Eve rocket seaplane range challenge

[Pds314]

Eve rocket seaplane range challenge

The goal of this challenge is to take off in a rocket-powered seaplane from a lake on Eve and go as far as possible from your starting position, then land in the water again.

 

Rules

1. Put something at your starting position to measure distance from it.

2. Staging is permitted, however, the piece that finally lands should still be your original seaplane. You may strap fuel tanks or rockets to it if you wish. They can have small stabilization fins or small floats on them, but no staging away your main wing.

3. No non-rocket-based propulsion. If you find a way to use an ion engine that's fine. An electric prop is not. And nor is an electric waterwheel or a ladder drive. If you want to use a rocket turboshaft or whatever, I won't stop you.

4. No rover wheels or landing gears. Go from water to water. Landing on land is not permitted.

5. Stock parts only. Stock atmosphere only.

6. I will not stop you from building a rocket-propelled boat rather than a seaplane, but you're probably better off flying.

7. Breaking Ground and Making History are permitted.

8. You may hack your vehicle onto Eve.

9. On the extreme offchance someone gets to orbit, they automatically beat those who don't and score is determined by periapsis.

10. You must have a Kerbal onboard.

 

Scoreboard

1. 66.1 km in the Bad Eve Seaplane mk3 by Jodo 42

2. 47.9 km in the Eve Fish 1 by Pds314

3. 16.8 km by Klapaucius

4. 13.9 km in the Bad Eve Seaplane Mk1 by Jodo 42

 

Good Luck!

Edited July 6, 2019 by Pds314

[Jodo42]

I hate building or flying planes of any kind anywhere in KSP, and I know almost nothing about watercraft in this game. Sounds like the perfect challenge for me.

Inspired by the famous Cessna Caravan. 13.9km. Improvements/redesigns to come.

[Pds314]

2 hours ago, Jodo42 said:

I hate building or flying planes of any kind anywhere in KSP, and I know almost nothing about watercraft in this game. Sounds like the perfect challenge for me.

Inspired by the famous Cessna Caravan. 13.9km. Improvements/redesigns to come.

Nice! Allmoving elevons isn't necessarilly what I would have done and that plane looks over-stable by the end of the flight, but it is a good run nonetheless.

Edited July 4, 2019 by Pds314

[Klapaucius]

14.9 km. Unfortunately, I recorded the video and uploaded before realizing I forgot to leave a Kerbal as a distance measure. I forgot that f3 is totally inaccurate (it claimed 30km!). So, the video shows the flight, but I redid it and the photos show the actual distance with reference Bob.  The plane can also take off and land on land, so there is a bit of that at the end, plus a very odd crash 

 

The plane is based off a design that has worked very well for me. One variant is a landplane/seaplane/submarine combination.  That gravity and atmosphere are just fuel killers. 

 

 

 

Edited July 5, 2019 by Klapaucius

[Pds314]

19 hours ago, Klapaucius said:

14.9 km. Unfortunately, I recorded the video and uploaded before realizing I forgot to leave a Kerbal as a distance measure. I forgot that f3 is totally inaccurate (it claimed 30km!). So, the video shows the flight, but I redid it and the photos show the actual distance with reference Bob.  The plane can also take off and land on land, so there is a bit of that at the end, plus a very odd crash 

 

The plane is based off a design that has worked very well for me. One variant is a landplane/seaplane/submarine combination.  That gravity and atmosphere are just fuel killers. 

 

 

 

Curious why you don't zoom climb. You set a new record though.

Edited July 6, 2019 by Pds314

[Klapaucius]

1 hour ago, Pds314 said:

Curious why you don't zoom climb. You set a new record though.

Not sure what you mean....

[Pds314]

Just now, Klapaucius said:

Not sure what you mean....

Climb after getting to speed to then glide and get a better record.

[Klapaucius]

7 minutes ago, Pds314 said:

Climb after getting to speed to then glide and get a better record.

Yeah, I was not sure if I would waste more fuel doing that, since I was able to maintain level flight with the throttle way back.  I'll give it another go this evening.

[Pds314]

I don't have a video since I knew it would take far too long, but I managed 47.9 km in my Eve Fish 1!

Screenshot-heavy spoiler:

Spoiler

Takeoff:

Acceleration:

I thought I was running lower on fuel than I was so I started climbing earlier than necessary. I only reached about 2000 meters before I was under 80 m/s and needed to level out and accelerate again or I would not be using the rocket engine efficiently. This is the start of my next climb.

Continuing the climb:

Nearly at fuel burn out:

Somewhat after peak altitude:

I see an Island in the distance and consider diverting course. Fortunately I realize I probably won't reach all the way to the Island:

Flaring on final approach:

Landed. 47.9 km from where I started.

 

Edited July 6, 2019 by Pds314

[Klapaucius]

3 hours ago, Pds314 said:

Climb after getting to speed to then glide and get a better record.

I tried this. Slight improvement, but nothing drastic. I got 16.8.  The distance text was barely visible in the game, and it is about impossible to see in the screenshot. Nice run by the way!

This is really good challenge. Harder than I thought it would be.

 

[Pds314]

[Roblox Oof noises]

[Pds314]

sTrUcTuRaL fAilUrE oN lInkAgE bEtWeEn





At 0.4 G no less... Hmm.... Alexa play despacito for this pleen. Stock aerodynamics failures are confirmed.

*Turns on invulnerability*



Alexa, also play despacito for the speed of light. FTL drives confirmed.

Edited July 6, 2019 by Pds314

[Pds314]

Okay, note-to-self: 2000 tonnes is too big. R I P plane that will likely never fly without cheats. Your Robotics parts Elevator and virtually non-functional robotics parts Ailerons will not be forgotten.

Maybe if I make something that's like... 3.75m instead of 5m tanks, and less of them....

Edited July 6, 2019 by Pds314

[Pds314]

PSA: making fairing the root part deletes their bouyancy!

 

I am not in game right now but broadly I think there are three main problems with my approach to building big seaplanes.

1. Fairings need autostruts or they don't work.

2. Fairings can't be root or they don't work.

3. Wings snap and/or disintegrate under excessive load. Even engaging engine thrust seems to be enough to snap long wings attached at a single point. Even if that point is a FAT-455 wing.

Edited July 6, 2019 by Pds314

[Jodo42]

66.1km.

Still no clue what my velocities or altitudes should be. Double tailfins was a bad idea.

[Pds314]

1 hour ago, Jodo42 said:

66.1km.

Still no clue what my velocities or altitudes should be. Double tailfins was a bad idea.

That is a really good run. As for speed and altitude, as fast as possible and ending as high as possible. With jets/rockets you get nearly constant thrust, so you should maximize your V*L/D, not L/D. I.E. 150 m/s with an L/D of 4 is more efficient than 50 m/s with an L/D of 10. Get the most use you can from the Oberth effect without throwing it into drag losses.

 

This is complicated however by the changes in performance with altitude. With jets you want to hug the water until drag starts to grow nonlinearly fast because their thrust decreases with altitude. This is not the case with rockets, as their thrust increases with altitude. Particularly on Eve where even the best engines lose a large fraction of their specific impulse at sealevel.

Additionally, at higher altitudes you can reach higher speeds with less drag.

On your descent, you probably should just maximize L/D and glide ratio.

Edited July 6, 2019 by Pds314