There and back again (again)

[Quaaraaq]

Going to Mun is easy, returning is a tad more difficult, but can you go back to Mun again after returning to Kerbal? how many back and forth trips can you achieve?

[Kosmo-not]

In my opinion, returning is the easiest part of the trip.

[Gojira]

Back and forth fifty times.

I win. 8)

[Quaaraaq]

Back and forth fifty times.

I win. 8)

in one flight? i doubt that

[Kosmo-not]

in one flight? i doubt that

You could edit an engine\'s config file for no fuel consumption.

[Quaaraaq]

You could edit an engine\'s config file for no fuel consumption.

Then lets say stock parts only, can anyone make it back to Mun after re landing on Kerbal?

[Caesar15]

Then lets say stock parts only, can anyone make it back to Mun after re landing on Kerbal?

you know if you used a refueling plugin that dosent esist

[scotty]

i can always get to the moon, but never land D:

[sneakeypete]

To complete this challenge one must create a spacecraft that can land on kerbin with enough fuel to enter orbit again, if you can\'t do that you won\'t be able to do it and go to the moon aswell, so i\'d suggest that be your first challenge.

Honestly, i\'m not particularly interested in trying to create such a rocket, but its probably doable.

[EpicFishFingers]

I\'m currently doing this on Reddit, before i found out about this challenge. Using stock parts and an old C7 pack. A bit unfair, but meh.

I was partially successful... http://www.reddit.com/r/KerbalSpaceProgram/comments/qztci/tried_going_to_the_mun_getting_back_then_taking/

Trying again now

[Majiir]

I\'ve been working on this using stock parts.

My concept involves using a space tug for the high delta-V maneuvers. The main ship launches into a low Kerbin orbit, and from there a tug boosts it to the Mun. After entering Mun SOI, the tug maneuvers both ships into a low/medium (<100km) orbit, burns hard retrograde to reduce the orbital velocity of the lander as much as possible, and then burns prograde again to maintain an orbit.

Switch now to the lander, which has a full half-tank of fuel. In my tests, I can perform the powered Mun landing and just barely launch back to a low Mun orbit (20-25km). The tug meets up with the lander and burns on a Mun escape trajectory. (If you do it right, you\'ll be on a deorbit trajectory when you re-enter Kerbin SOI.) The tug either burns to stay in orbit or lands.

Now, for a simple Mun-Kerbin mission, this is pretty inefficient; the tug is a good bit larger than a Mun lander. But when you want to go to the Mun and back twice, it looks a lot better. The first step is to minimize the design for the round-trip Mun mission, but my approach of late has been a little more demanding on the design. I wanted a decoupler below the capsule because otherwise the crew will die when doing a water landing, and I wanted an ASAS to make docking and landing easier. (I might drop the decoupler requirement since the tug can maneuver the ship into a KSC landing.)

Now, step backwards. That ship, launch vehicle and all, needs to be able to land on Kerbin. That means lander legs and parachutes, and as I found out the hard way, more weight and a launch vehicle that no longer gets you into orbit. So this is where I\'m going back to the drawing board.

Orbital rendezvous and docking has become trivial for me, so I\'ve been trying some trickier moves, like ballistic rendezvous and aligning launch windows for an 'instant' rendezvous. I might also try capturing a craft in Kerbin orbit and carrying it down on a landing platform.

It may be possible to accomplish this without using any tug ships, but you\'d need to design a ship which can, in reverse order:

• 
  [li]Land on Kerbin[/li]
  [li]Leave Mun SOI for Kerbin deorbit[/li]
  [li]Launch from Mun into orbit[/li]
  [li]Powered landing on Mun[/li]
  [li]Transition from lunar injection to stable Mun (de)orbit[/li]
  [li]Translunar injection from Kerbin orbit[/li]
  [li]Launch into Kerbin orbit[/li]
  

...all while carrying a ship which can, in turn, do all of those things. The delta-v requirements are high, but the landing weights are enormous. You can land a Mun ship on Kerbin pretty easily, but take that, add enough fuel to launch from the Mun and get it back to Kerbin, and then give it enough fuel and thrust to deorbit and perform a powered landing on the Mun. (Remember, no aerobraking.)

So yeah, I\'m going with tugs. The total launch mass may not even increase much since the tug is responsible for a significant portion of the delta-v, but its thrust requirements are low. (My light and medium tug designs use just a single landing engine; I expect the heavy tug will do the same, as long as it\'s only performing orbital operations.)

[gabyalufix]

A few patches ago, I did a single-craft mission that:

(1) Launches from Kerbin

(2) Lands on the mun

(3) Launches from the mun

(4) Lands on Kerbin

(5) Launches from Kerbin

(6) Lands on the Mun

(7) Launches from the mun

(8) Parachuted water landing, on kerbin, just off the KSP coast.

Used a bunch of mods, as is my wont. Mostly Nova/novapunch and KW\'s stuff.

I wrote a quick explanation here

And a photo album here.

It was basically several ships, stacked on top of one another. It holds my personal record for most total delta-V in a single mission.

It was a huge pain. Pre-persistence: whenever I lost a craft several stages in, I wanted to cry. Also, this was before the folding landing legs with suspension, so the landing legs would all snap off if you landed at more than 1 m/s in a big craft.

[Rascal Nag]

I may try a tug as well, if I get around to this. Probably will have it so the tug stays with the ship and then parks in lunar orbit, because I want to be able to fit the lander in a SpaceJanitor-like thing easily. Only problem is making sure the things don\'t slip apart, I\'d have to have them separate after the initial injection burn, then warp, then rejoin as they near Munar periapsis, then enter an orbit, then carefully exit and land. Then do the same thing again, but backwards.

Will be an adequate test of skill.

[Majiir]

I may try a tug as well, if I get around to this. Probably will have it so the tug stays with the ship and then parks in lunar orbit, because I want to be able to fit the lander in a SpaceJanitor-like thing easily. Only problem is making sure the things don\'t slip apart, I\'d have to have them separate after the initial injection burn, then warp, then rejoin as they near Munar periapsis, then enter an orbit, then carefully exit and land. Then do the same thing again, but backwards.

Will be an adequate test of skill.

You definitely need to separate before warping. I met in low Kerbin orbit, then again near apoapsis to boost periapsis, then again near periapsis after entering Mun SOI. (I was on an escape trajectory at this point.) Rendezvous is time-consuming, but if you\'re close enough to maneuver with RCS, it\'s pretty fast. You need to give yourself time to dock before you reach your burn target, though. I find I can do a full Mun mission with a reasonably heavy craft using less than one RCS tank; it just takes some care with the controls. (Precision mode is your friend.)

[Finrandojin]

I\'ve been working away at doing an all stock single craft Kerbin-Mun-Kerbin-Mun-Kerbin, and after a solid week of failures I\'ve attained partial success, My craft was able to get as far as Kerbin-Mun-Kerbin-munar orbit, ran out of fuel after attaining a roughly circular 15 x 18 km orbit, need to optimise my trajectory and maybe tweak the craft a little but I\'ve got a feeling it\'s not far away.

[edit] attached to this post is a craft file that is capable of Kerbin-Mun-Kerbin-Mun-Kerbin trip, requires a good computer as the first two stages are a slideshow for me.

[boolybooly]

Here is a stock ship doing the mission. I took some liberties with making the video, mixing footage from a couple of attempts only one of which was actually completed. So the video does not show the initial Kerbin orbit which lead to the successful completion by conserving enough fuel to make it possible. The straight climb shown used too much fuel because this craft initially has a thrust to weight ratio on the low side. But it does show how the craft stages to good effect and keep the vid short (6 mins) as there is a lot to pack in.

I used making this vid as an opportunity to try a trial version of Cyberlink PowerDirector and so please forgive the 5 seconds of intrusive water mark at the beginning and my tinkering with gratuitous transitions and some crude animation. I made and uploaded it as an 1080p HD MPEG4 to see how that worked as well, so at least HD is available.

Enjoy!

http://youtu.be/sPJYljAaomQ

[SunJumper]

Bravo!

Can you do this with the Min?