thiosk

Hi Everyone! I guess I forgot everything about kethane from back a couple versions ago, and I fired it up in .25 and built the plain jane minmus refinery station. I have a small satellite that runs two converters, not connected to anything via fuel lines. It pumped perfectly and filled up an orange tank docked to it. I flew that home and went to duna, success. So now I've upgraded my driller, flew that to minmus. It again has a medium converter, but didn't run on the planet surface. Took it to the station, and docked it despite putting the RCS in 2fold symmetry instead of 4. Oops. Nothing. Couldn't fill tanks with the satellite as before. I then went back and figured all this stuff out about fuel lines and directions of connections. OK, but, why did it work before and not now? Any tips? works http://imgur.com/CZer0EO,CZwaK4L#0 doesn't work http://imgur.com/CZer0EO,CZwaK4L#1

I learned how to do everything I needed to do vanilla- flying, docking, landing, etc. However, I use MJ extensively for the DV calculator (engineer wasnt updated yet, so I learned MJ) For highly routine missions (circularizing an orbit after an aerobrake, for instance) I've just started to toy with using mechjeb to do that. Sometimes I find it annoying to hit a zero inclination so I'll ask for that and go get a cup of joe or what have you. and setting maneuver nodes, occasionally executing them. If I need to do a 15 minute nuclear burn, I might just let mj do it. Any time I've tried to use it to do something more sophisticated, its been a disaster. I asked it to dock once. What a nightmare. My ship exploded from severe uncontrolled wobble.

This was the method I stumbled upon quite by accident. It was astonishingly cheap, once I corrected inclination problems.

This sounds like my first docking attempt. Question: Did you put ports on correctly? I ask, becuase my first foray with docking I had that 6 way station adapter, and my ship with a docking port, and I was up there rubbing the docking port against the adapter all day. Turned out, you have to put docking ports on the station adapter. That was a shock for me. Another time I had them put on edit: whoops incomplete thought I put them on, redid the launches, and boom dock.

i had no idea you could stack them like that. i've been using side boosters and quad couplers.

Simple question about economical ways to return from jool. I've noticed large increases to requisite dV after leaving planetary SOI, a function i assume of the oberth effect. So heres my question. Lets say I leave vall orbit and slingshot off tylo for a nice kick to high jool orbit. Now I wait. and wait, and wait, and pop heres the return window. Unfortunately, as luck would have it, I've ended up 50 days from the correct point in orbit for an ideal ejection angle. Last time this happened, I overbuilt the mission so I had 4k dV I was returning with. This time its going to be a nail biter. What does one really want to do in this situation? Go ahead and go solar orbit and then hohmann down to kerbin? Set up a return from the complete wrong side of the orbit? I've heard of people parking beyond pol for cheap returns, but I imagine this happening every time. Suggestions?

First thing: Docking is something you have to be intuitively trained on. Astronauts train on this a long time. A mir cosmonaut complained that he wasn't prepared for docking, and borked it up, and seriously messed up mir by whacking into it. It takes a lot of experience that its hard to explain in forum posts. So let me run through how I learned about docking. First, I had randomly constructed ships and I tried to dock to one of those 6 way core connectors. For hours. Failure after failure. Thats when I realized, I had to put docking ports ON the docking connector part! Oh the humanity. So, then I started slowly getting better at docking. I was able to at least link ships up, but it was a painful, awful process. But I got better at it. I tried putting together ships in orbit for interplanetary missions though, everything came out crooked. Lining up was horrible. Took forever every time, but at least I could do it such that it was no longer the critical step of a mission. The key concept for me was learning about RCS balance. You see, those jets you're using to manipulate your ship, if one end of the ship pushes harder than the other, the ship twists all over the place in response to every kick you give it. WHAT A PAIN IN THE BUTT. So, find the center of mass of the ship (accounting for the fact that fuel drains..) and put space two sets of 4-symmetry thrusters equidistanct from it. The further the better. So now your ship is level. Time to learn the nav ball. Theres a lot of tutorials on this, and from your post it sounds like you can get near the ship, but you aren't really approaching it. See where it says "orbit" and velocity on the nav ball? Set your target to the ship you'd like to dock, and click "orbit" velocity screen. The nav ball changes to "target" mode and shows speed relative to the ship. This was an omg moment for me. It takes practice, but you learn to intuitively push the prograde and retrograde vectors around to optimize your approach. Usually I come in from behind the target, then I push the retrograde vector to line up with the ship. When I get within a click of the target, I fire and zero velocity. Then, I use my balanced RCS space craft to get lined up and docked. I make it sound easy here. It is easy, but its hard to "get it". As soon as you do, its like riding a bike. Finally, theres a docking port camera. This takes practice to really intuitively understand, the tutorial makes it seem so easy. But at least you can figure out how to get pointed in the right directions. Now, I use that sucker and whip stuff together in orbit so fast it makes your head spin. Heres what I'm working on this week: It has a big booster on the bottom because I'm taking the whole thing to laythe-- but I have to add the rest of the parts I need. That thing with the solar panels coming off it-- thats a seperate space station core. I'm putting one in orbit around every moon of jool, and the whole thing is designed to be intercompatible. The reason this is relavent is because its really just a gigantic docking operation. I'd never bother unless docking was the easiest thing to do in the game.

This is getting to the issue, though the discussion here is critically important to me as well. I've so far failed anything other than the most basic of planes, and am having a lot of difficulty with the transition from jet flight to rocket. The true purpose of my mission is to carry a full long kethane tank from laythe surface to the orbital space station. Thats a big, heavy payload, and so far, theres no way I can envision accomplishing that without a net loss in fuel- I tried to put together an SSTO that could land and move a full orange tank payload, and it just wasn't tenable. It may not be tenable even with modded kethane jet engines that can drink off their payload, necessitating less rocket. Captain Sierra's comment about 10 rams/jet is jaw dropping, I didn't realize it was possible. More jets apparently enable higher altitude flight before flameout, which is really what I expect I'll be needing. This evening i've got some time to spend working on my designs, so I'll post some pictures of my development process here. Please feel free to continue debating ascent profile, with the caveat that we are talking about laythe-centric SSTOs for space station resupply so dropping the engines is strictly a no-no.

I've become interested in SSTO payload launches for operations on environments like Duna and Laythe. I'm curious about jet-turbine powered initial ascents. It seems like for Kerbin and Laythe, jets are quite powerful for working within the atmosphere. Do folks have experience with an initial stage that burns up to 22,000 and then fires a central core to get into orbit? I'm interested in knowing what how the use of non-detach jets affect design and flight profile. I'm using couplers with 2 ramintakes per jet turbine. If one uses a stage like that, are there any ballpark guesses for how many dV such a launch might shave off my rocket stage? in my last failed run (clustered center stage fried the skiper, I had a nice profile that carried me up to 22000 m and let me speed up into the 800s m/s before going back to 45 deg when the rocket fired. I'm interested in knowing folks' ascent profiles. My ultimate goal would be to enable a kethane tank return from laythe for net fuel gain, though now that I'm working with the process that seems untenable. I'm not averse to those kethane-powered engines. It seems somewhat unweildy for kerbin, but I'm thinking the lower gravity of laythe would be workable with normal parts.

That looks great! It shall be employed.

Since you've gotten a duna intercept (and presumably, return) under your belt, I think its time to do a probed landing on eve and a kerbaled landing on gilly and subsequent return. Since it looks like nuclear drives are an option, you likewise might consider kerball'd mission to the outer moons of jool. Although, vall is really quite easy. They're easy to land on and return from. Save landing on the inner moons for a bit later, as making sure you have adequate engineering and fuel to do complete, multimoon missions might be tough if you ran out of gas on a duna mission.

I would love an imperial aquilla...

I've recently gone beyond stock in my designs, adding kethane and a fuel balancing mod, and then docking large vessels together and sending them throughout the kerbol system. I use mechjeb for dV calculation in .23. I've noticed that the calculator does not seem to factor fuel held and linked by docked crossfeeding as available wet mass. Sometimes. Suddenly, I dock a small probe, and instead of the 837 dV available previously, now it reads 5300 dV, a more realistic number. Any ideas for whats going on and how to determine the fuel of complex docked ships reliably?

I don't think its the right forum. But its a good question nonetheless. the mod didn't move it This game takes a faux-physics approach to spaceflight. When you get an internal conceptual framework for how it works, typical spaceflight becomes trivial. Its like driving a car, you know innately how to navigate turns and stay in your lane. Spaceflight is the same way, its just that you need that internal concept that space is sideways, not up, and you slow down when you want to speed up. You've learned orbital mechanics the same way you learned how to drive a car-- got some basic instruction, and practiced. It took probably 100 hours of steam-played-time before I made mun landing truly trivial. I'm now up to 300 hours in (note, this includes a lot of idling in the constructor, so its not really a good measure) and am mastering the use of gravity slingshots to save dV for various activities, have fully mastered docking, and am now embarking on an effort to build bases on many of the moons and planets in the game, while improving designs of ships beyond "good enough" and up to "really frigging cool." Krag's planet factory might see an install here soon (SIDE NOTE: HEY, wasn't there a Kerbol Remixer mod that put kerbin around jool, and jazzed up a lot of the planets?)

I understand why they show up, but I must admit they pollute my flightlist.

Add a vote for 350x2. Mine are at 300. This is a great, useful orbit. IT doesn't take TOO much juice to get circular there, and the circle is big enough that its feasible for eject with nuclear engines. I'll explain this: last night I had my ship in 150x150 orbit. I was going to do a jool transfer. I had these two orange droptanks on board, 2 orange tank equivalent fuel, and only two engines. The orbit was way to fast to let me do a reasonable burn. I ended up doing two passes to get an escape, then had to burn outside kerbin SOI. This ended up adding in the neighborhood of 500+ dv to the trip (but I got to jool with 2 full orange tanks of fuel to facilitate my ongoing science operations there!!) From the 300x2 orbit, it would not have been so bad. For long timewarps, I have a package sitting on kerbin with a protractor mod on it. I switch to it and let the clock run when its time to await windows.

Taking off is easier than landing. No atmo, no drag. You can get stable orbit above about 12.5km. From there, a science sample returns are quite viable. low altitude docking is hard, but My botched laythe takeoff tonight showed that you can grab the experiments and bail out, then EVA to finish up a degrading orbit. My mission might be under built. It's minimalist and I'm worried about twr.

I'm glad I'm not in the game development business. Even in friendly communities, people freak out over everything.

My first mun landing was pretty epic. A few Eve transfers, duna transfers and returns, and a couple Joolian probes later and I'm getting pretty good at this game, so its time for tougher challenges. My tylo is scheduled for this evening. When I pull that landing and sample/science return off (WHEN!!) its gonna be epic. I hope I have enough thrust...

theres some good advice here, but really it comes down to experience. When you gain an intrinsic understanding of how different burns effect various orbits, it becomes second nature to tune and adjust the nodes. Before having that experience, its god damned voodoo.

I certainly agree. The strength of links could be jazzed up. Tanks in particular shouldn't break in half under most circumstances. I also find docking ports to be a bit too weak. I find the need to stitch primarily in two cases: 1. when the suggestion to not strut side boosters to the payload is ignored. 2. for very tall rockets. I find weakness in payloads that protrude by ~2 orange tanks from the central booster, usually presenting during the early stage of the gravity turn. I've seen my turns shear off the payload at a variety of locations. My own improved rocket design has greatly decreased the need to stitch, but I still do it occasionally out of habit but in general for very large boosters (3x orange tank) and occasionally for side boosters of very heavy rockets- when the simulation starts and the whole vessel drops against the launch supports, everything gets a good test jolt. I joint strut extensively when I get failures then. Having docking ports in line requires a lot of struts too. I often shear heavy components at the docking port-->seperator attachment.

I'm currently hauling a lab to Jool for a Joolian tour. I've got a tylo lander AND a second lander for the other moons. I forgot to bring my joolian atmo probe, though :*( Don't process from the lab. I have set up my lab as a return ship. Its meant to go back to Kerbin at the end of the mission. My last couple runs I had 25+ expts saved up in it-- the duna exploration was quite effective, as was my mun trip (I did the minmus hop with a single large vessel because its so big). Massive gains. I expect that from the lab you can transfer the experiments to a seperate lander for the return and thus save the lab, but Ive already got a nice setup that returns the lab, and my jool mission will finish out the tree, so there won't be much reason NOT to return it. I expect in the future keeping the lab in orbit may be more cost effective, but for now, money is literally not an object.

One thing I want to make clear on wibbly wobbly timey wimey spaceships: MOAR STRUTS is the answer, but they can also be a source of the problem as well! The key advance that made my ships tough as nails was to realize how loads were distributed and change during flight. You start a ship on the launch pad with a ring of mainsail'd boosters. Those boosters are strutted to the payload and to the center. Seems right, moar struts! However, as the boosters drain, the TWR goes through the roof. The struts are rigid, and they start PUSHING ON THE PAYLOAD substantially more than the center booster is! this causes a string of failures that can cause unexpected damage in unexpected parts of the ship, which reorients the structure, which makes it behave unpredictably. Instead, you want your side boosters pushing the central booster, which in turn pushes the payload. So you want to strut parts IN LINE together, and you want to use standoffs and such, but you don't want to just strut willy nilly. Strut the boosters to their neighbors, strut the tanks together at the seams, and strut the boosters to the center. At the top of the central booster, put a ring of structural standoffs (octahedral struts or girders) and use those to strut higher up the payload. I like to put them on the booster and on the separator. Its pretty, its functional, and the massive performance gains of .23 (yes, they're massive, at least on my machine) really relaxes the demands of the added parts.

I'm actually doing my ~20 minute burn to get to jool now, with my tylo sample/science return lander. 2 goo, a science jr, and a full suite of instruments for both near-surface measurements and on surface. Its got a whopping 3700 dV for the landing (hopefully enough?). The kerbal can get out, bounce around, bring all the science back up to the pod, and then a small rocket with about 2600 dv blasts off the top leaving the dead weight behind. My tug then goes in for the pickup, hopefully, because the little lander has no way of manuevering at all. I just hope its got enough thrust! I put it on the back of my nuclear tug just now, and the exhaust gave me some damage reports. I really hope the thing makes it. Node in one minute. I've never flown two simultaneous missions anywhere before! The tylo lander and space station left about an hour after the laythe-bop-pol lander and the lab/crew return module.

I'm posting here because oh my god it works with every hatch. In large contraptions I always forget who is sitting where, and thus I eva everyone on the list one by one until I get the kerbal I want. Left click. Who left clicks?