Claw

Agreed on the ladders. I find them too finicky when trying to grab onto, especially without using EVA fuel. If I was going to try this as a challenge, I think my first attempt would be with a caged probe (like what I posted) that has seats on it. Gently scoop up the kerbal, then get him into the seat. The cage might help keep them from bouncing off while rejoining/switching and allow for a little less precision.

If someone is filing a bug report, I see the same thing happening when rejoining behind the Mun. I've done Hohmann transfers to end up close behind the Mun where it won't show an encounter (to be in a fake L5 position). However, when I actually fly the trajectory it will suddenly switch SOIs without warning.

I've been working more on rovers myself and find them a little frustrating. It seems they are either really wide and flat to aid stability, or I make something interesting looking and have to drive like I'm about to lose my license. Anyway, I have found a lot of what Kasuha says has helped. - My controls were already decoupled, since I put reaction wheel rotations on my num pad, and left the rover forward/backward/left/right on WASD. I didn't set it up that way specifically for rovers, but it certainly helps. - The reason why the above helps me is because, I too, found that adding reaction wheels can help. I find that when I'm driving the rover at high speed and turn just a little too sharply, I can recover it by reaction wheel rotations with my separate keys. If I had disabled the reaction wheels completely, this would not be the case. Also, I have recovered a few rovers with the mighty strength of SAS. - I also sometimes add extra cubic struts around critical components, just so there's a crash cage/crumple zone. If your rover flips just by turning with no speed, it's probably your controls set up. If it happens while you're moving, then the CoM is probably too high for the wheel base (as others have said). I've also compensated a little for this by turning on precise controls (Caps Lock).

I agree, I'm actually a bit curious to have the save file and give this a try. I enjoy tasks like this. Haha, thanks! It was for another challenge.

Recommend saving wherever it's convenient to give yourself a chance to try out several different options. Then you can be the expert in rescuing kerbals slinging through Kerbin's SOI. Anyway, here's an idea that may help capture them. This is all stock, except for the inclusion of MechJeb which is not required. The idea is a little probe with a claw attached. You could increase the number of claw points to provide a better cargo hold for the kerbals. Or attach seats somewhere on the probe for them to sit in once captured in the claw. The probe has roughly 6000 dV, so it might be enough to accelerate for a rejoin, capture, then decelerate to stay in Kerbin orbit. Then you could fly a follow on mission with empty capsules (or more EVA friends) to actually pick them up. Send two probes and you might be able to rescue the craft too.

Awesome! I've not bothered to look at the code for these. Thanks!

Yes this. Although sometimes it can be really hard to click on the hatch, so don't hesitate to move the camera around and slowly hover the mouse while searching for the right spot.

Well sure. KSP stock aero has some problems, but the lift equations aren't based on craft mass. To answer your question: Lift equation for Control Surfaces: sin(AoA)*pressure*speed*lift rating Lift equation for Wings: sin(AoA)*(1-|sin(AoA)|)*cos(AoA)*pressure*speed*lift rating As you can see, the lift equations for wings and control surfaces is different. If you look at the math, there's a bug with the control surface equation in that the lift continues to increase all the way to 90 degrees. The stock drag equation is a weighted sum of the drag coefficients. I don't have that equation off hand. However, because it's based on mass and drag coefficients, you can get away with creating craft that would be extremely draggy in the "real world." As I understand it, FAR does some modification to Kerbin's atmosphere and fixes the drag model which helps if you want more "realism". Although nothing stops you from making "realistically" smooth aircraft in stock. I don't know how FAR effects the lift equations, but I'm sure it modifies them. Use FAR if you'd like, use stock if you'd like. Stock has some bugs, but it's still based on a set of rules.

Haha, yeah. 2 tanks isn't much of a slinky. Seems like you could squeeze out two challenges. One for least number of donuts, and one for the most number of donuts. mmmmmm, donuts....

If it's happening part way into your flight, throttle the engines down a bit as you burn off fuel. It might be because it's a weak link (large SAS and couplers seem weak for their size). If your rocket is accelerating too hard and snapping it, throttling back might help. (Although your TWR doesn't seem too high...) If you're okay with MechJeb helping you out a little, here's how I have used MJ for stuff like this. Pull up the "vessel info" and "utilities" tabs. In the Vessel Info tab, there's a "Current acceleration" parameter. Fly your rocket however you normally do. Watch in the current acceleration parameter. Where ever it breaks, take off a couple m/s^s and put that in acceleration limiter in the utility tab. Hopefully you'll still have a descent TWR after throttling down. If you fly it by hand, don't forget to throttle back up after staging.

Oh sorry, I didn't see that it had to be an SSTO. Here's version 2 (first four pictures). Same album, so the non SSTO version is the last four pictures. Still took too much oxy with me.

Well, I thought I'd have time to work on this but I guess I'm too slow. I figured I'd post it anyway. Here's the Donut challenge. I think I hit all the rules. Has no structural parts or struts. Has one SAS under the probe pod. No tanks clip inside each other Nothing is in between the tank stack. No cheats, no mods. Stock parts. Engines are on bottom. Fewest tanks I can manage: 2. No other fuel tanks. Not much of a slinky though.

That's pretty harsh. If you feel the need to pre-apologize to a mod, then perhaps you shouldn't post that.

The altitude may slowly go up or down even if your orbit is close to perfect. However, if you never dip into the atmosphere the orbit will not decay. In other words, if your craft's maximum altitude is say 100,500m and the lowest is 99,500m around Kerbin, it will stay that way unless you mess with it. The altitude will slowly drift between those two altitudes as the craft orbits. Press M in-game and take a look at the map. It will show you the highest (apoapsis) and lowest points (periapsis) of your orbit. As long as they are > 70km around Kerbin, your craft won't come crashing back down..

Your idea is right but I think there's a mistake in the math.The craft didn't gain dV because it turned. It gained a vector adjusted amount of the body's orbital velocity. So in your eample, the "free" gain isn't related to the 400 m/s approach speed.

The Voyager probe made extensive use. Try this... http://en.m.wikipedia.org/wiki/Gravity_assist Conservation does apply, the craft is stealing momentum from the planet. It doesn't really come from gravity, but the body's orbital energy.

Yeah, that's probably it. SAS on during reentry isn't usually too big of a deal. In fact, you might need it initially to prevent the ship from flipping around. But if you leave SAS on after chutes are out (like you said in the OP), then it's going to drain the batteries very quickly. Same thing after you land. The reason is because reaction wheels (or pod torque) use more electricity when they are active. They don't use any electricity if SAS (or you) isn't providing input. Unlike lights or probe cores (not the torque part) which draw a steady amount. So if the chutes are deployed and SAS is on, the SAS tries to turn the craft against the pull of the chutes back to the orientation before chutes were deployed. Hence the rapid battery drain. If you think you need SAS for landing, turn it off after chute deployment to let the craft settle, then turn it back on right before you need it. Turn it off again after you land.

Yes, this is exactly my point. The concept of Oberth is unrelated to setting up an elliptical orbit first. Setting up an elliptical orbit first is a byproduct of other factors. (And this is why I dislike throwing around example numbers.)

Again, dropping from an elliptical orbit and doing an interplanetary transfer burn at an LKO PE only helps harness Oberth if you have low TWR. Gravity does play a part in this, but it's inherent to the orbit so it's not apparent when intraplanetery. There's a reason why you get the highest solar AP when burning on the midnight side of Kerbin. (Multiple reasons really.) Anyway, the advantage of descending from Minmus or the Mun is that you could have a refueling station there and still have some control over the start of the elliptical orbit. So if you have a high TWR and aren't planning on refueling, the gain you get from creating an elliptical orbit to "maximize Oberth" will be minimal and is probably not worth the complications of setting it up. At the risk of throwing out numbers, I just completed a challenge where my design forced me to make an elliptical orbit to maximize Oberth. It used a nuke and took over an eight minute burn for the entire fuel load. Setting up the elliptical orbit netted a gain of around 200 dV for a roughly 3000dV burn (the entire fuel load). So actually not a bad gain. But, if I had 4x the thrust, the burn would have been 2 minutes, I wouldn't have to do the ellipse, and I would have had fuel left over.

Thanks! It works great for rescue missions, especially if there's science involved. I think you could expand that idea to 16 probe bodies on one mothership and do all of the big tanks in one launch, but my computer was slow enough with this.

That would be my guess as well, since I have had problems getting a kerbal to just stand up when dropped on an inclined structural panel. Also, the Kraken isn't a fan of things bumping against each other. Not to mention that you wouldn't be able to time warp because your ship/kerbal would float right through the ring. I love the concept though. Might have to try it out.

I'm having a hard time imagining exactly what you want based on your description. If you mean you need more horizontal gap between your vertical Rockomax tanks, you can try stacking decouplers (decoupler on a decoupler). Or mount one of the modular girder segments (or cubic struts) to the decoupler, then mount the tank on that.

Okay, so it won't get to the Mun in 13 seconds, but it made 6106m.

And it's really only advantageous for Oberth if you have a low TWR. Otherwise you're just killing time. Besides, if the goal is to ease using Oberth, using the Mun for such activities is way more simplistic since the delta V is pretty close to Minmus, but you don't have to wait nearly as long for the orbits to line up or have to deal with orbital inclination.

This looks like something I've been working on, though I haven't had the guts to go to Laythe with it.