Is this REALLY this expensive in Delta-Vee?

[CCKinnison]

[Answered]

Polar Orbit to Equatorial, or the reverse.

Explanation - I have a MapSat/Kethane mapper in orbit of Kerbin. It's no longer needed there. I wanted to top it's tanks off, and send it to another planet (Mun and Minmus were covered by other probes). My station and refuellers are in an equatorial orbit, of course. In a roughly 100km orbit (106 and change, nearly circular), and playing with maneuver nodes, I came up with 3181 m/s to shift the orbit to equatorial, keeping it roughly circular in the process (which also does bad things midburn, but that's another story).

Is there a more efficient way to do this? Or do I just bite the bullet on refuelling any polar probe... it'll be expensive, or worthless to do?

I'm not new at this, but I've not done much in the way of refuelling/docking, so I'm wondering if I'm missing an obvious bet here.

Edited July 19, 2013 by CCKinnison
Got my answer.

[Robbii6]

Unfortunately i dont think there is anyway around it a tip if you didnt already know if your getting an intercept the best thing to do is to try and get your plain as you want it way before you get there and this will be more efficient that changing it once you are in orbit with it.

[maltesh]

That sounds about right. A plane-change of 90 degrees costs about 1.414x your current orbital velocity.

In general, for plane changes over about 55° it's more cost-effective to burn to push your apoapsis out to near the edge of the SOI, do the plane change there, then return and recircularize. That tends to max out at about 0.85x of your current orbital velocity.

Personally, I'd porbably just leave the mapper where it is and launch other probes based on its design to head to interplanetary destinations.

[stupid_chris]

Instead, you could try getting it on an intercept to the Mun from your polar orbit. Done right, you could end up with a near equatorial orbit, and then from there you could launch to space (or back to Kerbin if you prefer).

[Cashen]

Another alternative is to boost your apoapsis way up, perhaps 1000km or higher, and do the plane change out there. Plane changes are expensive, but they get cheaper the further away you are. You should boost your apoapsis at the point you cross the equator.

[CCKinnison]

[ANSWERED]

Thanks for the help, everyone.

Maltesh, I'd already figured I could launch more probes... I just didn't want to waste the hardware if it could be saved. I did NOT know about the relative cost of orbital altitude, and will remember that trick for the future.

Stupid_Chris, Thanks... when I first started the inclination change, I saw the orbit increasing, and using that to rendezvous with another fueling station would have occurred to me... if any were in place yet. D'oh.