Kulebron

@all: I see some of you asked me for more proof and Laie mentioned not being naive. I have to say, that the ascent ship I posted was just a show of concept, not a submission to this challenge. I don't pretend anything with that, just showed that a lighter lander is possible.

I don't get it. There was no refuelling restriction in the original post, and I don't see how making this design decision makes you more worthy than one who worked more optimally. (I can make a jet powered reusable lifter for instance.) Like if Apollo missions were not really worthy because they used a specialized lander and rendezvous. I agree it's harder to launch all the huge stuff in one rocket, but it's as big a merit as launching an entire space station at once.

I think this mission is too big to restrict refuelling, and more than that, it makes no sense in any way. Who cares in how many parts you moved something if you did it? So basically, if you refuel, you can simplify tanks operations, and send as many orange tanks as needed, with wheels and a few legs, rather than excercize in extreme landing gears.

Of course not, I was testing just the ascent stage with Hyperedit.

Here it is. Stock + MechJeb. No control surfaces or glitch exploits, even only 6 massless parts. (I get some good thrust with monopropellant engines, but those can be replaced with T100 tanks and 48-7S engines in asparagus.) Not sure I want to complete the whole challenge. I guess I can throw it (empty) in orbit (attached upside down), and then start refuelling. What a long story... [edit] Ah, Signo went even lower in mass. Maybe I'll absorb his ideas.

I just made a rocket that weighs 130t and is able to ascend from Eve with a lander can. Making final demo run shortly.

That was my finding, here. Cubic struts sink and stick into ground, not letting you take off, while decouplers do not. It's basically a free (zero mass) bulletproof landing gear. By the way, the biggest NASA decoupler is massless too, so you can get a very big free landing gear. Many lateral tanks, everything looks very fragile. Like it can't be hard anymore and wants to reach hydrostatic equilibrium.

I thought this would be relatively easy if I minimize the Eve ascent stage and just lift it from Kerbin on jet engines. But, Jeesus, Eve stage quickly grew to 300t. That's insane! @Vaporo: your ship looks scary! Did you turn off pad destruction?

They do start and are used, although a lot less. Usually owners try not to stress their cars at these temperatures. We have commercial services that bring your car to life in strong frosts. But you can do it yourself. Normally cars are built for not lower than -20. Lower than that 4 things go wrong: first and most often battery loses charge. You have to heat it up to get any electricity. Secondly, the most expensive thing with -30 and lower is dampers get stiff and damage themselves if you ride over bumps (and ice bumps are abundant in winter). After some ride they heat up and become soft, but you can already damage them. A dozen rides like this, and they're dead. Then, oil becomes viscous, makes harder to start the engine, and something may happen to the coolant. Apart from that, no issues. Here are some tricks to turn the car on: 1) Most popular: equip the car with auto heating. After the engine cools below some threshold, it turns on for a minute. Monthly fuel usage raises 4 or 8 times in winter. 2) Put heat insulation coat on the engine right after you turn it off. Next 12 hours it's warm enough to start normally. 3) In army, they just drain oil and coolant in pales and bring them indoors, as well as the battery. Sometimes they heat them up before putting back. But this is too much work for a city dweller. 4) Electric heater, exhaust heat exchanger. If you didn't take care ahead, there are workarounds: 5) Ask someone to "light a cigarette", which means you connect your dead car's batteries to his working car, and run the starter as long as you need. 6) Use electric air heater (like in the photo above) 7) If nothing helps, heat up the engine with fire. It's risky to say the least, but some think they need this badly. Every year hundreds cars are heated up like this, and several of them burn up. This guy heats up the oil in the rear differential, which must have locked rear wheels.

^^ Pic is not loading. (Probably not allowing direct linking, try uploading to imgur.) Yep, it's continent vs shore climate. You enjoy Gulfstream. Here, winters are cold because of the huge continental anti-cyclon, with center over Kazakhstan, which dries air, closes circulation and makes this place a good freezer. I lived in North Europe, and the difference is stunning. Didn't like it. When I came back, I couldn't believe: it's sunny almost every day. Even Moscow is too cloudy and humid for me. But guys from deeper in the continent (Baikal region or Kazakhstan) complain that it's humid and cloudy here.

Almost all of it melted down last week actually, but now it snows again. Can't help but take photos.

@OP: I also once flew Dubai=>Rio de Janeiro, 14 hours, but before that I had 2 connected flights, 4.5 hours + 4.5 hours (OVB=>SVO=>DXB=>GIG). BTW, the return trip was BSB=>GIG=>LHR=>DME=>OVB. On topic: the problem with this challenge is that it can be won with some insane effort, and normal person will lose to a nutter. I know one guy who drove alone in an online racing 24 marathon. I'd never dare to compete against him, just because, come on, this is a game.

Thanks! I hope I don't kill interest to the competition.

I don't think something like this can happen to Kerosene (why am I writing it with kapital K?), but worth mentioning. At 4:12 watch a cylinder lift off like an SRB. (This is what happens when 90% of drivers are first generation of car owners.)

I did this: 2 take-offs and 2 landings, half of planned, and I still have more than half of the initial OX and LF (ox 396=>301, lf 900=>483). So 4 times are definitely doable, it just needs tweaks to ascent profile. (Shown in the screenshots. First takeoff: 9/31, 2deg 20%, second takeoff 9/32 2deg 25%.) 26.9 * 100 * (4 - 1) ^ 2 = 24210 For end mass you can actually count the empty craft, with tanks dropped. Initial mass is 20.6 t, minimum possible is 10.6 t, or 51.5%, or 25728 pts, which is more than 24210, so total will be 24210 * 2 = 48420. Here's the savefile, here's the craft. In case you're interested, this is the same craft empty. If you want to fly it, only MechJeb is needed. Set it to manage air intakes and prevent flameouts (in utilities window). P.S. Interesting idea with 2 leaderboards. Well, it not only gets very boring, it takes eternity. Average landing takes 45 minutes, because it requires travel, circularizing, undocking, fine tuning of landing, landing, then take off and rendezous, and docking. One cycle took me about 6-8 hours.

me like this more. Worth watching, there's 3d animation of the field.

Ok, thanks a lot! I'll tweak it and do the take-off and landing sequence to prove it's possible.

IIRC, NK-33 (or RD-170) has TWR of well above 100, which means it's not heavy (or it's crazy powerful). I wonder, back in 1970 this kind of engine was the most efficient in terms of Isp. Now there are liquid fuel engines with similar Isp, how did they reach this efficiency? How using gas as a propellant improve efficiency?

^^ You need water on board, and it's a bad idea to not recycle it. Disposing of water will be a significant waste, especially in long trips like to Mars or other planets. This will make a much bigger start mass. The efficiency if 1 / square root( molecular mass ). MM of H is 1, MM of H2O is 18, so it's 4 times worse if same energy is applied.

Read Richard Feinmann's report on reliability of Shuttle. I don't know if it's easy to explain, but will give you some perspective.

My almost submission. This has not flown the entire route yet, just done one cycle (mission) of 4. I'm not sure I can endure all of them. (I'll have to put this on hold for a month, sick of this. ) Hattifnattar (strange small and light creatures that were searching for electricity and Moomins' magic hat) Lander with orbit module (tank) Carrier Technology: 1. Kerbin air-breathing lifter (no airhogging this time, exactly 4 intakes per engine) 2. Tiny lander (probe core + ion engine + 1 tank + batteries + cube struts as legs) 3. Xenon tank module (RCS + probe core + 4 xenon tanks + battery) Lifter pulls everything into LKO, then lander and tank undock, dock together and depart for the mission which includes landings at * Mün * Minmus * Ike * Duna * Dres * Vall * Bop * Pol There's enough Xenon fuel for 4 missions. Jebediah flies on the lifter in a lander can, just to repack parachutes. If I'm calculating correctly, this can gain Mun 2.5, Minmus 2.3, Duna 3.7, Ike 3.4, Dres 3.3, Pol 3.5, Bop 3.7, Vall 4.5. Total 23.6 (now it's my turn to make arithmetic mistakes) 26.9 points in a cycle. DV used is about 13Km/s, but it's actually bigger, because this is for lander + tank, and lander does landing excursions alone. Some notable things: * do not circularize the entire ship, let the tank go into the most excentric orbit. It's actually easier to launch and rendezvous with it this way. * when reaching Jool, aircapture at Laythe saves a huge amount of DV. It puts you in a high circular orbit around Jool, and also if you make it excentric, almost escaping, 1 m/s can throw you on much lower or much higher Jool orbits, depending on timing. In theory I can get 26.9 * 100 * (4 - 1) * (4 - 1) = 24210 pts Start mass is 20.1t, end mass is going to be about 13t (I use 6t of fuel and drop two tanks 375kg each), about 64.7%, so the score just doubles, to 48420 pts. If you look at screenshots, there's one problem: I'm a bit short of oxidizer in the lander to do 4 cycles, and I need 100 units of it, or 500 kg, 2% of mass. I don't think this changes performance, or I can outtweak it, and usage is going to diminish in later take-offs with dropped weight. So, question: if these lander and tank are the same in all 4 missions, should I repeat them, or this can be considered a sumbission?

I suggest another competition mode: show a model capable of doing something, compete in efficiency and forgive any hyperediting or crashes if the concept is working. This will be less demanding in flying experience. Although, develop something complex takes time and experience as well.

I thought this too. Ok, maybe I'll not turn them off then.

Correct me if I'm wrong, but reading press releases I don't see any mention of earlier successful flights. Like usually it's mentioned, "this was Nth flight". If this is so, then flying manned with a redesigned engine was a too risky decision. Nobody ever puts men on a spacecraft with a new engine or new/modified critical equimpent.

Just watched a trailer. So hollywood. I wonder why make such cliché-d movies at all? It's just so the same: people being happy first 5 minutes, birds tweeting and flute playing in the background, then bad things, symphonic orchestra, then they're gloomy and brave untill last minute, and then they're happy and there plays a typical orchestra sequence. Why repeat this over and over? There's little space for character there. Apollo 13 was I think the best in the genre, and they got it right by building the plot with some minor conflicts around the main plot line. Remove those, and it's just another Bruce-Willis-saves-everybody expendable thrash. Such a plot is too straightforward and predictable, and usually leaves no space for suspense or any conflicts between characters. Well, there are attempts to generate suspense, when characters have an argument while time's ticking and something's leaking, and director tries to scare you with it, but that's too obvious. The idea with the real physics and wormholes is great, but it would fit more plausibly into a completesy fantastic world, like in the Blade Runner ambient, with people vs people plot line.