Rune

It takes a lot of navigation skills, that's for sure. The only way to do it for the really big ones is to catch them in solar orbit, and plan your entry on the Kerbin system so you can both use Mun to take care of your inclination, and Kerbin's atmosphere to slow down into a capture orbit. Rune. Definitely a challenge, but very rewarding! Keep at it, because there's nothing impossible.

It's done and updated for 1.2, and as far as I know @sal_vager knows that it is still there. I guess it didn't make it in time for 1.2, given how it doesn't break the game that badly, but yeah, I hope they do take time to look on it one of these days. From what I've seen him doing lately, Cupcake has the whole drag system pretty much figured out. No empty nodes, no parts sticking radially, unless they are in a bay. If you think about it, the front section that they offer to air is minimal, and they are pointy, so the recent drag revisions could only benefit them. Mine, with their blunt noses... we'll see, they all have a bit of margin in there, and other than an overuse of the shielded docking port, I also try to streamline them a lot. Rune. I am not mucking about with 1.2 too much, no KER is like playing with a hand tied to my back... the windows calculator is protesting the overuse!

It's awesome. Among other things, it allows you to do stuff like this: Rune. The best source of screenies I have put together in a long time.

Yup, as @Andiron says, it's from roverdude's awesome pack. It does have a KIS container under it, tough, in case you are wondering what it's mounted on. It's a custom module with all my mod parts,so I can nuke them if need be and not lose the whole base. Rune. The rest of my mods are partless.

Actually, your album shows heat gauges on both kerbals in the second-to-last pic, so I think we can confirm that the bug still keeps on affecting kerbals, they are not occluded like landing gear or wheels, and you would have fried them if you went faster. The reason you couldn't is because you were using low temp. rating parts near the nose, and they blew up before the kerbals did. Rune. In any case, thanks for the confirmation!

Just wanted to leave notice that this bug is still going strong in 1.2, with behavior unchanged. I guess it didn't make the list... anyhow, a poke to @sal_vager can't hurt, right? Rune. Headed to the tracker to do pretty much the same thing.

Just because something is best, doesn't mean you can't do something else just for the lols (and the quick rocketlike ascent). That bird's GLOW is 409mT, 50 of which can be payload, or in other words, about 12% of GLOW get to be used in orbit. For a similar payload mass, the RAPIER-powered Claymore maxes out at about 180mT on the runway. Quite the striking difference, right? So yeah, the RAPIER is hands down the best engine for SSTOing, even if you only count airbreathing SSTOs, which are a subset of SSTOs in general. As I said, not best is not necessarily the enemy of fun. Go ahead and tinker! Just remember that a RAPIER will always do a better job, so shoot for lower payload fractions. Rune. Always RAPIERs... if we are talking about airbreathers, of course.

Actually, three Vectors. That's a rocket, Jim. But also technically a SSTO spaceplane, using Vertical Takeoff and Horizontal Landing, like the acronyms on the name imply. For low mass, high volume payloads, they work great, since the payload can sit on top with a fairing, and a gliding runway recovery is relatively easy to nail. Rune. There's more than one way to skin a cat.

Well... you asked for it : Not that I couldn't fit that payload in the last SSTO's bay, but just in case. Rune. When a bay is not enough, there are always payload fairings.

Let me quote myself here: That is, like, the first thing I said. If something works good at1x, it will work just as well at 8x. As proof, I offer my Claymore, which does actually better than my average design (>45mT to orbit in the payload bay), mostly because of some stuff like the cockpit, RCS system, undercarriage, that sort of thing kind of gets lost in the rounding, while you are doing the mass budget in such big birds. http://imgur.com/59Du952 And of course, it could just as well have twice the engine pods and a bay twice as long. It would also get a very slightly better payload ratio. Granted, at some point it's a bit harder to build bigger things, structurally speaking... but frankly, I doubt you really need a bigger SSTO than what you can build in KSP in an average computer, with a bit of thought (and lots of practice!). Rune. It's also easier to tailor your TWR to the perfect number when adding an extra engine is closer to 10% more thrust, rather than, say, 50%.

SSTOer to the rescue! Let this be a mini-guide to all things SSTO: First, rocketry is all about ratios. Thrust-to-weight and mass ratio, mostly, and we all know those two well and how they play with each other (high TWR means a lot of engine weight, so for the same payload, a lower mass ratio and thus less dV, for example). Well, SSTOing is even more so, since there are more ratios involved, and with airbreathing SSTOs, even more so. But there is a great thing about that: once you have a working design, you can extract the ratios from it, and be damn confident that if you build something exactly twice as big, with twice the thrust, twice the payload, and so on, it'll behave just the same. Science is great, ain't it? So, just what are good ratios, anyhow? Well, I, like many others, have my rules of thumb. First, I use one RAPIER for each five metric tons of payload, more or less (there are other engines, yes, but they are worse for SSTOing, no exceptions). Note that "payload" is anything other than engines, fuel tanks, and wings, so all cockpits and payload bays and landing gear and such count towards that. I then aim to get around 0,5 TWR on the runway using RAPIERs, but with all the fuel I can carry. I put about 400 units of extra liquid fuel per RAPIER to make the climb on airbreathing mode and then, it's all about aerodynamics and mass distribution, and also make it as pretty as I can manage. Aerodynamics are relatively simple, just make it pointy, leave no open nodes (they are great sources of drag), and make it fly stable-ish. Mass distribution takes much more, because you have to make sure that your plane is just as stable when full as it is when empty, but that it still has enough control authority to reenter at a high AoA and thus brake slowly. Just exactly where you place your fuel tanks is key, and a very good rule of thumb is "symetrically around the CoM, preferably right on top of it". With all that taken care of, there is still the task of flying the thing, which is anything but straightforward, but perhaps that would better be a topic for another time. Rune. Helpful so far, at least? That is bad advice, sorry. Use RAPIERs, like any good SSTO will always do. RAPIERs get to orbit the highest payload fraction, period. Mostly because they have the highest cutoff speed, but also because they have a way more than decent TWR on rocket mode, and thus you have the absolutely minimum engine mass in orbit. You can then talk about high-efficiency engines for in-space travel, but then you should go straight to nukes or ions, and count them and their fuel as payload, because we are talking about something other than SSTOing anyway. Rune. For proof of my assertions, I refer to the payload ratio challenge.

That, and tankage fraction. The round fuel tanks have the best ratio, Mk3 slightly worse, and Mk2 tanks are the worst of them. Adapters are also generally crappy but... between aesthetics and keeping it aerodynamic and short-ish, I ended up using a lot of them. Also, wing weight fraction is a joke on this design... saves me a ton of weight in orbit, and it gives me absurdly low drag losses, since it has a healthy 1,5 TWR (vacuum) at launch and is rather streamlined for such a thing. I didn't make it hard to glide for nothing! Rune. Chemical SSTOs explain perfectly how rockets work: TWR and tankage fraction are just as important as Isp.

Yup, called it perfectly. When building chemical SSTOs, they are by far the best engines, especially the Mammoth with its higher TWR. And I never use airbrakes...;) A lifting reentry is all about the descent profile! I reenter at high AoA, so I use the whole wing as a giant airbrake and slow myself down that way. If you reenter close to AoA, though, you will get to the lower atmosphere with much more energy, and you will need a much tougher leading edge part. My Heinlein, for example, is the ship I have that can get more temperature gauges showing, because it does a ballistic reentry pointy side first. Rune. Airbrakes have awful temp ratings when extended.

Ok, I kept on reading, you did your math (and with more precision than I did!). Anyhow, if the Red Dragon mission architecture turns out to work, not only will SpaceX pretty much prove points #1, #2, #7 and #8 by then (assuming SES' launch proceeds some time next year), you can also dispense with all the LMO refueling flights. Red Dragon will enter Mars straight from TMI, relaying on areodynamic forces to capture and slow down for terminal descent. I too didn't believe it would work even half as good as it apparently does, until I saw Scott flying a Dragon on realism overhaul, and he could control his descent rate with astonishing ease (I know lift is all about speed, but still, seeing the principle in motion to fly what is basically a brick in what is basically industrial vacuum, and control vertical speed to attain level flight at hyperbolic speeds is pretty rad). Anyhow, after landing in a single stage from LEO, and given surface ISRU (which I concurr, won't be anywhere as simple as it sounds), then 5km/s are close enough to do straight shot home, I think, assuming just a slightly bigger mass ratio (5,5km/s per the wiki, I'm sure there are slightly lower energy trajectories, and MR4 is actually 5167m/s, 5,5km/s would be only MR~4.37). That simplifies the mission architecture, a lot. And the Falcon staging speed actually reinforces the idea of a beefy BFS with a high mass ratio. Rune. Incidentally, MR5 and 380s gives you a beautiful 5999'66m/s. I'd totally set that as a design goal.

Exactly my view of the matter. The only thing I would amend is that if the rocket equation isn't failing me, and Raptor's Isp is 380s, then it would be more like 5 refueling flights for each outbound Mars trip. They are gong to need the BFS to be somewhere around mass ratio ~4 when wet (~5km/s dV). If the BFR is just big enough to loft an empty BFS and its payload to LEO (on first analysis, somewhere around 200mT), then they would need around 600mT of propellant to launch the whole thing to Mars and land it there afterwards, meaning either six BFS with 100mT of propellants instead of payload, or a slighty more mass-efficient, purposely built thing that manages a better ratio. In any case, at the very least five BFR launches per Mars launch. Rune. And that is why the BFR could make sense to reuse.

Definitely a WiP, but also definitely a SSTO. One that can carry >50mT up! And as easy to fly up as any rocket. Now, flying down, that is another thing... it is intentionally about as good a glider as the Shuttle was... which is to say, "not a whole lot". However, runway recovery is where the √ are! A lesson in energy management if you want to reach it, that's for sure. Also, KSP tank body lift is certainly bugged: when sideways, tanks create all short of issues by acting as sideways wings. And while we are at it, the lift visualization tool in the SPH doesn't take them into account at all, which means making this flyable took a lot of fiddling, manually finding out the true center of pressure by trial and lots, lots of error. Rune. The plus side is, the margins are big enough to fly it back on main engine power for a short while, in case you just miss KSC.

Awesome to see the capability confirmed. And quite the unconventional deployment! You do know you have powerful ventral engines to VTOL, right? Plus, a probe core positioned so it gives you the right control attitude to VTOL rocket-style (tough I would do more of a rocket-assisted glide in Duna myself). Still, awesome in any case! Rune. Working on new boost options for the box, BTW.

Good news guys! I finally managed to make those recoverable boosters on Tsiolkovsky Station, well, recoverable. The instability problems are now a thing of the past, and I think I was getting them mostly because the control surfaces were a bit bugged. In any case, the new Korolev reusable booster has been tested in a wide variety of flight conditions, form hypersonic to subsonic, and it seems to behave nicely even when it is completely empty of fuel. Also, I set up the action groups booster-by-booster, so now the fuel cells do indeed turn on on liftoff, and the airbrakes work as intended on all boosters, not just one in eight. Plus, slightly cooler-looking profile, with the delta a bit further back, the canards noticeably smaller, and a new compound tail 100% for looks. Same DL link, tough. Rune. Pretty much everything that has a tweak menu has been tweaked in there.

Awesome. And for just a tad more complexity (about 50% more parts, tops), you could substitute the front intake with a docking port, slap some radial intakes and RCS, and have a dock-capable little ship. Rune. Plus, the shielded docking port has an absurdly high temp. rating. And it's cute.

Oh yeah, it's a bit tricky. Feel free to turn on the nuke as soon as you go into closed cycle, it already gets >790s and it will improve your TWR slightly, so there is really no downside. But I'm rather sure that it is possible to do it without the nuke on until you run the oxidizer tanks dry, if you just keep the SAS on a fixed heading and just let the AoA increase. Much more efficient (and easy!) to do it maximizing TWR, tough. And yes, I should make manuals. But I'm lazy, and I always thought that a good post-sale customer service makes people forgive lots of things. Rune. Flying SSTOs is also a thing that takes lots of practice. You gotta 'get a feeling' for the atmosphere and the engine curves to milk them.

You're welcome. And, you know, for sciency and math reasons, the "sweet spot" of the rocket equation is a mass ratio of E, or 2.7 something (1.7something kgs of fuel per kg of empty ship). For a 800s Isp, that works out to 7,848m/s (Isp*9.81), so anything beyond that and you are in "diminishing returns" territory. Rune. Then again, there's very few mission plans that require more than 5km/s in the kerbol system.

It is a nice ship, but with that low TWR, be prepared for long burns. That's not a bd thing, but it takes time and planning. Oh, and once you add payload... suffice it to say after a lot of fiddling about with ultra-efficient designs, I've set up a house rule of having at least 0.1 G's at my disposal if I can help it. Rune. Also, pulling things behind you usually works better than pushing them.

Right, I almost forgot! And it was so exciting! See, it is definitely a bad idea to make a nuclear SSTO nuclear-powered. I blew the RTG. So, since I am not crazy enough to try aerobraking from interplanetary +300m/s in one go, I actually did a whole orbit without any electricity generating stuff and without active pilots (the mission was over 15 days and I run USI LS). Thank Kod the nuke has an alternator to top up the batteries before reentries! On the plus side, the battery capacity is enough to handle the flight, and it's a good thing kerbals wake up when you go under ...25kms is it? Because I also tested whether you can do a dead-stick landing without reaction wheels: And dingdingding! Six new lvl3's ready to throw into interplanetary missions: And of course, while I'm at it, you can grab the thing at KerbalX... now equipped with heat-resistant solar panels. Rune. Oh, the irony...

There's actually this: Which is basically the new Dart. But frankly the old one works just as fine so, you know, whichever strikes your fancy. Rune. You can ind it on my KerbalX page, which is also linked in the OP.

Hum. Perhaps now is the time when I add that you should move all remaining fuel to the big kerbodyne tank closer to the front of the vehicle? In fact, if you move it to the nose, it'll become too nose-heavy to reach high AoA. Rune. Might have forgotten to mention that anywhere.