Kerbal X Economy Challenge

[Ultimate Steve]

The goal: Launch the stock Kerbal X and fly to the Mun and back using the least fuel. Your score is the fuel remaining in the upper stage tank at the time you decouple it for re entry. The Kerbal(s) must survive landing.

No getting out and pushing, no modifying the craft in the VAB, no kraken driving, no including extra stuff in the inventory at launch. You know it, but also no debug menu, no mods that change craft performance, etc. No autopilot mods like MechJeb but if you want to do it to see how low you can go I guess I can put it up as an honorable mention. No assistance from other craft.

However, there are still some edge cases, so I've decided to split this up into two categories. Jeb mode is exclusively about piloting. You must launch with three Kerbals with the default inventory, you may not modify the craft with the construction tool, you may not crash or burn up to remove parts, etc. Basically, keep it as close to the default Kerbal X experience as possible.

Val mode allows some modifications. You may alter the number of Kerbals carried, and remove things from their inventories (but not add them). You may use the EVA construction tool to modify the ship, but of course you are limited to what is on the ship. You may not modify the ship in the VAB. You may use lithobraking and atmospheric heating to delete parts. Still no Kraken drives or getting out and pushing, though.

Additional restrictions:

• No transferring fuel around. Score is measured as liquid fuel remaining. This opens the door to transferring out excess oxidizer to the lower stage, and given how annoying it is to get an exact amount transferred, I'm going to save us this headache and pre-emptively ban this. Oxidizer and liquid fuel levels must remain proportional.
• The command pod must reach the atmosphere intact, no abandoning the ship and jetpacking home the last 600m/s.

Jeb mode leaderboard:

1.  @Ultimate Steve 158 liquid fuel remaining

Val mode leaderboard:

1. @camacju 332 liquid fuel remaining
2.  @Ultimate Steve 278 liquid fuel remaining

My Jeb mode attempt:

Spoiler

Liftoff

Ascent was too steep

Came in too steep to the Mun and had to burn off retrograde

Landed

Launched

On a re entry trajectory, final score 158

Landed

My Val mode attempt:

Spoiler

I launched with two Kerbals, one engineer and one helper. This allows all of the unnecessary junk on the upper stage to be removed, including the landing gear, reducing mass and ascent drag.

The helper Kerbal is left behind.

Ascending. Timing on booster detach could have been better.

An EVA is conducted during the coast phase to remove the fins to shed mass.

The parachute is also removed.

After circularizing, the main stage sends us around the Mun.

It also conducts some of the braking burn.

Landing without gear is tricky. We try to pick a flat piece of land and turn off engine gimbal.

RCS is used to stabilize the landing. Come to think of it we could have burned off all or almost all of the monopropellant on the launch pad for an even more efficient launch, or used it in space to increase Delta-V.

Launch and return burn.

It took a few passes to slow down but the engine was not used after this point. Final score 278.

No parachute so our guy has to bail out.

Successful landing!

 

Edited August 9, 2023 by Ultimate Steve

[camacju]

ooh I've got some ideas for this one. Will take a crack at it when I get home!

[camacju]

Haven't quite finished my attempt yet. I'll post some teaser images I guess

Spoiler

Looks normal so far...

Wait, this isn't Mun!

?????????

 

[Ultimate Steve]

18 minutes ago, camacju said:

Haven't quite finished my attempt yet. I'll post some teaser images I guess

  Hide contents

Looks normal so far...

Wait, this isn't Mun!

?????????

 

Doing a gravity assist chain to get close enough to the sun to burn the ablator off of the heat shield... You never cease to amaze me.

[camacju]

Update: I finished the mission a while ago with 332 liquid fuel remaining. I haven't gotten around to editing the video yet.

[camacju]

On 7/30/2023 at 10:04 PM, camacju said:

I haven't gotten around to editing the video yet.

Oops, I forgot about this.

 

[PicoSpace]

I snookered my Poodle Engine on landing... there were explosions on lift-off so another Kerbal Will be Required in Attempt #2
"Val" Attempt #1 in a few photos - https://imgur.com/a/mJKfkdw