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zolotiyeruki

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Everything posted by zolotiyeruki

  1. Is there a substantial difference in apogee between RTLS vs droneship? Regardless, I suspect it's an issue of entry angle--RTLS comes nearly straight down, while ASDS landings come in at a much shallower angle, leaving more time to aerobrake before hitting the denser atmosphere.
  2. True, and it's worth pointing out that the $1-2 million is SpaceX's cost, not the price they charge to customers.
  3. Holy smokes, they're now expecting $1m per 100 tons? I.e. $10/kg? Last I heard it was $2m. That's going the opposite direction of what usually happens.
  4. All those issues sound a lot like Floating Point error, and it's a very real (and troublesome!) thing. I seem to remember that several years ago, someone from the KSP dev team posted on the blog about the issues they face. Part of the problem is that we expect great precision (on the order of a centimeter, when docking), across enormous distances (Eeloo is something like 100,000,000,000 meters from Kerbol), so you're looking at 13 orders of magnitude.
  5. To be honest, probably not by me--while I've done a fair bit of programming in my time, the extent of my knowledge for building plugins only goes as far as being able to recompile them against new versions of KSP, and I'm woefully short on spare time to pick up yet another hobby
  6. Alright, I finally have my first entry for the Voyager division. I managed 19x times around! Woohoo! https://imgur.com/a/Ms6hE72
  7. Cool, cool! Er.....I mean.....nicely done! And without Rapiers, no less!
  8. Does attaching wings to objects inside the fairing mess with the aero or thermal? I seem to remember there being some odd behavior about that.
  9. jinnantonix now leads both of the competitive leaderboards. Y'all aren't going to let that stand, are you? jinnantonix, can you share how you attached your wings? It looks like you have your whole fuselage in a fairing, which would preclude attaching wings in that way.
  10. Wow, that landing had me holding my breath a bit--you nearly stuffed the nose into the dirt. What a ride! I think you could take a few more seconds' credit, since you actually got to 0 m/s.
  11. Grrr, I've been working/tweaking/optimizing my own entry for the Voyager division, and I have a design that I think will take the cake. But the capsule keeps overheating after two and a half hours of Mach 5+ cruising
  12. On the topic of P2P Starship delivering rapid cargo, what if they stuck the cargo in its own re-entry vehicle, and lofted it on a ballistic trajectory with SS? Then SS releases the cargo, and (now unladen) burns to put itself onto a one-around orbit. The cargo reenters to its destination, and SS lands back where it started.
  13. Sounds like the Waddington effect to me. The guy's story is pretty interesting--he and his team looked at how the British were waging war, and pointed out seemingly simple (and sometimes counterintuitive) things that made a big difference. One of their findings was that bombers had the greatest amount of unplanned maintenance (i.e. things broke) right after their 50-hour overhaul, and had fewer and fewer problems the longer they went from the 50-hour maintenance. And they told the RAF that the 50-hour maintenance period was too short and caused more problems than it solved. In essence, what they told the RAF was "if it ain't broke, don't fix it."
  14. Alright, I have a question about the appearance of the rocket exhaust, and could use some education: 1) At launch, what is the composition of all those billowing clouds? Is the rocket kicking up that much dust from around the launch pad? Or is it imperfectly-burned LF/Ox? Or is it a whole lotta condensed water vapor from the exhaust? A combination of the three? Something else? 2) At low altitudes, the exhaust is a bright yellow flame, and then around Max-Q it's more of a transparent orange, and then at MECO, it's almost invisible. Why is that? Is it because the exhaust expands more at higher altitude, so there's not such a concentration of light-emitting hot/burning gasses in the plume?
  15. Yeah, the test craft was about 11 tons and 1 rapier. You'd be dealing with a lot more lift-induced drag with that much mass.
  16. An addendum to the shock cone intake on the rear of the fuselage: I took that slapped-together craft, and tweaked a few things--replaced the probe core with a faired Mk1 capsule, and set the wing incidence to 3 degrees instead of 5. And then I tested it with and without the nose cone on the tail, at two different speeds, 1,650m/s and 1,715m/s, in level flight. For a given speed, both versions of the plane flew within about 100m of the same altitude (slighly lower for the version with the SCI due to the added weight). I ignored max temperature and used infinite fuel and electricity to get to a steady state. At 1,650m/s, total drag was decreased by 4.9% by adding the shock cone intake to the back of the rapier. At 1,715m/s, total drag was decreased by 11.2%. It's interesting to note that, as noted earlier, the lift-induced drag (as reported by the game) is strongly affected by speed--going from 1650 to 1715 resulted in a higher altitude, but also about 10% less lift, as the plane gets closer to orbital velocity.
  17. I can confirm the above--I just did a simple test, and that is 100% true. As for the silliness of banning nose cones on the back of rapiers, in the same simple test, I took a craft and tested it with and without the shock cone intake on the back of the engine. The difference was about 2.2% total drag. Granted, this was a thrown-together design with the wings at a 5 degree angle of incidence, so the wing parasitic drag is higher than you'd use for competition.
  18. Well, you could do the math. Let's say you've got a 50cm vertical jump on earth (because that makes the math easy). 0.5 = 1/2*9.8*t^2, and your fall time is about 1/3 second, and your vertical speed is 1/3*9.8 ~= 3.3m/s. On the moon, with roughly 1.6m/s^2 gravity, your fall time would be about 2 seconds, so you'd make it 1/2*1.6*2^2 ~= 3.2 m off the floor. That's a standing jump, upwards. If you launched at a 45 degree angle, your initial vertical velocity would be .707*3.3 = 2.3m/s, which works out to a fall time of about 1.5 seconds. If we neglect air resistance, you'd fly 1.5s * 2 * 2.3 = 6.9 meters. If you're a bit more athletic, or you get a running start, then yeah, crossing a 9m room in a single bound is within the realm of possibility.
  19. I imagine the passive stability enforced by the much larger rear fins would be plenty to minimize the adverse roll effects from the canards.
  20. So you're telling me that you constantly corrected the roll offset for over seven hours!? Or, if you were at 4x time warp, for almost two hours!? Holy smokes man, you're dedicated! (Incidentally, that's why I've taken on the maintenance of Pilot Assistant, so you don't have to do exactly that) Congratulations, you're at the top of the leaderboard. You certainly earned it. Even before 1.10, the engine noises got so irritating that I turn off the sound when running this challenge.
  21. That's a fair point about the yaw/roll coupling, although I wonder how much roll you'd actually get, given the much larger surface area of the (hypothetically fixed) rear fins.
  22. That's an interesting aside. When I've done a mk1-sized craft with a single RAPIER, near the end of the flight, it's only generating a couple kN of thrust to sustain near-1700m/s speeds at 27km altitude. An LV-909 at max thrust will burn 3.5 units/second of fuel, according to the wiki (is that LF only, or combined LF/Ox?), and produce 60kN. If it only needs to produce 5kN, that's 1/12th max thrust, so 3.5/12 ~=0.3 units/second. Two FL-T800's would give you about 800 units total LF/Ox, which would be more than enough for the 40-minute trip, assuming you use a RAPIER to get you up to 1700m/s and 27km. In fact, it's better than that, for two reasons: 1) using a rocket engine would allow you to fly at 29,900m and encounter significantly less parasitic drag 2) higher altitude and velocity means you're closer to orbital speed, and you need less lift to maintain altitude. It gets a bit nerdy, but I figured out that the amount of lift you have to provide is proportional to (GM/R^2 - V^2/R). With some hard numbers plugged in, if you're at 1700m/s and 27km, you only have to supply about 48% of the baseline lift, and at 1,900 m/s, you're down to about 36%. Note that the percentage of lift you have to supply doesn't change much with altitude. Actually, thinking about it a bit more, just using a RAPIER in closed cycle mode would probably be better, despite the Isp hit, since you'd eliminate the dead weight and drag of a second engine.
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