gm537

Wow that's a tough one! Some of the "Rescue from around the Sun" missions are brutal. As far as options it's going to depend. Is the 10 km/s of dV you mention at Kerbin surface or in LKO? (if it's not a LKO number I don't think even rendezvous will be possible) The biggest problem here by far is getting turned around retrograde, this will be easier at higher altitudes the Eve assist idea probably won't work, basically gravity assists can't typically turn you around though they can make the turn less expensive (oberth) but in that case I recommend doing it at Jool due to Jool's orbit speed around Sun being slower. From there as worir 4 mentions you can probably drop the craft into a Jool capture and make the return to Kerbin much easier. Although as I say this I am remembering that I have not done aerobraking at Jool since re-entry heat was a thing, that could make the whole plan moot. In that case you will almost certainly need more dV. I'm not sure of the orbital speed of the craft you are rendezvousing with but basically if you go up to a very high altitude and then turn around you usually end up spending between 2 and 1 km/s depending on your patience. I would then guess that the rendezvous will cost about 1.6 km/s dV. (based on estimating that craft's orbital velocity as 3.8 km/s) Going home to kerbin should then be around another 2 km/s though that will bring you in backward and very fast so again reentry could be serious problem. Those are my thoughts. I may try a bit of a simulation run in a sandbox edition and see what I find. All-in-all it seems like a really interesting challenge.

This section seems like as good a place as any, there is definitely a type of challenge to it and it's really unique. So a lot of people have already touched on specific impulse with numbers for a biological or mechanical arm producing between 3 and maybe 20, but we haven't touch much on thrust. While the idea of continuous thrust for a the mechanisms we are talking about is kinda silly we could certainly get an average. Thrust is pretty simple and is: T = v*dm/dt or basically how fast you can throw stuff times how much stuff you can throw in a given time. If we take zarakon's hunks the size of baseballs example we can say v = 27 m/s while it probably takes about 3 seconds to prep and throw a baseball sized object which weighs around 150 grams (so google has told me) thus the dm/dt term is 0.15/3 or 0.05 kg/s multiplied by the velocity of 27 m/s and we see a thrust of 1.35 Newtons... well that's basically nothing to a 10 ton ship. (I'm going to assume metric tons since that's what KSP uses and it keeps it simple) At the start the acceleration produced is 0.000135 m/s2 or put another way it's going to take us about 55.6 hours to burn our 10 tons of "fuel". Like zarakon said a VERY sore arm.

Thanks man that definitely helps! It's good to know I'm not crazy. I will probably also make the said config changes. Of course it's a bit annoying that my install is then not stock and thus there are some forum challenges I might not be able to enter, maybe at some point Squad will come back through and change things to be linear as we hoped. Regardless thanks for the answer and the math for this!

So as background to this question: Prior to 1.0 I realized that the ISP of a rocket engine in KSP (I'm not considering airbreathing engines in this thread) scaled linearly with atmospheric pressure. Thus if you had an engine with 200 ISP vacuum and 100 ISP at 1atm you would get 150 ISP at 0.5 atm. And I was under the impression that this is exactly how real world rockets work. Now I also like to go to Eve and I realized Squad was doing us a huge favor by making ISP not drop any lower once atmospheric pressure got higher than 1atm. So when I heard they had changed this in 1.0 I was pretty excited for the new challenge and I figured I could just design my rockets using the linear extrapolation idea: If a rocket has 300 ISP at Vac 250 at 1atm then it must have 200 @ 2atm, 150 @3, and so on. But after some Eve tests didn't make sense I just peaked in the config file and lo and behold that's not at all how it works. Instead each engine seems to have some (arbitrary?) pressure (between 4 and 20 atm as I have seen so far) at which it goes to (almost) zero. So my question is: Is this a real physics phenomenon that Squad has worked to model? Or is this a game-play related decision? And then the follow-up of: Why? I'd be fascinated to know what physics would cause one engine to scale: 0: 300, 1:280, 7:0 (when a linear approach would say 7:160) and another engine to scale: 0:340, 1:170, 4:0 (here a linear approach would say 4:-340 or rather 2:0). Like for real I think rocket engine design is super interesting stuff. And if it's a gameplay decision does anyone have insight to how a more confusing and less consistent system helps gameplay? It baffles me. Thanks for any help you guys can provide to any or all of the questions! Yall rock!

Alright I've got one and would like to claim the 25km World's First. (Sorry the pics are in the wrong order...) Looks like I got 26,600 - - - Updated - - - Okay so new idea for gm537, read the rules BEFORE posting. It's okay I already have a new submission and this time I show the resource panel. Looks like I get the 30km world's first as well. These challenges are so much fun because you just keep trying over and over...

No worries Laie! Do I get my name on the list of awesome now too?

A 1000 kerbal station would be pretty impressive especially if you actually had 1000 kerbals (as opposed to just seats for 1000 kerbals) as that seems to me to cause a significant amount of game lag. I hope to see what that looks like.

Yeah RSS is hard. I think the biggest thing will be mass fractions to certain locations. The current points system of +100 per station ton and -2 per launch ton means that a station which has a mass fraction of 2% only "breaks even". And stations below that are actually negative, thus adding multipliers would actually hurt the score at that point. (Of course there are points other than tonnage but you don't really want to be forced into bringing Bob, Jeb, and Bill just to try and cancel negative points.) I think that's the situation you would find trying to go to Mercury; it simply may not be possible to put 1 ton in orbit around Mercury with a launch vessel which is lighter than 50 tons. What do other's think? I have only played a bit of RSS so I might be off on my mass fractions but as I remember in the real world just getting 4-5% into Earth orbit is basically great. Still who said challenges were supposed to be easy? haha

Based on other entries I am pretty sure the dash separates 'not comfortable' from 'comfortable'. In other words the 'comfortable' seats are those in: Hitchhikers, Cupolas, OKS Habitation, Mk2 or Mk3 passenger, etc. Any seats in those are 'comfortable'. Meanwhile seats in: Pods, lander cans, or cockpits are 'not comfortable'. I'm pretty sure the external seat would also be 'not comfortable'. That was my reinterpretation upon a second read because I agree it kinda sounds like almost nothing is 'comfortable'. Is that explanation correct Norcal? PS: A RSS attempt would be pretty cool, though it will be quite the challenge for Norcal to decide how is should affect the scoring especially if he hasn't played it before.

Okay I have decided to just keep it simple and build my stuff with MRS, SpaceY, and stock engines. I use some KW fuel tanks (in part cause I already had some lifters designed with them, and in part cause I like the style) and other parts from that pack that I didn't touch. I have also learned that Kerbals are the main source of lag... I have a habitation module that I flew a test flight and it was fine, fill it with Kerbals and my frame rate drops a lot... Does anyone know mods to address this?

Thanks Laie! Does my name get put on the front page of awesome-ness? Haha So far I think Astrobond for his super inexpensive entry (when counting reusable launcher) is probably my favorite. That's some serious engineering.

This looks like a fun challenge and it has been quite a while since I built a station so I'm gonna go for it! As a question I think I know the answer to but want to ask anyway: What about modding mods that are under-powered? Specifically I am a big fan of KW rocketry, the parts just look good in my opinion, but the CFG files have not been touched since pre-Nasa parts which means they are woefully underpowered. And so when I download the pack I go through and re-balance them. I do my best to make it follow the sort of Higher TWR = lower ISP methodology. And so the heavy lifter engines have things like 350 or 340 Vac ISP. (Usually still at a lower TWR than the KR-L2 because it's basically Overpowered.) What are your thoughts here? Would the modified KW Rocketry parts still be allowed in the mods category? Or is that just a total no go cause it would be so hard to decide fairness? (Obviously I can provide the configs if you need them to make the assessment.)

Oh dear I just went back through my pictures and it seems I too generally don't have the resource panel shown. I have provided the craft file so that you feel a bit more comfortable about my submission. I apologize about that I get very used to doing things just for myself and so I tend to try and hide as much hud info as I can unless I need it right then. That's my bad for sure if there is anymore info I can provide to make my submission valid let me know and I will see what I can do. I have been thinking about reworking the craft for 0.90 so maybe when I do that I will remember to have the resource panel while flying...

Ah ha a man after my own heart. I have just finished my Eve Rocks challenge and I had many of the same goals as you. I wanted a craft that didn't just take one kerbal but a few and could do level 3 or Jeb level. - - - Updated - - - So I finally completed my Eve Rocks challenge. (Basically work, other games, and 0.9 stopped my 0.25 submission mid tracks) This submission is for the Jeb level. The craft was the Eve 4 Man Lander IV (and in all fairness is like the 3rd generation of Eve 4 man lander... Sea Level Eve is hard...) On the Kerbin Launch pad this thing is 5,163 ton, 2.32 million funds, 803 part beast. Once I land on Eve it's only 341 parts and about 668 tons. (I say "about" because I burn some fuel during landing and I'm not sure exactly how much) I used game version 0.25 and the only Mod was KER, though I did use some online trajectory calculators to get my transfers right-ish. Here are the pictures from Kerbin and the transfer: http://imgur.com/a/A3jsh#0 Next set of pictures shows landing and take off from Eve. I tried to show all the science I got on Eve's surface and enough of the take off to be pretty sure of what was going on. (Basically I have an image for each stage) One picture I am missing is something near landing which I missed because "landing" is a suicide burn around 120m and is stressful. Haha http://imgur.com/a/WIlET#0 And finally they return home: http://imgur.com/a/acbmV#0 I'm definitely most proud of simply completing this mission but I'm also happy that I did it without a lick of space debris. All Kerbin lifter stages end up on Kerbin and the transfer stage along with all Eve lifter stages end up on Eve. Some things to be wary of with this craft are: one a true sea level launch will be very difficult, and two you need to take off at a time of day when the sun is mid morning or so that way when you hit apoapsis and are using your Ions to finish the orbit you will have maximum solar power. My craft Well that's it! Glad to be part of this challenge! - - - Updated - - - Oh that just updated my other post? Whatever... - - - Updated - - - Dang! I applaud you sir! That's one impressive craft, and is one of the few here that feels very elegant, even my own entry isn't elegant.

Hi all, first I want to say "Thank you" for completely eating my Saturday evening and much of my Sunday with this challenge as I tried to get a rocket which broke the 5,000 km mark. I am proud to say I was successful and here is my entry. I have a few more photos than the usual req since the flight pattern is non-trivial. Basically I a have both basic jets and turbojets at launch. I start off with some intakes disabled to reduce drag. Those get re-enabled around 8km (action group '1') The first stage drops the basic jets which should be done around 10km. The second stage will drop some of the Turbos and should be done around 18km. The final turbojets will take you to about 22-23km before they burn out and unfortunately they burn out kinda violently and can send you into a spin that will ruin your run. From there on out it's standard rockets until burn out around 4 1/2 min into flight. The final altitude was 5,212,147. I'm certain that just optimizing flight path on this craft could yield another maybe 50-60km and there is more altitude to be had in other designs. Can't wait to see what folks come up with! http://imgur.com/a/z4aMC#0 Craft file (Also how do you do that beautiful in post IMGUR album? I remember being told once but have forgotten, and one other time the method given ended up with like the whole webpage with like the Imgur border being in the post not just the pictures which is what looks good)