The "build your way home" challenge

[dnbattley]

With the new 1.11 reassembly function added, the goal of this challenge is simple, but deceptively hard: design and build a ride home.

Rules: At least 2 kerbals (1 pilot, 1 engineer) are to be stranded on a target body. You may cheat them into position if you wish.

A probe piloted "rescue package" must be de-orbited and landed for them to use to make their escape.

From this package, craft a new vessel capable of bringing them home.

Scoring system TBC, but my thinking is along the lines of ((# of kerbals rescued/mass of rescue package in tons)^(relative surface gravity*))*100

*Where relative surface g = 1 for Kerbin, 0.3 Duna etc.

 

Kraken-powered entries are discouraged but will be permitted: resulting scores will be held separate from normal, glitch-free entries.

[Vanamonde]

Neat idea, but is it possible? I'm finding some of the necessary parts are too big for a Kerbal to manipulate even in free fall. 

[dnbattley]

6 hours ago, Vanamonde said:

Neat idea, but is it possible? I'm finding some of the necessary parts are too big for a Kerbal to manipulate even in free fall. 

There appears to be a limit of 60kg/relative surface gravity, as far as I have tested so far, which corresponds to 60kg on Kerbin, about 35-odd kg on Eve, and 200kg on Duna. Somewhere like Minmus should, though I haven't tested it, have a limit of 1.2T, making it effectively the same as in space.

Parts can also be emptied of fuel before loading and then filled via fuel flow.

[sturmhauke]

Are the stranded kerbals allowed to have anything on the surface with them? For instance, an intact command pod or a rover or something.

[dnbattley]

6 hours ago, sturmhauke said:

Are the stranded kerbals allowed to have anything on the surface with them? For instance, an intact command pod or a rover or something.

I was in a couple of different minds about this. I think it is fine to salvage parts from a "crashed ship"... including siphoning fuel, provided that you are not simply repairing that original ship. My related thought was to look again at the scoring and remove reference to the rescue pod weight and instead use a discrete "number of cargo pods used" as the denominator.

I'm open to other suggestions, however.

[sturmhauke]

Perhaps you could multiply the score from your formula by the percentage of the final craft by mass that is composed of rescue parts. So like:

score[final] = score[formula] * ((mass[escape vehicle] / (mass[rescue package] + mass[crashed vehicle]))

[Pds314]

One option might be to use fuel transfer so that parts like oscar-B can be used in moderate gravity.

[dnbattley]

I've put together a proof of concept mission for this challenge.

Spoiler

When disaster struck... Bill pronounced the engine DOA.

 

A rescue mission was hastily put together

 

And after only a few short years...

 

The team could see their salvation

 

Landing nearby...

 

Bill quickly got to work...

 

And by detaching the cabin, new boosters were affixed

 

And we were away!

 

However, after a poor launch, deltaV was looking tight, so an audacious mechanic was used to create a staging process... first empty the relevant tanks...

 

...Then laser them off!

 

And so orbit was achieved.

 

Unfortunately this brought an end to the mission, as a result of some new bugs I identified, which may mean that  this challenge is going to be better attempted once they are fixed.

Specifically:

1. A fuel bug appears to sometimes use a prior fuel level for a part when it is attached, which can effectively "create" fuel, although this did not bring any benefit to this particular mission
2. Attachment nodes sometimes disappear in the engineering mode under certain circumstances, making non-radial attachment impossible (this is what actually killed the mission as I removed one of the two engines hoping to re-attach it to the base of the capsule, only to find that no nodes were available, including in its original place, meaning it could not be reattached).
3. Detached parts are only tested for compliance with weight AFTER being detached, leading to a circumstance where parts cannot be dropped, for which the only solution is to exit the engineering mode, making the part disappear.

Once I've done some more investigation into these bugs I'll aim to report them to the bugtracker.

 

[Kerminator K-100]

I feel like this is impossible with the stock weight restrictions. Maybe KIS would be a better challenge?

[dnbattley]

2 hours ago, Kerminator K-100 said:

I feel like this is impossible with the stock weight restrictions.

It certainly needs planning, but it is possible to work within the restrictions, as my concept mission proved. There are issues with the current engineering mode which I'd like to see these fixed asap, but I think they can mostly be worked around.

What specific weight limit are you coming up against that's preventing your mission?

[joshudson]

You only have to get into orbit of the body? Infinite score possible.

[dnbattley]

7 hours ago, joshudson said:

You only have to get into orbit of the body? Infinite score possible.

Infinite score = 0 kg mass rescue package. Hmmm... are you thinking about just escaping a low mass body using just a jet pack? If so then does this clause:

On 12/21/2020 at 1:17 AM, dnbattley said:

capable of bringing them home

impact that plan?

[joshudson]

On Minmus the jetpack has enough delta V to return to Kerbin from the surface. People are still reporting successful reentries with an EVA kerbal.

[Bej Kerman]

On 1/1/2021 at 8:36 PM, Kerminator K-100 said:

I feel like this is impossible with the stock weight restrictions. Maybe KIS would be a better challenge?

Look at the speedrunning community, everyone who says their run is unbeatable is always wrong. It's rather silly to claim this is impossible.

[Martian Emigrant]

Hi all here is my rescue mission.

Jeb and Bill are stranded on the Mün.

Part ship in Mün orbit.

62m doesn't get better than that for me.

Thanks. See you later.

Plenty of sunshine for the ions.

Nice low circular orbit.

That ain't so hot.

Time to bail

Kerbals always stick together.

Where is that chopper?

 

ME

 

Edited January 12, 2021 by Martian Emigrant

[Kerminator K-100]

On 1/11/2021 at 1:35 PM, Bej Kerman said:

Look at the speedrunning community, everyone who says their run is unbeatable is always wrong. It's rather silly to claim this is impossible.

I may have been a bit too hasty to say this. I have tried out the inventory system some more and it seems much more likely.

[sturmhauke]

4 hours ago, Kerminator K-100 said:

I may have been a bit too hasty to say this. I have tried out the inventory system some more and it seems much more likely.

It's not just likely, it's been done. Twice.

On 1/11/2021 at 4:07 AM, dnbattley said:

Infinite score = 0 kg mass rescue package

= no rescue package sent. I'd argue that with no rescue package, it doesn't meet the challenge requirements. But that's for you to decide.

[dnbattley]

On 1/13/2021 at 1:55 AM, Martian Emigrant said:

Hi all here is my rescue mission.

Firstly: apologies for taking so long to actually comment, but congratulations on the first truly successful submission! An impressively efficient mission demonstrating your process, and well done getting the symmetry on those solar panels looking so good! I know what a pain that can be in engineering mode... 

On 1/13/2021 at 2:35 PM, sturmhauke said:

I'd argue that with no rescue package, it doesn't meet the challenge requirements.

I don't want to derail the thread by inviting legalistic interpretations of my original wording, but in short I agree with this entirely.

[Mikenike]

On 1/11/2021 at 6:07 AM, dnbattley said:

Infinite score = 0 kg mass rescue package. Hmmm... are you thinking about just escaping a low mass body using just a jet pack? If so then does this clause:

impact that plan?

Unfortunately, @joshudson is right..... With the amount of Dv that an EVA pack has, it is possible to return using only the jetpack, but he forgets that he must return both Kerbals on the same ascent to orbit..... He has been required in the orginal post that it must be in a command pod..... While he may try it, I believe that he idea here would not be an accepted score. As for the challenge itself... I cannot do it, as EE is at 1.10 right now.

[Martian Emigrant]

15 hours ago, dnbattley said:

Firstly: apologies for taking so long to actually comment, but congratulations on the first truly successful submission! An impressively efficient mission demonstrating your process, and well done getting the symmetry on those solar panels looking so good! I know what a pain that can be in engineering mode... 

I don't want to derail the thread by inviting legalistic interpretations of my original wording, but in short I agree with this entirely.

Hi.

Thanks.

I have been playing with returning 2 Kerbals from Duna and the "Engineering mode" is a pain for a more complex ship.

The symmetry is a problem. So far (I admit I haven't looked really deep into it) it looks like when you pull a part with an arrow it seems to use local vertical as opposed to part vertical and parts are then offset...

Plus the parts below move as if relieved from the weight of the part being moved. Again compounding symmetry issues. A bigger problem with an atmosphere.

Anyhoo I will be working on a simpler design (Actually I have already but have not try building it in situ). And if all else fail I will try to find some place that is flatter for the build.

 

10 hours ago, Mikenike said:

Unfortunately, @joshudson is right..... With the amount of Dv that an EVA pack has, it is possible to return using only the jetpack, but he forgets that he must return both Kerbals on the same ascent to orbit..... He has been required in the orginal post that it must be in a command pod..... While he may try it, I believe that he idea here would not be an accepted score. As for the challenge itself... I cannot do it, as EE is at 1.10 right now.

Just a comment.

I have reread the original post and there is no mention of a command pod.

On 12/20/2020 at 10:17 AM, dnbattley said:

From this package, craft a new vessel capable of bringing them home

Therefore my decision to use command chairs.

Using a command pod doesn't make it impossible. Just harder.

One could build a command pod tipped ship that makes it to orbit and several refuelling/rebuilding drones that could rendezvous with it.

So a much more complex ship could then be built in orbit.

 

Or perhaps build a command chair thing-a-ma-bob for Duna to Ike.

Then build a command pod ship there for the return to Kerbin.

 

ME

 

Edited January 14, 2021 by Martian Emigrant

[dnbattley]

To clarify I'm happy with lawn chairs, but the kerbals must leave the target body on a vessel which has been created in situ. Whether and when they then EVA is up to the mission planner.

19 hours ago, Martian Emigrant said:

The symmetry is a problem. So far (I admit I haven't looked really deep into it) it looks like when you pull a part with an arrow it seems to use local vertical as opposed to part vertical and parts are then offset...

I have the (unproven) theory that it might be calculating absolute symmetry relative to the VAB: Which is obviously moving in any other reference frame except Kerbin, and meaning "absolute" is anything but...

[Martian Emigrant]

6 hours ago, dnbattley said:

To clarify I'm happy with lawn chairs, but the kerbals must leave the target body on a vessel which has been created in situ. Whether and when they then EVA is up to the mission planner.

I have the (unproven) theory that it might be calculating absolute symmetry relative to the VAB: Which is obviously moving in any other reference frame except Kerbin, and meaning "absolute" is anything but...

That is messed up (The VAB part not the lawn chairs part).

I have been working some more on the assumption that it uses local vertical and local north....

It makes for building mutiparts-homebuilt-spaceships hard to balance....And to fly straight.

I have tried and tested a DIY ship on Duna surface with enough Delta-v to make it to Kerbin.

The trial went well with only one decoupler hanging onto Bill's head for a moment before falling down to Duna.

I will work on doing the deed in one gameplay and come back with a diaporama of the events.

 

ME

Edited January 15, 2021 by Martian Emigrant

[yfmiracle]

I had a lot of fun with this challenge it's my first one., and it was an adventure, the post is a bit long, just wanted to share it with all of you guys. Hope you guys enjoy.

 

Jeb needed to get his 5 star Pilot's license, So he went on a mission with Bill, But they were stranded on Eeloo.

So we sent him an entire Crane equipped twenty foot equivalent shipping container.

 

 

And a Truck!

2D View

Engines on the Bottom for deorbiting

Lower Booster stages

Booster Separation

Low Kerbin orbit

After just 17 short years, eeloo encounter, Hope they don't hate us yet.

Circularization

Landing trajectory

Landing boosters, those are a thing right? Also i love the "shrimp" SRBs, they are adorable.

Landed, with crane intact

Ramp was damaged in transit, fortunately we have an engineer with us.

Jeb mans the crane from inside the lander can

Now Bill builds the ascent vehicle from the bottom up.

Bill worked into the small hours of the morning.

Liftoff!

Once we reach orbit, ditch excess weight

Jeb pondering the efficacy of what was just done.

After a fiery Re-entry

our boys are home

But most importantly, Jeb got his stripes and stars.

[dnbattley]

18 minutes ago, yfmiracle said:

I had a lot of fun with this challenge it's my first one., and it was an adventure, the post is a bit long, just wanted to share it with all of you guys. Hope you guys enjoy.

Incredible! I love the ingenuity throughout this submission: a shipping container, replete with patriotic decals, extra parts and even a crane to assist the engineer? Brilliant! Thanks for sharing it, and I'm glad you had fun with it.

And I also just noticed the reentry speed... crazy!!!

[yfmiracle]

Thanks  you're very kind. I also found an interesting interaction with the attachment nodes and a few interesting quirks.

• Attachment nodes disappearing:  Move your engineer within about ~5 meters of the root part, the nodes will re-appear. Found the interaction while lugging the command pod around.
• Fuel feed priority is largely a mixed bag. i had no say in which tanks were drained first. and fuel lines made no difference for me.
• If a part is slightly too heavy for a kerbal to handle, accelerate towards the ground by jumping  or eva jets can allow you to attach some parts (within reason)
• Broken parts cannot be manipulated. Bring lots of repair kits.