Kerballed Duna mission and back, how to plan it?

[Pawelk198604]

My kerbal visited orbit of almost every planet orbit, (Moho, Eve, Duna and even Jool but the on Mun and Minmus is the only place that i allowed them l'm little a bit like overprotective parent, a little bit like mu Mum:D But i afraid that after landing i will not have enough fuel to bring them back to Kerbin, because landing cost considerable amount of dV and i'm rather lousy at math:) And i don't want strand my kerbal in space, it strange but i feel affection to all my crews.

Even IRL nor NASA nor Roscoms made sample return mission from Mars or any other planet of our solar system, because it's so difficult.

But i think about solution than can work for Duna(it's quite long time since i played ksp, due my university study, i started play again after release of 0.24)

I think that i can send fuel tank, a probe with big fuel tank to Duna orbit, than send Kerbals to land on Duna, i didn't know how to build Mars, oh yeah Duna lander:D (thus i'm not know how such thing should look) and after mission the crew(actually i'm) will not have to worry about fuel because it's already here on Duna orbit.

PS. I'm wonder does NASA consider similar tactic for real life mission to Mars?

[hugix]

You can use tools like Mechjeb & Kerbal Engineer to see how much ÃŽâ€-V you've got per stage. Using the wiki pages it's easy to find out what you need per stage for such a mission.

And browsing these forums a lot help to. See how others do their missions give you quite the example of how (not) to perform such a mission.

[Pecan]

Chapter 8 of the tutorial in my signature has a 2-man lander for Duna. Chapters 7 and 8 together cover permanent manned space-stations, interplanetary transfer and lander vehicles. Probably more than you need but should give you some ideas. Without doing much math all you have to do is add up the numbers along the route in a deltaV map.

The lander looks like this:

[capi3101]

I've been to Duna a few times, and you pretty much can do it anyway you want to - either everything in one big shebang or performing various docking missions for whatever stage of the game you're going with. Your strategy (that of leaving a return stage in orbit) is sound and if you want to do it that way you're welcome to do so. Big thing of course is to make sure the final stage will have enough delta-V to get your Kerbals back.

Bit rushed at the moment, otherwise I'd post the numbers.

Largest number of Kerbals to Duna at once for me: 6. Just FYI.

[Guest]

Even IRL nor NASA nor Roscoms made sample return mission from Mars or any other planet of our solar system, because it's so difficult.

Sending Kerbals anywhere in their own solar system is nothing like real life. For one, no life support to worry about. For two, the delta-V requirements are far less.

Your plan of sending fuel first is a good one. FWIW. if you have a lander that can land on Moho and return to orbit you have a lander that can do the same on every landable body save for Tylo, Laythe, Eve, and Kerbin.

[Pecan]

...FWIW. if you have a lander that can land on Moho and return to orbit you have a lander that can do the same on every landable body save for Tylo, Laythe, Eve, and Kerbin.

Moho requires 870m/s for landing and again for re-orbit, while Duna requires 1,300m/s each way. Are you just pointing out that you can save loads on Duna with judicious use of parachutes?

[Pawelk198604]

For now i have to make Duna Probe, i also play Take on Mars, with give my inspiration can i have send probe do Duna with science module and Mystery Goo, using separatron as barking engine?

[cantab]

Yes. Duna's atmosphere is quite thin so you often will need some engine thrust for touchdown, but you can shed the bulk of your speed without them. Just be careful - if you come in fast over high ground your chutes can rip off on fully opening.

[Pecan]

Tweak them to open high ;-)

[Guest]

Moho requires 870m/s for landing and again for re-orbit, while Duna requires 1,300m/s each way. Are you just pointing out that you can save loads on Duna with judicious use of parachutes?

Moho requires 1400m/s each way, according to every delta-V map I've ever seen and personal experience.

E: Interesting. Every delta-V map I've seen has been wrong. 10km orbital speed is @ 800m/s.

Edited August 18, 2014 by regex

[Pecan]

Moho requires 1400m/s each way, according to every delta-V map I've ever seen and personal experience.

E: Interesting. Every delta-V map I've seen has been wrong. 10km orbital speed is @ 800m/s.

I'm using this deltaV map - it says 870 - but at least we're getting to the right ballpark. I seriously thought you were just making the parachute point.

[Guest]

I seriously thought you were just making the parachute point.

Nope, I've always built my Moho landers to make 3000m/s or better. That will get you "there and back again" pretty much anywhere (as noted).

I used GM straight from the Wiki without calculating it myself, so I might be wrong, but 870m/s is probably a good number. That 1400m/s might be from when Moho had an atmosphere...

Edited August 18, 2014 by regex

[Taki117]

Here's how I plan my Interplanetary Missions.

I first visit This dV Map to calculate the rough total of dV I will need to make the trip.

I thin go HERE for some yummy porkchops, and to figure out when my launch window is and how long it's going to take to get there.

I then build my ship and off I go.

[Rusty6899]

First of all you work out what you want to bring back from Duna (i.e. a capsule + any science equipment). I, personally, try to get my Duna lander back to Kerbin without staging as it only requires an extra 500 m/s dV and I try to make my Duna landers fairly wide so that I can mount plenty of parachutes and science equipment on radially attached fuel tanks. This makes staging awkward if you want to return all the equipment.

So you need a lander with ~2000 m/s dV. Design your lander and calculate its total mass, then make yourself a LKO --> Duna transfer stage, with ~1200m/s dV. Then it's just a case of getting the thing into orbit. If you're travelling light, it shouldn't weigh much, 150t is plenty.

[Michaelo90]

I've been confused about that 1400 m/s for Moho too. It's smaller than Duna, has less gravity and no atmosphere, so there is absolutely no reason it would require more dV.