Icarus: My first attempt at an SSTO (stock). (I think it can get into orbit)

[XOIIO]

Hey folks, I finally wanted to give SSTO's a try, and came up with this design, it's a couple hours work in total, I traded out a R.A.P.I.E.R for the toroidal as the rapier just wasn't being as efficient, and I call this Icarus. No real reason, except the mythological link to failure, which is what I was expecting XD

A couple things were important, namely style, and that I didn't really take any shortcuts having parts clipping into each other, such as multiple air intakes.

It also has a thermoelectric generator, small battery pack, in line clamp-o-tron as well as a communications antenna (the collapsible one), and two parachutes because I won't be able to land these for a long time XD It also has Mechjeb, if you don't use that I can upload one without.

I'd love to hear what you guys think, and give it a try. I have gotten close, but not actually into orbit, but I am notoriously bad at getting into orbit, I'm not sure if maybe I am doing it wrong or I just don't have enough fuel. I am hoping it is my technique, because I'd hate to have to make the craft any longer. Good news is I was able to glide it over a kilometer to a fairly high island to land safely with parachutes, I can't imagine planes do well in water.

Anyways, on to photos and downloads!

https://www.dropbox.com/s/cgx2hysr2ym3p1w/Icarus.craft

I want to make something similar with the mk3 cockpit as a space taxi, but there just doesn't seem to be enough variety in parts to make it look good. I'll try more once I get smaller craft down though. I try to stay away from mods that add totally new parts because if support for them drops, or the game changes you need to wait for an update or lose your vehicle, unless KSP differs from other games and has some back support for it somehow.

[XOIIO]

Heh, just noticed jeb's face in the last image, priceless XD

[Rune]

Hum. Some tips on SSTOing, though you seem to have started on good foot:

Airhog more. Even with a 1-1 intake ratio, you should be able to go over 1,500m/s before switching to rockets, at around 20-25,000 meters or more (the higher, the faster, but you need more intakes). That will help with delta-v.

The aerospike makes a poor airbreathing SSTO engine. It is heavy, and its only advantage is a high isp at sea level. In a SSTO you don't light it up at sea level. So pretty much any other engine will do better, since only vacuum isp and T/W are important on a SSTO.

You need more aviation fuel! Don't underestimate what the turbojet can do for you, they can do more than half your work to get to orbit. In fact, if you take it to the extreme (I'd only recommend as a learning exercise), you can actually make orbit on jets and ions to circularize.

Rune. Other than that, good job! Check the thread in my sig if you want SSTO examples, they are kind of my thing.

[Voculus]

Coming from flight sims, I stayed away from the spaceplane hangar for a long time, thinking I would be too frustrated with KSP aerodynamics. Though a bit wonky and uncooperative at times, it ended up being a ton of fun. I live and breathe spaceplanes now, and if you really want to assemble some sexy craft, you owe it to yourself to download the B9 aerospace pack. You'll feel like a kid in a candy store! It's an excellent mod pack. I would also highly recommend Procedural Wings. You essentially drag and "draw" your wings into any size and shape. KSP aircraft, whether they reach orbit or not, are very rewarding. You have a solid design there, and thanks for sharing.

[XOIIO]

Hum. Some tips on SSTOing, though you seem to have started on good foot:

Airhog more. Even with a 1-1 intake ratio, you should be able to go over 1,500m/s before switching to rockets, at around 20-25,000 meters or more (the higher, the faster, but you need more intakes). That will help with delta-v.

The aerospike makes a poor airbreathing SSTO engine. It is heavy, and its only advantage is a high isp at sea level. In a SSTO you don't light it up at sea level. So pretty much any other engine will do better, since only vacuum isp and T/W are important on a SSTO.

You need more aviation fuel! Don't underestimate what the turbojet can do for you, they can do more than half your work to get to orbit. In fact, if you take it to the extreme (I'd only recommend as a learning exercise), you can actually make orbit on jets and ions to circularize.

Rune. Other than that, good job! Check the thread in my sig if you want SSTO examples, they are kind of my thing.

Problem is I really don't want to stack ram air intakes, I've also seen people line multiples up in a row, I can't figure out how they do it. That would be a bit more acceptable, but still borederline on cheating in terms of design. I ended up lighting the rocket because I ran out of air.

Adding 5 more ram intakes got me a bit higher, to 40km before I ran out, but looks fugly. Even at low levels the ram intakes never get 100% for some reason.

I am going to make a new one that is bigger, your first one is nice, thats somewhat what I wanted to do at first, now I need something different. hmm

[Rune]

Problem is I really don't want to stack ram air intakes, I've also seen people line multiples up in a row, I can't figure out how they do it. That would be a bit more acceptable, but still borederline on cheating in terms of design. I ended up lighting the rocket because I ran out of air.

Adding 5 more ram intakes got me a bit higher, to 40km before I ran out, but looks fugly. Even at low levels the ram intakes never get 100% for some reason.

I am going to make a new one that is bigger, your first one is nice, thats somewhat what I wanted to do at first, now I need something different. hmm

Oh, before you run into "intake spamming" territory, you still have a way to go. 1-2 ram intakes per turbojet will get you easily into 1,300-1,500 m/s if you control your climb rate (handy indicator next to the altimeter!) when the air starts getting thin at around 20kms to speed up without rising too fast. Try how fast you can get, and how high, with a 10m/s climb after you level at 20kms, and you will see what I'm talking about. With practice you will be able to get to that speed and altitude, faster, but everybody needs to fool around with ascent profiles till they become comfortable with them.

The stacking trick with intakes, BTW, is to clip them in a column of cubic orthogonal struts. Can be done without it, but the easiest way to replicate is through part clipping on the debug menu (ALT+F12).

[Woopert]

Nice job. Personally I haven't botherd/done much with SSTOs anyways.

[XOIIO]

one of the problems I'm having is making bigger wings that look good. The wing connector doesn't line up with the whole thing, and you can't put it in the same direction as a wing without it going through and/or looking bad :/

I'm also wondering the point of adding just liquid fuel when you can take some from the rocket engines anyways. For now I only want it to get to orbit, interplanetary missions with stock parts won't really be good I think. I cant find a way to use the mk3 fuselage and cockpit that looks good because of this wing problem. Big gaps in the middle of the plane between wings look bad too.

I want to stay with stock parts but I think the game has just too far to go with spaceplanes as it stands now :/

Edited January 22, 2014 by XOIIO

[XOIIO]

I've decided it's not really feasible to get it into orbit without stacking ram air intakes, and it does make it look cleaner, I just wish the buggy texture wasn't there :/ Most of the community seems to support it though so may as well cave in and join.

Now I just need to get good at getting into orbit. I made a second version of this with a bit more fuel, 550 or so if I recall correctly.

[XOIIO]

Well, going better with Icarus II, I did the stacking, 5 ram intakes for each engine, I may need to add another one or two, not really sure. This is an example of my best flight, by the time I get up to 1200 M/s on jets I'm practically out of air even with all these intakes, then I aim straight up best I can to get into orbit. Once I get my AP to 80km, I let mechjeb take over the circularization. It usually looks like this.

Anyways I've learnt that I need to lower my refueling station from it's 250km orbit, to something like 100km. I ran out of fuel after the hohmann maneuver, I would need an extra 60 or 80 fuel to be safe with the station at it's current orbit, I think changing the RCS tank to fuel, and using two 40 unit containers of RCS fuel would will work out better.

Anyways since I was going to revert the flight anyways, I used infinite fuel, here is a shot of it docked with my refueling station. It should work great when my station is lower and I have a wee bit more fuel to play with, enough for my mistakes to not matter much. I'll do all that tomorrow.

It's a shame the air intakes are so inefficient though, having to use this many seems a little extreme, especially when SSTO's are pretty much the only thing that is being made in the SPH.

edit: hmm, scott manley's seems to do much better, I'm not sure if something has changed since 0.18 perhaps, or maybe I just suck at it, but he has a fair bit of fuel and his ship is smaller as well as having many less intakes. Have intakes changed or something? I was below .9 air much faster I'm sure, though I may be cutting the engines out too soon. I'll see tomorrow.

Edited January 23, 2014 by XOIIO

[XOIIO]

Oh yeah, the new setup. The middle skinny section is longer than I would like but not much I can do.

It seems R.A.P.I.E.R's need less intakes, even though they have less thrust, I wonder if changing to just two of those would be better or not. It would look less cool, that's for sure, and they do eat a crapton of fuel in rocket mode.

[Finwolf]

You could try losing the radial intakes, adding a few more wings for that weight and changing the inline clamp-o-tron for a normal one (you can stick it basically anywhere. Doesn't look that nice though).

[Giggleplex777]

Since the R.A.P.I.E.R. was implemented, I would recommend it as the engine for first-timers' SSTO because of how easy it is to get it to orbit. The auto-switching makes asymmetric flameouts a few hung of the past.

[jlrdsr]

Coming from flight sims, I stayed away from the spaceplane hangar for a long time, thinking I would be too frustrated with KSP aerodynamics. Though a bit wonky and uncooperative at times, it ended up being a ton of fun. I live and breathe spaceplanes now, and if you really want to assemble some sexy craft, you owe it to yourself to download the B9 aerospace pack. You'll feel like a kid in a candy store! It's an excellent mod pack. I would also highly recommend Procedural Wings. You essentially drag and "draw" your wings into any size and shape. KSP aircraft, whether they reach orbit or not, are very rewarding. You have a solid design there, and thanks for sharing.

I came from flight sims too! And ive found that im making vtol jets, but i struggle to even land on the moon im yet to download any mods but i probally will soon. Its sooooooo much easyer with a joystick isnt it

nice spaceplane too, its alot like my first effort, although i used a differnt assent profile. I felt lile using the rapier was taking the easy route so i gave myself a challenge. Im going to try some of the things people have said in this thread on my second spaceplane. Thanks for all the tips guys.

Edited January 23, 2014 by jlrdsr

[Bean]

I just had a try of the first one that you posted, makes a 80KM apo on jets pretty easily, I usually put a jet fuel tank where you have the engine nacelles though. I had 190 LF and 492 Ox once I'd finished. That means I used 213 LF on the jets

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[XOIIO]

I just had a try of the first one that you posted, makes a 80KM apo on jets pretty easily, I usually put a jet fuel tank where you have the engine nacelles though. I had 190 LF and 492 Ox once I'd finished. That means I used 213 LF on the jets

http://imgur.com/a/nnMcD

Now that I am a bit better at flying them I got similar results, although I had a bit less liquid fuel and half as much oxidizer. I am going to swap out the engine nacelles, I hardly see them used.

What ascent profiles do you guys use? I pretty much get to a 50 degree angle as fast as I can upon liftoff, wait to 20km, nose down, and try to keep level and get as much speed as I can, then nose up 90 degrees and rocket until my AP is good. (mix of a couple tips ive seen and trial and error.)

[Pds314]

I notice in the image you have a bunch of oxidizer and only a bit of liquid fuel after high suborbital trajectories, that is bad. That extra oxidizer is just dead weight at that point. Unlike liquid fuel which can power jets with only IntakeAir, oxidizer can do nothing on its own.

[XOIIO]

Hmm, is there a way to carry just oxidizer in some small tank? got my AP to 80, had 400 fuel, and 200 oxidizer or so. Ran out before I could circularize.

I did modify the shorter version, I think I will need to add a tank again, but trading the nacelles for fuel helped a lot.

[Captain Sierra]

one of the problems I'm having is making bigger wings that look good. The wing connector doesn't line up with the whole thing, and you can't put it in the same direction as a wing without it going through and/or looking bad :/

I'm also wondering the point of adding just liquid fuel when you can take some from the rocket engines anyways. For now I only want it to get to orbit, interplanetary missions with stock parts won't really be good I think. I cant find a way to use the mk3 fuselage and cockpit that looks good because of this wing problem. Big gaps in the middle of the plane between wings look bad too.

I want to stay with stock parts but I think the game has just too far to go with spaceplanes as it stands now :/

Pwings fix that. They are more stable, look nicer, etc. Also, you sound like me where you don't like to go above a 4-1 intake-engine ratio. The solution is to bring more rocket fuel so you can brute force your way to orbit. Also try to bring some reaction wheels and gimballing rockets (LV-45 offers better ISP and more thrust than aerospike, plus less weight and gimballing). Don't let "most of the community" dictate how you play the game. I've been fighting with SSTOs for months and I still haven't gone above 4 intakes to an engine. Another trick I use is to use the engine nacelle in place of a structural fuselage. It's actually lighter and gives you air. Win win. Use 4 jets. use a bigger plane with 4 jet engines. Then shut off two when you reach higher altitudes. This lets your intakes feed all their air to less engines and maximizes your altitude and speed. I can get to 24000m and 1300m/s on a 2-1 intake ratio.

The trick is to cruise for a while to get that speed. For me, it takes about 60-70 liters of jet fuel per engine to get to rocket ignition. Also, the radial intakes lose almost all effectiveness above 20km. They become dead weight at that altitude.

[Rune]

Now that I am a bit better at flying them I got similar results, although I had a bit less liquid fuel and half as much oxidizer. I am going to swap out the engine nacelles, I hardly see them used.

What ascent profiles do you guys use? I pretty much get to a 50 degree angle as fast as I can upon liftoff, wait to 20km, nose down, and try to keep level and get as much speed as I can, then nose up 90 degrees and rocket until my AP is good. (mix of a couple tips ive seen and trial and error.)

Good to see you are learning fast! It looks good, and as I'm sure you have found out, the vertical speed indicator is crucial. What you do after flameout depends mostly on your T/W and speed, but it sounds like you are wasting tons of fuel pulling up too sharply. I know keeping inside the atmosphere will increase drag, so you want to leave it as soon as possible, but as long as you ascent speed is above 100m/s, you won't lose that much. So try to increase rate of climb just before you run out of air (when you are almost level at your top height and pretty much stop accelerating, pull up and build vertical speed until it flames out), and then only burn 10-30º up from your prograde vector, depending on T/W, and you will see some gains. As long as you get the vertical speed indicator to go over 100 during your rocket burn, and end it close or above 40kms, you should be fine.

As to building tips, yeah, only the ram intakes really make sense, since they are the ones that work best at high speeds and thin air, where the others don't do much if anything. And RAPIERS aren't really inefficient at all, just 10s less of isp than the LV-T30s, they just have a lot of thrust so run through the fuel faster. But that means they will lift more! And also that you can thrust closer to the horizon on the climb, and be more efficient on your climb. Plus, the automatic switching is very noob-friendly, you just have to remember to close the intakes so they stop producing drag.

And contrary to what Sierra is saying (sorry!) smaller is usually easier. A single tank (you can tweak the fuel load by right-clicking on it since 0.23), and a single RAPIER, cabin, and a couple of wings will get to orbit practically on its own. The important things are the mass ratios of the propulsion plant, the fuel, and the payload. T/W and delta-V come from those, and big designs make it more difficult to keep track of it.

But if you want to go big (we all do!), there are indeed ways of making the stock wings look good with a lot of surface. You could do biplanes that don't look like it (i.e: my white Dart), or something like this, where not only the wings are a composite of small parts, but the "hull" of the cargo bay also provides lots of lift:

Rune. Good job! You are on the right track. Now, you just need the hundreds of hours we have already invested in the game

Edited January 23, 2014 by Rune

[XOIIO]

Well, Icarus III was a total success, I changed the RCS tank for fuel and used two of the smaller RCS containers, the problem is I still got really low on oxidizer, I barely made it to refuel. Once back though I had enough for fly around for plenty of time, I checked out some mountain ice caps.

I know you can change the amount of liquid fuel/oxidizer, but can you add more oxidizer than the max amount somehow? It seems that you could change it to have less liquid fuel and more oxidizer.

[XOIIO]

well I don't know how I got a 32 second circularization burn last time, now it's back to being over one minute and I run out of fuel, sigh.

[XOIIO]

Made some more changes, added two more fuel tanks, and had to move the clamp-o-tron further up. I think I could have made it to refuel but I guess the tanks changed where it takes fuel from, jets were full, and I lost all fuel for the engine at the amount in the second picture.

[Silverchain]

I blatantly copied your design to give it a whirl and a tweak. I like those side mount pylons that hold the engine pods, though I had to add struts to keep them from wobbling.

Replacing the Aerospike with an LV-909 gives a good performance increase, and I set the jet fuel tanks to only partly full (90 each, which was quite enough) using tweakables which also helps.

[XOIIO]

Same, those hard points aren't very secure XD I always figured the LV-909 wouldn't have enough thrust to get me into orbit, but yeah once in orbit it would be great.

I have a new design, felt like calling it the "osprey". That little one wouldn't have really been able to take a payload into space, and these will just be for small satellites till I can make the big design look good.

It uses an LV-T30, the aerospike didn't have enough umph to get it into orbit. It also has four jets this time, and three intakes per engine

unfortunately, I got it into orbit, and I think I would have had enough fuel to refuel, except that I forgot the RCS fuel .

Anyways, since it burns fuel from the outside in I had no fuel for the jets coming back, these things spin like crazy with no propulsion, anyways I was able to land in the ocean at 10 M/s, but the whole thing ripped apart, so another parachute or two, and RCS fuel when I want to play more.

I need to find some video of good SSTO pilots on youtube to find the best way to get into orbit, I think I should have way more fuel than I do when I get up there.