Kerbin Circumnavigation on 400 Liquid Fuel

[Triop]

So do a Kerbin Circumnavigation using only 400 LF.

Rules: No mods.

* Any container will be fine, but no more then 400 LF can be used.

Highest fuel left is the winner I guess....

Goodluck, gentlemen.

(yes, I did it,)

52.70 LF left !

 

LEADERBOARD:

1. zolotiyeruki - 255 left

2. JW2016 - 180 left

3. Triop - 52.70 left

 

Edited March 3, 2016 by Triop

[zolotiyeruki]

Must the 400 units of fuel be contained in that specific tank, or can it be contained in something else, like the size 0 tanks, with no more than 400 units at launch?

Also, do we *have* to start with 400 units, or, can we start with less to minimize weight?  For example, if I think I can make it in 350 units of fuel, can I start with just 350, or do I need to lug the extra 50 around the world?  Must the craft carry a Kerbal?  Command seats allowed? Or can it be powered by a probe core?

Edited February 29, 2016 by zolotiyeruki

[Triop]

25 minutes ago, zolotiyeruki said:

Must the 400 units of fuel be contained in that specific tank, or can it be contained in something else, like the size 0 tanks, with no more than 400 units at launch?

Any container will be fine, but no more then 400 LF can be used.

[MarvinKitFox]

400 LF, no other limits?

 

Please explain why my ion-drive glider would not win the prize? (around the world on 3 cans of xenon)

.

Or, if more patient, how about the solar-powered amphibious rover?

 

More detail needed in the rulez, i think.

Edited February 29, 2016 by MarvinKitFox

[Triop]

1 hour ago, MarvinKitFox said:

400 LF, no other limits?

 

Please explain why my ion-drive glider would not win the prize? (around the world on 3 cans of xenon)

.

Or, if more patient, how about the solar-powered amphibious rover?

 

More detail needed in the rulez, i think.

Your ion-drive glider doesn't use liquid fuel and that is part of the challenge.

I don't think more rules are necessary...

[Majorjim!]

Nothing in the rules says we cannot just carry the fuel and use an electric rover. It could be done using no fuel at all.

Also, using jets and rockets is out. So if we HAVE to use the fuel that means only one option which is to use the fuel to power a fuel cell..

Edited February 29, 2016 by Majorjim

[Triop]

47 minutes ago, Majorjim said:

Nothing in the rules says we cannot just carry the fuel and use an electric rover. It could be done using no fuel at all.

Also, using jets and rockets is out. So if we HAVE to use the fuel that means only one option which is to use the fuel to power a fuel cell..

In fact, that would be awesome if someone would do that.

[Majorjim!]

Just now, Triop said:

In fact, that would be awesome if someone would do that.

Wouldn't the use of solar panels make this too easy? Then again not using them might make it impossible. Have you done this already? I think that is one of the points of setting up a challenge. I could be wrong though.

[JW2016]

3 hours ago, Majorjim said:

Nothing in the rules says we cannot just carry the fuel and use an electric rover. It could be done using no fuel at all.

Also, using jets and rockets is out. So if we HAVE to use the fuel that means only one option which is to use the fuel to power a fuel cell..

Why are jets out? I haven't' tried this but from what I remember it's totally possible with jets?

[Majorjim!]

Just now, JW2016 said:

Why are jets out? I haven't' tried this but from what I remember it's totally possible with jets?

Maybe, I was making an assumption about the jets, that is not much fuel, give it a go!

[Triop]

Well, here we go:

Spoiler

It gets HOT !

300 LF left...

200 LF left...

100 LF left...

Turning of engine...

And landing...

 

52.70 LF left !

[JW2016]

180 units left

 

[Triop]

@JW2016

180 left....Nice

Can you do that with a Kerbal and return him safe ?

It's not in the rules, but that would be awesome.

Edit: But what is happening here ?

Can you give us some more information on what you did ?

Edited March 1, 2016 by Triop

[zolotiyeruki]

I'm doing a run now, but my landing gear burned off

Since JW2016 crashed at the end, I assume a safe landing is not required?

EDIT: Well, here's run #1:  I kinda overshot KSC, and lost a wing while trying to slow down for a close approach.  I started with only 200 fuel, and had 44+ left over, which means I used a whopping 155 fuel total.  That means a score of 244, right?

Now I'm going to try to get all the way around on a single Juno.  50% better efficiency than the Rapier, but 1/4 the speed.  It'll be tough.

Edited March 2, 2016 by zolotiyeruki

[Triop]

22 hours ago, zolotiyeruki said:

I'm doing a run now, but my landing gear burned off

Since JW2016 crashed at the end, I assume a safe landing is not required?

EDIT: Well, here's run #1:  I kinda overshot KSC, and lost a wing while trying to slow down for a close approach.  I started with only 200 fuel, and had 44+ left over, which means I used a whopping 155 fuel total.  That means a score of 244, right?

Now I'm going to try to get all the way around on a single Juno.  50% better efficiency than the Rapier, but 1/4 the speed.  It'll be tough.

O.k, you are in...But I still have no clue how you or JW2016 did it.

I use no mods so your pictures don't tell me anything.

But I must say I am impressed..

[zolotiyeruki]

39 minutes ago, Triop said:

O.k, you are in...But I still have no clue how you or JW2016 did it.

I use no mods so your pictures don't tell me anything.

But I must say I am impressed..

Truth be told, this is just a really short version of the aviator challenge (where I went around 12 times on an air-breathing engine with no refuelling), and I learned a *lot* of optimization there.  There are lots of little tricks that incrementally add up to HUGE fuel savings:

1. fly high = low drag
2. fly fast = orbital mechanics start to kick in, and you need less lift = low drag
3. low weight = lower induced drag
4. Big-S strakes have fuel capacity with no weight or lift penalty compared to a traditional wing. IOW, add fuel without the dry mass of a fuel tank.
5. Shock cone intakes on *both* ends--they have the lowest Cd in the game
6. small landing gear bay is physicsless, so no extra parasitic drag
7. lower starting mass = less fuel used.  I could reduce the starting fuel in my run by 55, and I would still end up with leftover fuel, since I wouldn't be lugging that extra 275kg of fuel all the way around.

Mod on the left = Kerbal Engineer.  Informational only--I was using it to track my position so I would know when to cut off the engine.

Mod on the right: Pilot Assistant.  It's an autopilot that I used to hold the wings level, my nose on the horizon, and my speed down (to avoid overheating), so I didn't have to babysit the craft through the whole run.  In 1.0.4, I could have made the run with even less fuel burned, since the thermal model was more forgiving, and I could have flown faster and higher.

[Triop]

58 minutes ago, zolotiyeruki said:

Truth be told, this is just a really short version of the aviator challenge (where I went around 12 times on an air-breathing engine with no refuelling), and I learned a *lot* of optimization there.  There are lots of little tricks that incrementally add up to HUGE fuel savings:

1. fly high = low drag
2. fly fast = orbital mechanics start to kick in, and you need less lift = low drag
3. low weight = lower induced drag
4. Big-S strakes have fuel capacity with no weight or lift penalty compared to a traditional wing. IOW, add fuel without the dry mass of a fuel tank.
5. Shock cone intakes on *both* ends--they have the lowest Cd in the game
6. small landing gear bay is physicsless, so no extra parasitic drag
7. lower starting mass = less fuel used.  I could reduce the starting fuel in my run by 55, and I would still end up with leftover fuel, since I wouldn't be lugging that extra 275kg of fuel all the way around.

Mod on the left = Kerbal Engineer.  Informational only--I was using it to track my position so I would know when to cut off the engine.

Mod on the right: Pilot Assistant.  It's an autopilot that I used to hold the wings level, my nose on the horizon, and my speed down (to avoid overheating), so I didn't have to babysit the craft through the whole run.  In 1.0.4, I could have made the run with even less fuel burned, since the thermal model was more forgiving, and I could have flown faster and higher.

Wow, that's some clear information !

Thanks.