High speed stock Aircraft challenge.

[Cunjo Carl]

This isn't a challenge entry, but I figured I'd make mention of a surprising nose cone choice for some supremely fast flying. If you can believe it, the inflatable heat shield works wonders! Here's a whiplash+2NERV jet going escape velocity with flight all under 30km. The weakest link here is the wings, the nose cone could go much faster! My original intent was to deploy payloads to solar orbits from aerodynamic flight, but they invariably exploded   ...

 

  

 

Anyways, it seems to be less draggy in version 1.4 than when I tried it last, so it should even be a reasonable choice for air breathers with more than one engine... Rocket planes should have no troubles at all with its drag. Best of luck!

[HeronRocketry]

8 hours ago, Cunjo Carl said:

This isn't a challenge entry, but I figured I'd make mention of a surprising nose cone choice for some supremely fast flying. If you can believe it, the inflatable heat shield works wonders! Here's a whiplash+2NERV jet going escape velocity with flight all under 30km. The weakest link here is the wings, the nose cone could go much faster! My original intent was to deploy payloads to solar orbits from aerodynamic flight, but they invariably exploded   ...

 

  

 

Anyways, it seems to be less draggy in version 1.4 than when I tried it last, so it should even be a reasonable choice for air breathers with more than one engine... Rocket planes should have no troubles at all with its drag. Best of luck!

Apologies, but you are not allowed to use heat shields in the competition. Please look at the rules on the first page.

 

Edit: Oops, didn’t realize the wasn’t a challenge entry. Anyway, look at the rules if you want to participate!

Edited May 9, 2018 by HeronRocketry

[Cunjo Carl]

On 5/9/2018 at 4:55 AM, HeronRocketry said:

Apologies, but you are not allowed to use heat shields in the competition. Please look at the rules on the first page.

 

Edit: Oops, didn’t realize the wasn’t a challenge entry. Anyway, look at the rules if you want to participate!

Er, ablative heatshields are forbidden, but the inflatable heat shield happens not to be ablative. It has some nice properties like a high max temp, but doesn't actually have any of the ablator magic.

Thanks for the offer and I certainly have, but none of the categories are quite reaching out to me at the moment. I'm definitely outside the scope, as I'm currently tinkering with escape velocity flight, which works best with nukes in the 30-40km range and has an Ap out near Duna . Perhaps I'll have a stab at the jet-only at some point, though.

I guess it's a judgement call as to whether to tweak the heat shield rules to disallow it, but if not, I hope the interesting nose cone find proves useful!

Edited May 10, 2018 by Cunjo Carl

[TheTripleAce3]

On 5/9/2018 at 10:57 AM, Cunjo Carl said:

Er, ablative heatshields are forbidden, but the inflatable heat shield happens not to be ablative. It has some nice properties like a high max temp, but doesn't actually have any of the ablator magic.

Thanks for the offer and I certainly have, but none of the categories are quite reaching out to me at the moment. I'm definitely outside the scope, as I'm currently tinkering with escape velocity flight, which works best with nukes in the 30-40km range and has an Ap out near Duna . Perhaps I'll have a stab at the jet-only at some point, though.

I guess it's a judgement call as to whether to tweak the heat shield rules to disallow it, but if not, I hope the interesting nose cone find proves useful!

Or maybe make it so heat shields must be deployed at all times?

[Cunjo Carl]

20 minutes ago, TheTripleAce3 said:

Or maybe make it so heat shields must be deployed at all times?

  I tried this once mid-flight, it's exactly as hilarious as you'd expect!

[TheTripleAce3]

If they want to try to use the heat shields, I wanna see the thing deployed

[doggonemess]

On 5/11/2018 at 9:07 PM, TheTripleAce3 said:

If they want to try to use the heat shields, I wanna see the thing deployed

Challenge accepted!

I found it takes quite a few engines (40?) to push the heat shield when it's deployed. After a lot of spinning and exploding, this was the best I got:

Mach 3.62 - one second after this screenshot the plane ran out of fuel and then left the planet. It came down later, a lot more gently than I thought it would. It still exploded, but the heat shield really slowed it down nicely.

I know the autopilot mod is there, but I wasn't using it (just using the normal SAS). The thing had no freaking clue what to do with the plane, so using it was worse than no SAS at all.

[TheTripleAce3]

@doggonemessImpressive craft! But sadly it isn't the 2km/s that is required.

Although I'm not sure any craft could get going that fast with a 10m heat shield deployed.

[doggonemess]

10 hours ago, TheTripleAce3 said:

@doggonemessImpressive craft! But sadly it isn't the 2km/s that is required.

Although I'm not sure any craft could get going that fast with a 10m heat shield deployed.

Thanks! I can't think of how it would be possible without mods. The more engines I add, the more unstable it gets. It's hard enough to get to 2 km/s with everything perfectly optimized (I still haven't managed it stock), let alone with a giant balloon attached to your nose.

[doggonemess]

I played around with this for a couple hours last night, and I found that I was hitting a wall around Mach 5.8 (without the heat shield, of course). The RAPIER engine flames out at that speed for me. I tried adjusting the design, spamming it with intakes, etc, but it keeps doing it. I think the best I got was 5.83. I found a related post to the engine and flameout:

It describes what I'm seeing. Can 2000 m/s be done in the latest version of KSP?

EDIT:

So it can be done. I turned off heating and set infinite fuel. Then I built a flying needle with three RAPIERs. I let an autopilot mod handle the flying while I tweaked everything. After some trial and error, I managed 2008 m/s.

https://imgur.com/a/OBFk5AJ

BUT - only at low altitude. At high altitude, where you could possibly survive the heating effects, the engines flame out around Mach 5.8 like before.

On another note, can you imagine going 2 km/s at 3 meters off the water? If your finger twitches involuntarily, you'd hit the water and disintegrate without even realizing you messed up.

 

Edited May 21, 2018 by doggonemess
managed to go 2 km/s with cheats on

[TheTripleAce3]

6 hours ago, doggonemess said:

On another note, can you imagine going 2 km/s at 3 meters off the water? If your finger twitches involuntarily, you'd hit the water and disintegrate without even realizing you messed up.

I don't want to imagine that for many reasons.

[TheTripleAce3]

16 hours ago, doggonemess said:

Thanks! I can't think of how it would be possible without mods. The more engines I add, the more unstable it gets. It's hard enough to get to 2 km/s with everything perfectly optimized (I still haven't managed it stock), let alone with a giant balloon attached to your nose.

Shock cone intakes + precoolers + powerdives.

[doggonemess]

So, has anyone accomplished this in KSP 1.4.3? I have tried everything to build a craft that can go fast enough without burning up, and I'm really starting to think it's not possible without ignoring thermal effects. I've tried every trick I can think of to get more speed out of the engines, and only flying at low altitude has worked - which creates too much heat. 

Jamie

[TheTripleAce3]

I just barely accomplished this yesterday with an aerospike + Whiplash combo.

But I was more focused on flying than screenshotting it...

[doggonemess]

On 5/24/2018 at 4:44 PM, TheTripleAce3 said:

I just barely accomplished this yesterday with an aerospike + Whiplash combo.

But I was more focused on flying than screenshotting it...

I'm determined to do this if I can. It's become an obsession at this point.

What altitude?

J.

[TheTripleAce3]

41 minutes ago, doggonemess said:

What altitude?

It was at about 29k, so barely qualifying for my standards, my apo also went above 30k, so I'd have to carefully retread that whole part.

[doggonemess]

1 hour ago, TheTripleAce3 said:

It was at about 29k, so barely qualifying for my standards, my apo also went above 30k, so I'd have to carefully retread that whole part.

Ahhhh, wait a sec. I've been trying this with jets only. I think that I could make this happen with a hybrid design. But I'm not sure that the jet is possible anymore. I've tried over and over. I can't make it above 1800 m/s with jets without something overheating or the engines flaming out. There's just no margin between the two at any altitude it seems.

[TheTripleAce3]

Use Rapiers. They can operate all the way up to 27km iirc. They'll have barely any thrust, but you can still get up there on them.

[doggonemess]

2 hours ago, TheTripleAce3 said:

Use Rapiers. They can operate all the way up to 27km iirc. They'll have barely any thrust, but you can still get up there on them.

Yeah, I tried them. They are the ones that always flamed out at Mach 5.8. The forum post I linked above somewhere mentions the limitation. I really think they changed something and it's preventing the jets from reaching those speeds at high altitude.

[TheTripleAce3]

If you use a ton of precoolers and intakes you can get whiplashes all the way up to 28km, but Rapiers are still better imo

[doggonemess]

2 hours ago, TheTripleAce3 said:

If you use a ton of precoolers and intakes you can get whiplashes all the way up to 28km, but Rapiers are still better imo

I figured the precoolers and intakes would bog the thing down, I'm going to try that.

[TheTripleAce3]

It might do, but it also gives more engine nodes