cephalo

I've discovered that my ship is just not cut out for aerobraking, and the heat shields I brought are just dead weight. However, I'm finding that the Jool system is a gravity assist paradise. I started with a capture around Tylo, then with the help of both Jool and Laythe, I will arrive back at Tylo again, nice and slow at apoapsis, which is where I wanted to start anyway, for around 115 dv. Not too bad. The aerobreaking thing at 8000 ms is ridiculous. It is in no way feasible unless everything is well behind a heat shield and also inside a cargo bay, which pretty much rules out any large craft with multiple components. Even then, you would gain nothing because even fully shielded, you can't survive an atmosphere thick enough to slow you down. Being in an atmosphere at all at that velocity causes your craft to glow red, even before you see those red streaks that you would see on a Kerbin reentry. It seems odd to me that you would be generating that much friction in an atmosphere that can't even change your velocity. Is that broken, or realistic in some way? Shouldn't the change in velocity be directly related to the increase in temperature? It is friction after all that slows you down at the same time it generates heat. Do we have a math guy around here to figure this out for us? EDIT: For example, while I was at about 193km altitude on Jool, my whole craft was glowing bright red, and my apoapsis didn't change at all. If I burn my engines just outside of the atmosphere, it costs about 200 dv to cut the apoapsis down by 50 percent. That scenario seems very wrong.

I am NOT aware the direction matters. This is my first go at the Jool system. Please explain! I have a save to go back to before such decisions are made, but from a 150 days out, it seemed that my options were limited. I first wanted to try a Tylo grav assist but, Laythe was really getting in the way, so I thought I'd try Laythe instead. I guess I'm catching it coming at me instead of going away. I wonder if I can correct that. EDIT: It was very scary. I panicked, thinking I had left the time warp on, then realizing it was at x1... This is gonna hurt... and not slow me down.

I've been using a modified version of your 100t lifter, and it has saved me a ton of cash and time lifting a bunch of big kerbodyne tanks to orbit. I put 8 drogues on there instead of 2, and I don't have to worry about retro-firing or having fuel left over for soft landings. I just have to come in shallow enough and it works. Thanks for this very instructive series of designs!

The safe limit these days is 250 ms. If you can't get that slow before collision, use drogues first which are safe at 500ms.

Pretty soon you will read news stories about the latest pie in the sky suborbital airliner and be like "Oh yeah, I can build one of those no prob."

Sorry to necro this thread after a couple of weeks, but I have an observation to add. I tried aerocapture on Laythe at 8000ms, 45k altitude, and all of my ship parts exploded at once. I have heat shields covering what I thought were the sensitive bits, but everything is the sensitive bits.

On my lunch hour I tried a couple of times to do an aerocapture on Laythe. This is a large ship with some heat shields but not covering the whole thing. I'm moving about 8000 ms, and at both 25k and 45k altitiudes it was like hitting a brick wall. Is this possible to do in 1.05 or do I need a different way into Jool? I'm thinking that above 45k, there will be no aerocapture. The log shows everything exploding in the same instant, though there are items missing from the list. There was nothing left of my ship. I think I overloaded the capacity for logging explosions. I win. EDIT: Do explosions heat other parts? I did accidentally leave some nuke generators exposed, but they have already served their purpose and aren't strictly necessary. I wonder if their exploding cause a chain reaction of overheated parts. One of them was the first part to explode. Normally on Kerbin, I have been losing these without consequence to other parts.

Ok, I think I'm doing this right... here is my persistent.sfs file. Is that enough? The ship in question is in LKO called Jool Explorer. The staging past the immediate mother ship engines is mostly jumbled nonsense. It's the kind of thing you fix when the craft is separated. https://onedrive.live.com/redir?resid=CB0180222D11BD3E!11552&authkey=!ANI25lxLcwPNaAk&ithint=file%2czip

Both in 1.04 and 1.05, I have had some issues with mother ships reporting 0 dv while in space. It's where you have your main engines pushing around other craft that have inactive engines facing all over the place. Is there some way I can simplify things so that I can get a proper dv reading on the main ship? Sometimes it works for a while and sometimes it doesn't, and I'm not sure exactly what is tripping it up. It's always in very complicated situations.

Kerbals are very expressive when aboard a craft, but on EVA they always have a goofy smile. It would be useful for screenshots and stuff to be able to set their moods while on EVA.

Thank's for the ideas. After doing the math, I think I could spaceplane up 9 orange tanks without going bonkers. The process might even be fun. I actually would need 4 Kerbodynes lol. I can do this.

When I first played 1.05, I was at a point where the mission I was on was a massive costly failure. So I went back hoping to find an older quicksave where I still had money. What I found was that many of my old quicksaves were just pieces of ships and planes flying through the atmosphere. I'm quite sure I didn't save them that way. Did you set up this mining installation in a previous version of KSP?

Time is completely free in KSP. That's why a lot of people like the life support mods, it makes time something of a factor. You can warp all you like.

So my Jool 5 attempt mother ship is in orbit with all it's components! I did it in one launch so it's not ridiculously over built like my last failed attempt. However, it is fairly large and mostly empty of fuel. Here are the mission requirements. 1.) I need a great deal of fuel in LKO. Probably at least 3 big Kerbodyne tanks worth of fuel. If I fuel up anywhere else I have to spend fuel to come back to LKO, according to the rules of the challenge. 2.) I have around 5,000,000 in funds. 3.) My launch window is in 2 years. 4.) I don't want to make so many trips that I can't look at my computer screen without throwing up. I don't want to ruin KSP for myself. I have a mining installation on Minmus, but it's mainly configured for liquid fuel transport, as I used to use nukes for interplanetary travel. I no longer have the patience for nukes on large mother ships, so I'm going with Rhinos, that means I need LOX. If I go the mining route, I will likely have to rebuild the whole chain. I do enjoy flying spaceplanes, but I fear these fuel requirements will entail 50 or so trips in any spaceplane I can design. I'm not sure I enjoy spaceplanes that much. I don't suppose any designs out there can lift an 81 ton Kerbodyne? I need a way to gas up that is affordable and has a good work/life balance. How would you go about this?

See, that's the problem here. It's not the RAPIER, it's that nose cone technology hasn't kept up. Too bad we don't have a shielded air intake. EDIT: Actually there is a new inline air intake that seems pretty good. That should go well with the shielded docking port on small planes, or possibly a small heat shield has less drag than the docking port.

It also has very high thrust that doesn't depend on a particular airspeed. With rapiers you spend a good measure of fuel coaxing them up to speed. With spikes you just point at the sky at such an angle that you don't burn up. EDIT: I wonder if the RAPIERS sweet spot in terms of speed/air density is in a band that is too dangerous in terms of overheating. 900 kN of thrust is only useful if it doesn't fry your plane.

So I have been flying a new spaceplane that I plan to use on Jool, and I noticed that the new aerospikes are very good for Kerbin spaceplanes also. I'm getting to orbit with more dv to spare than a similar design with rapiers, without all the fuss of mode switching. It's basically like flying a rocket.

Kerbal Engineer Redux... NOW.

Heheh, I think I know what you mean. I suppose if your craft is light enough, you can have a situation where you can't actually shake it apart without an honest effort, but the problem is the same. Your front doesn't know what your back end is doing, and your indicators are way off as to your direction of travel. In theory it should be possible to correct for such things, but the game currently only cares about the command part in terms of reporting the ships state.

You can probably get into orbit without a mod with much trial and error, but if you don't know your dv, failures will become intolerable. Some mods are absolutely necessary. This is just one of those games that relies heavily on the community.

Flipping is one thing, wobble is another. When you say 'wobble' I think you mean that your craft just shakes apart, even in space. I failed my first attempt at the Jool 5 challenge because of this. All my components were pie in the sky and tested to completion, but when glued together with big docking ports, I could NOT get them to Jool. The floppy joints couldn't handle the escape burn. This happens because every craft has some small amount of torque, when you initiate a burn there will be some drifting off target that will need to be corrected. When a correction happens, either manually or with SAS, the craft will try to flex. If it is not rigid, it will bend and then try to straighten out. As it does this, different parts of the ship are acting on each other, changing the perception of the crafts direction of movement and making it less accurate. The front end throws the back end, and the back end retaliates by throwing the front end. Using SAS of course will shake the ship apart as it tries to compensate for these exaggerated errors. Even if you are not using SAS, your indicators will show a drift that will not represent your total craft, as the different parts are not moving together. It's impossible then to really know what you should do with the controls. You can stop wobble by making your craft more rigid with struts etc. or by not caring where your craft is going. If you just burn and let it drift, you won't know where you're going, but at least it won't wobble!

Another thing I'm looking at, is that Jool's atmosphere is quite a bit colder than Kerbin. I wonder if that means I can go faster without burning up.

Well, my theory goes like this: The wiki says that Jool's atmosphere is as thick as Kerbin sea level at 91,000 meters. So in the 120k range, it should be thinner than Kerbin at sea level. I also only need to bring down my velocity enough to not cook, so I'll be at 118k or so with about 1200 ms of velocity. All that should limit the dv requirement. My spaceplane uses aerospikes and almost makes orbit on Kerbin from the runway. Maybe I need to make sure I can get orbit with dv left over. I haven't used HyperEdit. It seems cheaty to me, but there's probably no other way to test my craft. Maybe I have to get over it.

I try to get to about 26k before switching to rocket mode. At that point I''m going about 1400 ms.

So, I'm planning a mission to Jools lower atmosphere, and since I haven't been to Jool, I'm not sure what to expect. The orbital speed is quite high. In order not to cook my spaceplane, do I have to spend a bunch of dv to slow myself down before descending below 120k altitude? Maybe I just need a very shallow descent angle? Does anyone have an idea of what dv it takes to get back to orbit from 100k altitude or so?