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About vyznev

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  1. vyznev

    air speed record

    Do we have to stay within the atmosphere? Because if not, just accelerating to any absurd speed you like in space and then aiming for a 69 km Kerbin periapsis seems like a winning strategy. If we do have to stay within the atmosphere, I suspect the winning strategy is instead a powered orbit (i.e. thrusting nearly straight up in order to stay at a constant altitude while moving faster than normal orbital velocity) just below 70 km.
  2. Even so, our spacecraft look remarkably similar. I admit to seeing your screenshots before I'd finished building my Kerbin ascent stage, so I may have been influenced by your design a bit there. But the return stages (which appear to differ mostly in part placement, and the inclusion of a docking port on yours) seem to be a genuine example of independent convergence. (It does look like my return stage is probably slightly lighter than yours, which suggests that a hybrid craft using your direct flight plan could do better that either of our current entries so far.)
  3. Well, I finished it. Without further ado, here's my reliable and elegant spacecraft: It's powered by 44,759 kg of solid rocket fuel, contained in one Kickback booster, three Thumpers, two Hammers and 36 Sepratrons (including four that I ended up discarding unused!). The total mass at liftoff is 56,857 kg (plus one Kerbal = approx. 94 kg). Here's the craft file, if you'd like to give it a try. But let's start by examining it from the top down, the way I designed it: Full mission report with screenshots here on imgur.
  4. We seem to be converging to a rather similar design: Your upper stages do look a lot lighter than mine. I'm not sure if your flight plan is more efficient, or if you're just being excessively optimistic. Oh well, we'll see. (FWIW, I'm sure this vessel can do it, since I've already flown each part of the mission separately in practice runs using Alt+F12. The Mun landing stage even turns out to have way more delta-v than it really needs, since I designed it for landing from a 15 km orbit rather than the 8 km orbit that I managed to reach when I actually tried flying the whole mission without cheats. It turns out, however, that the lower altitude and the excess delta-v also completely mess up my carefully planned landing burn sequence, so I'll probably have to give it a few more tries. )
  5. I'm assuming that using RCS for landing rendezvous with the surface would be cheating, right?
  6. vyznev

    The Jool atmospheric science challenge

    So we basically need to recreate this video? I wonder if Joolian physics have changed in any relevant respect since KSP v1.2.2.
  7. vyznev

    Minimal Mun/return for kids

    The way I see it, "can't be too close on the delta-v budget" and "requires Mun orbit rendez-vous and docking" are kind of incompatible in stock KSP. The problem is that returning from low Mun orbit to Kerbin takes only about 300 m/s of delta-v, give or take a few dozen, so pretty much any Mun ascent vehicle with more spare delta-v than that can just return to Kerbin directly. (Of course, the vehicle also needs to survive re-entry into Kerbin's atmosphere, but the default re-entry heating settings are pretty forgiving, too.) That said, I basically see two ways to go about doing this. One would be to try to recreate the real-life Apollo mission constraints as faithfully as possible: Must send multiple kerbals to the Mun, and leave at least one in orbit while the others land. No probe cores (at least, nothing more advanced than a Stayputnik). No EVAs except when landed, and no command seats. (Career mode will actually enforce this, if you haven't unlocked the necessary tech and building upgrades.) Optional: all kerballed vehicles occupied for more than, say, 15 minutes must carry some dead weight (e.g. ore tanks) to simulate life support equipment. The amount to be carried should be roughly proportional to the maximum kerbal-hours spent in the vehicle. (Or install an actual life-support mod, although most of them also tend to be pretty generous with the survival time / mass ratio.) Require an actual command pod for Kerbin re-entry. (No slapping a heat shield on a lander can or just riding a command seat down!) Hopefully, all these constraints should actually make leaving a proper manned return vehicle in Mun orbit and docking with it both necessary and practical. The other option would be the Kerbal approach: just cut down all safety margins to the bare minimum and, in particular, make the Mun lander so flimsy and lightweight that it actually cannot return to Kerbin on its own. Obviously, that's the approach I chose to go with. Here's my first (successful) try, the Krapollo 14: It carries a total of 9,200 kg of fuel and oxidizer at launch, which actually turned out to be way overkill; I'd read the delta-v chart wrong and accidentally allocated about 1 km/s more delta-v for the Kerbin-Mun-Kerbin transfer than I actually needed. Oops. Still, it's at least a decent proof of concept. Here's the craft file, if you want to give it a try yourself. Or you may prefer this improved (but untested) version with a probe core and RCS on the return stage. It's probably not the most kid-friendly craft to fly, but hey, it's pretty cool and kind of a fun challenge.
  8. Well, I wanted to make sure I wasn't talking bull**** there, so I designed this fine and elegant craft: It has basically the same upper stage as my earlier spaceplane entry, consisting of a single Terrier engine, an FL-T400 fuel tank and a command seat inside a fairing. The lower stages, however, have been replaced with an "air launch platform" using a giant balloon RTG-powered stock helicopter to lift the upper stage at a stately pace of 10 to 20 m/s all the way up to 10 km above sea level, where the Terrier engine works at almost full efficiency and has enough delta-v to reach orbit. After the first unmanned test flight, I also ended up adding an extra reaction wheel (plus batteries) inside the fairing for more stability and control. The upper stage is still aerodynamically unstable and requires careful steering to avoid tumbling over, but I only had to reload my quicksave twice before I (barely) managed a successful orbital insertion. More screenshots of the flight here. Craft file here. As I noted above, I'll leave it to @DAL59 to decide if this counts as a valid challenge entry or not. But if it does, then with just one Terrier engine it's pretty much unbeatable in its class (unless we come up with some kind of a tie-breaker, like maybe total mass lifted to orbit).
  9. You can actually pin the box that lets you adjust the propeller pitch in stock, and it will remain usable after switching back to the main craft. At least usually; I'm not 100% sure what the criteria are. And of course it does get kind of awkward if you have multiple props, or multiple blades on a prop that aren't linked clones, since then you have to adjust each blade separately. Unfortunately, I don't have a good propeller-driven craft on this laptop to show you a screenshot of, but here's an autogyro.
  10. I see where you're going with this, and yes, you could probably do this using just one Terrier and a stock prop. But I guess it's up to the OP if they'll accept it or not. It would still be a pretty cool craft, at least.
  11. vyznev

    Kerbal aircraft drag race challenge

    Well, I got it down to 1:07. I think a return time under one minute may well be possible with this craft, but it's going to take some more practice. The critical moments are stopping the ascent after the burn ends (which also affects the peak altitude, and therefore the time needed to come down) and braking to a halt after landing. I'm sure there are still seconds to be saved from both.
  12. vyznev

    Kerbal aircraft drag race challenge

    If you mean above the runway, my craft can pretty much do that. In fact, in one of my test runs I found myself coming down just above the middle of the runway, and had to steer east a bit on the way down just to make sure I had enough room for a westward landing. (That was probably unnecessary, since the craft actually brakes quite well once you get the hang of it. But I was still practicing.) Actually, I'd expect pretty much any entry with TWR much greater than 1 and sufficient control authority to be capable of that. Of course, since the runway is pretty narrow, it's easy to accidentally slip a few meters off sideways (and hard to know for sure whether you did or not). But basically it's just a matter of turning straight up after takeoff and coming back down the same way. (I really should try to do another run and see if I can improve my return time. Looking at the leaderboard, I think I might actually beat at least a few other entries if I practiced the turnaround and landing a bit more.)
  13. vyznev

    Can i upload missions here

    It's mostly challenges, yes, but technically mission ideas are also on-topic. Here's one example of a pretty detailed collaborative mission planning project. You can find more examples of mission ideas posted here with a search like this. As Blasty McBlastblast noted, mission reports belong in a different place.
  14. vyznev

    Kerbal aircraft drag race challenge

    Well, as promised, here's the kerballed version. Some might detect some similarity here with my entry to an earlier challenge. The main difference is that this time I'm using a lot more than just one sepratron. In fact, this craft has a total of 126 of them, arranged in five rings of 24 each, plus six on the wheels to counteract their drag. The craft can take off on its own from the runway; the launch clamp is only used to hold it still before launch, and to ensure that the mission timer doesn't start prematurely. For maximum velocity at the end of the burn, you need to turn nearly straight up immediately after launch. (In fact, holding the S key while launching is a good idea.) With a TWR over 18 at launch (and peaking at almost 81!), gravity is negligible compared to atmospheric drag. With decent steering, the plane (barely) breaks the 1 km/s barrier at the end of the five second burn. Unfortunately, it only does so for a small fraction of a second, and I wasn't quick enough to catch a screenshot with the maximum speed visible on the navball. But the F3 screen does accurately report the "highest speed achieved" as 1003 m/s. The glide back down takes a bit longer, as does slowing down using the "wheelie trick" (pitch up to make the wheel fairing drag on the ground). On this run, I managed to come to a full stop at 1:24, but several seconds of that were wasted precariously teetering back and forth on two wheels while trying to decide if I should keep the plane balanced that way or just let it fall on its tail. More screenshots in the full imgur album. The .craft file is here on pastebin.
  15. vyznev

    Kerbal aircraft drag race challenge

    FWIW, I'm going for the 5 second mark. Because that's how long sepratrons burn. This is the unkerballed version; I'll need to mount a command chair on it and see if it can still break the 1 km/s mark, or if I'll have to add even more sepratrons. Watch this space... (Also, it flies back as a glider, and a pretty lousy one at that. And it has no brakes, so coming to a full stop is a bit tricky. But it can return and land intact, although it's not going to be breaking any speed records for that phase.)