Foil. SSTM Crew Trainer.

[Trios]

You don't actually leave the atmosphere when the oxidizer runs out. But if you run out of air and switch RAPIERs to LFO (while turning on the nuke too!) at ~1,350m/s @ 22kms, as I said, and then touch nothing so the bird goes from 10º AoA to about 15º, then when they run out your apoapsis is already out of the atmosphere, or sufficiently close that keeping on thrusting with the nuke alone on that heading will push time to apoapsis up.

Rune. Oh, and angling the RAPIERs is giving you some cosine losses... may be irrelevant in airbreathing flight (or not), but it'll hurt you on the rocket climb.

Emphasis mine.

This is what was not clearly laid out in the original flight profile; when you switch to closed loop on the RAPIERs, you have to enable the nuke. It's quite efficient at that high of an altitude, nearly full efficiency. With the 3 engines running, I ran out of oxidizer at about 77km apoapsis, and continued burning prograde until I hit 95ish, turned off the nuke to catch up a bit to apoapsis for efficiency's sake, and then burned from 30s pre-apo until I was (nearly) circular at about 30 seconds after-apo.

[CrashTestDanny]

So Rune - how did you land on Min? I thought I saw you said something about landing with RCS, but in my tests that does not seem possible (and was almost disastrous!). I ended up coming down tail-first on the nuke and was a little worried about damaging it when I laid her down on the gear, but it turned out ok... departure was a little interesting as the RCS could only raise her to max rotation angle (as defined by main wheels to the first point on the tail to touch ground)... Vernors or puffs on the bottom might make a belly landing/departure more doable...

Danny

[How2FoldSoup]

Hi Rune, I always take inspiration from you craft(for building my own) but I've never commented on them before. In some of your screenshots you have the shock cone intake and in others you have the ram air intake. Which one is better? I know the ramair has more air intake and less mass I so I feel like that's the best intake to use. Is there a point to use the shock cone other than aesthetics? Thanks!

Soup

[Redshift OTF]

Looking good! But I feel obliged to warn you, those airliner wins will overheat quickly, their temp rating is ludicrously low. And them being in the leading edge, that could be an issue... Anyhow, regarding you sub-Foil performance: I think that RAPIER switch speed is waaay too high. How do you even go over 22kms and 1,350? The RAPIER thrust goes to hell! I recommend switching sooner to get a less shallow angle, you may be incurring huge gravity losses in the upper atmosphere. Oh, and this comment:

You don't actually leave the atmosphere when the oxidizer runs out. But if you run out of air and switch RAPIERs to LFO (while turning on the nuke too!) at ~1,350m/s @ 22kms, as I said, and then touch nothing so the bird goes from 10º AoA to about 15º, then when they run out your apoapsis is already out of the atmosphere, or sufficiently close that keeping on thrusting with the nuke alone on that heading will push time to apoapsis up.

Rune. Oh, and angling the RAPIERs is giving you some cosine losses... may be irrelevant in airbreathing flight (or not), but it'll hurt you on the rocket climb.

Thanks for the thoughts Rune! I've found the airliner wings get a little toasty but not significantly, perhaps about 650. The only part I need to be aware of is the RTG in the cockpit but most of the time it is fine. Switching height is something I should experiment a bit more but with my setup I can get an orbital speed of 1600 m/s at around 18 km I think and as I climb, even though the thrust drops it can maintain that speed quite high up. I usually allow it drop by about 50 m/s so I can engage closed cycle at a higher altitude in the hopes that the craft experiences less drag and I got more bang for my buck out of the oxidiser I'm carrying. It's probably debatable if it is worth more than the 50 m/s I lost and I do tend to put more effort in getting orbital speed than height so I guess I need to experiment more.

I've found that angling 2 of the engines is very useful! It helps keep the pitch of the plane closer to prograde which minimises drag losses enough to get higher orbital speeds in airbreathing mode. I may lose a bit from cosine losses but when closed cycle is engaged I'm still well in the atmosphere and it helps with that too I think. It might be worth looking at. Possibly it helps more when taking a more horizontal ascent though.

I'm planning a SSTO to Duna trip so hopefully your tips will make that possible. Has anyone done it with 1.0.4 yet?

Edited October 21, 2015 by Redshift OTF

[Rune]

Emphasis mine.

This is what was not clearly laid out in the original flight profile; when you switch to closed loop on the RAPIERs, you have to enable the nuke. It's quite efficient at that high of an altitude, nearly full efficiency. With the 3 engines running, I ran out of oxidizer at about 77km apoapsis, and continued burning prograde until I hit 95ish, turned off the nuke to catch up a bit to apoapsis for efficiency's sake, and then burned from 30s pre-apo until I was (nearly) circular at about 30 seconds after-apo.

Yeah, maybe I should have mentioned that. But as soon as your airbreathers cut out, it makes no sense not to use it... any additional thrust once you are not limited by drag cuts on gravity losses.

So Rune - how did you land on Min? I thought I saw you said something about landing with RCS, but in my tests that does not seem possible (and was almost disastrous!). I ended up coming down tail-first on the nuke and was a little worried about damaging it when I laid her down on the gear, but it turned out ok... departure was a little interesting as the RCS could only raise her to max rotation angle (as defined by main wheels to the first point on the tail to touch ground)... Vernors or puffs on the bottom might make a belly landing/departure more doable...

Danny

Tail first, and carefully. Don't worry, if you don't break it, the tail will make you tip the right way. And if you do, well, maybe it saves the nuke and you can still abort to LKO. And nope, don't even try landing on RCS. I placed as few RCS ports as I could! Taking off... well, mostly like an airplane. On Minmus on a plain it works beautifully...

On Mun (where I'm going right now), I recommend finding a suitably facing mountain, and pulling up hard after the first bump.

Hi Rune, I always take inspiration from you craft(for building my own) but I've never commented on them before. In some of your screenshots you have the shock cone intake and in others you have the ram air intake. Which one is better? I know the ramair has more air intake and less mass I so I feel like that's the best intake to use. Is there a point to use the shock cone other than aesthetics? Thanks!

Soup

First of all, thanks for the kind words! And yeah, now I understand the intake comments form before. To answer your question simply: hands down, the best intake to use is the shock cone. No question about that. Why? Well, because the air is enough, and the drag is the absolute minimum. That is why the file I gave you has shock cone intakes. But... have you seen how cool the ram intakes look when I tilt them down slightly? Plus, if I can do something with an intentionally sub-optimal modification, then it gives me more confidence saying the ship can do such a thing. So, that is why some of the pics have ram intakes, the bird I flew one of the test missions in had them. Hope that clears things!

Thanks for the thoughts Rune! I've found the airliner wings get a little toasty but not significantly, perhaps about 650. The only part I need to be aware of is the RTG in the cockpit but most of the time it is fine. Switching height is something I should experiment a bit more but with my setup I can get an orbital speed of 1600 m/s at around 18 km I think and as I climb, even though the thrust drops it can maintain that speed quite high up. I usually allow it drop by about 50 m/s so I can engage closed cycle at a higher altitude in the hopes that the craft experiences less drag and I got more bang for my buck out of the oxidiser I'm carrying. It's probably debatable if it is worth more than the 50 m/s I lost and I do tend to put more effort in getting orbital speed than height so I guess I need to experiment more.

I've found that angling 2 of the engines is very useful! It helps keep the pitch of the plane closer to prograde which minimises drag losses enough to get higher orbital speeds in airbreathing mode. I may lose a bit from cosine losses but when closed cycle is engaged I'm still well in the atmosphere and it helps with that too I think. It might be worth looking at. Possibly it helps more when taking a more horizontal ascent though.

I'm planning a SSTO to Duna trip so hopefully your tips will make that possible. Has anyone done it with 1.0.4 yet?

Yeah... wait until you try and interplanetary reentry And yeah, RTGs are explosion bait, and the upcoming update will only make them more so. My kingdom for a He turbine loop module for the Nerv! (Bimodal reactor for the googles, if you don't know what I'm talking about) In the meantime, my nuclear SSTOs are solar-powered. Yeah.

Regarding your ascent... I think I know what's happening now a bit better. See, I realize how it must seem great to be able to go so fast on airbreathers. But realize that you are incurring greater drag losses the faster you go! At some point, they are just overcoming hte huge isp of RAPIERs when running on air. Plus, when you finally switch them off, you are in a shallower angle even if you have the same vertical speed, because you are going faster, so you spend more time inside denser atmosphere, so the drag losses during the rocket ascent are greater. Not to mention my most-favourite SSTO tip: TWR! To reach such high speeds (1600m/s @ 18km? Surface? How!?), you must be carrying more engine weight than I am, proportionally, and that is a penalty to mass ratio once on orbit. Add more fuel to bring it down! I certainly have nowhere close to 0.43 on the nukes on this design, more like 0.2... (the only thing I can clearly see in the pics regarding TWR).

Rune. I'm really glad this build inspired others to build their own!

[Camaron]

I'm planning a SSTO to Duna trip so hopefully your tips will make that possible. Has anyone done it with 1.0.4 yet?

I did it with a modified version of Rune's ship featured on the both the first and the last posts of page 4.

[Rune]

Well, I can confirm the SSTM part is 100% doable, having done it myself. And that was with an awful ascent (I ended up with <1700 units of fuel), and an equally terrible Munar descent (>1km/s in dV, I timed it perfectly... to come to a stop 4000m above my target, then do the slowest descent in the history of ever, at about 20m/s and thrusting all the way). I also managed to visit a Munar station on the bay back, only part of the crew dismounted on the Munar surface... and due to the third mistake in the flight (running out of RCS while docking, because I though I had enough to break from a 20m/s closing speed), I actually had no change to refuel, even if I had wanted to, just hop across the crew as I floated by at 1m/s relative without monoprop. But hey, I didn't turn on that nuke close to the station, at least. The only well piloted part of the mission was the reentry, where I managed to break hard, then keep it flying level at 40kms as I slowly bled the rest of the speed, literally flying halfway around the planet at ~2,400m/s so I could reach the runway and redeem myself with some fancy precision landing. Still, in the end the crew was exchanged and the engineers at R-SUV are SO pleased with the margins, they are saying it is almost enough to be called "pilot-proof".

Rune. Don't let Jeb hear that last part!

Edited October 25, 2015 by Rune

[Majorjim!]

Well, I can confirm the SSTM part is 100% doable, having done it myself. And that was with an awful ascent (I ended up with <1700 units of fuel), and an equally terrible Munar descent (>1km/s in dV, I timed it perfectly... to come to a stop 4000m above my target, then do the slowest descent in the history of ever, at about 20m/s and thrusting all the way). I also managed to visit a Munar station on the bay back, only part of the crew dismounted on the Munar surface... and due to the third mistake in the flight (running out of RCS while docking, because I though I had enough to break from a 20m/s closing speed), I actually had no change to refuel, even if I had wanted to, just hop across the crew as I floated by at 1m/s relative without monoprop. But hey, I didn't turn on that nuke close to the station, at least. The only well piloted part of the mission was the reentry, where I managed to break hard, then keep it flying level at 40kms as I slowly bled the rest of the speed, literally flying halfway around the planet at ~2,400m/s so I could reach the runway and redeem myself with some fancy precision landing. Still, in the end the crew was exchanged and the engineers at R-SUV are SO pleased with the margins, they are saying it is almost enough to be called "pilot-proof".

http://i.imgur.com/W4Tw4Ss.png

Rune. Don't let Jeb hear that last part!

See! It wasn't that hard now was it. LOL, joking aside I'm glad you did this, it is important, I believe to actually do the things a craft can do before release. Good on ya Rune.

[Rune]

See! It wasn't that hard now was it. LOL, joking aside I'm glad you did this, it is important, I believe to actually do the things a craft can do before release. Good on ya Rune.

But it wasn't built to do that! As I've said a couple of times, the reference mission is six guys to lvl3 in a flight, and I did that twice before releasing And it would have meant another week for these fine folks to wait for the ship, of course... I only finished that flight yesterday. In any case, yeah, testing your stuff to be sure it can do what you say it can is good, in principle. But let's not get too carried away, if I build it for, say, Kerbin chemical SSTOing, I'm not going to test whether or not it can land on Duna, for example... primarily because I have never actually landed there myself, so it could be a loooooong wait for a craft file other than a SSTO or booster.

Rune. Besides, I encourage people to surprise me with what my stuff can do, like Camaron taking this to Duna.

[Majorjim!]

But it wasn't built to do that! As I've said a couple of times, the reference mission is six guys to lvl3 in a flight, and I did that twice before releasing And it would have meant another week for these fine folks to wait for the ship, of course... I only finished that flight yesterday. In any case, yeah, testing your stuff to be sure it can do what you say it can is good, in principle. But let's not get too carried away, if I build it for, say, Kerbin chemical SSTOing, I'm not going to test whether or not it can land on Duna, for example... primarily because I have never actually landed there myself, so it could be a loooooong wait for a craft file other than a SSTO or booster.

Rune. Besides, I encourage people to surprise me with what my stuff can do, like Camaron taking this to Duna.

Ah yes we have a miscommunication. We are in that case, both correct.

I meant what I said in my previous post. Oooh, what GPU/CPU do you have Rune? Is it a laptop? *Yup still pushing you for a video.

[Rune]

Oooh, what GPU/CPU do you have Rune? Is it a laptop? *Yup still pushing you for a video.

Yeah, I know, antialising is a thing that exists. But you wouldn't believe how much more stable the game runs under OpenGL... sadly, there is a prize to pay for no crashes in the last two weeks (before, I used to have one crash each half an hour, so a marked improvement). In this case, the prize is squiggly lines, and having to uninstall the awesome, much missed, scatterer. Maybe I should take the pics in a separate install running DirectX and visual mods, but frankly, let the people see what we have to do to have a stable gameplay. I hope 1.1 comes soon and I can max out graphics again and play! Oh, and my GPU is showing its age quite a bit... 9800GP isn't what it used to be... eight years ago was it that I bought it?

Rune. Plus, I'm horribly lazy

[Majorjim!]

I just meant the lack of a video. I thought I remembered you saying you where limited by performance.

There is some really good capture software now.

[Tangle]

A worthy predecessor to a starfleet academy training shuttle.

[ryan234abc]

[quote name='Rune']
Rune. I'm not too sure on the name, tough... Foil or Sabre? Which one do [I]you[/I] think suits it better?[/QUOTE]


Bit of a late response I guess, but I think Foil. Sabre, no matter how cool, is definitely overused.

[Rune]

[quote name='Tangle']A worthy predecessor to a starfleet academy training shuttle.[/QUOTE]

Thanks!

[quote name='ryan234abc']Bit of a late response I guess, but I think Foil. Sabre, no matter how cool, is definitely overused.[/QUOTE]

Good thing I did end up using it then! ;)


Rune. Also, I can confirm it works in 1.05 without any issues.

[Camaron]

And finally, after not playing KSP for a while, a hideous prototype of the promised "Giant Version" (I'm thinking of calling it "Diamondback").

It reaches orbit with a D/V of over 2600, after launching from the runway with less than half of its potential LF. It carries a drilling and scanning kit along with 30 Kerbals. KER says this plane should have around 6,750 D/V with full LF and empty Oxy.

 

[ibanix]

On 10/18/2015 at 2:43 PM, Rune said:

I actually go for minimal pilot input. I settle on about 10-12º AoA, which in this design means it will go transonic on its own below 10,000m. I might have to let it fall a bit to keep velocity increasing at all times on less sleek designs, or if I climb too steep, as Kerbin curves under me and AoA increases on its own. Once the velocity starts to ramp up seriously at about 12-14kms, I drop the nose again to about 10º with the prograde autopilot to maximize the time at full thrust and take vertical velocity down to about 50m/s. Once done that, back to normal SAS and touch nothing. As I speed up the vertical velocity and AoA increase on their own with minimal drag losses. When vertical velocity stop increasing at about 22kms and TWR 0.5, engage the RAPIERs in closed cycle to get outside of air quickly (again, don't touch the heading, by now your AoA will be closer to 15-20º over the horizon), and only engage the prograde autopilot once you are over 1,800m/s.

Every time I try this, I explode at around 18km, when heat exceeds 2500k. 

Yeah, I seriously can not get this out of the atmosphere for love or money.

Oh, and FWIW I got the White Dart to orbit without a hitch.

Edited April 21, 2016 by ibanix

[Rune]

7 hours ago, ibanix said:

Every time I try this, I explode at around 18km, when heat exceeds 2500k. 

Yeah, I seriously can not get this out of the atmosphere for love or money.

Oh, and FWIW I got the White Dart to orbit without a hitch.

That notice is a tad old, as evidenced by the formatting issues (the Foil is on track to survive at least two major KSP versions), but it is still mostly OK. If you are blowing up, that means you have to go a bit steeper, but the gist is still the same: get into a ~10º over the horizon attitude at takeoff (I just did it with something that looked about 8º), and let it increase on its own as the planet curves below you. You end up going past 1,000m/s at around 15,000m and with a >15º climb at that point, so the heat doesn't really have time to build up, you reach vertical speeds in excess of 150m/s. By 20kms you engage the nuke because why not, and when the RAPIERs start giving out (~22-25kms) you put them in closed cycle. I screwed up a bit (an action group snafu made me waste a second or two of oxidizer) and still got to >1,800m/s with a ~65km apoapsis before I run out of oxidizer just now. From there to orbit, you just keep the nuke burning and you AoA increasing due to kerbin's curvature until you time to apoapsis stops decreasing, then you slowly go back to horizontal as you circularize. Takes time, and it seems like the nuke isn't enough, but in fact it's plenty, you just take a couple of minutes burning that usually you would spend waiting to reach apo on timewarp.

 

Rune. Keep trying, you'll learn stuff!

Edited April 21, 2016 by Rune

[ibanix]

15 hours ago, Rune said:

That notice is a tad old, as evidenced by the formatting issues (the Foil is on track to survive at least two major KSP versions), but it is still mostly OK. If you are blowing up, that means you have to go a bit steeper, but the gist is still the same: get into a ~10º over the horizon attitude at takeoff (I just did it with something that looked about 8º), and let it increase on its own as the planet curves below you. You end up going past 1,000m/s at around 15,000m and with a >15º climb at that point, so the heat doesn't really have time to build up, you reach vertical speeds in excess of 150m/s. By 20kms you engage the nuke because why not, and when the RAPIERs start giving out (~22-25kms) you put them in closed cycle. I screwed up a bit (an action group snafu made me waste a second or two of oxidizer) and still got to >1,800m/s with a ~65km apoapsis before I run out of oxidizer just now. From there to orbit, you just keep the nuke burning and you AoA increasing due to kerbin's curvature until you time to apoapsis stops decreasing, then you slowly go back to horizontal as you circularize. Takes time, and it seems like the nuke isn't enough, but in fact it's plenty, you just take a couple of minutes burning that usually you would spend waiting to reach apo on timewarp.

 

Rune. Keep trying, you'll learn stuff!

I followed these instructions. Here's what happened to me:

1) Set full throttle, engage SAS. Action group 1 to engage engines. 

2) Lift off at end of runway, set AoA to 10º. No control input after this.

3) Hit Mach 1 around 2600m.

4) 500m/s around 10km, AoA is 15º.

5) ~1000m/s around 20km. AoA is 18-19º. Engage nuke.

6) 22km, change RAPIERS to closed cycle.

7) 36km. RAPIERS run out of oxidizer. Apoapsis is 45km. AoA is ~30º. Speed (relative to orbit is 1600m/s, to surface is 1400m/s). 

8) 53km, time to apoapsis is 0. Failure to orbit.

 

I am not using mods that change the atmosphere, like FAR/NEAR, or Deadly Reentry, or any of those things.

[Rune]

7 hours ago, ibanix said:

I followed these instructions. Here's what happened to me:

1) Set full throttle, engage SAS. Action group 1 to engage engines. 

2) Lift off at end of runway, set AoA to 10º. No control input after this.

3) Hit Mach 1 around 2600m.

4) 500m/s around 10km, AoA is 15º.

5) ~1000m/s around 20km. AoA is 18-19º. Engage nuke.

6) 22km, change RAPIERS to closed cycle.

7) 36km. RAPIERS run out of oxidizer. Apoapsis is 45km. AoA is ~30º. Speed (relative to orbit is 1600m/s, to surface is 1400m/s). 

8) 53km, time to apoapsis is 0. Failure to orbit.

 

I am not using mods that change the atmosphere, like FAR/NEAR, or Deadly Reentry, or any of those things.

Hum, that is indeed weird. I was getting comfortably more than 1,800m/s (orbit) by the time the oxidizer runs out, and >60kms apo. Maybe do it a tad more shallow by the end of the climb, when you are already making more than 150m/s of vertical speed? Until your TWR goes down when you run out of oxi, you can basically go as shallow as you dare (without blowing up), and it will work better. I certainly don't remember it being a difficult thing, and yesterday I did it after not playing KSP for weeks, first try... same 'no mods that affect aero' here, BTW.

 

Rune. Go for 7.5º instead of 10º on the runway, and if you don't blow up, you will make it for sure.

[AeroGav]

15 hours ago, ibanix said:

I followed these instructions. Here's what happened to me:

1) Set full throttle, engage SAS. Action group 1 to engage engines. 

2) Lift off at end of runway, set AoA to 10º. No control input after this.

3) Hit Mach 1 around 2600m.

4) 500m/s around 10km, AoA is 15º.

5) ~1000m/s around 20km. AoA is 18-19º. Engage nuke.

6) 22km, change RAPIERS to closed cycle.

7) 36km. RAPIERS run out of oxidizer. Apoapsis is 45km. AoA is ~30º. Speed (relative to orbit is 1600m/s, to surface is 1400m/s). 

8) 53km, time to apoapsis is 0. Failure to orbit.

 

I am not using mods that change the atmosphere, like FAR/NEAR, or Deadly Reentry, or any of those things.

Bit of an obsession of mine,  but can I just clarify everyone here understands the difference between Pitch angle   and  AoA , or folks can talk at cross purposes for hours  !  

Pitch Angle is the angle of the nose relative to the horizon.

AoA (Angle of attack) is the difference between the direction of travel (prograde icon) and the pitch angle - ie where the nose is pointed.

Eg. You could be running a pitch angle of 25 degrees (nose 25 degrees above the horizon).

If the prograde marker shows the trajectory (in surface mode) is of a 20 degree climb, the AoA is  25 - 20  = 5 degrees.  

That's a good situation.

However, with the same pitch angle, if your prograde trajectory was only 10 degrees above the horizon, then you would have an AoA of 15 degrees.  That's not ideal in most spaceplanes, you're going to have a lot of drag.

If the prograde was descending at 10 degrees, then your AoA would be even worse   25 - -10  =  +35 AoA.

That's over 30 degrees, meaning you just stalled !

------------------------------------------------------------------------------------------------------------------

I prefer to aim for a specific AoA than a specific nose angle, there's two ways you can do this 

1. Is to use pitch trim (Alt + S trim nose up, Alt + W trim nose down) with SAS off, and let the airplane "find" it's own nose angle.  The airplane will tend to settle at whatever AoA you trimmed for,  though the resultant nose angle will depend on how much power the engines are producing.      I generally use kerbal engineer to show critical thermal % and vertical speed, and watch the trends.   If I'm getting uncomfortable about the temperature and rate of climb isn't increasing, i add three or four notches of nose up trim.   Generally it's good to make small adjustments early.    This does take a bit of familiarity with the airplane and also the way rapier output increases with speed can mess with the airplane's ability to find it's natural nose angle.

2.  Angle the wings with 5 degrees AoA in the SPH relative to the fuselage.  Set SAS to Prograde.   The SAS will hold the body of the airplane to less than 1.5degrees AoA throughout the flight, but the AoA of the wings will always be 5 degrees more than the aircraft as a whole, and you should always have enough lift.

 

Why is AoA so important?   Because  it determines lift and drag.      Lift goes up with increasing AoA, as does drag.  The best lift:drag ratios occur at 2-5 degrees AoA.   Below 2 degrees you are probably not climbing steeply enough and are going too fast in air that is too thick.   Above 5 degrees AoA drag starts increasing much faster than lift, and causes losses in your ascent. 

[ibanix]

19 hours ago, Rune said:

Hum, that is indeed weird. I was getting comfortably more than 1,800m/s (orbit) by the time the oxidizer runs out, and >60kms apo. Maybe do it a tad more shallow by the end of the climb, when you are already making more than 150m/s of vertical speed? Until your TWR goes down when you run out of oxi, you can basically go as shallow as you dare (without blowing up), and it will work better. I certainly don't remember it being a difficult thing, and yesterday I did it after not playing KSP for weeks, first try... same 'no mods that affect aero' here, BTW.

 

Rune. Go for 7.5º instead of 10º on the runway, and if you don't blow up, you will make it for sure.

So I doubled-down and went for 5º off the runway. This got me to running out of oxidizer at 38km with an apoasis of 65km. I waited too long on circularizing, forggeting what terrible thrust the LN-V has, and ended up in an equally terrible 70-by-143km orbit, and 1800 fuel left. At least I made it to orbit!

[ibanix]

Most recent attempt: Finally made a 80-by-80 orbit with 1800 fuel left.

The Foil is a nice craft, but it's been the hardest SSTO I've flown yet. 

[Rune]

4 hours ago, ibanix said:

Most recent attempt: Finally made a 80-by-80 orbit with 1800 fuel left.

The Foil is a nice craft, but it's been the hardest SSTO I've flown yet. 

I'm glad you finally tamed it!

Once you figure out how it works it's not that hard, but yeah, its low TWR nature is tricky to work out if you are not used to such things. Not to mention it has seen a couple of version changes that have increased it's handling difficulty... in fact, I'm tempted to scrap it in the next R-SUV lineup, and substitute with something way less capable (would have to refuel on Minmus to achieve the same mission), but much simpler and rugged.

 

Rune. I certainly don't remember it being as floppy as it is now!

[ibanix]

I wouldn't mind SSTOs with less tech investment, since with CTT you have to be pretty far along to get all the best plane parts (including the RAPIER, which is at the very end of a tree).