Interplanetary Transfers - They take years?

[BrainiacBlue]

You might as well ask 'is space big?'

Yes. Yes it is.

[Wjolcz]

Be thankful you don't have to use gravity assists like in real life. That would take even more time.

[Jonboy]

Gravity assist eye candy:

Took over 10 years for Rosetta to get from Earth to Comet 67P (and it swung by Earth three times and Mars once to get there)!

[mrclucks]

That gif made me happy and jealous of skills

[wolfedg]

But it's inefficient, afaik it's best to do the whole burn to your target in one go dv wise. I usually do it from LKO using MJ as it has a brilliant, colourful porkchop plot which lets you decide when you want to start the burn, when you want to arrive and the dv required to do so. Probably the best feature MJ has.

That works fine if you are using mods, but it is (for me) extremely difficult to plot an interplanetary transfer from within kerbin's soi.

[martinborgen]

I always do my transfers from LKO. The trick is knowing when it's time to go: if the planet you're going to is outside kerbin, you should look when a tangent from kerbin straight ahead hits your target, if your target it behind, you should go when your targets tangent straight ahead hits kerbin. No time lost, usually if you leave kerbin's SOI, and do a manouvre-node, and drag it around, chances are you'll end up performing the manouvre at the same place anyways, but much less efficiently.

I never use any mods.

[uglyduckling81]

I always do my transfers from LKO. The trick is knowing when it's time to go: if the planet you're going to is outside kerbin, you should look when a tangent from kerbin straight ahead hits your target, if your target it behind, you should go when your targets tangent straight ahead hits kerbin. No time lost, usually if you leave kerbin's SOI, and do a manouvre-node, and drag it around, chances are you'll end up performing the manouvre at the same place anyways, but much less efficiently.

I never use any mods.

I don't understand what you mean. Straight ahead? Can you draw a picture of an example transfer to Duna?

I use mods to show transfer windows but I like to learn how to do it without.

The Mun for instance I read when your in LKO look toward prograde. When the Mun rises on the horizon of Kerbin burn. Sure enough I got an encounter.

My other transfers all take a whole lot of fiddling with manoeuvre nodes. With a couple hundred hours of play I've still only been to Duna and Kerbins Muns. I've probably played half my time flying around Kerbin though testing jet designs.

I've started a new career though with the intention of visiting all the planets.

edit: NM. This post made me take a look and I found this which already has a good description and pictures.

http://forum.kerbalspaceprogram.com/threads/27236-Tutorial-Step-by-step-Interplanetary-Hohmann-transfer-guide-and-tips

Edited May 14, 2015 by uglyduckling81

[martinborgen]

I don't understand what you mean. Straight ahead? Can you draw a picture of an example transfer to Duna?

I use mods to show transfer windows but I like to learn how to do it without.

The Mun for instance I read when your in LKO look toward prograde. When the Mun rises on the horizon of Kerbin burn. Sure enough I got an encounter.

My other transfers all take a whole lot of fiddling with manoeuvre nodes. With a couple hundred hours of play I've still only been to Duna and Kerbins Muns. I've probably played half my time flying around Kerbin though testing jet designs.

I've started a new career though with the intention of visiting all the planets.

edit: NM. This post made me take a look and I found this which already has a good description and pictures.

http://forum.kerbalspaceprogram.com/threads/27236-Tutorial-Step-by-step-Interplanetary-Hohmann-transfer-guide-and-tips

Cool, good explanaition. yes something like that. Mechjeb is probably more accurate, but with this simple rule of thumb you can always find a good enough launch window. Here's what I mean with the tangent match-up: (a tangent is a line drawin straight from the edge of a circle)

Of course, only for the circular orbits, it s a bit harder for the eccentric outer ones.

Edited May 14, 2015 by martinborgen