Duna rocket

[Demon of Elru]

I'm at a roadblock, admittingly so I am a poor designer and cannot build a rocket to go to Duna and back. Can anyone help guide me?

[RoofCat]

Duna lander needs just slightly more fuel than Mun rocket. Reduce Mun rocket payload, add dropable tanks instead... something like that.
Kickbacks - Twinboar - Poodle - Dropable tanks should do for 4..5 men plus some science.

Or make it even easier. First chute for Duna, second for Kerbin
http://steamcommunity.com/sharedfiles/filedetails/?id=815826304
If you can't design Duna rocket, how are you going to design one for Moho or Eve? Practice makes perfect. Experiment, have fun.

Sometimes it is a good idea to leave one tank on orbit on arrival. So you have less landing mass and can refuel on the way back. No need to carry return fuel like a dead weight on the part of the trip where it isn't needed, right?

[Farrel]

I've just built my first duna rocket, although I did pay a lot of attention to some good guides online. If you can, I'd really recommend trying to unlock the atomic engine. It doesn't need oxidiser and is incredibly efficient in space (use the fuel fuselage as a tank for it).

Otherwise? Are you familiar with the concept of delta v? As far as I can see, it's the single most critical concept of the game.

[Demon of Elru]

I do have the nuclear engine, so use that instead of the poodle for transfer to duna?

[Yuki]

If you can build something that can land on the Mün and return, you can build something that goes to Duna as well. Only requires more fuel. As a first at least.
Actually the very same vehicle could possibly be able to go to Duna already, just not return (depending on your TWR, but Dunas gravity is also quite low)

-Use droptanks. You dont want to carry dead weight around. Fuel tanks placed in such a way you can eject them. You may want to "enable crossfeed" on decouplers.

-Landing on Duna and returning is about the most easy of all.
Duna has an athmosphere. Even though a vey thin-you can still abuse it to slow down.
A drogue chute helps on stabelizing, for beginners i suggest a generally propulsive vertical landing though, just like on Mün.
Its low gravity and quite low atmo pressure then dont hinder you much to go back to orbit.

-Returning is the more tricky part and you may want to keep your return vehicle in orbit.
You will need a lot of fuel again. How are your docking skills? ;)
Although Duna is easy enough to potentially bring the return vehicle down with you. Roofy will behead you for inefficiency, but its more easy that way. Make it work before making it work proper.
Coming back from an interplanetary will mean a lot of speed. Duna is comparably harmless, but in general: Heat can now potentially become an issue. You will be slightly faster than on a Minmus return.

TLDR: take your Mün rocket, slap on some additional fuel tanks and test it. If you dont have enough fuel: repeat with more.

Edit because of posts while i was typing and my favorite engine got mentioned:
Dont. Do not use the NERV. Not for your first try.
While it is indeed useful for Duna, it will give a beginner more troubles than advantages.
Its high cost, high mass, bulky design. You will want to return it too. And thats where the trouble begins, besides its huge size as well.
Use Terrier instead, they will also be useful for landing. NERV are space engines only for orbit to orbit transfers.

[Farrel]

Originally posted by Demon of Elru:

I do have the nuclear engine, so use that instead of the poodle for transfer to duna?

The nuclear engine (as I recently found out) is super efficient. Especially if you use fuel fueslages instead of fuel tanks. It doesn't require oxidiser, only fuel... So you can really save on weight. Simply put, it's great for upper stages of ships. (yes, try it instead of the poodle)

With 3 or 4 fueslage tanks, you should be able to take a moderately sized ship anywhere in the solar (kerbolar?) system.

Just make sure that your lower stage has enough grunt to get to Kerbin's orbit first, nukes suck in atmosphere.

The second thing is learning how to do an efficient transfer between planets.

Depending on what you consider cheating, you might want to look into installing mechjeb to calculate your transfer nodes for you... Or start reading up on how to do a hohmann transfer.

Personally, I know the principles and -can- make my own nodes, but mechjeb is quicker if you don't mind it being a bit sloppy.

Scott Manley did a pretty good tutorial on that if you don't know how to do it already.

https://www.youtube.com/watch?v=u1SSHWM_phU

[RoofCat]

Originally posted by Demon of Elru:

I do have the nuclear engine, so use that instead of the poodle for transfer to duna?

really don't start your path with Nukes. They are great engines. And have incredible delta v. But you will miss (not learn) a lot that way. Even Moho can be reached with conventional engines, without nukes. Nukes are for lazy people or really advanced stuff. There is a reason nuke is available late in tech tree. Flying with Nukes to Duna is like replacing your local bus lines with Ferrari taxi drivers. Sure it works. But it is also expensive and overkill. I sometimes wish Duna was more like Tylo. So nobody would be able to go there with Nukes. Try to land at 0.8G with those

Also my cheapest Duna lander costs less than 8500$. Single Nuke engine does cost 10ooo$.
I know, there is unlimited cash and science in Sandbox. Doesn't make you better that mode. Go play career instead. Sandbox is the reason you don't know how to build rocket for one of the simplest targets in game yet have Nukes already.

You will need Nukes for Duna SSTO though later on. Again, advanced concepts.


I designed this one for some other beginner with problems a while ago. It is kind of stupid lander. Because such were requirements on forum for that one. Because it uses ~9t payload where all you need is like 4..5t. And still manages to move all that both ways for no reason.
http://steamcommunity.com/sharedfiles/filedetails/?id=879532538
1. never ever use MK1-2 Command pod. It is stupid heavy (4.12t) for just 3 persons. Space flight is all about mass.
2. don't return science stations (3.5t). Just leave them on Duna or orbit. It makes no sense moving them around at all. And honestly you don't need them at all in this game. Plenty of science even without processing. Except you want place for leveling astronauts.
3. you don't need full heatshield returning from many places. Returning from Mun, Minmus, Duna, Eve you need just ~200/800 Ablator on this one (or 50/200 on smaller one). Ablator = Mass. A lot.
You can even do that without any heatshield at all just aerobraking with 2..3 passes at Kerbin higher up. Science cabin (MPL) is a bit heat sensitive, though again - why return it ever in the first place?
4. with just 5t payload you can easily get 5 guys to Duna surface and back with some science stuff. MK1 command pod 0.8t (remove worthless monoprop), Hitchhiker can 2.5t. Size adapter 0.1t. Done. Some chutes, SAS, legs, electricity, science Jr., Goo and other crap. 5t top.

Space flight is all about moving mass.

[Astronaut]

use kerbal engineer redux