How do I get to duna?

[MrWalrus123]

Ok so I'm sending a multipart ship to duna for the first time (also in carrer mode:wink:) and I do not understand how to calculate dV, so giving eme an equation wont help. If your wondering the ship specs, it has to NERVAs one jumbo 64 tank shared by the to engines, and with two of the long fueltanks ment for small ships (the engines have their own, not two each.)

EDIT: I know how to get there, I'm just wondering if it has enough fuel.

Edited September 8, 2014 by MrWalrus123

[Taki117]

If you don't know how to calculate dV there's really not a whole lot we, as a community, can do other than give you the dV equation, which really isn't that hard to solve. Alternatively you can take a look at Kerbal Engineer and a dV map to figure it out. dV is dependent on the mass ratio of fuel to rocket. The more fuel you have (mass wise compared to your rocket) the more dV you have. The heavier your rocket (That's not fuel) the less dV you have.

[EdFred]

Hate to say there's a mod for that, buuuuuuuut, there's a mod (actually a few) that do that.

MechJeb/KER/VOID....

[Red Iron Crown]

Not enough information given to calculate delta-V. If you can give the total mass of your craft (given in the vessel tab in Map view) I can calculate it for you if you don't want to see the equations.

As the other responses above say, you would probably be better served by installing a mod that calculates it for you. I prefer Kerbal Engineer Redux, but MechJeb, VOID and possibly others will do the same.

[MrWalrus123]

Well, its still being contructed in orbit so the mass isn't final.

[Red Iron Crown]

That does make it a bit more difficult. Assuming you want at least 1500m/s for a one-way transfer with a comfortable safety margin, the propulsion unit as described could push up to 180 tons of payload (~230 ton total ship mass). If you intend to return and want 3000m/s for a two-way trip, the maximum payload is about 76 tons (~125 ton total ship mass). Landers are considered payload for these calculations.

[MrWalrus123]

Thanks, also the ship is going to go visit ike

[Red Iron Crown]

Not to be rude, but we're sort of getting into the situation where I'm giving you fish instead of teaching you how to catch them. If you are not interested in learning to calculate dV yourself but still want it calculated, install Kerbal Engineer and use one of the delta-V maps to figure out your requirements.

[problemecium]

I do concur on the recommending of KER or something similar. Especially with the new patch that makes it partless in the VAB, it's really rather useful if you want to know things like dV and TWR.

[Pecan]

1. Decide where you want to go
   
2. Determine the deltaV requirement to go there
   
3. Build a ship that meets the requirement
   

OR

1. Build a ship
   
2. Determine the deltaV capacity
   
3. Take it where it can go
   

OR

Chuck a firework at the sky and see what happens.

[SRV Ron]

In the Kerbal School of Hard Knocks, send a simple probe one way. Then work to a return mission and finally go manned.

[MrWalrus123]

Thanks, I'll look into KER, and add more dV using the free docking ports if I have to.

[DrMonte]

Do it Kerbal way. Percentage of success increases with experience.

[MrWalrus123]

One last question, how does the dV chart work?

[Red Iron Crown]

One last question, how does the dV chart work?

Add the values given on the segments between your origin and destination, the sum is the delta-V requirement.

[ndiver]

It will also depend of your launch window: http://alexmoon.github.io/ksp/

[Red Iron Crown]

It will also depend of your launch window: http://alexmoon.github.io/ksp/

There is a new mod that puts most of the features of that calculator directly ingame, Transfer Window Planner. I'm getting closer to using no external tools at all.

[MrWalrus123]

But what about areo-breaking?

[Red Iron Crown]

But what about areo-breaking?

Aerobraking can just about eliminate the dV expenditure for segments that support it. I add up the segments that will be reduced through aerobraking and budget 10% of the total rather than the full amount, this leaves a comfortable safety margin as the dV actually required will be less.