Entroper

Yeah... easier said than done with the way my craft flies. I mean, it's stable, but if I turn off the SAS to pitch over, I'm fairly sure I'll lose control. The extreme lag also makes piloting difficult. I'm up to 39 LFEs and over 130 fuel tanks.

I'm getting closer. 1 500 m/s on my last run, and I can add more fuel and SRBs to the design. The idea I had at work didn't pan out, but a variation on it did. EDIT: More fuel, 2 000 m/s. Added SRBs, but I went too fast in the lower atmosphere and flipped over. Can't add any more fuel at this point without making the rocket even more prone to flipping. EDIT: Final attempt for tonight. More SAS, more fuel, no flipping this time. 2 125 m/s @ 203 km. 72% of escape velocity. I think I can add fuel, SAS, and SRBs to go faster. The game runs at about 1 frame per second for most of my flight.

Is there an echo in here?

So it seems like, over the course of the next few updates, we'll have a new goal: Landing on the moon (Mun, Kluna, whatever it's called -- I'll use the non-proper 'moon' to refer to it). I thought I'd get the ball rolling (so to speak) and start figuring out how to get there. I'm going to assume a starting point of a low circular orbit around Kerbin, with the orbital plane synchronzied to that of the moon. We already know how to do those steps (even if the instrumentation for the latter part is a bit lacking at the moment), it's the next step that's the interesting one. At some altitude above Kerbin, between the planet and the moon, will be a point at which the pull of Kerbin's gravity is equal to the pull of the moon's gravity. It seems reasonable to me to start a Hohmann transfer orbit and aim for this altitude at apoapsis. Since the transfer orbit calculation doesn't take the moon's pull into account, you should end up overshooting this altitude by some margin, meaning you will end up on a path where the moon's gravity has more influence. At this point, depending on the moon's size and mass, you will likely be in an escape trajectory heading around the moon, and using standard orbital maneuvers, you can make a retrograde burn at periapsis to place your craft into a lunar orbit, and you'll be all set. Alternatively, if you overshoot your trans-lunar injection too far, you may be on a collision course with the moon, and may need to make a prograde or even a radial burn to increase your apoapsis to an altitude above the moon's surface before circularizing. Either way, you will have achieved lunar orbit. Now, backtracking a bit, we have a few more things to determine about the trans-lunar injection burn. Following normal orbital mechanics, in order to place the apoapsis of the transfer orbit closest to the moon, you would want to start your burn 180 degrees around Kerbin from the moon's location. However, the moon will be revolving around Kerbin, so rather than placing your apoapsis near where the moon is, you need to place it near where the moon will be after you make your ascent. This requires finding the period of your transfer orbit, and determining how far the moon will travel during this time. Then you must travel the same number of degrees past 180 before making your injection burn. One final note is that your orbit around Kerbin should be in the same direction as the moon's orbit. This sounds obvious, but the reason this is important is because it results in a lower velocity relative to the moon when you complete your transfer, since you and the moon are going in the same direction around Kerbin. It is certainly possible to do it the opposite way, but it will require more delta-V. Any comments? Anything I'm leaving out / getting wrong?

Gah, I always get design ideas for these challenges while at work! Can't figure out if they're even possible until I get home. My first design uses a first stage of 27 liquid engines and 63 fuel tanks, plus 8 SRBs. This makes for a nice, smooth liftoff, but doesn't have nearly enough impulse for escape. I want to see if I can fit 42, maybe 43 engines under there.

So, I've been attempting this challenge with stock parts only, and I've managed to get it to about 1 000 m/s, with a max altitude of 150 000 m. I haven't spent a ton of time on my rocket, but enough to know that reaching escape velocity will definitely be tough with stock parts! I'll be interested to see what everyone comes up with. BTW, to give credit where credit is due, and since I'm no modeling artist, I've used the mesh from SynthOrange's Fatboy Large Fuel Tank, and recolored the texture. Also, don't mind the SRB icon in the screenshot; I was messing with the .cfg file and trying to get it to show an overheating notification, which it never did. If anyone knows how to get this to show up, let me know and I'll update the part.

Alright, so you've gotten into orbit, into an escape trajectory, and far beyond. The government of Kerbin has seen fit to commission your engineers for an important mission: disposing of the highly radioactive waste generated from experiments in nuclear-powered propulsion. Some things to know: [li]This waste is made up of mostly trans-uranic elements, so it is extremely heavy.[/li] [li]In accordance with keeping the weight down, the storage tank is made of a thin, strong alloy. This makes it highly sensitive to collisions and temperature. Exercise caution when handling![/li] [li]The waste has a very long half-life. This is both good and bad; on the plus side, it means that the radiation is weak, and short-term exposure should not cause any ill health effects. On the minus side, it means it really needs to go, or it will be a hazard on Kerbin for hundreds of thousands of years.[/li] Because of the extremely long half-life, the government cannot run the risk of simply putting the container into a stable orbit, lest the orbit decay and many tons of radioactive waste be 'redistributed' throughout the atmosphere. So your mission is to put the storage tank on an escape trajectory, and to return the crew safely to Kerbin. All the parts you need are attached below. Good luck!

This is super annoying. The mun just flips over if it goes faster than 70 m/s.

I put this craft (see attachment) into a stable orbit. The 7 LFEs on the bottom still have 1 full tank remaining each, there are 6 SRBs ready to go after that, and when they detach, another stage with 5 LFEs and one LFT. The craft still has over 8 000 m/s of delta-V left.

OK, 10.2 km/s with Big and Tall and Boosted. More struts and a ring of SRBs at the bottom, and better piloting during stage 3. I've also thought of an easy refinement that should add a lot more speed.

Another positive score! 332 x 35 014 - 1133 = 10 181 751

So close! More SRBs and struts, maybe? Also, better piloting of Stage 3 while the SRBs are firing... boy is that thing wild. This iteration is named 'Big and Tall'. Stage 1 (18 000 m, 275 m/s) 19 LFE 57 LFT Stage 2 (320 000 m, 2 800 m/s) 12x SRB 7x LFE 28x LFT 6x struts connecting the bottom LFTs to the center Stage 3 (2 159 000 m, 9 850 m/s) 6x SRB 1x LFE 5x LFT Pod If you use this design, WAIT after jettisoning stage 1 before firing stage 2, or the whole thing will go up in one enormous boom.

Wow. With struts, 9 km/s was child's play. I didn't even refine this design, I bet I can crack 10 by just adding fuel. 'Fat Man': Stage 1 19x LFE 38x LFT Stage 2 12x SRB 7x LFE 21x LFT 6x struts connecting the bottom LFTs to the center Stage 3 6x SRB 1x LFE 4x LFT Pod I think I can add one 'layer' of fuel to each stage, plus SRBs to the last stage to get it off the ground, and this thing should scream.

Enjoy my donation and keep it up! 8)

Hm, I see what you mean. An un-centered force would push the 'light end' of the rocket off course faster than the 'heavy end', causing the flip.

The problem I'm encountering has little to do with where the thrust is located, and everything to do with the atmospheric drag, because the instability doesn't appear until I reach high speeds in the lower atmosphere. It would stand to reason that a low center of gravity helps to reduce drag instability for the same reason that a high center of gravity reduces thrust instability. Correct me if I'm wrong?

My design evolved to approximately this, and I got 2:04. The craft is impressively difficult to launch. 2:08 if I remove a LFT and put 3 more SRBs on the bottom.

I did 2:12 with just two liquid tanks and 6 SRBs strapped to the side. I'd like to see if we can beat 2 minutes with stock parts only.

Excellent! Now to see what I 'left out' of my 229 km design. I really want to have a final stage of just one SRB pushing the pod, but it blows itself up before it's halfway expended.

Well done! And you gave me an idea for my next version. ;D EDIT: Minor tweak, even better! I know 250 km is possible. I didn't want to say it when we were still in the 190s.

8)

Gah! As soon as I get ready to post my 204 km run, someone beats me to it. Well done. This time our rockets are very different.

Well, if the symmetry were perfect, then the net thrust and net drag would be through the center of mass. I think if we spread the boosters out and activate them a few at a time, the ship will waste less energy to drag. Wish I could play during the day.

Yeah, but the ships I was testing shouldn't have had any non-symmetry in any dimension, and were still flipping over. As soon as there was the slightest deviation from a perfectly straight flight path, it accumulated massively.

Yeah, even using the symmetry tool, there seems to be enough error present to throw the ship off balance under high drag loads. I may try again and just run partial throttle until the air thins out. Though I can't throttle down the SRBs. Trifinity and I made exactly the same ship.