Can't get SSTO to orbit.

[tbarcello]

Trying to design SSTO. Getting SSTRTL. Need help. Please!

It will go 12k, then i level and speed up till 1000, then pitch up and trottle down till out of air at about 35k. Nukes egnite at about 25k, because starting to loose speed due to throttle down.

If don't throttle down engines overheat and explode at around 1100 m/s. Always.

http://imgur.com/a/EUGGK

Please, ... am i doing wrong??

Edited September 3, 2015 by tbarcello

[X9Squared]

Hmm...

How I fly SSTO's:

1. Pitch up at about 40 degrees AOA.

1a. Slowly pitch down at 10k intervals until at about 30-25 degrees.

2. Wait until the ramjets start losing speed and you stop accelerating.

3. Switch to nukes/RAPIERS (try adding RAPIERS to your design to kick it into orbit, using the nukes in the atmosphere might be a problem.

4. Do random orbital stuff.

5. YAY!!

Also don't throttle down, keep throttle at full. Add some radiators if you really need to.

Hope this helps,

-X9

[Nothalogh]

Riddle me this, does that even LOOK hypersonic?

[tbarcello]

Riddle me this, does that even LOOK hypersonic?

Mach 3+. Does anything in KSP?

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Hmm...

How I fly SSTO's:

1. Pitch up at about 40 degrees AOA.

1a. Slowly pitch down at 10k intervals until at about 30-25 degrees.

2. Wait until the ramjets start losing speed and you stop accelerating.

3. Switch to nukes/RAPIERS (try adding RAPIERS to your design to kick it into orbit, using the nukes in the atmosphere might be a problem.

4. Do random orbital stuff.

5. YAY!!

Also don't throttle down, keep throttle at full. Add some radiators if you really need to.

Hope this helps,

-X9

Probably nukes aren't enough powerful. I'll have to escalate it, oh boy...

But please, just tell me this: what speed are you doing with ramjets? Because those explode from overheating above mach 3. You can see precoolers and radiators right there on the screenshot!

I hate typing on phones! I'm so frustrated now! Aaaaaaarg!

Edited September 2, 2015 by tbarcello

[tbarcello]

I mean, guys, I know, Rapiers and stuff, right? I know other engines and stuff, right? But this time it's all about having 0 oxidizer CAPACITY on the ctaft.

[Nothalogh]

I know Rune has built a Jet+Nuke SSTO in 1.0.x, but it's tricky as hell and there's no real meaningful payload fraction either.

Even I have yet to get one properly to orbit on just liquid fuel.

Also, reduce drag wherever possible

[tbarcello]

I know Rune has built a Jet+Nuke SSTO in 1.0.x, but it's tricky as hell and there's no real meaningful payload fraction either.

Even I have yet to get one properly to orbit on just liquid fuel.

Also, reduce drag wherever possible

Yeah, ill have to rebuild the hell outta this craft to support at least 4 nukes. I was hoping jets will take me high enough...

[Mesklin]

One less turbojets, one more nuke can really help, see my craft as example:

http://forum.kerbalspaceprogram.com/threads/117415-SSTO-to-laythe-and-beyond?p=2151601&viewfull=1#post2151601

[Nothalogh]

Yeah, ill have to rebuild the hell outta this craft to support at least 4 nukes. I was hoping jets will take me high enough...

That's pre 1.0 thinking, jets now have ceiling regardless of velocity, thus you must get all the power out of them while you can

[tbarcello]

That's pre 1.0 thinking, jets now have ceiling regardless of velocity, thus you must get all the power out of them while you can

The heating ceiling, i mean seriously whatta...

- - - Updated - - -

I'll have to speed up the development, my let's play footage is catching up already...

I guess i don't have to start from scratch, do I? I mean i can just make 4 nukes and it will go, right?

- - - Updated - - -

One less turbojets, one more nuke can really help, see my craft as example:

http://forum.kerbalspaceprogram.com/threads/117415-SSTO-to-laythe-and-beyond?p=2151601&viewfull=1#post2151601

What does "one less turbojet" mean?... Oh, that is interesting... Is one TJ is enough nowadays? .... Jesus! 2013th craft design advices... Don't wake a hulk in me!

Edited September 2, 2015 by tbarcello

[Stoney3K]

But please, just tell me this: what speed are you doing with ramjets? Because those explode from overheating above mach 3. You can see precoolers and radiators right there on the screenshot!

Ramjets will get you up to Mach 5 just fine as long as you have enough intakes (one Shock Cone per jet is more than enough). They have a power falloff when going above 18km, so that's a good point to kick in your rockets/nukes.

Precoolers don't cool, they're just circular fuselages with a fuel tank and an intake, despite their name.

And yes, one jet and a rocket (or a single RAPIER) can get you really far with the new aerodynamics. You're better off with huge wings than with fast stubby ones because fuselage drag is the main factor you need to fight.

Edited September 2, 2015 by Stoney3K

[tbarcello]

Ramjets will get you up to Mach 5 just fine as long as you have enough intakes (one Shock Cone per jet is more than enough). They have a power falloff when going above 18km, so that's a good point to kick in your rockets/nukes.

Precoolers don't cool, they're just circular fuselages with a fuel tank and an intake, despite their name.

Are you serious?! They don't?!! Goddamnit! How do i keep them cool then? I promise you, they never went to mach 4!

[Scarecrow88]

Most of my SSTOs manage around 1200 - 1300 m/s at 22k altitude before running out of steam and I have to change to rocket power. Never tried using a nuke on a SSTO due to the weight and lack of thrust, so that may be part of your problem.

[tbarcello]

Most of my SSTOs manage around 1200 - 1300 m/s at 22k altitude before running out of steam and I have to change to rocket power. Never tried using a nuke on a SSTO due to the weight and lack of thrust, so that may be part of your problem.

See,it is my problem. I'm delusional. But I guess that can't be fixed.

I know what to do now, I have a plan in my head, just need to try it tonight.

First, replace tail part to have 4 nukes.

Second, add 2 more ramjets.

Add more fuel.

This will end up being too heavy and ugly and i will never use this craft again, i know...

And you see? You said "running out of steam". I have problem with that statement, because my problem is heat. I never run out of steam, damn ramjets explode.

[DCWarHound]

Based on personnel experience and looking at the craft in the OP.

1.It does not have enough fuel to get to LKO (perhaps just enough)

2.The wings are too long,at higher speeds you want shorter wings that run the length of the body.Long wings are for gliding at low speed (long wings will also cause your SSTO to spin during re-entry on some occasions)

Your ascend profile should look like this,

1.Take of from the runway once reaching 100-200m/s

2.Pitch to 45 degrees and climb to 9000m (9km) (on larger planes you will have to pitch up 25 degrees)

3.Flat out to 0 degrees once you reach 9km

4.Gain speed until you reach 800m/s and then pitch up to 25 degrees

5.Your engines should last to around 15-20km and your apoapsis should sit at around 40km

6.Once your engines give out,keep them off until you reach around 30km and start burning toward 20 degrees

7.Keep burning until your apaopsis is above 70km and circularize like you normally would.

Descending is also rather simple,circularize your orbit to 70-80 km and then drop your periapsis to 50km,keep your nose pointed at 25 degrees during the entire descend to avoid burning up (rcs thusters under the nose can help).Turn your jet engines on and put them on full power so they can give you some horizontal speed so you can start gliding and the rest is just basic landing like with a normal plane.

[tbarcello]

Based on personnel experience and looking at the craft in the OP.

1.It does not have enough fuel to get to LKO (perhaps just enough)

2.The wings are too long,at higher speeds you want shorter wings that run the length of the body.Long wings are for gliding at low speed (long wings will also cause your SSTO to spin during re-entry on some occasions)

Your ascend profile should look like this,

1.Take of from the runway once reaching 100-200m/s

2.Pitch to 45 degrees and climb to 9000m (9km) (on larger planes you will have to pitch up 25 degrees)

3.Flat out to 0 degrees once you reach 9km

4.Gain speed until you reach 800m/s and then pitch up to 25 degrees

5.Your engines should last to around 15-20km and your apoapsis should sit at around 40km

6.Once your engines give out,keep them off until you reach around 30km and start burning toward 20 degrees

7.Keep burning until your apaopsis is above 70km and circularize like you normally would.

Descending is also rather simple,circularize your orbit to 70-80 km and then drop your periapsis to 50km,keep your nose pointed at 25 degrees during the entire descend to avoid burning up (rcs thusters under the nose can help).Turn your jet engines on and put them on full power so they can give you some horizontal speed so you can start gliding and the rest is just basic landing like with a normal plane.

Thank you so much for detailed answer.

You have just confirmed what my ascend profile looks like.

I fly like this: it takes off at about 80, then speeds up very fast, so I keep it almost vertical. My ascent rule of thumb is speed = altitude (km) x 50, so I'll be going 300 at 6km, 500 at 10km, 800 at 16km, then 1000 at 20km... And then it always start getting too hot, and suddenly. So i throttle down to about 20%, so the temperature would not rise, and it will keep climbing and loosing speed, which means fail. Or, i egnite nukes and shut down ramjets. At that point my apoapsis is around 40 with time to apoapsis being 40 seconds and counting down, even at full nuke throttle. I guess that is the only problem.

[Val]

Are you serious?! They don't?!! Goddamnit! How do i keep them cool then? I promise you, they never went to mach 4!

It sounds to me like your physics.cfg is broken, or did you turn up atmospheric heating. I've never had air-breathing engines overheat during flight.

[tbarcello]

It sounds to me like your physics.cfg is broken, or did you turn up atmospheric heating. I've never had air-breathing engines overheat during flight.

Overheat only at speed around mach 3. It doesn't show any signs of heating before that. But at alt 20km it gets to 1000m/s and suddenly heat gauge appears and filling fast. If i wait 3 seconds - boom. During flight at mach 2 engines perfom at around 150-200, but at 1000 they are at around 500 power.

[DCWarHound]

Thank you so much for detailed answer.

You have just confirmed what my ascend profile looks like.

I fly like this: it takes off at about 80, then speeds up very fast, so I keep it almost vertical. My ascent rule of thumb is speed = altitude (km) x 50, so I'll be going 300 at 6km, 500 at 10km, 800 at 16km, then 1000 at 20km... And then it always start getting too hot, and suddenly. So i throttle down to about 20%, so the temperature would not rise, and it will keep climbing and loosing speed, which means fail. Or, i egnite nukes and shut down ramjets. At that point my apoapsis is around 40 with time to apoapsis being 40 seconds and counting down, even at full nuke throttle. I guess that is the only problem.

i also get heating problems but i can be flying at 25 degrees at 1300m/s (15km high) and my engines will still not overheat.My engines have never overheated before my intakes and usually my plane explodes before my engines blow up (they are usually the last surviving parts)

Looking at your last post,you may be experiencing a rare heating bug (i call it "ghost heat") where something would randomly heat up and then explode.Most people can reproduce it by putting a MK2 probe core witch rcs behind an MK2 cockpit,the part will either randomly heat up during time warp for after ending time warp.

You don't use time warp during your ascend profile,right?

Edited September 2, 2015 by DCWarHound

[tbarcello]

i also get heating problems but i can be flying at 25 degrees at 1300m/s (15km high) and my engines will still not overheat.My engines have never overheated before my intakes and usually my plane explodes before my engines blow up (they are usually the last surviving parts)

You keep saying "my engines" which is really confusing. Ramjets or not ramjets?

[DCWarHound]

You keep saying "my engines" which is really confusing. Ramjets or not ramjets?

Whiplash and Rapier engines.

Edited September 2, 2015 by DCWarHound

[selfish_meme]

I know Rune has built a Jet+Nuke SSTO in 1.0.x, but it's tricky as hell and there's no real meaningful payload fraction either.

Even I have yet to get one properly to orbit on just liquid fuel.

Also, reduce drag wherever possible

I built a VTOL SSTO for Kerbin with a nuke, no one cared

[tbarcello]

Whiplash and Rapiers engines.

You mean you are using both at the same time or you mean it doesn't matter?

Either way, I think i know what the problem is and I'll report back after tasting.

[Val]

Overheat only at speed around mach 3. It doesn't show any signs of heating before that. But at alt 20km it gets to 1000m/s and suddenly heat gauge appears and filling fast. If i wait 3 seconds - boom. During flight at mach 2 engines perfom at around 150-200, but at 1000 they are at around 500 power.

Yes, that's what I mean. I've never had the overheating you describe.

My ascent profiles go like this.

1. Take-off and ascend to 9 km.
   
2. Build up speed to 1000-1050 m/s in level flight.
   
3. Ascend at 15 degrees. (10 degrees for low TWR, but yours has plenty)
   
4. Engage nukes at 18 km.
   
5. Should reach 1200+ m/s at 20 km.
   
6. Keep ascending at 15 degrees.
   
7. Turn prograde when AP is above 70 km.
   
8. Throttle down when AP is above 80 km and coast to circularization.
   

[DCWarHound]

You mean you are using both at the same time or you mean it doesn't matter?

Either way, I think i know what the problem is and I'll report back after tasting.

Both,so far the most efficient SP SSTO's use both or only Rapiers (Rapiers give more thrust but also consume more fuel).It's also a bad idea to have an engine as dead weight while in the atmosphere but it is even worse if you have an engine on in the atmosphere with a bad surface ISP.