What Engines Do you Use for Missions to other Planets?

[Red Comet]

I've been debating what engines to use when planning missions to other planets and moons in the solar system and I'm curious what everyone else uses on these missions.

I really like the efficiency of the LV-N, but it's thrust is so low that I think it makes more sense to go with an LV-T30 or T45. The Poodle looks like it's best for large fuel tanks in a vacuum with its thrust to ISP ratio, but certainly the more powerful large engines have dramatically more thrust with only slightly lower ISP values.

So what engine or combination of engines do other people use for their missions to other planets? Has anyone found something that has consistently worked well for them no matter where in the solar system you've traveled?

[sierra_one_]

I use an array of LV-N Atomic Rocket Engines, usually up to four per payload. Of course, it takes patience, but it's nearly twice as efficient as its competitors and can fit 1.5m payloads.

[A Fat, Angry Serval]

LV-N. Don't worry about thrust when you're already in orbit, you don't need it.

I also use the NovaPunch parts pack, so I have access to a 2.5m nuclear engine with similar power to two standard nuclear engines.

[Red Comet]

Originally posted by sierra_seven_:

I use an array of LV-N Atomic Rocket Engines, usually up to four per payload. Of course, it takes patience, but it's nearly twice as efficient as its competitors and can fit 1.5m payloads.

I used a fairly similar setup to travel to the Mun and back for the first time. It took awhile, but it worked. Thing is though, I was able to duplicate the mission using half as many engines and fuel tranks, while using the LV-T30 engines instead of the LV-N engines.

Sure the LV-N engines were more efficient, but the low thrust took away the advantage of the efficiency.

[Red Comet]

Originally posted by {RLT} VestedGamr:

LV-N. Don't worry about thrust when you're already in orbit, you don't need it.

I'm not sure I understand what you mean. Without the thrust to back it up, doesn't it diminish the value of the efficiency of the engine?

[Koranis]

Until the breathable oxygen becomes a resource, you have plenty of time in orbit, you can plan your approach to other planets using wide low-thrust trajectories - this is where a nuclear low-thrust engine comes handy.

[reality/fiction]

I use the nuclear engines for getting to the planets, and I use Poodle engines for the landing stages

[reality/fiction]

[A Fat, Angry Serval]

Originally posted by Red Comet:

I'm not sure I understand what you mean. Without the thrust to back it up, doesn't it diminish the value of the efficiency of the engine?

Not at all.

Using the standard FL-T800 and a small inline probe core, and using Mechjeb to calculate delta-V stats to remove any chance of error, the LV-45 provides 3871 m/s of delta-V in a vacuum while the LV-N provides 6882 m/s, almost double the amount of delta-V on the LV-45. With the same setup, a mainsail provides only 1534 m/s in a vacuum. As you can see, the thrust/delta-V ratio lies on an inverse exponential curve.

[[m00] insane_eon]

Originally posted by {RLT} VestedGamr:

As you can see, the thrust/delta-V ratio lies on an inverse exponential curve.

Buh?

The Rockomax 48-7S would probably be better in that setup. It saves 2.15 tonnes for only 300m/s less delta v than the nuclear ;)

I like using LV909s for interplanetery travel. It feels weird using nuclear engines but not nuclear fuel. The LV-N is probably the most sensible option though.

[Maverick]

Took a shine to a mod using radial nukes - saves the arsing about trying to get LVN to fit in single stage builds etc.

Mainsail on 1st, 650 for 2nd, make orbit and then the nuke mods for wherever I am going. Always use dumps for IP anyway so never phased about fuel shortages if I go for a bit of "get this done yesterday" missions.

Mun etc. I generally do non-nuke - because I can is about the only reason :)

For launch, boosters are optional but I generally go asparagus on big lifts and maybe small boosters to push single mainsail on final asparagus. If it doesn't work, payload is reconfigured.

ISP not an issue after orbit so small radial nukes ftw.

[bpivk]

For interplanetary travel the LV-N is the only way to go if you don't want to refuel constantly or use cheats.

For reaching Mun and Minmus use any engine if you have enough fuel. Although I use LV-N for every mission that involves space and me getting somewhere.

[Bomoo]

LV-Ns and their larger variant from the KSPX. Long burn times, but very efficient. If you refuse to install any mods whatsoever, you can use a stack splitter to replace the large atomic with 3-4 small ones. http://steamcommunity.com/sharedfiles/filedetails/?id=170226973

[Hesstig]

Originally posted by Bomoo:

LV-Ns and their larger variant from the KSPX. Long burn times, but very efficient. If you refuse to install any mods whatsoever, you can use a stack splitter to replace the large atomic with 3-4 small ones. http://steamcommunity.com/sharedfiles/filedetails/?id=170226973

I'm not getting mods until one succesful landing (duna, mun, minmus)

[Bomoo]

Originally posted by bojjen123:

I'm not getting mods until one succesful landing (duna, mun, minmus)

Eh, depends on what you get. KSPX is more like early versions of stock parts that have yet to be added, as the developer of it was hired by Squad and is working to do just that. Those new parts in 0.21 were originally KSPX parts, for example. And some tools like the fuel balancer, crew manifest, subassembly loader, and alarm clock merely add useful UI functionality. It's really a case of playing vanilla+ rather than some radically different game, if that's what you're worried about.

[Red Comet]

So, I'm sold now that the nuclear engines (whether you're using stock parts or Mods that add more types) are definitely the way to go for planetary missions. Last night I completed my first Duna landing and was able to get the lander back into a stable orbit afterwards:

http://steamcommunity.com/sharedfiles/filedetails/?id=173306785

Now I need to work on making the ships/lander more efficient.