Most Efficient Kerbin Circumnavigation in Atmosphere

[championofcyrodiil]

Start Economy

R-11 Baguette	FL-T400	Total Starting on Runway
24.3 Lf	72 Lf	96.3 Lf
29.7 Ox	88 Ox	117.7 Ox

End Economy

R-11 Baguette	FL-T400	Total Ending on Runway
19.27 Lf	57.11 Lf	76.38 Lf
23.56 Ox	69.80 Ox	93.36 Ox

Total Cost (standard units)

Liquid Fuel	19.92
Oxidizer	24.34

Total Time: 1d, 00:34:32 (From Take-off to Landed Screen shot during Taxi)

Name: Prototype III (Steam Craft Download)
Cost: 23,404V

https://ibb.co/Cs9RWzZ

More Details:

Using a radial array of 8 Fuel Cells, at 8.5km with a Ducted Fan Blade Deploy Angle of 57°, there is more than enough fuel to supply the electricity to maintain the two EM-325 Standard Rotor's Torque of 9.2%. In this thin atmosphere, we achieve efficient consumption rate of <=0.009 Oxidizer & Liquid Fuel per second.

Set Autopilot to maintain only heading and vertical speed of 90° and 0 m/s. One thing to note is the Drag coefficient of less that 30.0; Which I think is pretty decent. Now it's time to go to sleep and see how far we can make it.

NOTE: I did not start from the runway with a full tank of gas, as that provides too much weight to climb. 

https://ibb.co/gZwVWBx

Woke up this morning and saw that I did it! Luckily, I was just pulling up on KSC Runway 09.

The Solar Panels on the aircraft must have certainly reduced consumption while passing through the day lit portion of Kerbin! With 94.62/77.42 Ox/Lf left, we could certainly make another 5 trips around Kerbin.

This means my aircraft could have flown roughly 6x trips!

https://ibb.co/cLYsyd1

Here is a view of the Aircraft while in flight:

https://ibb.co/NFbxRZ5

https://ibb.co/qgG9mZ4

Details on Steam: https://steamcommunity.com/sharedfiles/filedetails/?id=2319300830

Edited December 13, 2020 by championofcyrodiil
Fixing Images

[ralanboyle]

What is the challenge? 

[fourfa]

Neat!  Though worth noting - your screenshots are pure black, no craft visible at all

[championofcyrodiil]

15 minutes ago, ralanboyle said:

What is the challenge? 

Get around Kerbin in Atmosphere with the least Fuel consumption? (aka how long can you fly in Atmosphere)
Honestly, it's less of a 'challenge' for the community.  I just thought I'd share.

Just now, fourfa said:

Neat!  Though worth noting - your screenshots are pure black, no craft visible at all

Ah, this is my first time sharing.  They are Steam links and I'm logged in via browser, so they probably show up for me.  Let me see if I can share them a different way.

9 minutes ago, fourfa said:

Neat!  Though worth noting - your screenshots are pure black, no craft visible at all

Should be fixed now. Please let me know.

[ralanboyle]

You might consider making a fuel type requirement because it is possible to navigate the globe using only electric charge. 

 

Edited December 14, 2020 by ralanboyle

[camacju]

Okay I'm going to take a slightly lateral thinking approach to this challenge. I assume the challenge is to see how much or how little fuel is needed to circumnavigate Kerbin while never leaving the atmosphere. So I think the best solution is to go into a 69999m orbit and coast around Kerbin a few times before landing.

https://imgur.com/a/ZntUz6B

I got really impatient and decided to timewarp which vastly increased my orbital decay. With proper station keeping I bet I could have lasted at least two months in the atmosphere before running out of fuel. But I don't have that kind of time.

Total ground distance covered: 140703910 m
Kerbin circumference: 3769911 m
Number of circumnavigations: 37
Amount of fuel used: 85.5 oxidizer and 70 liquid fuel
Highest altitude: 69989 m

Liquid fuel used per circumnavigation: 1.89
Oxidizer used per circumnavigation: 2.31

If the craft is kept orbiting long enough, the initial fuel cost will be amortized to nearly zero. This is probably the most efficient way to do this using only liquid fuel and/or oxidizer.

[championofcyrodiil]

On 12/13/2020 at 12:45 PM, ralanboyle said:

You might consider making a fuel type requirement because it is possible to navigate the globe using only electric charge. 

 

Forgive my ignorance,  but how does this craft maintain electric charge? 

[championofcyrodiil]

On 12/13/2020 at 5:37 PM, camacju said:

Okay I'm going to take a slightly lateral thinking approach to this challenge. I assume the challenge is to see how much or how little fuel is needed to circumnavigate Kerbin while never leaving the atmosphere. So I think the best solution is to go into a 69999m orbit and coast around Kerbin a few times before landing.

Nice outside of the box thinking here.  However I'm curious whether or not you have enough atmosphere at 69999m to be in the spirit of this challenge.  An interesting twist to this challenge would be to fly halfway around Kerbin and then turn 180° and fly back at an opposite heading  90°/270°. My craft would require slightly more fuel,  but not as much as yours i think. You would need like 4790 dV more just to turn around. 

Edited December 15, 2020 by championofcyrodiil

[championofcyrodiil]

On 12/13/2020 at 9:35 AM, fourfa said:

Neat!  Though worth noting - your screenshots are pure black, no craft visible at all

I see on my phone what you mean.  Interesting. My desktop monitor doesn't show these images as black.  I wonder if it is my AMD & Freesync settings?  Or HDR configuration probably? So many graphics settings these days.  But it makes sense to be that dark since it was night in the game and there is no lighting on that craft.

Using Astronomers visualization pack mod as well. 

Edited December 15, 2020 by championofcyrodiil

[championofcyrodiil]

I figured out why the images are so dark.

 

The Samsung Galaxy S9 has four user selectable Screen Modes: Adaptive Display, AMOLED Cinema, AMOLED Photo, and the Basic Screen Mode, which matches the Standard sRGB / Rec. 709 Color Gamut that is used for producing most current consumer content.

My LG monitor supports like 15 different color modes, and the default was "Custom" which attempts to deliver "HDR" with something like BT.2020 and includes a large range of colors.  So on my desktop I don't see "black" I see a lot of other 'colors' in there.  For now I've switched my Picture mode to Rec. 709 since KSP doesnt seem to support HDR well, and this explains why colors  often have a 'washed out' or 'gradient' look for me on this monitor.

https://www.unravel.com.au/understanding-color-spaces

[king of nowhere]

3 hours ago, championofcyrodiil said:

Forgive my ignorance,  but how does this craft maintain electric charge? 

i myself have a propeller plane powered by rtg. can fly nonstop as long as i want

[ralanboyle]

3 hours ago, championofcyrodiil said:

Forgive my ignorance,  but how does this craft maintain electric charge?

A crap ton of RTGs. 

[swjr-swis]

On 12/13/2020 at 11:37 PM, camacju said:

Total ground distance covered: 140703910 m
Kerbin circumference: 3769911 m
Number of circumnavigations: 37

In theory this sounds like easy math.... except the distance numbers on the F3 display are known to be utter nonsense, and you divided by the circumference at sea level instead of at 69989 m (slight difference, 4,209,665 m). You'd have to have been flying at 3202 m/s at sea level to get that many laps, or 3576 m/s at the edge of the atmosphere. Crispy, even for a missile.

Your total flight time is a much more accurate source to figure out how many laps were made during your flight. My estimate would be 23 circumnavigations. Still a very impressive number, mind you.

Spoiler

Math: since the whole premise was to conserve fuel and to stay within the atmosphere, you only throttled the bare minimum to maintain orbital speed at just under 70km. With orbits taking around 30 mins at that altitude, you could have done a theoretical (!) maximum of 24 circumnavigations in just over 12 hours. That's not counting the acceleration at the start and deceleration at the end, both of which eat enough time to easily cost a full orbit.

Even taking the one screenshot with a higher-than-orbital speed (2345.9 m/s) and the lower end altitude of 63750 m and disregarding accel/decel time, you'd still only get a theoretical max of 24.4 orbits, so that's a quite solid high boundary.

 

Edited December 15, 2020 by swjr-swis

[dawg]

On 12/13/2020 at 6:36 AM, championofcyrodiil said:

Get around Kerbin in Atmosphere with the least Fuel consumption? (aka how long can you fly in Atmosphere)
Honestly, it's less of a 'challenge' for the community.  I just thought I'd share.

Ah, this is my first time sharing.  They are Steam links and I'm logged in via browser, so they probably show up for me.  Let me see if I can share them a different way.

Should be fixed now. Please let me know.

I have effectively orbited Kerbin multiple times within the atmosphere on zero fuel and landed back at the runway. I used batteries charged by solar for takeoff and solar power was sufficient to keep the batteries charged and the props running indefinitely. I simply flew to a specific altitude and adjusted the prop pitch until I was flying at the sidereal rotation velocity of Kerbin.

[camacju]

I know this probably won't count but I made a dragless craft which can orbit Kerbin infinitely long in the atmosphere.