Atomic Motors Not Worth It

[tavert]

More current experience than what? My landing calculations are the only finite-thrust maneuver calculations I've seen anyone do around here, besides the optimal atmospheric ascent pseudospectral code that alterbaron got working for one example.

Again, name a specific maneuver and types of constraints and we can get to formulating the mathematical statement and solution. For capture you could calculate a finite burn that either maintains constant periapsis or points retrograde and therefore changes periapsis as it goes, and look at how capture delta-V depends on initial orbital energy and periapsis, gravitational parameter of the body, initial TWR, specific impulse, burn start time before periapsis, and final apoapsis at burn end.

Edited October 4, 2013 by tavert

[loknar]

Well.. I for one appreciate "tavert's fantastic (and very complete) engine efficiency analysis" The only thing I would ask is how many engines are at point X and how much less efficient are the other engines below it.

Perhaps using a web interface, those graphic plots can have a context popup at each point that lists each other engine and how less efficient in % they are. And also how many of the engines are use on this Point. thx in advance

The graphs ensured me that my crazy 8-LVn tug ship is not totally useless. I need 0.7 TWR because I don't want to spend 10 minutes burning just to go to Duna. With enough payload and desired dV it works. Thanks

(Back On Topic) It also shocked me to find that LV-909 is useless.

[tavert]

I did put up some additional-info plots on which engine type comes in second place at each point and what the mass margin of victory between first and second place is, see http://forum.kerbalspaceprogram.com/threads/45155-Mass-optimal-engine-type-vs-delta-V-payload-and-min-TWR?p=644257&viewfull=1#post644257

You could possibly port my Matlab code to Javascript or something to get a web interface... a few folks have been working on interactive versions of similar calculators here http://forum.kerbalspaceprogram.com/threads/48744-Transfer-Stage-Design-Helper-v1-2 (in Java) and here https://github.com/mueslo/KerbalPlot#kerbalplot (in Python). Neither of these will exactly match my data quite yet, though if you follow the discussion towards the end of RadHazard's thread I think he is intending to implement discrete fuel tank choices soon.

[loknar]

I'd like to load your data in a database, then set up a server using an api such as google charts, saving a lot of time. The results would be nice, but I barely have time to play the game - programming feels more like work.

No I was mostly joking. Anyone can interpret your graphs for any analysis they want to make about engine efficiency, if they put some time into it.

[tavert]

Check page 4 of my thread, I put together an interactive version based on Mathematica CDF. You'll need to install the Wolfram plugin, but it should do the trick.