Lt_Duckweed

Not to toot my own horn too much, but if you want to learn nor about how lift and drag is calculated, and how wings work in ksp, I highly recommend you check out my 2 videos: Then, you will want to check out F00FlGHTER's ssto tutorial: Between the 3 videos, you will get a pretty solid understanding of how the KSP aero model works, how to optimize for it, and how to implement those optimizations into a spaceplane ssto.

One big-s wing is .5 tons, 5 wing area, and 300 fuel storage. 5 big-s strakes is .5 tons, 5 wing area, and 500 fuel storage. In other words, each pair of big-s wings that you replace with 10 strakes saves you the need for either: 1 mk1 tank (250kg dry mass) or 8 mk0 tanks (200kg dry mass) Another way to think about it, each strake replaces 2 mk0 tanks (the absolute best liquid fuel tank) so it is essentially 2 mk0 tanks (50kg) + a half mass wing (50gk per area instead of 100kg per area)

You can change the number of engines the engine plate can hold, up to 8+1. Any engines attached directly to the plate nodes are shielded from drag while the engine plate shroud is still attached. The engine plate is a decoupler. It's a multiadaptor, interstage fairing, and decoupler rolled into one part. If you need to mount a cluster of engines, for example nervs, they save on part count, and can save on mass as well, depending on what exactly they are replacing

Imagine that the planet has 10km/s orbital speed, and is traveling from left to right. Further, let us imagine our spacecraft has a relative velocity to the planet of 2km/s In A and C, the spacecraft has an orbital velocity that is faster than the planet, 12km/s. It then catches up to the planet, wraps around, and heads off back the direction it came. Instead of 2km/s faster (12km/s orbital speed) it is now going 2km/s slower (8 km/s orbital speed), so we lost speed overall. In B and D, the opposite occurs, we are going slower, the planet catches up to us, then flings us forwards. So we gain speed. The way I like to look at it is this: Compared to the orbital path of the body we are assisting off of around its parent, was our trajectory bent so that it is closer to prograde than before (ie, did the angle between the bodies prograde, and our prograde, get smaller)? If so, we gained speed. Was it bent closer to retrograde than before (ie, did the angle between the bodies retrograde, and our prograde, get smaller)? If so, we lost speed.

Yes it is intentional. Notice that your heading marker is above your prograde marker, this means that some portion of the airflow is impacting the underside of your fuselage, which in ksp generates a lot of drag. The best way to do this is to make sure the body of the craft points prograde. But, you need angle of attack for the wings to make lift. The way to solve this is to "build in" angle of attack on the wings by angling them a few degrees relative to the fuselage. One tick of the rotation tool while holding shift and in snap mode should do the trick, this will give 5 degrees, which is very efficient at supersonic speeds. This is called angle of incidence.

Kerbol space low is actually at 1 million km, not one thousand. With perfectly ordinary heatshields and radiators, you can get to about 200,000 km. You can go progressively lower with more and more esoteric heating exploits and get as close as the edge of the atmosphere itself (600km)

If you look carefully in your screenshot, it says in the top middle of the screen "physics easing in progress". This means the crat does not weigh the full amount, as it was trying to ease the physics as you landed, but presumably you never touched the ground.

You have plenty of lift. Your issue is that your Center of Lift is very very far from your Center of Mass. This means the plane wants to nose down very strongly, and you do not have enough control authority to bring the nose back up. You need your wings farther forwards, and/or larger pitch control surfaces, and/or pitch control surfaces that are farther from the Center of Mass.

Even for stock LKO, liquid fuel only Rapier-Nerv spaceplane SSTOs enjoy a performance advantage over pure Rapier LFO SSTOs. As you go upwards in scale, they lose performance at a much slower pace as well, due to the much higher ISP. The end result is that the hit to performance going to JNSQ is not as harsh as many assume. Of course, special attention needs to be paid to the harsher ascent and entry heat (especially on ascent, as ascent is lift supported nearly the entire way to orbit), but this is ultimately manageable via smart design, and payload fractions near 30% should be achievable.

They are much more difficult, but by no means impossible, and can still be very effective and carry payloads to orbit, and go interplanetary. However, JNSQ SSTOs are much less forgiving. I would describe SSTO building as following an curve with skill that has a very sharp inflection point. That is, for a very long time, even as you get better at making sstos the overall quality of your craft doesn't get that much better, but once you hit a certain point, it explodes very rapidly. For usable stock scale SSTOs you don't have to have found your way past the inflection point. For JNSQ SSTOs you do. In other words, for a very long time JNSQ SSTOs just don't really work, and then suddenly at a certain skill level they work just fine.

Been a while since I fooled with Eve, and since then the devs nerfed the mass of the mk3 crew module, so I figured it was time to take another look at it and redesign my old gross Eve crew SSTO: Into a new, sleeker craft

We do actually have examples in real life of extremely large, volatile poor superearths. https://en.wikipedia.org/wiki/Mega-Earth. Kepler-10c was originally thought to be one before its radius and mass were more accurately measured, but there are a few other examples with more rigidly constrained masses and radii. To be fair though, these usually orbit their stars in very tight, hot orbits that drive away volatiles.

FYI you can't actually cheese reentry/ascent with radiators anyways. Anytime the external plasma temperature (note this is not the same as the current part skin temp, which will be significantly lower) exceeds the radiators max temp, the radiators are hard-coded to shut down. The end result is that by the time you would want them to be helping cool the ship, they are shut down, and rather than radiating heat away they are absorbing heat. And also making lots of drag.

This will NOT work for higher speed reentries. This only works for relatively low drag craft on low speed entries, where the limiting factor over a long entry is the internal temperature of a weak part getting too high due to heat bleed. For high speed entries (well over 3000) you are instead limited by the maximum skin temperature of the weakest part. Often this entirely prevents you from dipping bellow 40km, as any lower and your craft turns into a meteor shower as parts instantly turn into flashpaper. For these types of entries you are forced to stay high, and need to generate as much drag as possible using an extremely high AoA. If my ssto design can't sustain at least 40 AoA from entry through to sub Mach 3, I redesign it. As an example, on a recent mission I hit atmosphere at 4300 m/s. Any lower than 44km and the craft burns up due to exceeding skin temp, so it has to scrub over 1000 m/s in a single pass at 44km at 90 degree AoA. As a matter of fact, I have NEVER had a craft that dealt with problems with internal overheating on reentry. The only time I have ever had an issue with that was with a craft that needed to do an extended hypersonic glide halfway around Kerbin post reentry, and one of the science parts (1200 internal temp max) got close to blowing up. TL:DR - A properly designed spaceplane is going to be able to generate enough drag that it can scrub speed fast enough for skin temp to always be the limiting factor, not internal temp.

Please reread my post. I said an elliptical orbit BELLOW your current circular orbit. Moho is in an elliptical orbit BELLOW your current solar orbit when coming in from Eve. The most efficient way to reach it is to lower pe to match near Moho Pe while also matching planes in the same burn. Since Eve-Moho Dn is quite close to Moho Pe, you want to do your Eve assist at Eve-Moho An. Off the top of my head, to properly match planes and lower pe takes 2 assists because relative velocity to Eve is too high to do it all at once.

This isn't actually true. A normal rendezvous/transfer has the same properties as this Moho transfer. When transferring to an elliptical orbit that is bellow your starting orbit, starting from a (mostly) circular orbit, you need to: Drop your Pe to touch the target orbit. At your Pe, reduce speed enough to match the rest of the orbit. When you do this via transferring to target Ap you essentially: 1. Hohmann transfer to target Ap. 2. Circularize at target Ap. 3. Perform the Pe lowering of another Hohmann transfer to lower your pe to match target pe. When you transfer to target pe you: 1. Perform a Hohmann transfer to target Pe. 2. Abort the circularization burn at Pe partway through, when the Aps match. Perhaps after work I can work out the math on this to provide a proof. Edit: another way to think about it, when transferring to an elliptical orbit, you want to match your Pe vs its Pe, or your Ap vs it Ap

When descending to the surface from a low orbit, you should not be doing a pure retrograde hold descent (aka a suicide burn). Instead, you burn at an angle between retrograde and vertical, so that retrograde is always pointing directly at the horizon (ie, near 0 vertical speed) and only let the craft start to descend when you are nearing the end of the burn and are approaching your landing site. This is called a constant altitude descent. Ideally you start it at the lowest possible altitude that does not result in you smashing into the terrain surrounding your target landing site, and come screaming in just above the hilltops. Done correctly, this actually uses even less fuel than a suicide burn.

You can push off water with a propellor. Its called a boat.

It is due to the drop in the speed of sound. The temp difference is enough to cause this issue. Remember, your total blade apparent speed is a vector sum of the craft forward motion, and the blade rotational motion. To decrease blade apparent speed by, say, 20 m/s (the approx drop in speed of sound going from 4km at the equator to 4km at lat 60) requires 1 of 2 things: A decrease in forward velocity of greater than 20 m/s. (Your case) Or, A decrease in forward velocity of 20 m/s and a reduction in blade rotational speed via reduced rpm. Basically, as speed of sound changes, ideal blade rpm must change. Which is why at high altitudes on Duna for example, you get better performance running your blades in the mid 300's rather than 460 rpm.

Today, I flew into the Sun: The exact techniques and exploits used for something like this are a bit complicated to explain, but I have a couple tutorial/explanation videos in the pipeline that will cover them, among other things.

Lift induced drag is the very bottom value in the aero gui, and for this craft looks to be pretty small.

Open and then close your service bays. For whatever reason, when you close service bays, the gui glitches out and keeps using the last drag value for everything in the bay, in this case, your props. They don't actually contribute any drag, but the GUI will still add their "drag" to the total value. That makes up for a large portion of the drag. The rest is lift induced drag, because the lift from wings in ksp is perpendicular to wing surface, not to velocity.

This is amazing! You have single handedly made 1.12.2 playable for me, as I like building craft out of sections in orbit, and the drift bug was killing anything that landed on the surface afterwards.

Why would you be discussing rocket engines though? Every rocket engine in the game produces 0 thrust when near Jool 0 altitude because the atmospheric pressure is so high. Also, you can belive me or not. But I have had 0 issues with controlling throttle and all other functions of a craft at Jool 0 altitude. This is across multiple varying ssto designs.

It was already posted earlier in this thread