Mining on duna

[MagicFireCaster]

Hi guys, i'm making this thread since i've been struggling trying to make a ship capable of going to duna and mining some ore for a mission, how should i build a ship to be able to come back to kerbin, or at least orbit duna again, does it need to be really big or something? it would help me to have a craft file you can share, at least to understand waht kind of craft (or crafts i like building bigger ships on orbit) i need

 

Thanks a lot 

[Snark]

There are a lot of ways to go to Duna. 

One thing I'd suggest:  don't try to bring everything back.  Mining setups are heavy.  If all you want to do is satisfy a contract ("extract N units of ore," or whatever), you may want to consider sending a ship that has all the needed mining capability, but which leaves most of its mass (i.e. the mining equipment) behind when it goes home:  use a decoupler to separate a top stage that's just command pod, fuel, engines.

Without knowing the exact parameters of your mission, it's hard to give specific advice, but a few general pointers:

• Try to use aerobraking.  You can save a lot of dV by using Duna's atmosphere to slow down on arrival.
• It's worth putting some drogue chutes on your ship (don't need many, probably just a couple will do).  Reason:  Duna's atmosphere is thin, it can be hard to slow down enough to deploy regular chutes unless you get some help from drogues first.
• Definitely put parachutes on your ship.  But don't try to put enough to slow down to a safe landing speed-- Duna's atmosphere is so thin that by the time you've packed on enough chutes, you've wasted too much mass.  Better to add just a few parachutes (enough to slow down to under, say, 50 m/s), then use a brief burst of rocket power to slow to a safe speed just before impact.
• Make sure you use a good launch window (generally when Kerbin is about 45 degrees behind Duna).  Time it right, and you can get to Duna for not much more dV than going to the Mun.

Beyond that, though:  would really help to know your requirements.  What exactly are your criteria?

 

Edited December 29, 2015 by Snark

[Plusck]

As Snark said: don't try to bring everything back.  Or rather: split your ships so that you fulfil the contract with the minimum of what you can get away with.

I don't tend to do too many exact calculations for my vessels. I don't use KER or MechJeb either (though I am sorely tempted). However, I have a contract to take 1150 ore from Ike to Duna. I already have a mining ship on Ike (easy enough - it is much like the Mun only further away) but it will certainly not be able to land on Duna, so I am currently sending this thing to do the contract bit of the job:

Spoiler

So once I connect it to my mining ship, I will (a) gather 1150 ore from Ike, (b) have 1150 ore on my vessel, and (c) land 1150 ore on Duna. Hopefully...

Edited December 29, 2015 by Plusck

[MagicFireCaster]

I just need to mine 550 units of ore (around 5 radial tanks or 2 small ones), i taked mision when i was goign to set foot on duna for the first time, but i failed, so i reloaded the game and did it without mining, since then the contract has been on my to do list, but i  can't make a ship capable of going in and then make it back to kerbin, even leaving some mass, also i want a ship that cost no more than 362000 funds so i don't spend more than i'm going to earn.

[Snark]

10 minutes ago, Plusck said:

I have a contract to take 1150 ore from Ike to Duna. I already have a mining ship on Ike (easy enough - it is much like the Mun only further away) but it will certainly not be able to land on Duna, so I am currently sending this thing to do the contract bit of the job:

So once I connect it to my mining ship, I will (a) gather 1150 ore from Ike, (b) have 1150 ore on my vessel, and (c) land 1150 ore on Duna. Hopefully...

Do you actually have to land it on Duna?  In my experience, "take ore from A and deliver it to B" contracts generally only require you to bring it to B's sphere of influence, not land on B.

And for that matter, I suspect you don't even need to bring that specific ore to Duna.  Just have any 1150 units of ore on any ship anywhere in Duna's SoI, some time after extracting ore from Ike.

(The extreme example of this is "deliver ore from Mun to Kerbin" contracts, which I believe you can satisfy by, 1. mining some ore on the Mun, 2. leaving it there, 3. build a ship in the VAB that has some full ore tanks, 4. launch it to the launch pad.  Don't even have to take off.)

[Plusck]

I'm not sure how easily you can do this for under 362000 funds, but I think you need ideas more than a solution, so here goes:

- take your time.

- use Ike. Really, really use Ike. It is not that hard to get down and up from Ike, since it is very Mun-like, so whatever you big ship you use to get from Kerbin to Duna, I would recommend sending a miner down to Ike to drill, mine, convert to fuel and resupply your main expedition before you land on Duna.

- if that same miner / drill ship has parachutes, you can land on Duna without too much of a problem. All you need is enough TWR to get back to orbit, so you ideally want to disconnect the drill / ISRU and have 909s or whatever to get you back up off the surface with your ore. Once off the surface TWR is irrelevant so you could redock with an LV-N to get you back to Kerbin. Since in this scenario you would have used the LV-N to get to Duna in the first place, your initial Ike mining tour should have been enough to fill up its LF tanks, so you don't need to use any of Duna's ore to send you back home.

Edited December 29, 2015 by Plusck

[MagicFireCaster]

52 minutes ago, Snark said:

Do you actually have to land it on Duna?  In my experience, "take ore from A and deliver it to B" contracts generally only require you to bring it to B's sphere of influence, not land on B.

And for that matter, I suspect you don't even need to bring that specific ore to Duna.  Just have any 1150 units of ore on any ship anywhere in Duna's SoI, some time after extracting ore from Ike.

(The extreme example of this is "deliver ore from Mun to Kerbin" contracts, which I believe you can satisfy by, 1. mining some ore on the Mun, 2. leaving it there, 3. build a ship in the VAB that has some full ore tanks, 4. launch it to the launch pad.  Don't even have to take off.)

Weren't you here to help me? XD

And plusck i'm taking my time, but is kinda difficult to do it, maybe i will try what you said and just land the same miner (maybe leaving it there)

Edited December 29, 2015 by MagicFireCaster

[Snark]

1 hour ago, MagicFireCaster said:

I just need to mine 550 units of ore (around 5 radial tanks or 2 small ones), i taked mision when i was goign to set foot on duna for the first time, but i failed, so i reloaded the game and did it without mining, since then the contract has been on my to do list, but i  can't make a ship capable of going in and then make it back to kerbin, even leaving some mass, also i want a ship that cost no more than 362000 funds so i don't spend more than i'm going to earn.

Okay, that makes it much simpler.

First, why do you need to bring it back?  Does the contract require that, or do you just need to mine some ore?  If you only need to mine the ore, then just leave it there.

"But I need to bring the crew back!" I hear you cry.  Well, what if you send it unmanned?  A mining ship can operate totally uncrewed.  It'll be hellaciously slow to mine, but if all you need is to extract 550 ore and not do anything with it, you're not in any hurry.  So what if it takes a few days to fill the tanks?

Now, if you want more of a challenge, or want to make it manned so you can combine it with your first manned Duna landing, that's fine.  But still, you can make it so that only a tiny part of the ship (the crewed part) separates and goes back to Duna orbit.

It's worth considering an orbiting-transfer-stage design.  Fly to Duna and aerobrake to Duna orbit first.  Then separate in orbit, with one piece that goes down to the surface, and another piece (with fuel) staying in orbit.  When your crew section comes back up, it only needs to have enough fuel on it to get to Duna orbit.  Dock with the orbiting tank, refuel, and go home.

It shouldn't cost you anywhere near 362K for a Duna mission that will do these things.  It shouldn't cost even half of that.  Just keep things small small small and don't include stuff you don't need, and really make sure to follow a good transfer window.  The dV to go to Duna is only around 100 m/s more than the dV to go to the Mun, if you do it right.  ("Right" means "use a good transfer window, and use aerobraking.")

[MagicFireCaster]

1 minute ago, Snark said:

Okay, that makes it much simpler.

First, why do you need to bring it back?  Does the contract require that, or do you just need to mine some ore?  If you only need to mine the ore, then just leave it there.

"But I need to bring the crew back!" I hear you cry.  Well, what if you send it unmanned?  A mining ship can operate totally uncrewed.  It'll be hellaciously slow to mine, but if all you need is to extract 550 ore and not do anything with it, you're not in any hurry.  So what if it takes a few days to fill the tanks?

Now, if you want more of a challenge, or want to make it manned so you can combine it with your first manned Duna landing, that's fine.  But still, you can make it so that only a tiny part of the ship (the crewed part) separates and goes back to Duna orbit.

It's worth considering an orbiting-transfer-stage design.  Fly to Duna and aerobrake to Duna orbit first.  Then separate in orbit, with one piece that goes down to the surface, and another piece (with fuel) staying in orbit.  When your crew section comes back up, it only needs to have enough fuel on it to get to Duna orbit.  Dock with the orbiting tank, refuel, and go home.

It shouldn't cost you anywhere near 362K for a Duna mission that will do these things.  It shouldn't cost even half of that.  Just keep things small small small and don't include stuff you don't need, and really make sure to follow a good transfer window.  The dV to go to Duna is only around 100 m/s more than the dV to go to the Mun, if you do it right.  ("Right" means "use a good transfer window, and use aerobraking.")

Thanks! That's all i need to know, before i go, do you have any  pic of a ship with the orbiting transfer design, i'm not sure if the one i'm testing will be able to go into duna orbit.

[Snark]

1 hour ago, MagicFireCaster said:

Thanks! That's all i need to know, before i go, do you have any  pic of a ship with the orbiting transfer design, i'm not sure if the one i'm testing will be able to go into duna orbit.

Don't have a pic handy, but there are a lot of ways to do it and once you have the basic idea I'm sure you can figure it out. 

Some options:

• Option #1:  Send two separate missions with two completely separate ships.  One ship, the orbiter, has an empty command pod, and a probe core. It flies to Duna, aerobrakes enough to enter orbit, and then parks there.  It has an engine and enough remaining fuel for, say, 800 m/s of dV at this point.  The other ship, the lander (with mining equipment) flies to Duna and lands.  When you're ready to come home, the ascent stage flies up to Duna orbit and rendezvous with the orbiter, then your kerbal just EVAs across to the orbiter and flies it home.
• Option #2:  Same as option #1, but with docking.  The orbiter doesn't need a command pod, it's just a flying gas tank with a docking port on it.  When the Duna ascent stage reaches orbit, it docks with the orbiter and refuels from it. Then the Duna ascent stage goes home.
• Option #3:  Like option #2, but you send them together.  The orbiter and the lander are initially connected together with a stack separator, one of them sitting on top of the other (doesn't matter which one's on top).  Launch them together as a single ship.  Fly to Duna, aerobrake to orbit.  Blow the separator.  The orbiter stays in orbit, the lander does a very small burn to lower its periapsis into atmosphere and then lands.  The return path is the same as option #2.

The orbiter can be very simple.  For example, if you're going with option #2 or #3, it might just be:  docking port, probe core, fuel tank, a reaction wheel somewhere, some small amount of monopropellant, some RCS thrusters.  If you perch it on top of your lander, stick a nosecone on top with a decoupler for when you're launching from Kerbin.  If it goes under the lander, then aero is the lander's problem, not the orbiter's. 

A few other general bits of advice:

• Keep your lander as small and light as you can possibly get away with.  Every kilogram of mass on the lander means many kilograms on the pad at Kerbin.
  • Example:  If your contract only needs you to mine 550 units of ore, not have 550 units of ore, then you don't have to have a bunch of ore tanks.  Just a tiny ore capacity is enough; you can fill it up, then empty it (there's a right-click option on the ore tank to jettison the contents), then refill as needed.
  • Example:  If your lander's ascent stage is also the Kerbin return stage, and if you have an engineer on board level 1 or higher, then you don't have to take two sets of parachutes.  Just one set will do.  Use them to land on Duna, then when you're back in orbit, use the engineer to repack the chutes and you can use them again to land on Kerbin when you get home.
• If you're going with an orbital docking design:  You know how to dock, yes?  Docking's a skill that takes some practice, and in-Duna-orbit is not the place to be trying it for the first time.  Practice in Kerbin orbit first.

By the way, one good way to get help on the forums:  Go ahead and try it out, then if you have problems you can post a screenshot of your ship with a "what's wrong with this ship?" question.  Then people can give you very specific advice on how to fix it.

Edited December 29, 2015 by Snark

[Plusck]

4 hours ago, Snark said:

• Option #3:  Like option #2, but you send them together.  The orbiter and the lander are initially connected together with a stack separator, one of them sitting on top of the other (doesn't matter which one's on top).  Launch them together as a single ship.  Fly to Duna, aerobrake to orbit.  Blow the separator.  The orbiter stays in orbit, the lander does a very small burn to lower its periapsis into atmosphere and then lands.  The return path is the same as option #2.

Frankly, if you're going to send them together and redock them later, I wouldn't bother with a stack separator. Build the two parts with docking ports already attached (or if you want to keep the top section facing the right way with an engine on the bottom, simply using a docking port on the bottom section as a connector) and add struts for in-flight rigidity. Unless of course that would end up being heavier... but I doubt it.

6 hours ago, Snark said:

Do you actually have to land it on Duna?  In my experience, "take ore from A and deliver it to B" contracts generally only require you to bring it to B's sphere of influence, not land on B.

And for that matter, I suspect you don't even need to bring that specific ore to Duna.  Just have any 1150 units of ore on any ship anywhere in Duna's SoI, some time after extracting ore from Ike.

(The extreme example of this is "deliver ore from Mun to Kerbin" contracts, which I believe you can satisfy by, 1. mining some ore on the Mun, 2. leaving it there, 3. build a ship in the VAB that has some full ore tanks, 4. launch it to the launch pad.  Don't even have to take off.)

Annoying forum software didn't show me this post when I responded last night.

Yes, the contract is specific about having to "land" it on Duna. I sent a standard reusable mining ship:

Spoiler

before getting the contract, so it's neither powerful enough to do anything on Duna nor equipped with parachutes.

Incidentally, MagicFireCaster, if you end up taking any pointers from the attached image, be aware that the ship is seriously underpowered, even for Ike. Takes a very long time (and a lot of gravity losses) to get up from the surface of Ike when full.

[MagicFireCaster]

Hi guys thanks fot your help, first of all i've never tried aerobraking on another planet that ins't kerbin, how high should my periapsis be to have a good speed reduction?

Also my returning stage should have a rockomax X200-16 or X200-32 fuel tank so it can get back? If u have any pic of a heavy duna lander it would help 

 

[Snark]

34 minutes ago, MagicFireCaster said:

Hi guys thanks fot your help, first of all i've never tried aerobraking on another planet that ins't kerbin, how high should my periapsis be to have a good speed reduction?

It depends on the ship's mass and shape, and on how fast you're going when you arrive.  One thing you can count on:  no matter what number anyone says, it will almost certainly be wrong, especially if you want to aerobrake to orbit rather than to the surface (which you do).  The margin of error is razor thin:  Duna's atmosphere is thin, and the planet's diameter is small, and the atmosphere drops off very rapidly with altitude.  All of those factors combined mean that the difference between "not enough aerobraking, go flying off into space" and "too much aerobraking, go down to the surface" can be only a few hundred meters of altitude.

So the way to do it is, hit F5 when you're still a good long distance away from Duna, pick a periapsis altitude (say, 18km to start?), and try it out.  If it's too much or too little, reload, burn radially in or out by a few m/s to adjust your periapsis in the right direction, and try again.  Don't be surprised if it takes you several tries to get it right.  Duna aerobraking is notoriously finicky.

 

34 minutes ago, MagicFireCaster said:

Also my returning stage should have a rockomax X200-16 or X200-32 fuel tank so it can get back? If u have any pic of a heavy duna lander it would help 

Again, it depends on the mass of your ship, what sort of engine you have, etc.  The way you design any ship is to start with the amount of dV you need and work backward from there.

To get to low Duna orbit from the surface, I think you need something around 1400 m/s of dV.  Then to get from low Duna orbit to Kerbin, you need another 600 m/s or so, maybe a bit more, if you have a good launch window.

With that in mind, just design your ascent stage, look at the dV, and make adjustments if needed.  If you're going to be refueling in orbit before heading home, your ascent stage needs a dV of 1400 m/s (to get to orbit before you refuel).  If you're going all the way home from the surface, you need at least 2000 m/s of dV.  Plus, in both cases you want to allow a reasonable safety margin.

So let's say, for example, that you're doing a direct home trip from Duna surface.  That's 2000 m/s; if we allow, say, 500 m/s as a safety margin, that's 2500 m/s.  So if you've got that much dV, you should be good.

To calculate a rocket's dV:  Take the wet mass (i.e. total mass including fuel), divide by the dry mass (i.e. when your fuel tanks are empty), this is your mass ratio.  Take the natural log of the mass ratio ("ln" on your calculator), multiply by 9.8 m/s2, then multiply by the Isp of your engine.  This is your dV in m/s.

So, for example, suppose your ascent stage is a lander can, plus a fuel tank with 2 tons of LFO, plus a Terrier, plus some parachutes, batteries, etc.  Total (wet) mass will be about 4 tons or a bit under.  Let's say 4 tons.  That includes 2 tons of fuel, so the dry mass is 4 - 2 = 2 tons.  4 / 2 = 2, your mass ratio.  The vacuum Isp of the Terrier is 345s.  (You're not starting in vacuum, but Duna's surface is pretty low pressure, and the pressure will drop very fast with altitude, so you can use the Terrier's vacuum Isp as a good approximation).  So ln(2) * 9.8 * 345 = 2300 m/s, which is in the right ballpark though with a fairly narrow safety margin.

So:  if you can get your ascent stage under 4 tons, powered by a Terrier with 2 tons of fuel, then you have approximately enough dV to get home directly from Duna surface.  The margin is narrow.  To make it more safe, either have a lower mass, or pack on a bit more fuel, or do a refuel in orbit (since over 2/3 of your fuel is used up just getting to Duna orbit from the surface-- the trip home to Kerbin is cheap in comparison).

If you do the mission and it turns out that you have not quite enough dV:  another option, when you run out of fuel, is to get out and complete the trip in a spacesuit.    Kerbal EVA suits have a ridiculous amount of dV in them, like 600 m/s.  An EVA Kerbal in low Duna orbit has almost enough propellant to go all the way home to Kerbin!  So if you start your trip and don't have quite enough fuel to complete your homeward burn, you have the option of going EVA, taking any science from the ship, and then using your EVA pack to complete the trip.  That does mean you'd need to launch a rescue ship to snag the kerbal upon Kerbin flyby, since there's no way your kerbal would be able to reenter Kerbin's atmosphere without frying.  So it's not necessarily an approach I'd recommend, just a last-resort possibility to be aware of in case things go pear-shaped.  And KSP is nothing if not a proving ground for wacky hijinks. 

 

Edited December 29, 2015 by Snark

[FancyMouse]

Isn't the suggestion always - if you can make a rocket do Mun landing & return, then throw parachutes and you'll be good to go for a Duna return trip?

And OP said he just needs to mine 550 Ore (not confused with the other 1000+ Ike->Duna contract reported by another person). So I don't even think the Ore needs to be lifted a meter up. Just send a probe deploying a small drill and let it mine.

[MagicFireCaster]

Hi, i will try to aerobrake then, i packed some airbrakes in my ship just to be sure, is going to be big, i will leave the mining equipment on duna and then the rest of the ship when the fuel runs out, the las stage will be a mk1 pod with a fl-t400 fuel tank and a terrier, along with parachutes some science things and a docking port in case i need to refuel, the ship is going to look like this (the ship on top):

Is it too big? i always use the lower stage of the ship fot inteplanetary trips, and the upper stage (other ship that got docked to it) to get back to kerbin or other things.

[Snark]

23 minutes ago, MagicFireCaster said:

Hi, i will try to aerobrake then, i packed some airbrakes in my ship just to be sure, is going to be big, i will leave the mining equipment on duna and then the rest of the ship when the fuel runs out, the las stage will be a mk1 pod with a fl-t400 fuel tank and a terrier, along with parachutes some science things and a docking port in case i need to refuel, the ship is going to look like this (the ship on top):

<screenshot>

Is it too big? i always use the lower stage of the ship fot inteplanetary trips, and the upper stage (other ship that got docked to it) to get back to kerbin or other things.

Be aware that airbrakes are of limited utility these days for orbital reentry-- low temperature tolerance, they tend to go boom.  And on Duna, drogue chutes will do a better job than airbrakes will at slowing you to safe parachute deploy speed.  I'd suggest leaving the airbrakes at home, or at the very least, having some drogues as a backup plan in case the airbrakes don't work out.

As for the screenshot-- honestly, it's really hard to tell what I'm looking at, everything's so dark.  Could you post something with a better lighting angle?

[MagicFireCaster]

Here is a screenshot of the actual ship, i just docked both of them, the large stage is going to get me to duna and hopefully with aerobraking there will be enough fuel to help me to get back to kerbin.

 

[Snark]

1 hour ago, MagicFireCaster said:

Here is a screenshot of the actual ship, i just docked both of them, the large stage is going to get me to duna and hopefully with aerobraking there will be enough fuel to help me to get back to kerbin.

Woot!  Startin' to look real.  A few suggestions:

• Lose the engines (Skippers, yes?) on the radial tanks for the main stage.  You don't need them, they're just more dead weight to move.  (Reason:  If you're already in orbit, you really don't need much TWR at all.  Better to save the mass and have fewer tons of engine.)
• That's far, far more monopropellant than you need.  Suggest ditching the jumbo tank and adding a couple of the smallest-size radial mono tanks.
• Those few airbrakes aren't going to do much of anything, there's too much ship and too few brakes.  They'll add aero stability causing the ship to stay pointed nose-first in atmosphere, but that's about it.
• No heat shield?  You can probably manage without one, Duna's not too brutal in that regard, but make sure you have a good transfer window so that you're not going too fast upon Duna arrival.  Don't want to get fried.  Especially since you're carrying the jumbo solar panels, whose temperature tolerance is a wimpy 1200 degrees.
• The lander sure seems to be packing a lot of engine power.  Is that four Reliants you've got on there?  What's the mass of the lander?  I would guess you could probably get by with just a couple of Reliants (or, better, Swivels-- they have better Isp at low atmospheric pressure).
• It's hard for me to tell-- how much parachute is the lander packing?  And does it have drogues?  That lander is definitely going to need drogue chutes.
• Just to confirm-- you've scouted (or have plans to scout) Duna for ore distribution before your lander arrives, yes?  Would kinda suck if you landed and then discovered there's no ore at your landing site.

Edited December 30, 2015 by Snark

[MagicFireCaster]

Well 2 of those engines are going to be discarded on the first burn to duna they're just for that. Also i used them on my first duna trip since i didn't know about aerobraking back then, they helped me to get into  duna orbit the hard way

I make i lot of mistakes (including saving after making them mainly when docking) sometimes that monopropellant isn't enough to cover them so i always pack a bit more that i'm going to need.

Yup you told me about the airbrakes, but at least on kerbin they work when i need to entry a plane without exploding in mid air (they sure reduce a lot of speed) so i guess they would do on the duna aerobraking too.

Where should i put the heat shield? And maybe i will need to move those panels.

I made the lower stage of the lander so it's able to almost enter LKO by itself, since kerbin is the best place to make a test for an atmospheric lander

Like 6, 4 on the lower stage and 2 on the last stage (which i'm going to repack to return to kerbin) and i've got 4 drogues 2 on each stage too

Yup as i said i tried to mine on duna before

[Snark]

1 hour ago, MagicFireCaster said:

Well 2 of those engines are going to be discarded on the first burn to duna they're just for that.

Yes, what I'm saying is, you don't need them for the burn to Duna.  Just the single engine in the center.

You only need hefty rocket power when you're launching from the surface of a planet.  Once you're already in orbit, the fewer engines you have, the better.  The fuel tanks are good to have, but you don't need the engines.  Getting rid of them will save you several tons of mass, which in turn will give you more dV.

1 hour ago, MagicFireCaster said:

I make i lot of mistakes (including saving after making them mainly when docking) sometimes that monopropellant isn't enough to cover them so i always pack a bit more that i'm going to need.

Amen, I hear that!  Always good to have a safety margin.  Just sayin' you have about a dozen times more monopropellant than you need.  Anything that saves mass is good.

1 hour ago, MagicFireCaster said:

Where should i put the heat shield? And maybe i will need to move those panels.

With a broad design like that, there really isn't anywhere to put a heat shield-- using a heat shield for protection requires designing the ship in a compact "footprint" so that it fits behind the shield.  I'm not saying "you have to have a heat shield", I'm just saying "you have to be careful".  Try to keep your arrival velocity at Duna from being too high before you hit the atmosphere.  Best way to do that is to have a good transfer window.

If there's some way you can move the panels to a place where the body of the ship shields them during reentry, that would help.  An even better option would be to get rid of them and use the shrouded 1x6 panels, the ones that are extendable/retractable.  Those can tolerate 2000 degrees, as opposed to 1200 for the Gigantors.

1 hour ago, MagicFireCaster said:

I made the lower stage of the lander so it's able to almost enter LKO by itself, since kerbin is the best place to make a test for an atmospheric lander

Like 6, 4 on the lower stage and 2 on the last stage (which i'm going to repack to return to kerbin) and i've got 4 drogues 2 on each stage too

Sounds good.  You can probably go down to 2 drogues on each stage, you really don't need a lot of them.

I'd also suggest adding some control surfaces to the tail fins on the back of the lander, so that you don't "lawn-dart" the entry (get stuck in a nose-first position and unable to steer because you're too aerodynamically stable).  With control surfaces, you're more steerable so you can do things like use body lift to slow your entry still further-- that can help mitigate entry issues when you don't have a heat shield, and can also help slow you down to give your chutes a chance.

[MagicFireCaster]

Ok i will make some corrections on the ship and fuse it again i will change the panels and try to remove the engines when i get into orbit
Edit:
Here, this is how it looks now:

 

Edited December 30, 2015 by MagicFireCaster

[Snark]

6 hours ago, MagicFireCaster said:

Ok i will make some corrections on the ship and fuse it again i will change the panels and try to remove the engines when i get into orbit
Edit:
Here, this is how it looks now:

Lookin' good!   Assuming that all your tanks are full there, you should easily make it to Duna with plenty of dV to spare.  I'd say you're ready to go.

In particular, your main big booster (the one with the big orange tank, Skipper, and two outrigger tanks) looks like it'll have lots more than the 600 m/s dV you need to get to Duna, which is great:  it gives you a lot of flexibility.  For example, if you find that you're going too fast to aerobrake safely when you arrive at Duna, you have enough spare fuel that you could apply some retrograde thrust to slow down.  And once you're in Duna orbit and separate the lander, you can just leave your big orange guy parked in Duna orbit with a fair amount of remaining fuel, which means you can use it to refuel other Duna missions in the future.

And your lander should easily be able to make it back from Duna.  Even just the uppermost stage (command pod, 2-ton tank, Terrier) has nearly enough dV to go home to Kerbin from Duna's surface without assistance or refueling.  If you start with the bottom stage (the one with the drills and Reliants on it), then you should easily make it home to Duna with dV to spare, without refueling.

About the only thing I might suggest adding would be to put some ailerons on those fixed fins you have on the back of the lander.  Will make it easier to steer when you're on your way down to the surface.  You may be fine without 'em, it's more of a just-in-case thing.  One thing you'll quickly learn in KSP is that there are many different ways for an interplanetary mission to go wrong, so it's worth giving yourself a little more flexibility to respond to unexpected problems.  Being able to steer is one of those things that can come in really handy.

Edited December 30, 2015 by Snark

[MagicFireCaster]

1 hour ago, Snark said:

About the only thing I might suggest adding would be to put some ailerons on those fixed fins you have on the back of the lander.  Will make it easier to steer when you're on your way down to the surface.  You may be fine without 'em, it's more of a just-in-case thing.  One thing you'll quickly learn in KSP is that there are many different ways for an interplanetary mission to go wrong, so it's worth giving yourself a little more flexibility to respond to unexpected problems.  Being able to steer is one of those things that can come in really handy.

Well the ship is already on its way to duna, so i think i will take the tip for another mission, and the transfer took all of the fuel from the 2 tanks and has almost all fuel on the big tank to i think i could use that extra fuel as an emergency supply as you said.

On final question regarding other mision, i'm trying to fill the contract "Return from jool" and i need to know what is better, should i park my ship around it, or it would be better just to fly by and return to kerbin when possible?

[Snark]

7 hours ago, MagicFireCaster said:

On final question regarding other mision, i'm trying to fill the contract "Return from jool" and i need to know what is better, should i park my ship around it, or it would be better just to fly by and return to kerbin when possible?

Totally depends on what your goal is.  Jool's a big-ticket item.  Whole lotta options there, ranging from a simple flyby at the low end, to a massive multi-moon-exploring expedition on the high end.

Bopping around the Jool system does eat up quite a lot of dV; capturing to (and escaping from) Jool orbit is considerably more expensive than other planets.  So if you just want a minimal rocket that will go there and come back, a flyby would be the thing-- set up your approach right and pull off the interplanetary billiards shot "just right", and you can come back to Kerbin reasonably soon after the flyby.  On the other hand:  exploring Jool's moons is fun.  You could make it a more extended thing, send crew, check out all the moons.

If you go the route of an extended, multi-moon-visiting, crewed mission, then you'll definitely want to bring along drills & ISRU unit for local refueling.

Exploring Jool & environs is a whole other topic in its own right, if you want to get into that, it's probably worth starting another thread.

 

[MagicFireCaster]

16 hours ago, Snark said:

Totally depends on what your goal is.  Jool's a big-ticket item.  Whole lotta options there, ranging from a simple flyby at the low end, to a massive multi-moon-exploring expedition on the high end.

Bopping around the Jool system does eat up quite a lot of dV; capturing to (and escaping from) Jool orbit is considerably more expensive than other planets.  So if you just want a minimal rocket that will go there and come back, a flyby would be the thing-- set up your approach right and pull off the interplanetary billiards shot "just right", and you can come back to Kerbin reasonably soon after the flyby.  On the other hand:  exploring Jool's moons is fun.  You could make it a more extended thing, send crew, check out all the moons.

If you go the route of an extended, multi-moon-visiting, crewed mission, then you'll definitely want to bring along drills & ISRU unit for local refueling.

Exploring Jool & environs is a whole other topic in its own right, if you want to get into that, it's probably worth starting another thread.

 

Thanks, then i'm just going to make a fly by since i'm not prepared for moon encounters, maybe if i had landers. well that's all thanks for your help