First interplanetary attempt

[Some Kerbal]

Getting to the point where I am ready to start moving out to some of the other planetary bodies. I have been able to launch some satellites toward most of the planets and not using proper launch windows for most of them will require extra dV and travel time. Satellites aside, I picked Duna for my first manned missions.

I have a sweet little ship that has the science lab and science modules sitting atop some atomic engines with enough dV to get me there during the upcoming launch window. I also want to send out a little lander to drop to the surface a gather up science and a mining unit of some sort. I have questions about the mining set up.

I have been able to make a self contained extractor/converter for use on Mun and Minmus - I know it is not as economical for Mun as it is for Minmus but there were mining contracts to be had and the ship completed the process without too much hassle. I used the cheat function to float this ship out to Duna to do test landing and return to orbit and found that I am getting slightly worse rate of return than the Mun setup so I was considering a multi unit mining operation. I toyed a bit with creating it in the VAB when i got to wondering how I was going to get the multiple parts to Duna and land them. So I figured I would ask others what their mode of operation would be for something like this. Say you have a 3 piece mining base - Extractor/converter, fuel holder (something on wheels to shuttle between the converter and the transport ship), and a transport ship to run the goods to orbit - How would you get the pieces to the destination planet? One big conglomeration or multiple ships?

[bewing]

First, from your description, it seems you may not realize that the ore production rate depends on exactly where you land on each CB. It varies a lot. You can't really just land in one spot and say "Oh, the production rate on Duna < Mun < Minmus". If you send an orbital survey scanner, you can get a much better idea of where to land to get good ore production. Your Duna extractor may actually get a lot more than your Minmus extractor if you land carefully.

 

Beyond that, generally, the way it works for me is this:

It is fairly useful for me to have a decent-sized load of fuel in LKO as early in the game as I can. Because of the short trip times, this actually means that it's easier for me to set up my first drill on the Mun. Also, exploring the Mun's biomes takes a lot of fuel, and exploring Minmus takes almost none. So, when I have the very first opportunity I send one drill each to both the Mun and Minmus, but the Mun one goes into operation first. And that one gets most of my focus. I have a drill that's stationary, an ISRU + fuel tank on a rover, and a small ascent tanker to take the fuel to a waiting tanker in orbit. The drill is an independent ship, and the rover + ascent vehicle is one more ship when I launch them from KSC. So I make a bunch of fuel early. I have a bunch in LKO and orbiting Mun and Minmus.

And then I start getting contracts for additional drilling rigs on Mun and Minmus. So maybe I launch one more each. So now I have too many, because I already have all the fuel I need. But I make a couple extra high-tech ISRU rovers. And they all refuel themselves. So now they are all ready to leave.

So, eventually the Duna and Gilly xfer windows open. And the drills I send are the extra ones. Along with the high tech ISRU rovers. Along with high-tech landers that double as ascent tankers. Which is the nice thing ... by the time I'm ready to go interplanetary, I've got all the high tech goodies already built and in space. Usually the drills have Skipper drives, so it works best to dock them to a high tech lander (with nuke engines) to do the traveling. But I never build anything new to go to Duna or Gilly. I reuse a lot of my now-extraneous infrastructure.

 

[Streetwind]

4 hours ago, bewing said:

First, from your description, it seems you may not realize that the ore production rate depends on exactly where you land on each CB. It varies a lot. You can't really just land in one spot and say "Oh, the production rate on Duna < Mun < Minmus". If you send an orbital survey scanner, you can get a much better idea of where to land to get good ore production. Your Duna extractor may actually get a lot more than your Minmus extractor if you land carefully.

I could be wrong, but the way I read it, what he means with "rate of return" is how much fuel is left over in his tanker after reaching orbit. Taking off from Duna takes more fuel than taking off from the Mun, so if he tried it with the same tanker, than that tanker would be left with less once in orbit.

 

5 hours ago, Some Kerbal said:

Say you have a 3 piece mining base - Extractor/converter, fuel holder (something on wheels to shuttle between the converter and the transport ship), and a transport ship to run the goods to orbit - How would you get the pieces to the destination planet? One big conglomeration or multiple ships?

Depends on the wheeled vehicle, really. It will be asymmetric by definition, so whether or not you can neatly stack all three parts together for launch (or even for in-orbit assembly) will be determined by how you build that.

If it was me? I'd go the path of least resistance. If I can stack it on a single launcher in the VAB, then it all goes to Duna on that. If I can't, it goes via three separate standard launches.

Of course, I probably wouldn't bother with a three-part refueling base in the first place, as lazy as I am Just the thought of trying to line up docking ports between a rover and a stationary structure over and over again just to provide what's literally the cheapest part of any mission gives me massive "can't be arsed" vibes. If I really was so low on cash that I couldn't send enough fuel for my needs directly from Kerbin, then I'd probably already have a Minmus mining operation in place (with drill-refinery-tanker combo vessels, or using mods to skip the rover middleman), filling some absurd mega-tanker in orbit that joins the exploration ship on the way to Duna and provides all the refueling ever required without any in-situ operations. That mega-tanker could then again return to Kerbin together with the exploration ship, and fulfill the same role with every other destination planet in the system as well. It would have to, considering the up-front investment compared to how dirt cheap fuel is. Buuut... well, I'm not usually that low on cash, so eh. Monolithic expendable mission it is.

Edited December 22, 2016 by Streetwind

[bewing]

It may be the cheapest part of any mission, but it's also the heaviest, by definition.

And your reading may indeed be more correct than mine.

 

[Palaceviking]

Mine on ike, unless you have a mining contract for duna, it's easier and you'll get better return even after transferring to duna orbit.

[James Kerman]

I have a standard mobile ISRU called the "Wide Load" that fits inline in the rocket and functions as the base of my lander.  I design a lander/ascent sky crane that sits on top of the docking port sr.

With this combination you can do Ike and Duna in the same mission.  Ike first without undocking because you don't want to try and lift the rover back through the duna atmosphere.  Once refuelled the sky crane heads home and the claw becomes the fuel delivery system because trying to line up docking ports on uneven terrain is painful.

Deployed on Duna with a science rover.

Edited December 22, 2016 by James Kerman
Edited to make more sense.

[Ohm is Futile]

It might sound a little stupid, but I have to ask: why bother with the mining rig? Is it because you want to or because you feel you have to? If it's the latter, then no, you really don't need to. Just send extra fuel straight from Kerbin if you really need it. If it's the former, then you were given good advice by @Streetwind. As @Palaceviking said, you should mine on Ike, much easier and more efficient and @James Kerman's rig looks good, using the claw to dock and transfer fuel to a tanker.

As for my own personal tidbit, for large missions I find that mutiple launches make designing the initial ascent from Kerbin stages a million times easier. Better yet, launch top stages without/nearly without fuel and use an LKO refueling station to fill them up before going interplanetary. The reduced weight means you can get by using a much smaller, easier to manage and cheaper launch stages. It all depends on your patience for the number of steps and docking maneuvers you are willing to tolerate before heading off to another planet.

Edited December 22, 2016 by Ohm is Futile
Makes more sense

[Some Kerbal]

Having the mining capability at the moment is more of a want to than a requirement. I had it in my head that trying to figure out how to transport a mining operation would be easier than taking enough fuel for extraneous operations like a couple landings with a science ship. 

Thanks all. I will ponder on the answers

[Some Kerbal]

16 hours ago, James Kerman said:

the claw becomes the fuel delivery system because trying to line up docking ports on uneven terrain is painful.

Am I reading this correctly? You can connect two ships using the claw and then transfer fuel? 

I thought you had to be connected by a docking port

[bewing]

32 minutes ago, Some Kerbal said:

Am I reading this correctly? You can connect two ships using the claw and then transfer fuel? 

I thought you had to be connected by a docking port

You read it correctly. A klaw is a type of docking port. My favorite type, in fact.

 

[James Kerman]

You should test it on your vessel on Kerbin first to make sure the vessel you want to refuel can be "grabbed" at various angles and inclinations. 

The claw will merge the rover with the target vessel so I make the rover automated and I get the engineer bonus if I have one in the vessel being refuelled.

[Palaceviking]

4 hours ago, Some Kerbal said:

Am I reading this correctly? You can connect two ships using the claw and then transfer fuel? 

I thought you had to be connected by a docking port

It depends on your settings when you started your career,  whether you unticked allow crossfeed across all parts (can't remember the wording). 

[Some Kerbal]

On 12/22/2016 at 11:42 PM, James Kerman said:

You should test it on your vessel on Kerbin first to make sure the vessel you want to refuel can be "grabbed" at various angles and inclinations. 

The claw will merge the rover with the target vessel so I make the rover automated and I get the engineer bonus if I have one in the vessel being refuelled.

James, I copied your 'wide load' idea above to get an idea but I was having problems getting drive power to the wheels. I put a probe core on top to give me command of the vessel and put it on the launch pad. While I could steer, I did not seem to have power to go forward or backward. The only movement I got was slowly rolling off the pad toward the VAB as the pad appears to be slightly unlevel. The breaks did work. I could stop the movement but I could not get the vessel to move in the opposite direction.  It seems like I should. Any idea what I might be doing wrong? I pretty much copied your model above

[Ohm is Futile]

The probe core could potentially not be facing the right direction compared to the wheels, which leads to all sorts of strange issues with either wheels or rocket controls.

[James Kerman]

5 hours ago, Some Kerbal said:

James, I copied your 'wide load' idea above to get an idea.

Merry Xmas,

I have had some problems since the new wheel model was introduced but I do have 2 of these things working.    Also I built those ones before I finished the tech tree so I would upgrade to the ruggedized tyres.

First hack gravity using the debug console (alt + F12 on windows).  Then try disabling drive and steering on one end and see what happens.

A test to make sure the wheels are not in opposition is to observe them on the pad just steering in one direction or the other.  Are they all rotating correctly or are they opposed?

[bewing]

7 hours ago, Some Kerbal said:

 I put a probe core on top

Nope. The probe core or other control point must absolutely be facing in the direction you want to be "forward" -- otherwise you are guaranteed lots of problems. Like wheels fighting each other and not pushing you forward.

[Wanderfound]

On 23 December 2016 at 2:24 PM, bewing said:

You read it correctly. A klaw is a type of docking port. My favorite type, in fact.

.

Not any more; Klaws default to no crossfeed allowed now. Which is how it always should have been, really.

When I'm doing a mining operation, I usually don't bother with a separate mining rig. You lose too much fuel while you're bringing it to orbit.

Instead, I normally just build the mining rig into the mothership and land the whole thing. You don't need a huge vessel if you do it right:

 

[bewing]

You don't need fuel crossfeed if you just use manual transfers. Which work just fine.

 

[James Kerman]

8 hours ago, bewing said:

Nope. The probe core or other control point must absolutely be facing in the direction you want to be "forward"

Thanks mate, great advice.  I was wondering why it works properly when I select a claw and "control from here" but not in other circumstances.

[juvilado]

I'd make a rocket with a landing module, that landing module has two stages, the bottom is ISRU and the top a tiny return probe. For landing aerobraking and some chutes, can use radial engines of return probe to slow down, then refuelled with ISRU. If you want, can make ISRU mobile attaching wheels, but will be boring to move and the % of ore gain wont be much. Suggest landing on Duna Pole, i think there is better ore.

[psychogre]

Like you, I am intending to go interplanetary 'soon'.
My previous foray (using v0.90) did not go well - ran out of fuel far too soon, and ended up relying on the 'infinite fuel' setting to complete my goal of landing on a few of the moons of Jool.
Restarting my career mode with v1.04, I wanted to do things 'right' on my next interplanetary trip, so bringing along an ISRU is a requirement for me.  I'd never used one before, so I set up a mining base on Minmus to get the hang of the whole process.  Rather than a single self-contained setup, I ended up with a collection of smaller landers: drills+ISRU, power+storage, fuel ferry, science lander, and an orbiting base ship.

I also started using the KAS/KIS mods, which has enabled me to also go salvage cast-off rocket stages orbiting Minmus from earlier flights, collect stranded Kerbals and their derelicts - these I attached to those salvaged parts, fueled up and sent them back to Kerbin (I've sent some supply ships with extra docking ports, heat shields and parachutes for these operations).  I use the KAS pipe connections to link the mining base ships together, and to also transfer fuel to the ferry ship.

 

On 12/21/2016 at 11:11 PM, Some Kerbal said:

Say you have a 3 piece mining base - Extractor/converter, fuel holder (something on wheels to shuttle between the converter and the transport ship), and a transport ship to run the goods to orbit - How would you get the pieces to the destination planet? One big conglomeration or multiple ships?

One of your questions has gone unanswered:  how to take a collection of smaller craft on an interplanetary trip.
Docking landers to the front of your main ship may be prone to wobbling during a burn.  My first solution to this problem was a ship that I call the 'Bison', where the lander is tucked on the backside, being 'pulled' along.

 

Having had more practice with ship modifications using KAS, I have taken this idea to the next level, connecting two of these 'Bison' ships to make five places for my mining base landers to be docked for an interplanetary trip.  I probably will need to pay attention to the balancing of mass of those docked ships.  This 'carrier' ship is still under construction (a set of 4 NERV engines are enroute), but I am hoping this will all work how I think it should.

 

This imgur album shows a bit more of the construction involved: http://imgur.com/a/2k1Vi

[IncongruousGoat]

 I would argue that bringing an ISRU rig along in the first place is unnecessary. The thing is, the rig is heavy, power-hungry, and difficult to use correctly. It's probably less mass to just build a ship with enough delta-V to do the mission. I mean, it's Duna, so even without aerobraking or gravity assists the delta-V cost LKO-LDO is only ~1800 m/s. Return is only going to cost 700-800 m/s, since (I assume) you're aerobraking at Kerbin. Then you just need a couple of small landers for Duna and Ike (and yes, the Ike lander can start in low Duna orbit). With nuclear engines, those transfer delta-V numbers aren't particularly big. Trying to use ISRU here just seems like over-complicating things, especially if this is your first interplanetary voyage.

[Wanderfound]

For your first interplanetary run, I'd recommend doing it real style.

First, send a one-way robot probe. Then a robot sample return mission. Then send some Kerbals.

Get the trial and error done before you start spreading little green entrails over the scenery.