Duna and back again.

[FREEFALL1984]

So here's the situation, I have recently designed a craft to reap the sciencey benefits of a dunan landing on my currrent career, Its comprised of a nuclear tug, with about 8k DV unloaded, a 15 ton lander/lifter combination, and a 10 ton rover. my Dunan lifter has about 3k dV total and my rover is retrofitted with rockets for an assisted landing with a total of about 1050m/s dV, All these components are currently in orbit over kerbin waiting to be assembled.

So here is my issues

Firstly I have too many kerbals aboard my station, I have 1 in my rover, which I didn't even realize was aboard when I launched. I have 3 in my MK1-2 command pod, and I have Jeb in my dunan lander lifter waiting for the duna transfer window. My intention is to just send Jeb to duna, should I perhaps allow one of the kerbals to reenter kerbin with his EVA pack, or should I rescue him.

Also I have since decided that I need more science. My rover has all the basic sci junior and goo, thermometer and barometer, same as my lander. problem is I only have a single pod with which to store the science gathered on my roving missions. as my rover itself will remain on the surface So I ask, how can I best retrieve science from Duna. and when I say retrieve, I mean for return to kerbin. My original thoughts where a fleet of unmanned mini rockets with enough DV to leave dunan sands and fly back to kerbin at every launch window

Also can anyone suggest a good way to get my landing sites within a few KM of each other as I'm not looking forward to the drive lol

[el_coyoto]

I quite like the idea of unmanned drones tugging back sweet, precious science to Kerbin while the Kerbals are having fun exploring.

For precision landing, you have several options.

1. Luck : using quicksave/quickload, rinse, repeat. Not very rewarding.
   
2. "Drop like a stone" : very inefficient, but you could reduce you orbital speed to 0 right over your target, then drop like a stone onto your landing site, using your projected orbit to aim for it. Again, highly inefficient.
   
3. "Atmosphere shmatmoshpere" : you could do a more reasonable de-orbit burn (periapsis above your target), keeping some forward velocity and killing it precisely over your landing site, just like a Munar landing, basically treating Duna atmosphere as nothing more than a nuisance. Slightly less inefficient than the previous one.
   
4. If you like sliderules and charts, there is an awesome resource that tells you "if you come at that speed, by putting you PE at this height over your target, you will be aerobraked more or less onto your target" (version for Duna is here).
   
5. If you don't mind using mods, MechJeb has a very good landing prediction that takes the atmospheric drag and the planet rotation into account.
   

Hope this helps!

[FREEFALL1984]

If you don't mind using mods, MechJeb has a very good landing prediction that takes the atmospheric drag and the planet rotation into account.

Hope this helps!

I am currently using MJ but in my current career, I haven't unlocked the accent/descent path guidance modules, So imma have to wing it, that said I recon once I get a feeling for the atmosphere I could kinda best guess the landing site. Also because I fully intend to get my ships back into orbit and like a nice margin of error, I think a dead stop is a little risky

[Skorpychan]

For moving the science, you can tug it out of pods and instruments, and cram it into different pods. Thus, you can rip the science out of the rover, stuff it into the lifting module, and go off with that.

You don't need mechjeb to land on Duna. Just pack enough chutes, and take a nice low aerobraking entry to make use of them. Screw 'picking out' a landing site. Precision doesn't matter if you're making a single landing. Just land where you fall.

[el_coyoto]

I recon once I get a feeling for the atmosphere I could kinda best guess the landing site. Also because I fully intend to get my ships back into orbit and like a nice margin of error, I think a dead stop is a little risky

lol atmosphere on Duna = thin and traitorous...

Without MJ assistance, I guess the best plan would be ignoring the atmosphere and do it the usual "Apollo" way...

The chart is fun too, I've had some good results in early career with it.

And yeah, the "dead stop" solution has all sorts of problems.

[FREEFALL1984]

For moving the science, you can tug it out of pods and instruments, and cram it into different pods. Thus, you can rip the science out of the rover, stuff it into the lifting module, and go off with that.

You don't need mechjeb to land on Duna. Just pack enough chutes, and take a nice low aerobraking entry to make use of them. Screw 'picking out' a landing site. Precision doesn't matter if you're making a single landing. Just land where you fall.

I want to be able to take soil samples from all dunan biomes and return them to kerbin which wouldn't be possible with a single return pod, since each pod can only carry IIRC one of each experiment. Hence the need for a multitude of empty command pods. Also my rover will be manned but operatable by remote, and Jeb will be riding in my main lifter, meaning he can only perform science near the lifter until the rover comes to collect him, I don't fancy driving 5000km to collect jeb then turning around and driving off to find science. Also with regards to parachutes I have about a dozen radials and 3 XLs on my main lifter which weighs in at 15ton, and while my 10ton rover does have 4 xl chutes, it also has 4 rocket engines with about 1000dv and a kerbin TW of 1.5 and it flies like a dream so it can happily touch down unassisted if needs be

My plan is to land my unmanned mini lifters at strategic locations around duna, which I can travel to in my rover and store experiments from the surrounding area, the mini lifters then return to orbit and either, refuel ready for their return trips or redock with a hub attachement on my tug and get dragged back to kerbin. each mini lifter will have command pod a materials bay, a goo tank, a thermometer and a barometer, and enough fuel to reach orbit and rendezvous with the main ship.

[AlexinTokyo]

I kind of hate to say this, but Duna only has one biome, so there's really no need to drive around to do science.

Unless you are roleplaying, in which case that does sound like an awesome mission profile.

[FREEFALL1984]

Yeah its more a personal mission of mine in preparation and experimentation for future game updates when hopefully duna Eve and the other planets will have biomes added, I did use it on minmus and the mun in a single mission (hence my big heavy rover has 1km/s dV) as an experiment and I managed to get a whole bunch of science in one fell swoop although rather than docking my mini lifters to the main ship I just sent them straight back to kerbin individually.

[AlexinTokyo]

That makes sense.

My max-out-the-science-from-Minmus mission was a more standard affair. I put an MSL into orbit with a big fuel tank attached and a small lander (one-man lander can, science pack, small engine and enough fuel for descent, landing, ascent and rendezvous).

Land, science, take off, dock, rinse (out the used experiments) and repeat.

Two mistakes I made: I put the Minmus Orbiting Science Lab in an equatorial orbit, so I wasted a lot of fuel in lander plane changes; and I didn't have landing legs on the MOSL itself, so I couldn't deorbit it safely back on Kerbin and had to ferry the crew and science down in shuttles.

[FREEFALL1984]

When I did minmus using the same drop pod technique, I dumped almost all the drop pods more or less on the equator and drove out to the different biomes, then brought the science back to the nearest mini lifter for return to kerbin which wasn't really necessary since my mini lifters where grossly overpowered lol Also I worked against the rotation of minmus to maximize daylight hours and due to the fact that minmus is only tiny I farmed it for science in about 3 maybe 4 days and hit every biome. But when I sent replacement mini lifters to the mun for the mun phase of the mission however I placed them in the correct biomes and used them as waypoints since the mun is so much bigger (plus I couldn't be bothered to drive from equator to biome to equator again then back to biome repeatedly and old jeb was beginning to look a little homesick and more space crazy than usual)