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Nicias

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Posts posted by Nicias

    [1.7.3] Community Delta-V Map 2.7

    in KSP1 Tutorials

    Posted

    I recently did a trip to Dres with life support, using this mod, and found that I had a trip home only about ~90 days after I arrived based on the map I was prepared for a stay of over a year. I looked into the maths some more and I realized the following:

    1) I think the "average time between windows" you calculate is just the synodic period.

    2) I think you can work out the time to return window as follows.

    Let say we have two planets P1 and P2 with orbital periods T1 and T2. We start at P1. Hohmann transfer to P2, dwell there for time D and Hohman transfer back to P1.

    We can calculate the time required for the (round trip) transfer orbit from the periods P1 and P2 of the planets. Call that time Th.

    I am going to measure angular position out of 1, rather than 360 degrees of 2pi radians for simplicity.

    The total time the mission takes is D + Th. In that time P2 makes (D+Th)/T1 laps.

    The vessel does half a lap on the way out, half a lap on the way back and does D/T2 of a lap at P2.

    If we set these two numbers to be equal we get:  (D+Th) / T1 = 1+ D/T2

    Solving that equation for D gives:

    However, we don't actually have to solve that equation. The two sides don't have to be equal, they can differ by an integer (which is 360 degrees) so we actually solve the equation:

    (D+Th) / T1 = 1+ D/T2 + k

    to get:

    D= (1 + k - Th / T1) / ( 1/T1 - 1/T2).

    And use the smallest positive D we can get by trying different k's.

    That gives dwell times of:

    Moho: 79 days

    Eve: 554 days 

    Duna:  529 days

    Dres:  89 days

    Jool:  340 days

    Eeloo: 250 days

    I haven't checked these times out in the game, but the math works. Might you want to include that information on the map?

    Also, could we please get an update for the OPM map that includes Karen?

     

     

    Frustrating Launch

    in KSP1 Gameplay Questions and Tutorials

    Posted

    5 hours ago, Aegolius13 said:

    Sounds like you have a goodly amount of drag in your payload.  The Cupoa is pretty blunt, and other little add-ons like radially-attached docking ports will add a little drag of their own.  One little trick I use when launching the Cupola is to put a BACKWARDS 1.25m decoupler and an advanced nose cone in front of it, and release this once I hit orbit.  This does not negate all the drag from the Cupola, but seems to help a bit.

    You could also consider putting the payload inside a fairing (as narrow as possible to surround your stuff).  I find myself doing this on most launches despite the weight.  It's a nice insurance policy against both drag and heat, and I think it makes rockets look more attractive / realistic.  

    Echo what others said on keeping close to prograde, and putting fins on the back. 

    I like to do both of these. Going up from the cupola, 1.25m decoupler backwards, then 2.5m fairing (upside down) then big nosecone. This big fairing goes down to cover all of the draggy bits.

    How long your first stages last?

    in KSP1 Discussion

    Posted

    3 hours ago, Tyko said:

    I try to time my first stages to last until I've increased my time to AP to about 55-60 seconds. At that point I want to reduce thrust to maintain that time to AP most of the way to orbit. This works out to around 1500-1600 m/s DV. So my first stage (or SRB burnout if I'm using them) Is set up with 1500-1600DV. This also happens to put me at a high enough altitude that vacuum engines are at or very near 100% efficiency. 

    So, first stage with a lifter engine and 1600DV, 2nd stage with vacuum engine and just about 100 DV short of full orbit. This lets me drop the 2nd stage when it's on a sub-orbital trajectory (no space trash). The payload then uses 100DV to circularize.

    I usually do exactly this except I use one LF engine all the way to orbit with combined SRB/droptanks.

    Parachute Reset Mod

    in KSP1 Mods Discussions

    Posted

    1 hour ago, MeCripp said:

    You could last time I checked like if you have landed and get out you can click on them to repack them hope it helps

    Thanks for your post. I know that is possible, I want to avoid some of the drudgery. Like AutomatedScienceSampler does for science.  

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