tavert

Well, for one thing your drag force is being applied in the direction opposite to orbital velocity instead of surface velocity.

This is not correct in the stock game. The Rapier has the same Isp-vs-pressure curve as the turbojet, and requires the same ratio of intake air per unit liquid fuel. So for a given amount of thrust, the Rapier uses the exact same amount of intake air as a turbojet. The intake mechanics did change between 0.22 and 0.23, so turbojet aircraft don't need as many intakes as they used to.

The insertion dV of that Kerbin-Eve transfer if you were to hypothetically burn into a 100 km Eve orbit at the end would be about 1540 m/s, and the ejection burn of the Eve-Jool transfer at that window is 2650 m/s (from 100 km). So the numbers all seem reasonable to me. And I don't think I've seen people get all that far from just the first Eve assist, from what I remember it usually takes one or two more Eve and/or Kerbin encounters to get all the way to Jool, depending how many powered flybys (and how large) you want to do. How did the geometry of your encounter look inclination-wise? I'm not exactly an expert when it comes to gravity assists, but from what I've seen it helps to have some normal and/or radial component of your incoming trajectory for the gravity assist to bend around into a prograde component. In a normal Hohmann transfer you tend to come into the encounter mostly parallel with the planet's orbit, so it helps to actually go a bit past the optimal transfer on your initial burn.

Here's a tool that'll give you some numbers on how to maximize payload fraction for airless-body landing and/or takeoff (currently only looks at single-stage vehicles): http://forum.kerbalspaceprogram.com/threads/61659-Wolfram-Web-App-Optimal-Single-stage-Lander-Design-Tool

The most efficient way of getting to really high speeds with stock parts that I know of is doing a bielliptic transfer, first out to the edge of the solar system (almost but not quite solar escape, as far out as you have the patience for), then down to a very low solar periapsis. Burning the rest of your fuel at a low solar periapsis will give you a big Oberth boost, but since you're more or less guaranteed to be on a solar escape trajectory at this point you'll have to time things carefully so you intersect Eve as you cross its orbit.

You're talking about different metrics. More payload mass means longer burn time for the same delta-V, but same burn time for the same amount of fuel.

Remember the top speed is surface-relative, so 2200 m/s surface is pretty much orbital. Ah, interesting that the ignition threshold seems to actually matter now. Worth noting that it's different for the Rapier, at 0.33.

Same Isp in air-breathing mode. 190 kN from 1.75 tons for the air-breathing Rapier vs 225 kN from 1.2 tons for the turbojet. And the turbojet has a 200 m/s higher top speed than the air-breathing Rapier.

By the time you're out of the atmosphere, you don't really need as much thrust as the vacuum-mode Rapier provides, considering how many of them you would need to get an acceptable vertical-lift TWR off the pad. Turbojets have better TWR and top speed in air-breathing mode, and you can add a smaller number of rocket engines to finish the orbital insertion with the mass you save.

HTH. Yes, KE tells you "design dV capacity" before taking into account any losses due to gravity, atmospheric drag, or steering (non-prograde thrust). I forget whether KE will actually measure those individual losses while in flight, I know MechJeb does. Neither KE nor MechJeb do any simulations of the ascent performance of your design, or optimization of gravity turns, etc. The "design dV capacity" just tells you that if you were to burn through all of your craft's fuel (in a vacuum for vac dV, or at constant sea-level ambient pressure for atmospheric dV) and stage immediately when you should, what will be the result of integrating gross engine thrust divided by total craft mass over time.

Yes, essentially. In simple cases without fuel crossfeed or parallel staging, it reduces to just applying the rocket equation on each stage. KE assumes constant Isp for each engine, either vacuum or atmospheric. Hence the distinction between "vacuum dV" and "atmospheric dV." Drag losses are a function of trajectory, for a fixed design. A given design has an inherent max delta-V capacity, your trajectory and throttle settings determine how far you can get with that delta-V capacity. For the most part, yes. When there is fuel cross-feed, KE does a fuel flow simulation to determine which engines draw from which tanks during each stage. When there are multiple types of engines, the overall weighted effective Isp depends on the combinations of engines that are burning, and this can change at each stage. Yes, it assumes a best case where you drop each stage at the exact instant the fuel flow simulation predicts it will run out of fuel.

Cool, did you take notes about what you had to tweak to get it to run? I never actually ran alterbaron's PSOPT code, but I have tried implementing something similar off-and-on in various other tools (ACADO, Pyomo, Mathematica, custom OSiL) and nothing has quite worked yet.

More power to you, but one thing you can never do better than a computer is repeating the exact same experiment under controlled conditions.

I'd put that down to difference in trajectory. Have MechJeb fly them with the same trajectory settings, then let us know. Wings can counter some gravity drag, and let you take off with less-than-1 initial TWR. But really you want to get out of the lower atmosphere as quickly as you can whether you take off horizontally or vertically, a vertical launch just starts you off pointing the right direction to do that. What numerobis is talking about is whether you're going totally horizontally in the 20-30 km altitude range to build up speed with a jet (higher if you've got lots of intakes), or if you're continuing to ascend on a typical gravity turn trajectory with a rocket. At those altitudes drag and lift are fairly minor, so wings are mostly just dead weight.

These are pre-0.23 numbers, right? Have you experimented much with 0.23 yet? From my limited time in 0.23 and various other people's observations, it seems the tweaks to the way intake air works now mean you don't need as many intakes to get the same performance.

You might have left an acceleration limit enabled in MechJeb in your 0.23 install?

Why not start with the flow disabled on the monoprop (or EVA propellant, if it's intended to be something separate like a cold gas thruster) tanks in pods? Tweakables should make that a viable solution. Isn't Kerbal EVA refueling a separate system from RCS fuel flow anyway? I'll second the suggestion for persistent Kerbal resource tracking across getting in and out of pods. If it was only 5 units of monoprop, that's 0.02 tons, a little over 20% of the mass of a Kerbal. Why not reduce the dry mass of a Kerbal accordingly, and fix the jetpack to properly obey the rocket equation? A zero-density resource is a hacky fix. The only advantage from a gameplay perspective is being able to see jetpack fuel levels without clicking on the Kerbal now. Here's hoping you'll continue to refine the feature, as the 0.23 implementation was a very minor player-facing change and leaves a lot to be desired. Thanks for the background info though!

I find it hard to believe that major of a change would not be mentioned in the changelog. What I do see in settings.cfg is that the default value of MAX_PHYSICS_DT_PER_FRAME is now 0.1, where it used to be 0.03. I suspect this could account for more of the subjective change in feel than anything else I've seen.

Evidently it was first performed on STS-90: http://en.wikipedia.org/wiki/STS-90 When you have multiple propellant types, it's more efficient to use the lowest-Isp propellants before the higher-Isp propellants, or in this case use the OMS as early as it makes sense to. For missions that aren't expected to require all of the OMS' fuel capacity, and if everything goes nominally during launch, then it's probably good for another few hundred kilos of payload as compared to an otherwise identical mission that brings the excess OMS fuel back from orbit.

It starts out stationary relative to the surface. Then if you burn straight up, there are several things going on. You increase in altitude, and the Coriolis acceleration of the rotating reference frame (see equation (20) here https://dl.dropboxusercontent.com/u/8244638/Constant%20Altitude%20Landing%20and%20Takeoff%20Derivation.pdf) will tend to decrease your horizontal orbital speed. However atmospheric drag will tend to damp out any nonzero horizontal surface-relative speed. The elliptical arc drawn in the map screen is showing your orbital path and doesn't take into account the effect of drag. That will generally show a prograde path, but the surface of Kerbin rotates below you as you traverse that path so by the time you reach the surface again you should end up to the west of where you started.

It's just simple surface rotation. KSC is very close to the equator, rotating 2 pi times 600 km (plus a few meters above sea level) per 6 hours, giving you about a 175 m/s eastward orbital velocity when you're stationary relative to the surface.

Probably not, but you'll have to ask Alan Bond

Octave is a volunteer-maintained open-source attempt to mostly clone the Matlab scripting language. It has almost identical syntax and is designed to allow simple Matlab .m scripts and functions to work with a minimum of changes. It has a lot of deficiencies though: it doesn't have replacements for many of the toolboxes (notably Simulink), there's no official GUI, they don't yet support the revamped object-oriented programming style that Matlab implemented over 5 years ago, etc. Unless you are really attached to Matlab for any reason, I'd say you should avoid Octave. There are better options for free open-source technical computing and general-purpose programming languages. Have a look at either Julia or Python.

There are also height and I believe weight requirements (kind of old, but here's one source on height requirements http://usatoday30.usatoday.com/tech/science/space/2007-04-02-astronaut-size_N.htm). A few years back I met a nice woman at an alumni event who worked for NASA, and was pretty close to being in one of the earliest groups of female NASA astronauts, except at about 6 feet tall she was way outside the initial height/weight requirements they had set for women.

You're going to have to be more specific than "far"... one Rapier and about 4 tons of fuel is plenty for solar escape: