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Everything posted by zolotiyeruki

  1. Agreed. I love my LV-909s, but they look ridiculous on a 2.5m tank. And they don't stack well.The same goes for LV-N's
  2. Count me in here as well. I've had several situations where I've had a LV-N-powered upper stage on top of a boost stage that had some leftover liquid fuel and oxidizer. It would have been *really* nice to vent the unused oxidizer and burn the remaining liquid fuel in the LV-Ns before staging. In short, everything Monstah said, I agree with. Accessible through the right-click menu, and I don't care all that much about speed. I'd recommend just have it go as a % of tank/second, so every tank would vent in the same amount of time.
  3. I consider myself rightly chastised. I *do* have a quicksave from just before I started my descent, so maybe I can go back and re-do the landing, and stick it on the runway this time I took screenshots more or less over KSC on each circumnavigation (can we just call 'em circles?), and it looks like the first time around took 42 minutes from takeoff to passing over. My speed started off at 1694 and gradually decreased as I got lighter and higher, down to about 1655. Bill was passing over KSC for the 5th time at 3:17 (hh:mm), so that gives an average time of about 39 minutes for circles 2-5. Given the fact that I had no landing or takeoff time for those circles, that makes those 38-minute runs really impressive! EDIT: Ok, I went back and re-did the landing, and updated the imgur album to show the F3 screen. I swear, this thing doesn't want to land when it's empty. It naturally sits with the nose down a bit, but the wings are still angled upward. The approach was still hot, so when I flared in order to land on the main gear first, the stinkin' thing started climbing again. I thought I was going to have to fire up the engine and go around, but I finally got it down and stopped right at the end of the runway.
  4. Once upon a time, I had a kerbonaut that I was trying to return from Minmus, but ended up with my Pe just barely out of the atmosphere. I needed, literally, 10 m/s dV in order to get my Pe under 70km. So Jeb (or whoever it was) had to get out and push. Let me tell you, it was tricky trying to keep the capsule from spinning too much. Probably took half an hour of careful EVA in order to get things lined up.
  5. FWIW, I wasn't sitting in front of the computer the whole time. I would take a screenshot, set a 20 minute timer, go do something else, then come back to take a screenshot. Thank heavens for Pilot Assistant!
  6. It's remarkable how much you can accomplish in life if you eschew social situations.
  7. And we now have 7 TIMES AROUND! Bill arrived safe at KSC after a nearly 5-hour flight, having circled the planet 7 times. Whew, I'm going to bed. Had a bit of a hard time staying on the runway after such a long flight, but so would you! Werner Kerman just realized that if they can squeeze about 1% more efficiency out of this thing, Bill can make it to 8.
  8. The trick is to keep your nose as close to prograde as possible. Start your gravity turn early (around 100m/s), then stick close to that marker. The whole unbalanced lift thing only gets out of control once you've exceeded your craft's ability to counteract it with engine gimballing and control surfaces.
  9. I've begun my multicircumnavigation run! I've made a few minor optimizations to my craft: eliminated the battery (I only need a little bit of torque when levelling off), emptied the monoprop tanks in the fuselage. I did some tests to see if a ram air intake would provide better efficiency, or a nose cone + precooler. Neither were better than a shock cone intake. I also am trying something new: since my wings are already angled up, and my drag is minimized when I'm traveling exactly prograde, instead of following my carefully-plotted altitude spreadsheet, I'm using Pilot Assistant to maintain a 0 degree AoA, and as the craft lightens up, it'll naturally float to a higher altitude. So far, the results are promising: I'm flying both faster and with lower fuel consumption than I did in my tests at the same weight. Which is good, since my ascent consumed more fuel than I had anticipated. EDIT: 3 laps down! Efficiency is now quite close to expected values. Bill is wondering why on earth he decided to have that extra cup of coffee before taking off 2 hours ago. EDIT2: 4 laps down. Bill was napping when he passed over the KSC. That was ok, though, since the entire KSC staff had gone home for the night anyway. EDIT3: half way through lap 5. Bill wakes up to realize he completed more than half a circle while sleeping. His gas mileage is showing about 24km/unit (liter?) of fuel. Let's see a Prius beat that at mach 5.5! EDIT 4: Bill: Mission Control, I'm ready to begin my initial descent. Mission Control: ... Bill: Mission Control, repeat, I am ready to begin my descent. MC: ... Bill: Aw crud. There's nobody at the tower, is there? No lights, no beacons. (looks at fuel gauges) Well, I suppose I could go around one more time... EDIT 5 (End of circle #6!): Bill: Mission Control, can I land yet? MC: Bill, the morning shift just got in. Can you give us 20 minutes to get set up? Bill: Seriously? In 20 minutes I'll be halfway around the globe again! MC: You don't have enough fuel for that, do you? Bill: Oh, I've got plenty of fuel. It's just that Bob ate all the snacks again, and I'm starving!
  10. Whew, I finally have all the data I need in order to make my run. That took....a long time. Enable infinite fuel, set the weight by emptying the fuel tanks in the SPH, fly it up to 23.5km without losing stability, let it sit at that altitude for 10 minutes to stabilize speed and thrust, go up 250m, repeat the 10 minute wait, do that until efficiency drops. Then revert to the SPH, lower the weight some more, and repeat, in 1 ton increments from MTOW down to empty fuel tanks. I've got my flight profile now, just a bit of math left and I'll have to find 3.5 hours where I'll be around the house and can periodically come back and check my progress. With almost empty fuel tanks, my cruise altitude will be 27,500m (!) and my thrust will be a whopping 8.1kN. Seriously, 8.1kN will be enough to maintain that altitude at >1600m/s. No wonder re-entry from orbital velocities is so hard--there's hardly any air until you're under 30km! - - - Updated - - - Is that because you start at the west end of the runway?
  11. I seem to remember doing a comparison test with the wet strakes vs the basic ones, and noticed increased drag, but my recollection might be wrong. Your craft had 2400 fuel vs my 1600, so I have to be a lot more optimized in order to make it the same distance. I'm lucky so far with CoM--it's almost exactly in the middle of the four tanks, so there's no need to balance at any point during the flight. Descending from 26km and 1600m/s took about 30 degrees of longitude, when I tested it. That's a fair distance! I wonder how much fuel you could have left at home and still made the distance...
  12. Yeah, well, I'm a bit of a geek, so I did a lot of testing before the 4-circle run, to find the optimal altitude for the craft as it burned off fuel and lost mass. Now, I'm doing it all over again. I think since my design has a lot fewer wings and uses the flat strake instead of the Big-S strake, I have a lot less parasitic drag from the wings. That makes the parasitic drag from the fuselage a bigger factor.I'm still running all the tests to find the optimum altitudes throughout the flight. The craft starts at 12.8 tons and runs dry at 4.8 tons, so I get up to altitude (start at 23.5km), burn down to 12t total, then enable infinite fuel and let Pilot Assistant hold the altitude until the speed/thrust stabilize. Then I write down an "efficiency quotient" = (speed/thrust). Then I go up 250 meters and do it again, and then another 250m, etc, until the efficiency starts dropping. After that, it's a matter of burning of 1000kg of fuel, dropping down to 23.5km, and then measuring the efficiency every 250m. It takes a lot of time to run all the tests (burning 1t of fuel at 0.5-0.8kg/sec takes a long time), but it has a huge impact on fuel efficiency. Just a 250m change in altitude can change the gas mileage by >5%. When you're shooting for 5x around the planet, that's a quarter of a circumnavigation right there.
  13. Oh, my, I've had that happen a LOT of times. Here are some things I've found that help: 1) Mount the boosters so that their tails are behind/lower than the tail of the center engine. That way, if they try to go toward the middle after decoupling, your rocket will already be beyond them. 2) If the boosters are SRBs, mount them as low as you can on the decouplers, so that when when you decouple, the top of the SRB moves away from your rocket more than the bottom 3) If the boosters are liquid-fueled with multiple tanks stacked, attach the *top* tank to the decoupler and additional tanks/engines below it, so that the top of the booster is the part that gets pushed away. 4) Right is right--point surface prograde. 5) Get more practice using sepatrons . Stage separation is what they're (intended) for. Can you post a picture or a craft file for a ship that's having trouble with stage separation?
  14. I finally got around to completing my 4x circumnavigation. Started at 23.5k, ended at 26k. Landed with 90 units of fuel left, enough for 40% of a 5th circle. Used Kerbal Engineer for calculating efficiency, and Pilot Assistant to keep me sane. The craft is pretty simple--shock cone intake, Mk1 inline cockpit, four fuel tanks, one rapier, a 1k battery. R8 Winglets in the front and as the vertical stabilizer, wing strakes and small control surfaces in the back. On the last lap, my fuel consumption dipped to 0.09 units/second. First time attempting to embed an imgur album. Let's see if this works... So....I have enough fuel for almost half another circle. I also noticed that my AoA at altitude started near 8 degrees at the beginning of the flight, and was still over 3 degrees at the end. That meant my tail was a full diameter lower than my nose, and with my (limited) understanding of KSP aerodynamics, that makes it draggier. So, this morning, I took the same craft, and angled all the lifting surfaces by 5%. A quick test showed a 30% increase (!) in MPG at full take-off weight, and a much higher speed (1676m/s vs 1615). That gives me hope for an easy 5x circumnavigation. I also noticed that using time acceleration incurred a slight (1-3%) efficiency penalty, which means the next flight will need to happen in real-time. 40 minutes/circle, 5 circles...It's gonna be a long night. EDIT: crud, I went back and re-read the rules, and I took my screenshots on the wrong side of the planet. doh! C'mon, just look at my speed, my fuel flow, and my flight time in each screenshot, and that should be proof enough, right? EDIT2: I now realize that my craft is awful similar to ExaltedDuck's. I guess that means I just need to either A) beat his 5 circle time, do it with a smaller/lighter craft, or C) get 6 circles. Hmmm. If I can do 5 circles on 4 tanks, I wonder if I could manage 6 circles on 5 tanks...
  15. I've got a craft that I think will make it around 4x, averaging around 1600m/s. And it starts off at <13T. I spent way too much time last night finding the most efficient altitude as it burns off fuel. I think during the last circle, it'll be burning a whopping 0.1 units of fuel per second...
  16. CoL/CoM wasn't the issue, it was MechJeb being useless I had no problems bringing the nose back to prograde after MJ would mess things up. Which craft? The lawn dart or the one with big wings?
  17. I see I'm not the *slowest* circumnavigation, but it appears I'm close. There's probably enough fuel in there to make a second orbit, but I only discovered the challenge after completing this run. Yeah, I coulda made it more efficient and/or with less wing, but I wanted to use basic jet engines and go for a Rutan Voyager-style layout. It's a bit light on the TWR--I could barely get it above 8000m. Here it is at the end, with 30% fuel remaining: Craft file I also built this, which made the trip in about 1h10m, but I lost the screenshot, so it doesn't count. It also had well over 30% fuel left after one cirumnavigation. Craft file While I'm here, did anyone else have issues with MechJeb's Spaceplane Guidance up in the upper atmosphere? It seems like I can't get it to hold an altitude once I go above 18000m--it just wants to pitch the nose straight up.
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