCITY BY NAVBALL AND HOPE! Worked out okay, though the resultant docking operation took longer and used more monoprop than I'd've liked. And now, the multiple time-sensitive burns in too-quick succession over, everyone is settling in to the new Munar Station (Jeb is already plotting a clandestine EVA to paint over the official "Munar Station One" insignia with "Jebediah Kerman's Gas-and-Go Fuel Stop and All-Night Diner: The View Is Out Of The World") and I get a well-earned respite. And attempt to act on the lesson learned: Don't Do Too Many Things At Once.

The short answer: retrograde burn. The slightly longer answer: The direction you are moving is "prograde". The opposite direction (where you've already been) is "retrograde". (In space, the direction your craft is MOVING is not necessarily related to the direction your craft is POINTED.) You need to point your vehicle retrograde ("backwards"), and fire up the engine. This will slow you down, which in turn will lower your orbit. Lower your orbit enough and you will hit atmosphere, reenter, and eventually land. (You did bring parachutes along, right?) The navball (bottom center of your screencapture) can help you with this: the orange icon in the middle of the navball (looks like a letter V with wings) is the direction your spacecraft is pointed. The yellow icon slightly to its right on your screencap (looks like a circle with airplane wings and tail) is the prograde marker. If you turn your craft so those two icons line up, you will burn in the direction of travel--this will increase your velocity and your orbit will grow larger/higher. That is the opposite of what you want to do. So what you want to do is turn your craft around, and find the yellow icon that looks like a circle with an X in it and three rocket-fins. That marks "retrograde". To de-orbit, line up direction icon with that retrograde icon and throttle up. Edit: Ninja'd. Multiple times. Clearly I need to learn how to be less wordy!

What everyone else has said already about history and programming convenience. Also, it's not a KSP-specific programming convention. Professional-grade rocket/missile trajectory simulators (at least the ones I've worked with, to the best of my recollection) all use the same sort of stage numbering: start at 0 or 1 for the final payload, and increment stage number in reverse order of separation (so the highest-numbered stage is the first section to get dropped on the way up).

With all the traffic here on the Forum complaining about how the science track is TOO EASY, I think it's good we hear the occasional "too hard" post. Folk with a pre-existing stable of finely-tuned craft and vast experience in both ship design and piloting are found in abundance here...but those are not the people that the science track is intended for. The science track and tech tree are a LEARNING TOOL for beginners. And I think it's important that our heroic and hardworking devs hear from those people, not just from those who do a crew-return from Tylo before breakfast. That said, I see you wished for a Minmus contract before tackling Mun. I'm with you there--and you actually can make that happen. If you have a vehicle with the dV to get to Minmus orbit, you can get to Mun orbit with the same vehicle. Right? So: Launch your Minmus lander. Yes, I know, you don't have a contract. Don't sweat it. It's going to take DAYS to get there, and you'll have your contract soon enough. Once it's left LKO and is on that long coasting trajectory for Minmus rendezvous, DO NOT WARP, DO NOT FINISH THE MISSION. Go back to KSC and make a second launch of the same type ship. Target this one for Mun. Don't worry that it doesn't have the T/W or dV to land, you're just trying to get to orbit. That trip takes about 5 hours one-way. Get into orbit, transmit a crew report. That gives you half of the criteria for the "Explore the Mun" contract, and that's enough. Go back to KSC, and there should be a nice juicy "Explore Minmus" contract waiting for you. (You may have to do a bit of churn by rejecting some offerings and maybe taking a few "science from space near Kerbin" or "science from space near Mun" contracts. Which you can do, because you have a ship in Mun orbit and I assume you've got something in Kerbin orbit specifically to pick these up. But the Minmus contract WILL show up, well before your Minmus lander actually GETS to Minmus.)

Time for the after-action report, since I jumped the gun last night: (Quote greatly edited to avoid Wall-o-Text) In the end, it came off swimmingly (and for Jeb and Rodwin, who did the EVAs, that's not a metaphor). No pics during the two-way crew transfer, because I'm not as good a jetpack-jockey as some others, and I had my hands full. But here's Mun 1, stopped dead floating less than 10 meters from the station and on the correct side to get easy access to both the Mun lander hatch and the Hitchhiker hatches, before the crew transfer: And then AFTER Rodwin jetpacked over to Mun 1 and grabbed the ladder, Jeb crawled out of the capsule and started toward the station, Rodwin climbed into the Mun 1 return vehicle, and Jeb successfully navigated to the Eagle Advanced Mun Lander: All in a day's work for some of you, I know, but for me this involved a certain amount of nailbiting. Formation flying of any sort always makes me nervous...and this little orbital dance required choreography for 4 separate flyers. I'm pleased with how it turned out. (And for the last feather in my cap, Rodwin managed to bring Mun 1 in to a safe landing less than a km from the KSC launch pad!) (EDIT: Okay, that's obviously not the preferred way to post a picture...)

Mine isn't so much a "what did I do today" as "what do I plan to do". It's one of those "kind of stupid, maybe I shouldn't be trying this in a career save" things. Wish me luck.... Experimental early-tech Mun lander turned out to be a decent orbiter, but had a design flaw that made it a deathtrap to land with. So Jeb's coming back without leaving footprints--and that Will Not Do. In the meantime, tech has advanced and now there's a space station with an advanced two-Kerbal reusable lander waiting for him...and Jeb is NOT going to let someone else steal his glory by being first. So Jeb is on final approach to a rendezvous with the station. His primitive vessel has no docking port, so the plan is to match velocities, send one of the station crew to Jeb's ship (it has science that needs to get back home, so it must be saved), then Jeb makes the jump over to the station so he can get aboard the new-tech Mun lander and still be First On Mun! It was after making the rendezvous burn, during that final half-orbit before matching velocities, that I realized Jeb's primitive ship is missing something else in addition to a docking port. It also has *no RCS jets*. So we're going to have to maneuver the whole great honkin' space station (woefully unbalanced at the moment due to the aforementioned reusable Mun lander and its orbit-transfer tug...) to meet up with Jeb in whatever almost-but-not-quite-good-enough semi-matched orbit he and his tiny ship end up in. And maneuver IT for stationkeeping as required while I'm simultaneously doing the free-floating EVA crew transfer. Fun times. Wish me luck....

I usually have boring, utilitarian names. "Mun 1" or suchlike. But there are a few exceptions. When I get to the point in any save where I'm building orbital infrastructure, the first two general-purpose tugs are ALWAYS named "Flying Dutchman" and "Fata Morgana". Minmus seems to bring out the goofy in me (it's doubtless the EVA and Crew reports responsible for that). So my first crewed landing mission (long before I ever tried landing on Mun) was known as Project Minty Dessert. Later, once I'd mastered rendezvous/dock, there was the orbital station "Bill-n-Bob's All-Night Dessert Diner" with reusable landers "Julep" and "Key Lime". (Jeb had already claimed the Munar orbiting station and called it "Jeb's Gas-n-Go", so once again Bill and Bob are copycat also-rans.) Mun lander names include Eagle and Armstrong. (Mun seems to inspire me, rather than make me giggle...) Every save also eventually gets a transfer/refueling/construction station in LKO, generally with some variation on the theme of "Kerbin High Port". And of COURSE I have used "Kerbpollo" (as does everyone). Project Red Planet is pretty self-explanatory. That's about it for interesting names. The rest are either prosaically descriptive (like "20-ton Lifter") or express my frustration ("Orbit or Bust V3c" was an early effort).

Well dang. No joy. Now that I know what to look for, I can verify that the I-beams are indeed SURFACE ATTACHED to the docking ports. On the plus side, I edited the docking ports suggested in Claw's thread, and when reloading the edited persistent file, Kerbin High Port did NOT explode (yay!). On the minus side, the I-beams remain solidly welded to the edited docking ports (boo!) The next thing to try would presumably be to make a similar edit to the I-beams so that they are node-attached rather than surface-attached. But to do that right, I'd need to know how far the I-beam would have to MOVE to be properly aligned, yes? EDIT: Curiouser and curiouser! After loading the edited persistent.sfs, trying to decouple the I-beams from the ports (and failing), then quitting out...KSP re-edited my edits. Now the docking ports are all back to 'state = Ready' (I had edited them to 'state = PreAttached' per instructions) and for some reason KSP decided that the I-beams are attached to the BOTTOM docking port node rather than the top node. (Which would certainly explain why I can't undock from them...!)

Thanks, I'll look into it. (I have a sneaking suspicion that I may have connected the beams to the node surfaces; but I'll poke at it and see what happens. Worst comes to worst, I evacuate the station and destroy it, then launch again. Huzzah for a healthy bank account!)

There seems to have been a rash of docking port issues of late. And I've got another. I launched a space station core recently. It's a variation of a design I've used before, and I know from prior experience that its Clamp-o-Tron Sr attachment to its booster is too wobbly to survive launch unaided, so I provide launch restraints in the form of struts attached to I-beams which I then discard once it's safely in orbit. One of the ways in which this was a "variant" was that I added Clamp-o-Tron Jrs to its fuel-storage tank and attached the launch-support I-beams to those. Idea was that I could then get rid of them by undocking the port, and the I-beam floats away. I've done this before in other contexts (though I confess this was the first time I did it with Jrs). Works just fine. Except this time it didn't. I click on the docking port, and the ONLY option I am given is "control from here". No "undock" option. All 4 of these docking ports behave identically; but I also set up a quad of Clamp-o-Tron Srs the same way, and they behaved as expected. My first thought was that maybe the Jr was too small, and the I-beam slopped over onto the tank and was thus irrevocably attached. However, this does not seem to be the case, at least with a visual inspection. Looking at the responses to other folks' docking port issues, I imagine I can edit my persistent.sfs to fix the port...IF I knew what to look for and what to change it to. (Alternately, I could "cheat" with a more "game-y" solution and just delete the I-beams from persistent.sfs...but I suspect I'd have to change something about the docking port's state rather than just delete the I-beam, and I don't know what changes I'd have to make to the docking port.) Help?

For the most part, I'm holding off on filling those contracts until I get enough science for aircraft. Then it's a simple matter of flying at the desired altitude and velocity, then hitting "stage" or "test" (as appropriate). Much easier (and CHEAPER) than trying to design a custom craft and/or mission profile to hit the altitude/velocity window with a rocket. Though I note a potential drawback to that strategy: is there a maximum number of active contracts? I have 8 at the moment, and the new offers seem to have stopped coming. (I may have to hit the airplane branch of the tech tree sooner rather than later...)

Oooooh, EXCELLENT! I took a contract to test the Rockomax SRB without really paying attention to the conditions: suborbit at 90-frickin'-km! (And I'm VERY early in my first v0.24 game; wasn't really sure how I was going to [1] get a fully-loaded BACC that high, and then [2] FIRE IT in a way that ensured safe crew return.) I was seduced by the enormous bankroll offered for success....

My Kerbals are finally getting ready to go interplanetary in a big way. That obviously means nuclear propulsion. But 'interplanetary' means I'll be doing larger-dV single burns (>2000 m/s in some cases) ... and with fuel-efficient but low-accel craft? That means long burn times. Where "long" (by my very rough calculations) is going to mean "a substantial fraction of LKO orbital period". An 8-minute burn is a quarter of an orbit... and the Maneuver Planner assumes "instant" dV applied to a specific moment/location. Which in turn adds significant differences between the impulsively-planned maneuver and the actual long-burn-time maneuver. I haven't ever needed to burn longer than about 5 minutes in any of my trips to date, and even that was starting to noticeably adversely affect the actual trajectory vs the planned trajectory. (And Minmus's SOI from 46Mm is a huge target compared with, say, targeting Dres's SOI on the other side of the Kerbolar system.) If I were doing this with my professional hat on, I'd crank up one of the trajectory-optimization packages, integrate the EOM, and get a burn profile that accounted for the time spent in the burn (and associated orbital V-vector change during that time, etc.). But that's Way Too Much Like Real Work...and I know most of you don't have those sorts of tools ready to hand (and therefore are doing it--successfully--without such tools.) So I'm casting about for an accessible, low-tech, play-friendly solution. The first thing I thought of was to start by climbing into a much higher orbit with a longer period, so that it's still a reasonable approximation to model a 10+ minute burn as impulsive-dV. But that technique is wasteful of the selfsame fuel that I am using nukes to *conserve* in the first place. And I haven't seen anyone calling that out as a convenient way to improve the accuracy of interplanetary departure burns, so I assume you folk have hit on something else. So how do you more-experienced Kerbonauts approach the problem of maneuver planning for interplanetary departures with very long burn times?

Thanks, all! It sounds like I've had the right approach all along, I just need either a) more practice, give up "pure stock" and set up a mod that gives me better/more-accessible data, or c) both. Last night I managed a reasonably-fuel-efficient descent/landing and wound up aligned with but 8km short of the target, in a less-than-ideal mostly-flat-but-cratered area (craters really screw with techniques that rely on velocity as a function of height above ground...). Sounds like I'll get there with patience and practice. I do rather like the idea of tweaking the engine thrust after deorbit but before landing. I hadn't thought of that. I deliberately built this lander with an overpowered engine to see if I could reduce my total fuel requirements with a) better Isp (ooooh, that seductive 390 secs of the LV-909!) and lower gravity losses. It seems to have worked for that, but at the cost of reduced fine control in terminal descent as noted in this thread. Thanks again!

Now that I've figured out (even if not precisely 'mastered') rendezvous/dock so I can 'routinely' fly Apollo-profile missions and visit space stations, it's time to add another skill to the mix. Namely, precision landing at a predetermined site (on a vacuum world). I've seen plenty of screenshots of bases/colonies that clearly required multiple landings at the same site, so I know there are folk out there who've mastered it. I've managed to get kinda-sorta close (within a couple km, anyway) to a desired landing site on Mun or Minmus by the simple, if fuel-wasteful, expedient of killing ALL my orbital velocity when essentially directly over my desired landing site, plummeting for a while, then burning to remove the accumulated vertical velocity in order to accomplish a "landing" rather than a "new crater". But there has to be a more elegant (and fuel-efficient!) method than that. One that more closely resembles a launch-in-reverse (short "decircularize"/deorbit burn something less than halfway around the Mun from the desired landing site, cruise in to low altitude and some distance uprange of desired landing site, fire engines and come down in a 'reverse gravity turn'). I can do that kind of landing without too much problem (as long as no mountains/crater walls are near the LZ!), but the actual touchdown site is...well, let's just say I can hit the correct biome pretty much every time, and usually come down in the desired area of that biome. But it sure as heck isn't likely to be within convenient EVA distance of the actual target point, let alone the precision I've seen in screenshots, where multiple landing craft are lined up like a suburban housing subdivision. Any tips/hints/tricks/techniques from you more experienced KSP'ers? (Yeah, I know, "MechJeb". But I'm looking for all-stock, all-manual solutions. And that's NOT a declaration of religious crusade, or saying that anyone else is 'doing it wrong', or anything like that. I just happen to play stock/manual, myself; YMMV, and that's fine.)