How much do you use drop tanks?

[Provisional Name 12]

I haven't used drop-tanks or asparagus for a while now. The reason is that I have switched to a single recoverable booster and this brings costs down by recovering the craft. I also don't have to build large rockets because I use skycranes for everything, my rockets only need to be launched to orbit then the skycrane can pick it up. Sometimes this does mean switching between cranes to land on the mun for example, or waiting for my one giant skycrane to finish a cycle to start another one, but it is way more cost effective. I am surprised that I don't see more people in career mode doing this.

[suicidejunkie]

Do your crane payloads have any engines themselves?

Basically all my payloads put themselves into orbit since they have engines anyways to do what they were going to do, and there is infrastructure to refuel from.  Main booster drops into booster bay for recovery, and the SRBs from the high velocity launch pad stage drop onto the beach.

Might be nice to have some high thrust tugs for dragging things around, but I don't mind a 3 minute burn for efficiency's sake.

[Terwin]

On 6/19/2018 at 12:11 AM, Provisional Name 12 said:

I haven't used drop-tanks or asparagus for a while now. The reason is that I have switched to a single recoverable booster and this brings costs down by recovering the craft. I also don't have to build large rockets because I use skycranes for everything, my rockets only need to be launched to orbit then the skycrane can pick it up. Sometimes this does mean switching between cranes to land on the mun for example, or waiting for my one giant skycrane to finish a cycle to start another one, but it is way more cost effective. I am surprised that I don't see more people in career mode doing this.

Unless you crank down the funds severely, funds are not much of a constraint and play-time is the big thing that needs to be optimized.

So getting 2/3 as much done for 1/4 of the funds cost in the same amount of play-time is often a net loss for most players, especially if the tasks being done are high pay-out contracts where completing that extra 1/3 usually brings in more than the 3/4 of the costs that were used to get things done with less play-time.

But then again, that assumes that you enjoy completing tasks/reaching objectives, if you derive greater enjoyment from squeezing every last bit of efficiency from your missions, you probably get more enjoyment from getting 2/3 as much done in the same play-time so long as you can do that 2/3 in the most <X>-way possible.

[Sidereus]

I don't use them very often. When I do, it's usually on a small lander on a non-atmospheric body, like the Mun, Minmus, etc.

My go-to first lander for the Mun is almost always a small 1 seater (either a Mk1 Lander Can or one of the new Pea pods) on top of a 1.25m service bay which contains a probe core (I usually man it with a scientist), batteries, the small reaction wheel, and the smaller science experiments; then a Material Bay, a FL-T200 Fuel Tank, and a single LV-909 for the sole engine. The engine will be fed for most of the trip with a pair of drop tanks, which are attached with radial decouplers that crossfeed into the central FL-T200 tank. Each drop tanks consist of an FL-T400 and an Fl-T200 tank, and will also have the landing legs and sometimes a Stratus-V Roundified monoprop tank on top, if I'm using RCS for that mission.

That combination will get me from LKO to the Mun's surface with just about 200-300 or so dV worth of fuel left in the drop tanks, and makes for a compact lander with a wide footprint that is fairly stable, even on steeper slopes.

The drop tanks get jettisoned a bit after leaving the Mun's surface but before I've made orbit, which neatly disposes of them. Then I have just enough fuel left in the central FL-T200 tank to get back to Kerbin.

 

[Provisional Name 12]

My payloads do not have any engines at least within the orbit of kerbin. I do not have any exterior bases that have production on them other than science and have not put any skycranes in them yet.

 

On 6/20/2018 at 7:38 AM, Terwin said:

Unless you crank down the funds severely, funds are not much of a constraint and play-time is the big thing that needs to be optimized.

So getting 2/3 as much done for 1/4 of the funds cost in the same amount of play-time is often a net loss for most players, especially if the tasks being done are high pay-out contracts where completing that extra 1/3 usually brings in more than the 3/4 of the costs that were used to get things done with less play-time.

But then again, that assumes that you enjoy completing tasks/reaching objectives, if you derive greater enjoyment from squeezing every last bit of efficiency from your missions, you probably get more enjoyment from getting 2/3 as much done in the same play-time so long as you can do that 2/3 in the most <X>-way possible.

This is possible, but I often can use mecjeb to preform these maneuvers while I do other stuff so it isn't a huge burden. Also I made a habit of trying to buy all the items in the tech tree as I go through leaving me really short on funds. This is made worse because I have a lot of mods including some that have very expensive nuclear reactors that I have decided to buy because if it isn't developed bought from the tech tree it no longer shows up in the build menu.

That said, I might change it up, my heavy tug is insanely hard to drive since a patch made the nuclear engines continue to operate after being deactivated and I have a lot of the money thing figured out at this point since I recently started enriching uranium on minimus and sending it back for profit. This has rendered all non-rescue missions basically moot for me and made my new goal off-world colonization and science. Which means I should look at upgrading to a more recent version than 1.3.1 before I start going crazy on bases that will likely be permanent.

I am also somewhat attached to my tugs and become really upset when I get them in accidents that I cannot reload them from. Every time I build a new one I am modifying it to meet a new spec that I failed to account for or try a new design/load capacity or whatever. I am definitely into the building part of the game, I will rarely build the same thing twice and love all the research and planning I put into my crafts/bases. I think that my like of my tugs might make sure that I am incorporating them into my planning as well as the fact that going forward I am looking at building real colonies instead of just one off missions. That said, I still don't know how I will colonize Eve and Duna and the inability to recover the components as on kerbin there will definitely factor in.

 

If anyone has suggestions I would love to hear them. Oh and I am using USI mods for resources if that makes a difference.

Edited July 2, 2018 by Provisional Name 12

[Bill Phil]

For nuclear stages they're very helpful. Nuke engines are inherently massive, so, dropping dead weight as soon as possible is a priority.

Beyond that, I mainly use them on landers, or small interplanetary stages to get some extra, quick and dirty, delta v. 

I've noticed that even small drop tanks can increase delta v a decent amount.

As for the SRB trick, having a fully loaded center stage is beneficial, and thus the concept functions similarly to asparagus/onion staging, but the tanks aren't feeding other engines.

[SkyKaptn]

This is a bit on the side, but regarding SSTOs I sometimes du a pylon attached build where I jettison all chemical engines and tanks once in orbit. This still is a legit SSTO, if one jettison after orbit is achieved. Makes one heck of a TWR boost for the rest of the planned mission(s). Just do a SPH/VAB check to ensure that the dry weight CoL/CoM balance is OK for eventual atmo re-entry.

[Cavscout74]

19 minutes ago, SkyKaptn said:

I sometimes du a pylon attached build where I jettison all chemical engines and tanks once in orbit

That's an interesting idea.  I've used drop tanks on SSTO's to boost range for an interplanetary transfer - my preferred Laythe interface SSTO doesn't quite have enough dV to transfer to Laythe, but since it's a one-way trip from Kerbin, I don't need the extra tanks once I do my transfer burn, so they get dumped.  But I never thought of dropping entire engines too.