cantab

Bear in mind KSP's stock aerodynamic model isn't much like reality. I suspect most aspects have been covered, though I don't recall anything specific on fuel-efficient climbs.

There's always the option of stacking your engines vertically, a la the Lightning fighter. Though that would probably look silly for any more than three or four.

First up bear in mind you're still going to have to stage, at least in stock. There's been lots of discussion and research on the possibility of stock non-glitch-exploiting Eve SSTOs, but nobody's made one yet. I suspect that without jets the ideal ascent will be similar to a regular rocket. Firstly ascend out of the thickest atmosphere using minimum fuel per metre of altitude gain, then climb and gain speed. Unless you want to make an aerodynamic landing somewhere afterwards, you're best off dropping your wings when their weight exceeds their usefulness.

Circumnavigate Kerbol in a rover made from hollowing out Gilly.

Capturing into highly elliptical Eve orbit will require around 1300 m/s less than capturing into low orbit, but when you're coming in from an "express" transfer you need to shed a lot of speed either way.For the OP, if you're throwing enough delta-V at the problem to make a 17 day transfer, you may as well throw more to do a power-assisted capture, burning hard retrograde just before entering the atmosphere.

Expected lifespan vs performance factors in too. Modern road cars are very reliable, their engines, gearboxes, and so on can do thousands of miles before they even need any maintenance, and hundreds of thousands if looked after. Formula One cars, on the other hand, regularly suffer gearbox failures and engine failures, because their gearboxes and engines only need to last a few race weekends (and not so many seasons ago they only needed to last one race) and they need to be as light as possible. The inevitable random factors though mean that sometimes one will break in a race. It's the same for (non-reusable) rockets. They only need to last one flight and they need to be as light as possible to maximise payload, so they aren't going to be built for thousands of flights. The upshot is that sometimes they'll fail in that one flight.

Something like a Tu-160 might do well. A 600 m/s start at 12 km up isn't huge, but I reckon it'd translate to a 10-15% payload increase. With a 40 ton payload on the plane you could get a few tons into orbit, rather more than the Pegasus's half-ton payload. In terms of payload to orbit, I think the aircraft cargo capacity is more important than its height or speed. As magnemoe says, the bigger benefits are on secondary factors. Launching from a choice of latitudes and above the weather, and being able to use a first rocket engine optimised for higher altitudes. And not having the expense of a ground launchpad.

I would expect so. The standard voltage is 1.8V, so I doubt you'd encounter memory that won't operate correctly at it.

Seems like there's been a decent amount with ion propulsion and similar. The Dawn mission probably couldn't have been done with a chemical thruster.

It's not a fail since it was deliberate, but Matt Kerman will not go to space today, or ever. He flawlessly touched down in his Duna rover - on Eve.

Illegal in Britain, for what it's worth. Making any sort of solid rocket motor yourself is regarded like making an explosive device and so heavily regulated it's out of amateur reach really. The ready-made motors are easy to get though.

Here's what I'd do: No need to change the target ship's orbit. Set it as target when you're flying the rendezvousing ship. The following assumes rendezvous with a ship in a higher orbit. Change appropriately if the target is in a lower orbit. Set up a prograde burn that raises your apoapsis to just touch the target ship's orbit. Put this manouevre: if you have a big inclination difference, at the AN or DN, whichever is closer to the primary (Kerbin for you). if the target orbit is very eccentric (yours isn't), directly opposite its apoapsis. otherwise, at your periapsis. If your inclination is more than a degree or so different to the target, set up a normal burn at the AN or DN, whichever is further from the primary if there's a big difference. You may need to add a retrograde component to keep the apoapsis in the same place. You should after doing this, if you didn't already, have a closest approach marker. If the AN/DN is at apoapsis, combine this burn with the next one. Set up a prograde burn at apoapsis that gives you a closest approach on a future orbit as small as you can get. For typical rendezvous in Kerbin 2 km or less is what you want. Optionally, add further dummy manouvres around the orbit, each one just before the last (because actually that places it nearly a complete orbit after), to show the closest approach for more orbits in the future. Once you have that set, set the navball into target mode by clicking the speed indicator. This measures the prograde and retrograde directions and speeds relative to the target ship rather than the planet. When you get close to the target, point retrograde and burn until the speed shows zero. Congratulations, you've rendezvoused! Now carefully fly closer to dock or just EVA Kerbals over.

In pure delta-V terms, wouldn't an elliptical Laythe orbit be even better, since it would require less delta-V to escape from? It would be a practical nuisance mind, since you'd be limited in suitable ejection and entry angles. Also, while the landing doesn't matter for delta-V usage, it will for fuel usage. Say your station is at Laythe, then for the Laythe landing you just need to fuel to get the lander down and up, but for the Vall and Tylo landings you also need the fuel to ship the fully-laden lander to its target, and if desired to ship the empty lander back to the station. For a fixed on-the-ground payload, the Tylo lander's going to be the heaviest, not sure about Vall vs Laythe.

Start by picking a moon to give you the slingshot and setting it as target. Tylo is the most "powerful", I think Laythe can work too and maybe Vall. If your orbit intersects the one of that moon, you should get a marker - if not, adjust your orbit until it does. Then, go about getting an actual encounter in a similar fashion to rendezvousing with a target ship in Kerbin orbit. Once you actually have the encounter and projected onward course, set up a correction that gets you booted appropriately from the system.

Well I don't do many planes anyway. But yeah, if you've got intakes clipping into each other, or on parts that clearly couldn't feed the air (like a girder or the thin edge of a wing), then that gets into airhogging. Radial intakes with obstructed flow, including by other radial intakes, too. But if you put one engine on a Rockomax tank, then four rams on the other end and six radials around it, well I suppose that is airhogging, but it wouldn't feel so cheaty.

Timewarp in the tracking station instead?

Circumnavigate Duna - with a rover entirely controlled by kOS.

Another factor to bear in mind is that with a turbopump you use the fuel and then toss it overboard. With an electric pump you're carrying the full mass of the batteries (or similar) for the whole time the stage is in use.

I would make a separate engine that slots in. That way you can test your engine and plane separately before flying under power - engine on the bench, plane in a glide with an inert dummy engine for weight. And yes, be careful with rocket fuel.

Yeah. At least for the ruggedised wheels, broken ones drag really badly and make it nigh-impossible to drive on. And I got lots of wheel breaks driving around near the space centre. Funnily enough the same rover drove over 60 km on Eve without a hitch.

Or what I always do is hold down W then click on another window. The Kerbal will keep running until I click back on KSP and tap S.

There's a tutorial on the forum about intercepting asteroids in solar orbit, but the key "trick" is to leave Kerbin's SOI in the direction the asteroid is predicted to enter. For some reason that naturally gets you a close encounter. You've certainly got ample delta-V to rendezvous with the asteroid unless you really hash it up. Depending on how picky you are about your final orbit, aerocapturing it shouldn't require that much delta-V - you just need a small correction shortly after you grab it to adjust periapsis, make the aerocapture, then a small burn to raise periapsis for a stable orbit. Off the top of my head a C-class asteroid should mass about 100 tons, and you ought to have plenty of delta-V with it in tow. I captured a 500-ton D class with about the same amount of fuel as you have there. Where your design has problems I think isn't power but control. I don't see any reaction wheels and it looks like there might be no RCS either. You're never going to claw the asteroid perfectly so you need to be able to handle a slightly off-centre mass and not end up spiralling, and you'll probably prefer to be able to rotate the asteroid for burns rather than having to unclaw, fly round, and reclaw. (The latter is often necessary for heavy E classes, but C's and below definitely shouldn't need it with a well designed tug).

Launch the "main event" ship first. Then, on a second PC or just a second window if your PC can handle it, open another instance of KSP to do the stuff like landing site selection in (presumably with timewarp). That should help you fill the journey time.

The LV-N is recommended as the go-to engine and rightly so, but for Duna it's not the only viable option. I knocked up two sketches of Duna ships, using the "Apollo-style" orbiter/lander arrangement. Specs were as follows: 3-Kerbal one-stage orbiter has at least 528 m/s of delta-V for the return trip, to be taken sans lander, and 1166 m/s for the outward, obviously taken with lander. These are 10% margins over this delta-V map:http://wiki.kerbalspaceprogram.com/w/images/7/73/KerbinDeltaVMap.png . That's a fairly slim margin I admit, but not unreasonably so. 2-Kerbal one-stage lander has about 1500 m/s Duna atmo delta-V (a little of which will be needed for touchdown) and plenty of TWR, and weighs about 7 tons. That's a more generous margin which I think is desired for a lander. With the lander, the orbiter has a Kerbin TWR of about .35, adequate for interplanetary travel. The version with one LV-N on the orbiter weighed in at 16.7 tons, while the version with two 48-7S's was 18,6 tons, just 11 percent heavier. So while in this case the nukes do win, there's not an awful lot in it. Nuke ship: https://flic.kr/p/opocuK 48-7S ship: https://flic.kr/p/opoqgq

If you fancy something less time-consuming, Gilly could be fun. Make it rover wheels only, no using downthrust.