Lelitu

Refuelling an SSTO in flight is very commonly done, as that's the easiest way to extend any vessel's available deltav. That said, Dres or Duna are not the places you'd put the tanker for a mission to Laythe. It would make the trip a lot slower and cost more fuel than a direct flight. For maximum benefit you want to refuel in low kerbin orbit, and again in Laythe orbit. Getting to orbit from kerbin/laythe is literally half the delta v of the one way trip.

that prompted me to do the back of the envelope math for just swapping out the NERVA for an LV-909 345 * 9.81 * ln(7.5/3.5) = 2579m/s, and the lightest total stage mass.. it's saved 2.5 tons total stage weight, That's going to appear as deltav gains all through the booster stack used to get that there.. might even save enough mass to drop 2 tons of fuel and use a FLT-400 tank, or just drop that stage entirely and use a slightly bigger ion stage, for the same total performance. KER makes doing the math for all this much easier, since it does the math for you.

For very light probes, the NERV is a bad idea, because it's very, very heavy. 3 tons for just the engine. For comparison, the LV-909 is a chemical engine delivering the same thrust for 0.5 tons. That 2.5 ton mass will completely outweigh the extra 455 seconds ISP when it's a large fraction of the total craft mass. For this design, the NERV works out even worse, since the FTL-800 carries LF and Oxidizer. NERV engines don't use Oxidizer, so the Tank is only half it's usual propellant volume. From the screenshot, you've also left the Oxidizer in the tank.That's another ~2 tons dead mass sucking away at your delta v. The reason the engine mass is such a problem is that with the lighter LV-909 you can carry an extra FLT-400 for the same craft total mass, but more than 2 tons less dry mass. Assuming a 10 ton vessel fully fuelled, with your current design, or a 909 and an extra tank, you get from the Tsiolkovsky rocket equation, isp * G * ln(Mfull/Mempty) = deltav current - 800 * 9.81 * ln(10/8) = 1751m/s with ox stripped - 800 * 9.81 * ln(8/6) = 2257m/s (not as bad as it looks, since you'll get more out of all earlier stages, from the 2 ton less wet mass. with lv-909 - 345 * 9.81 * ln(10/4) = 3101m/s nearly twice the deltav, for the same mass to orbit. with mk1 lf fuselage - 800 * 9.81 * ln(10/6) = 4008m/s best of all options for a 10 ton vessel. If the estimates of the dry mass are high, it'll tip in absolute favour of the lv-909 fast.

for me, it's always the landings. I suck at landing fuel efficiently, and usually don't carry large margins, so it's the landing burn that tells me if a rescue needs to have launched yesterday. life support can make the game so interesting sometimes..

Part of getting the very cheap capture burn is that the chart expects you to do the capture burn at the lowest safe periapsis to exploit the oberth effect. The chart also considers the delta v to capture, as just enough to go from a hyperbolic escape orbit to an eccentric orbit with apoapsis just inside the SOI, and periapsis just over the atmosphere. At Duna, you'll need to burn much more than this at the capture burn (most of the circularization burn), unless you're going to Ike, because Ike's massive SOI gets in the way, and you'll either slingshot, or collide with Ike in a very few orbits unless you get your apoapsis low enough To do this cheaply, you'll want to make a *very* small adjustment burn shortly after leaving kerbin, to set your periapsis. Done early enough, you can move your periapsis at duna from just grazing the SOI to just missing the atmosphere for about 2 m/s.

in my 1.3 install.. 58. They're there for a selection of reasons. Stock system is too small, OPM adds a lot more places to go, and getting there takes a lot more planning since solar panels don't work that far out, and flight times are measured in decades. TAC lifesupport makes long duration kerballed missions much more interesting, since you need to figure out how to feed them. There's a few part packs to go along with this. Near future tech, DMagic orbital sciences, Scansat. KIS/KAS for fixing up simple mistakes and expanding stations (I don't get a lot of use out of these tbh). Visual and audio overhauls improve the look and sound of the game. And lots of extra data, KER, Transfer window planner, precise node, they all add lots of information that's very useful as soon as you leave Kerbin SOI. Why? for challenge and realism mostly. I got bored with the stock game.

The relativistic equations are symmetric about C. This suggests weird possibilities for massive particles ect that move strictly faster than C, with faster massive particles carrying less kinetic energy. There are two physical possiblities for this, based on the observation that causality works (ie. effect always follows cause), and that a massive particle travelling faster than light is also capable of travelling backwards in time. Either particles faster than C don't exist, or massive particles faster than C cannot interact at all with anything at C or lower. Massless particles of course travel at exactly C.

well, I play with realfuels in a stockalike config. This means ullage motors are required to restart many vacuum engines. The little bit in the command pods is just about spot on for driving ullage burns.

More accurately, folding them up while clear of atmosphere is an excellent way to lose a probe. Once it's out of power, that's it, probe's dead.

They're quite useful on assymetric satellite designs, where symmetry may be hard to arrange, or result in carrying more massive comms arrays than needed. The aero forces can be enough to make the first 20km impossible without a fairing.

Mechjeb and KER both can display the LAN for the current orbit. KER for post burn too, not too sure about mechjeb. For a kerbin target orbit, it's easier to just eyeball it. if you launch when the orbit line passes directly over the KSC, you'll be able to get a LAN very close to target, which means small maneuvers to fix it later. Might even manage to hit it perfectly on the way up.

well, time to start maintaining an up to date backup where steam can't get at it.

1.25m service bay has hardly any mass, only 100Kg, pod has 800Kg mass. Assuming they're made of basically the same materials, that's 8 times as much heat before the pod overheats and explodes.

It has almost nothing to do with the heatshield's drag levels, and everything to do with highest temperature experienced.

Same way you deactivated them, click the little red circle.But, you have to have control of the craft to reactivate locked resources. Having control means a kerbal, or electricity and communications. If you don't have control, there's no unlocking locked resources, even if they would restore control.

This is all to do with limitations in the KSP heating model. A part takes exactly no damage until it exceeds maximum temperature. Once maximum temp is exceeded by any amount, it immediately explodes. Ablative heat shields burn off ablator above a critical temperature (~1500K) to stop heat conducting to the rest of the ship, and have a very high max temperature (3300K vs ~1500K or less). A shallow re-entry has quite low drag, but very high heating, as the heat flux scales with the cube of velocity, and air density but drag only with velocity squared and air density, so max temperature rises much faster than drag. Total heat load is heat flux times time, So a shallow reentry gets a relatively low temperature for a very long time, resulting in very high heat loads. KSP doesn't model part overheating very well, so this doesn't have the same effects it would in real life (roasted astronauts and computers, probably exploded pressure tanks too). A steep re-entry reaches denser air still travelling very fast, so it's exposed to *very* high temperatures, but not for long, since the high drag slows you down fast. This results in much higher G loads,and a much smaller total heat load. The lower total heat load means that much less heat soaks into the ship, and the interior stays relatively comfortable, despite the plasma filled hell just outside. In KSP, the big advantage is that a heatshield's mass is dependent on how much ablator it has, so the steeper the re-entry the less ablator you need to get through it alive. If you know you're going to come in steep, and only need ~30 ablator, you can cut back to ~50(to leave a margin) and save some mass through the whole rocket. The steep re-entry is a bit like opening the oven door, a blast of extremely hot air, but not enough to seriously overheat you. The shallow re-entry is more like climbing in to the oven (at minimum power)

If you're as brave as jeb, you can actually get out and push when it's that small. You'll need to do that at apoapsis, and have the pilot stay aboard to keep SAS hold going (tumbling makes it a crapload harder). Have one of the others get aligned with the center of the heatshield, and push with RCS thrusters It won't take much. dropping periapsis below about 50Km should be enough to bring you in on the next pass. just don't forget to save some RCS fuel to get back in.

I believe it's actually undefined, not infinity. They're quite distinct things. Any answer to x/0 is equally valid, they're all nonsense.

270 is a good amount to have from a low orbit, if you're not doing anything more than returning. Remeber, it takes some fuel to deorbit. You wouldn't want to cut the margins any finer. While playing around with your orbit, I had Val in a 71x140Km orbit, with no fuel, and 2 hours life support left. She had to get out and push to get back. It worked, then I forgot to deploy the main chutes

absolutely not. Floating point numbers in computers have concepts of + and - infinity, as well as NaN. NaN literally means "Not a Number", and is the result of an operation with mathematically undefined result, such as division by zero. Any operation on NaN, results in NaN. In math, infinity is quite well defined. If your speed had gone infinite, it would be +infinity.

Moving fuel from the terrier to the first stage means a greater fuel mass in the first stage, and smaller payload mass in first stage (stages 2+ are payload for stage 1). This gets you more deltav out of stage 1, but less out of stage 2.

Biggest thing that rocket needs is some fins. 3 of the smallest fins placed right at the bottom of the lowest tank will sort out most of the prograde wander. Moving some of that fuel from the second to the first stage will help as well. The terrier is very efficient, but low thrust, so pushing a FL-T200 tank, instead of the FL-T400 will work better, put an FL-T200 in the first stage, and you'll have the same fuel total, but will get significantly higher and faster before switching over to the terrier. If there's room, move the goo canisters into the service bay, along with anything else sciency on the pod. the drag isn't helping, but isn't the biggest problem. it's the fins. If it drifts a degree or two off perfectly equatorial, don't bother fighting it, the losses are trivial.

That is *not* what you said. You said that vacuum detalv isn't the right display. Technically, that's true, in that it won't show the actual deltav available. However, all the deltav maps available list vacuum deltav to orbit. Because the maps list vacuum deltav, it's easier to just use vacuum display and check against this value. This is done because vacuum deltav is easy to calculate and work with (vacuum isp doesn't change over time). Atmospheric deltav is a lot harder to work with mathematically, since you have to account for ascent profile due to ISP varying with atmospheric pressure. Also, no craft file or picture was provided by the OP, so we can't be completely sure of the available deltav. Further, 3400 vacuum is about the limit i've been able to achieve with a well streamlined rocket, and good ascent profile. I'm nowhere near the best pilot ever either. 3800 is enough to get away with some inefficiency to orbit.

3800 vac deltav is fine to reach LKO with an efficiently built rocket, with the right engines on the lower stage. the swivel and reliant are the right engines at early game.

Poll is missing an option. Partial reuse. There's a lot I recover or reuse, and a lot I don't. now that I've unlocked the docking port senior, I'll be doing a lot more reusable interplanetary stages. First stages(and solids) are recovered with stage recovery mod. Upper stages, landers, and low mass interplanetary probes are not recovered. I'm playing on hard, with lifesupport, so funds are at an extreme premium, and full reusability just isn't economically feasible yet (maybe ever)