I need to bring this lander to the Mun and back, help!

[little frank]

Hey there!

After all my munar landings I finally decided to start rescue missions for all those guys I got stuck on the Mun.

Here is my noob problem:

I have no idea how to dock, so refueling in orbit is still not an option for me.

I made this

http://imgur.com/a/gWewk#1

Lander wich I consider essential and minimalist.

However, no matter how many tank/engine/booster combinations and designs I tried, I still have a hard time bringing enough fuel in orbit and beyond.

Can you guys help me with the construction of a smart-designed rocket that can accomplish this "crazy" task?

Have a nice day!

[Francesco]

it's not essential, nor it is minimalist

no problem putting it into orbit with an adequate rocket, though.

the question is, do you need to bring that specific lander to the Mun, or just a generic 3-seat lander?

also, does your lander fire its engines to transfer from Kerbin to the Mun, or does it need to be carried there with full tanks?

[Specialist290]

Instead of a Hitchhiker Container, consider another large fuel tank, linked to the others by fuel ducts. Then stick a small probe core under that top parachute, and launch your lander unmanned. The probe core will provide the control, and the empty seats can be filled by the kerbalnauts you rescue once you're on the Mun. You'll also have to add a power source (solar panels or RTGs) to keep it active.

[Psycked]

Are you using the poodle engines? maybe try 2 or 3 nuclear engines, those burn forever.

[Atanar]

I would redesign your lander, it's way too heavy for what it's supposed to do. How many kerbals are on the Mun?

A lander like this would already be enough to bring back 3 kerbals:

(there is a generator clipped inside, I also forgot the fuel lines from the outer tanks to the inner one)

Edited May 14, 2013 by Atanar

[little frank]

You guys are amazing, I learned so much in a few posts!

@Francesco I would love to make my second stage last for as long as I can, just to make sure I can go around on the Mun with enough fuel to move around on the planet and rescue as many as I can.

[Logan.Darklighter]

One thing you can do in regards to building a rescue ship is to start with a probe body instead of a manned capsule for the "core" of your ship. Go ahead and use a standard capsule (or capsule + hitchhiker container to rescue however many kerbals you need to) but if you launch un-manned, then that's that many more seats available in the ship for stranded Kerbals to use to get home!

Alternatively, you could set it up so that you have ladders reaching all the way to the ground and before lift-off, remove 2 of the 3 Kerbals in a standard pod for small rescue operations.

[capi3101]

I agree with pretty much what everybody else has said; you've got a lot of unnecessary lander. Atanar's design would work well. Be sure to start off with a probe chassis on top, that way the Command Pod stays empty for the trip. For the booster you probably could get away with two stages each with a couple of FT-800s, an LV-45 in the center and LV-30s on the sides (say six or so; I'd have to do the math to be more specific). Run fuel lines from the exterior tanks to the interior, add a couple of winglets to the outside and that should do it.

[EndlessWaves]

You guys are amazing, I learned so much in a few posts!

@Francesco I would love to make my second stage last for as long as I can, just to make sure I can go around on the Mun with enough fuel to move around on the planet and rescue as many as I can.

You get much more range for the same overall weight by using smaller fuel tanks and decoupling them one or two at a time because you're pushing less dry mass for most of the journey.

Obviously the shifting geometry means it's harder to attach a lifting rocket and landing legs too but it's often well worth trying the lighter approach before resorting to brute force and attaching all your fuel in one lump with no staging.

Your lander gives you 3334m/s DeltaV and a TWR of 10 (the latter is a little on the high side for manual landings). Total weight is 55 tons.

[Kegereneku]

I've got several question before I can answer you.

- Where does your lander design will start from ? Earth Orbit ? Mun Orbit ?

- Do you intend to pick-up Kerbun at different place in the same flight ?

- How do you feel about low thrust landing ?

The reason I ask you this is that each point require special consideration.

- If you start from Earth's orbit, assuming 3334 m/s of DeltaV, you 'll use fuel like this : ~800 for TLI, ~200 for Mun orbit insertion, ~640 for each landing, then around the same for ascent and 200 for going back to Earth (with aerobreaking).

- If you need pick up at different place, you'll need more fuel, and have to do suborbital hop to save some fuel on the ascent. You may need more than one rockets.

- Last, you can double your DeltaV by decreasing the number of thruster. You'll keep more than enough acceleration to land on the mun, but it will be harder to shed velocity.

tips : put some lamp on your ship if you are landing by night.

Edited May 16, 2013 by Kegereneku

[Logan.Darklighter]

I've got several question before I can answer you.

tips : put some lamp on your ship if you are landing by night.

I want to repeat with emphasis here - spotlights on a ship is almost essential these days. It used to not matter in the earlier versions of KSP because your spacecraft would be lit by the sun no matter where it was. But now that they've modeled shadows and bodies blocking sunlight accurately, it has become much more important to have lighting. Both for docking purposes and for night operations planetside. If you're building a space station, you should place lights so that they'll illuminate the docking ports and areas around them. On a ship that's landing on the dark side of a planet, it becomes nearly impossible to see where you're going or how high up you are without lights.

One trick that Scott Manley has pioneered is placing the small batteries (that almost any space station is going to need anyway) all around a docking port. These batteries have a prominent glowing green LED style light on them. Place four or more of them around a docking port and even in poor lighting situations it'll help you line up your docking immensely.

They can really help with finding easter eggs too in some situations. There's at least one "Anomaly" on the Mun that you're almost going to HAVE to have a spotlight to find ---

[Hyomoto]

- If you start from Earth, assuming 3334 m/s of DeltaV, you 'll use fuel like this : ~800 for TLI, ~200 for Mun orbit insertion, ~640 for each landing, then around the same for ascent and 200 for going back to Earth (with aerobreaking).

Unless I haven't zoomed out far enough, I'm fairly certain it's impossible to fly from Earth to the Mun.

[Kegereneku]

I meant Earth's orbit.

[Ben Kerman]

I meant Earth's orbit.

He probably means that you should differentiate between Earth (as you know, the planet you are sitting on right now) and Kerbin (the planet you crash most kerbals on).

[little frank]

How did you calculate the delta V of my lander?

[little frank]

Damn, that was a hard answer with hard questions...

I am planning some rescue missions, it's not that I need that specific lander, It's just that the design looked "smart" (with no calculations of any type made AT ALL, because I have no idea where to start with that stuff, let's just call it "cool").

So what I need is a lander that can:

- get around the Mun

- land (possibly near someone to rescue!)

- go around and save a couple more green demsels

- go back to Kerbin and bring them home safely!

And why not, I would love to understand a bit more of mass/thrust ratios and the relation with delta V.

In the meantime, I will be just throwing stuff in the sky and still be amazed if I can actually accomplish anything at all

[gilflo]

Here 2 of my landers, fully equipped with ORDA mechJeb, HydroTech RCS, photovoltaic panel and so on.... You can see the total Mass of each and the TWR on the jun.The lightest 11tons, the heaviest 44 tons

I chose this 4 tanks around main one configuration because it makes landing very easy. There is only one engine on the main tank, with cross feed. Best for balancing and steering, lighter than a 4 or 5 engines config, you can even separate the 4 tanks if needed.

They are able to land to the mun and take from the mun for a refueling, assuming you arrive in orbit on a main Rocko max tank and separate this one during de orbiting.

[EndlessWaves]

I used the Kerbal Engineer Redux mod to show DeltaV but that lander is a single stage with identical engines in vacuum so it would be trivial to do it by hand, it's simply 9.81 * ISP * Log_n(Fuel weight / total weight).

EDIT:

I'd go for something like this:

It's around about 20 tons and as you can see you get at least as much DeltaV as your original lander for much less weight. It has one less seat, but it does come with a probe core so you can send it over unmanned and still rescue the same six kerbals.

The complete ship I used looks like this:

The launcher isn't brilliant, it's a reasonable weight (77 tons) but could do with another tank or two of rocket fuel and another couple of jet engines as it doesn't quite go as far as I'd have preferred, but it does the job (and looks sufficiently kerbal). You may need to redesign it to be a bit larger if you want to add lights and batteries to the lander rather than waiting for daytime, but it should give you some idea of size.

Craft file of complete ship (doesn't contain mechjeb or engineer):

https://skydrive.live.com/redir?resid=384BA28C8578E539!160&authkey=!AKoXNnPUW8c60Ro

Edited May 16, 2013 by EndlessWaves

[Kegereneku]

Damn, that was a hard answer with hard questions...

I am planning some rescue missions, it's not that I need that specific lander, It's just that the design looked "smart" (with no calculations of any type made AT ALL, because I have no idea where to start with that stuff, let's just call it "cool").

So what I need is a lander that can:

- get around the Mun

- land (possibly near someone to rescue!)

- go around and save a couple more green demsels

- go back to Kerbin and bring them home safely!

And why not, I would love to understand a bit more of mass/thrust ratios and the relation with delta V.

In the meantime, I will be just throwing stuff in the sky and still be amazed if I can actually accomplish anything at all

Sorry if I was being a little too engineers, I suppose it's what happen after years of Orbiter and KSP.

Looking at your first design, your lander should be perfectly able to do the jobs. You just have to put it into orbit without using too much of its Dv. (and put some light, long range pointing at the ground !)

It will not be really efficient. But can be a good things. Your design should be pretty forgiving.

For the "go around part", I'm not sure you will be able to do many sub-orbital "jump" after landing (it's more efficient than hovering or getting back into orbit).

But this is nothing you can't try with a quicksave ready. Keep at least 600 m/s to get into orbit then back to Earth with Aerobrake.

The relation between Thrust/Weight Ratio (TWR) and the deltaV can be simplified like this :

- More engine = Better Acceleration

- More engine = Less DeltaV

You could have more DeltaV using less engine (like one Poddle in the center) but then it may be harder to shed velocity before landing.

[little frank]

Okay, that was very clear!

I could not understand some of the replies here but yours was really good.

Thanks eveyrone, I will keep trying!

it would be trivial to do it by hand, it's simply 9.81 * ISP * Logn(Fuel weight / total weight)

:okay:

That is the part that discourages me when building rockets.

About MechJeb and other mods, I like to keep the game vanilla because I feel like I should learn more stuff before starting to use gameplay influencing addons.

I am using a few addons like the B9 pack and other stock-like parts because they will most likely be in the game anyway in the next update or two.

Have a nice day!

[little frank]

Okay I learned from all your responses and completely changed my plans and (thanks to some redditors too) I managed to get better at piloting and optimized the design A LOT.

So here is how the rescue mission turned out!

http://imgur.com/a/ZLkbC#0

Thanks everyone, you have been my ground control all along!

Now I will keep using this rocket design to rescue all of the remaining kerbals that are not "busy" in my Mun base (and here is my base, I'm very proud of it http://imgur.com/a/WT5bP)

Have a nice day!

[Iren]

I've been able to send your lander to the Mun, but I got a lil short of Delta-V for a return trip (nothing that some SRBs at the launch stage can't solve ), had to turn on the lander Poodle's to be able to reach orbit. Also, added some RCS tanks and ports because it was going to be a hell to control.

[Cdr_Zeta]

Hi,

Not to be a bugger - but first off - Earth is not part of this game literally speaking. In roleplay maybe; which in fact I am doing and including Earth ! We need to keep our names straight.

Doing rescue missions...a rescue mission, in my opinion, is just that...rescuing cause someone needs help. That may or may not have been the case here; if you feel guilty about leavin yer Kerbal buddies away for too long; then ya it's probly a rescue and you will catch double hokki stikks for waiting so long.

Normally missions are planned such that time frames are adhered to, or Kerbs die; of course we dont want that to happen.

Now anyone can do any thing they want and play the game any way they want to make them happy; this is just my take and mine alone and how "I" would 'play the rescue ops.

I would not use items that are normally used for other things besides rescue; like those hitchhiker pods. I know I know...they can be used for whatever; and I will probly even use them as a rescue once in a while; it just isnt the norm for my Kerbals and here is why.

Those pods are habitat pods not for transporting; in general (my gameplay mind you!); because we are all new and the game is new and our Kerbs are new, well they can make decisions too; and if they want to use those hitchhiker pods to rescue many Kerbs at one time; possibly.

The problem is that they are bulky, probly heavy; etc.

I would consider a rescue to be rescuing only one Kerbal at a time. Meaning maybe do several trips in small(er) pods and bring them back to a hitchhiker pod in orbit; this might be acceptable. For me it isnt a question about quickness or efficiency (I dont think, even tho efficiency plays a part too); it is about safety.

Your rescue team and equipment have to be better than the average ships, and withstand more damage; they arent out there for their fame and glory; they are there to bring fame and glory back home.

I would say that with the posts etc that you have done well to have accomplished your mission(s).

Also for me, looks is playing a big part in this game, and I still have a long ways to go balancing looks with efficiency!

I have yet to go to the Mun etc in real missions; and I hope to get krakken soon. I stream all my missions; for the last month or so all in the Kerbin Academy SIMULATOR; now it is time for me to make it 'real' - just as you are doing.

As for docking and lights etc...good luck to all of us...I am gaining slow but sure !

Cdr Zeta

Edited May 20, 2013 by Cdr_Zeta

[little frank]

Ahahah congratulations!

Now, that's one huge ship!