Lightest Vessel to Land on a Moon

[Andrew Hansen]

Hey everybody!

For this challenge you're going to make a craft that is capable of launching from Kerbin, landing on any of the four moons below, and returning to Kerbin with one Kerbal on board. The challenge is to make it as small as possible.

Moons you can go to:

-Mun

-Minmus

-Gilly

-Ike

RULES

• The craft must use only stock parts. Mechjeb or Engineer Redux is allowed for building purposes only, as well as other mods that are simply plugins.
  
• Part clipping is allowed.
  
• You must get the Kerbal back to Kerbin. If the rest of the craft is destroyed, that's fine - as long the Kerbal survives.
  
• You are allowed to "get out and push" your vessel back home if you run out of fuel.
  

To submit your craft, just post below with a link to a .craft file and picture proof that you actually got it to the moon (show it launching, in space, burning for the target, landing, etc.). One of the screenshots must show a readout from Mechjeb/Engineer showing the entire craft's weight, including any stages you used to bring it into orbit (not including launch clamps). If you could write a bit about your craft, too, that would be great.

That's it! Hope you have fun doing this challenge.

HIGHSCORES

Mun

1. Jebediah's Bicycle by Andrew Hansen - 2.868 tons
   

Minmus

Gilly

Nobody yet!

Ike

Nobody yet!

SPECIAL MENTIONS

• Voodou's Lander - 1.27 tons (didn't include ascent or transfer stages). Although it doesn't quite qualify for the challenge, it is quite an achievement to land on Minmus from orbit and return to Kerbin with a 1.27 ton craft!
  

Edited December 4, 2013 by Andrew Hansen

[Johnno]

You will have 48 hours to build your craft (submissions will be closed on Wednesday, at 15:00 Alberta time).

I would suggest removing the deadline alltogether. A lot of challenges take time, not to mention many players can't get enough playtime with such a short constraint. I'll be making an entry myself, hopefully, but I'd still like to point out that an open challenge draws more people and may well continue further if the competetive spirit is sparked by people improving their designs to beat others'.

Oh and below 1 ton Mün mission isn't feasible, even a unmanned one takes slightly more than that (if memory serves the current lowest mass to kerbin orbit record is 1.075 tons).

[Andrew Hansen]

I would suggest removing the deadline alltogether.

Thanks for the feedback! I removed that from the OP.

[ttnarg]

Would of liked it better if we could pick which moon but thats just me. I'm happy to aim for Mun. Will give this a go tonight.

(my last craft was over 2500 tons I'll try and make this one a little lighter. http://forum.kerbalspaceprogram.com/threads/57197-THE-ULTIMATE-JOOL-5-CHALLENGE-land-Kerbals-on-all-moons-and-return-in-one-big-misson?p=789853&viewfull=1#post789853)

Edited November 19, 2013 by ttnarg

[numerobis]

Almost there, about 200 m/s short. And, I know exactly how to increase by 200 m/s (and save 30kg while I'm at it) -- drop one of my two LV-1s. So, 2.49t should work.

1.78t first stage: jet, smallest jet fuel tank (of which I used a quarter; it would be nice if there were a smaller tank), 8 intakes.

0.713t second stage: FL-T100, 2x LV-1R, pod and seat, solar panel.

------

2.493t

0.09t Kerbal.

My path was a standard jet launch, apoapsis to nearly 230km and periapsis fairly high. Burn there to push periapsis to 70 km, burn at periapsis to get to 70000 km, adjust the periapsis to 11400 km (a mistake, by the way: that ensures your encounter has you going through the core of the Mun -- best to keep Pe a bit lower), retro burn at periapsis and land. But I used MechJeb to land, rather than implementing Kosmo-not's video. My loss.

Jump out, stretch legs after spending a few months in deep space during the bielliptic transfer, and fly back out. This time I did use Kosmo-not's method (in reverse), carefully calculating the angle I needed to keep in order to go upwards. I hit a mountain the first time; reloaded and flew a tiny bit steeper the second time, and got to a 600km Kerbin periapsis. A 20 m/s burn would get me in the atmosphere. I'd still need to survive the landing, too, which would require burning everything I can on landing. I do notice that survival isn't explicitly in the rules, though...

Edited November 20, 2013 by numerobis

[GuzWaatensen]

i have a vessel at 2.1 (which is still too much btw. still some fuel left) but unfortunately it doesn't really belong in this thread but rather in the forgot parachutes confession thread....

I'll post again once i've actually laded the thing....

[tavert]

I did it in 2.022 tons (not counting the Kerbal) a few versions ago, and with MechJeb flying: http://forum.kerbalspaceprogram.com/threads/39106-Exploiting-quirky-ladder-physics-to-get-to-the-Mun-and-back-in-2-022-tons

You can do it in just under 2 tons now using a 48-7S, FL-T100, probe, decoupler, a few intakes, and a jet. If we get tweakables in the next version, using a few round-8 tanks without oxidizer might allow you to go a little bit lighter.

@Johnno orbit is doable in 0.8 tons (or even lighter by exploiting infiniglide), go a few pages later in that thread you linked (using parts that were from KSPX at the time I posted, but are now stock - and have even more thrust than they did in KSPX).

Edited November 20, 2013 by tavert

[numerobis]

My spacecraft needs an extra 70kg actually, come to think of it: the single ant isn't enough to slow down the Kerbin lander, so I'd need the 48-7S. Unless I lithobrake on cubes for 50 m/s. I had avoided that engine because it was too powerful for the Mun landing.

[Johnno]

@Johnno orbit is doable in 0.8 tons (or even lighter by exploiting infiniglide), go a few pages later in that thread you linked (using parts that were from KSPX at the time I posted, but are now stock - and have even more thrust than they did in KSPX).

Yeah I wasn't counting infiniglide to begin with, from what I remembered the lighter than 1T entries were with FAR installed. I had a quick poke just now and 0.826T wasn't too much of a hassle to get into orbit, below that it was a bit iffy (couldn't be bothered keeping at it).

[Andrew Hansen]

Just a quick update.

Recently I've been busy with the BSC: Kerbal X challenge, but I'm going to make a submission pretty soon (tomorrow?). I already have the basic craft made (a heavily tweaked version of what you see in the OP). I'm glad to see there's been some more activity on this thread!

I did it in 2.022 tons (not counting the Kerbal) a few versions ago, and with MechJeb flying: http://forum.kerbalspaceprogram.com/threads/39106-Exploiting-quirky-ladder-physics-to-get-to-the-Mun-and-back-in-2-022-tons

Great job tavert! That's truly astounding. I learned some important things from your thread, like using a powered landing to slow your descent rather than a parachute.

Edited November 21, 2013 by Andrew Hansen

[Andrew Hansen]

Yesterday I said I might post my submission today. I was really hoping to, but unfortunately the design I had proved to be very difficult to fly with such marginal delta-V levels (I'm sure Mechjeb could do it). Therefore I will post my submission really soon. Meanwhile, here's the basic craft I'm going to use (plus or minus some intakes or fuel tanks).

Basically, I had enough fuel to land on the Mun, orbit, and then achieve escape velocity - but not enough to lower by periapsis below 1,500,000 m. That had to be done by taking my Kerbal and pushing the spacecraft. After completely emptying the EVA pack, the best encounter I had was a 63,000 m periapsis. After several aerobrakings, however, I got a Mun encounter that set me totally off and made the mission a failure. It was a pretty hair-raising experience!

[Andrew Hansen]

Here's my entry for the challenge. I call it Jebediah's Bicycle.

My craft weighs 2.868 tons. Below is a video of me doing the whole mission, and an Imgur album for those of you who'd rather view that.

Download link for "Jebediah's Bicycle.craft".

Javascript is disabled. View full album

Edited November 22, 2013 by Andrew Hansen

[Andrew Hansen]

Since I see that no one has yet made any submissions besides me, I want to encourage you all to by showing you something you can use to make your submission lighter than mine. You can use infiniglide.

In case you don't know, infiniglide is a feature (or bug) of Kerbal Space Program's current drag model that causes control surfaces to create thrust rather than drag when they turn the craft. This thrust can be more than enough to power a glider to supersonic velocities.

Since control surfaces are very light, many of them can be added and the infiniglide bug/feature can be exploited as the primary source of propulsion while still in the atmosphere.

[Andrew Hansen]

Hey everyone,

I really don't want this challenge to die, so I've decided to do something about it. The rules are now changed. You are allowed to build the lightest moon lander and send it to any of these four moons:

• Mun
  
• Minmus
  
• Gilly
  
• Ike
  

Have fun!

[darkfall13]

I too don't want to see this challenge die... I've been working since it was put up, man it's hard to build small things!

[Andrew Hansen]

I too don't want to see this challenge die... I've been working since it was put up, man it's hard to build small things!

I wish you luck! Don't worry, since nobody else has made submissions for other moons than the Mun, you can still be in first place even if your craft isn't the smallest one possible. My Mun craft wasn't!

[Voodou]

Hi! I'd like to know is docking allowed?

[Andrew Hansen]

Hi! I'd like to know is docking allowed?

By all means! Yes, docking is allowed.

Edited December 4, 2013 by Andrew Hansen

[Voodou]

Cool! I'll start to write up my journey to Minmus and Gilly!

[Voodou]

Well I made a trip to both Minmus and Gilly on the same ship, the actual lander weighed 1.27 tons with a full RCS and fuel tank, and this is its story!

I wanted to make a lander that would detach from the actual space craft to land on a planet and return by getting into orbit and rendezvousing with the spacecraft later on.

Early prototypes were... Distressing

But nevertheless we refused to weld parachutes into our Kerbals heads and made a much better design!

And it was ready to launch!

And launch we did!

After getting into orbit with a small amount of fuel left for the skipper engine, I started my burn for an encounter with Minmus with the little fuel I had left in the Skipper and the Massive amount for the poodle engine.

and after getting in orbit with Minmus, Melvis bravely detached himself from the craft to get his landing on the moon Minmus

And Melvis, still being as brave as he could be, started to burn for his landing on the moon!

He succeeded! With just enough fuel and RCS to get into orbit around Minmus without having to push.

Sadly my burns didn't get me into an encounter with the craft, so Kerbal Command took control of the spacecrafts computer controls and went for an encounter with the lonely Kerbal.

But when we got to the lander... The Kerbal was floating? He then disappeared whenever I tried to leave the seat... It kept doing this over 5 quick saves and stopped when I uninstalled the Interstellar mod for some reason.

But nevertheless our space tug proceeded to pull our Kerbal back to his craft!

And we refueled our lander for our next journey

And after waiting a god awful amount for the phase angle to Eve, I started my burn and easily got into an escape trajectory.

And then had to ditch the poodle engine (sadly)

And then got our Kerbal his encounter towards the mysteriously toxic planet!

And thankfully the dense atmosphere got us into orbit without using any fuel.

He does not look pleased.

and after getting my orbit with Eve, I burned to change my inclination and got an encounter with Gilly... A weird one

and started my landing which was MUCH easier than the landing and takeoff from Minmus

And after taking off and docking with the spacecraft (I forgot to take pictures, I concentrated too much on docking ) I waited in orbit around Eve for the phase angle to return to Kerbin, and got myself an escape towards the solar system!

We're coming home!

And after our long trip, we finally started to land!

And funnily enough this was my first interplanetary mission with a Kerbal that involved landing somewhere that actually went well!

And after that, I loaded the lander craft onto the launchpad, put a Kerbal in it and took a screenshot of the weight.

This was fun

[Andrew Hansen]

Well I made a trip to both Minmus and Gilly on the same ship, the actual lander weighed 1.27 tons with a full RCS and fuel tank, and this is its story!

Good job Voodou! I'll put a note beside your entry because you used a very large transfer and ascent rocket which I'm sure you don't want to be part of the weight. Your Minmus landing was very impressive! I'll say that you were able to use a craft weighing 1.27 tons to land on Minmus and return to Kerbin (I know you could do it with the rest of the RCS and a bit of pushing), even though you didn't do that.

Just for future clarification, however, the challenge is to make the whole ship as light as possible - the ascent stage, any transfer stages, etc. I'll update the OP.

Voodou, if you want to, maybe you could add a jet-powered ascent stage to your lander, remove the parachute, RCS, and docking port, and if necessary add another fuel tank to give you the extra Delta-V to make the burn for Minmus from LKO and come back.

When we're talking about heading off to Gilly, docking might be a good choice. For that, I think you can just add a jet-powered ascent stage to your transfer stage, and then I'll include the total weight of your whole craft in the original post.

Edited December 4, 2013 by Andrew Hansen

[Voodou]

Good job Voodou! I'll put a note beside your entry because you used a very large transfer and ascent rocket which I'm sure you don't want to be part of the weight. Your Minmus landing was very impressive! I'll say that you were able to use a craft weighing 1.27 tons to land on Minmus and return to Kerbin (I know you could do it with the rest of the RCS and a bit of pushing), even though you didn't do that.

Just for future clarification, however, the challenge is to make the whole ship as light as possible - the ascent stage, any transfer stages, etc. I'll update the OP.

Voodou, if you want to, maybe you could add a jet-powered ascent stage to your lander, remove the parachute, RCS, and docking port, and if necessary add another fuel tank to give you the extra Delta-V to make the burn for Minmus from LKO and come back.

Ah okay, I thought it was just the lander which needed to be light, not the entire craft. I might have another go later to see if I can make the craft as light as possible and get to Minmus, I have a few ideas still

[billehoj]

Is it okay that i make an entry tomorrow

?

[Andrew Hansen]

Is it okay that i make an entry tomorrow

?

Sure! You can make an entry whenever you want. If nobody posted anything on this thread for a month, then if you posted something it would be known as "necroposting." But since this is an active thread (as of this reply's posting date), you can post even a few days later.

Edited December 15, 2013 by Andrew Hansen

[darkfall13]

Is this challenge still moving forward with the new update?