Am I doing captures wrong? (0.25)

[Kip336]

Alright. So after lots of trial and error, I'll resort to ask for some help trying to capture myself in orbits around Duna & Eve (Probably every other planet too.)

I've set up two missions, one to Duna, one to Eve to land a small probe. For the first mission to Duna, I followed the tutorials and used the mechjeb interplanetary porkchop maneauver planner to setup my burn to Duna.

Que a few hundred days later, I arrive in the Duna system.

But where the tutorial mentions that aerobraking can be thrilling with speeds up to 2km/s, my probe happily dives to Duna at a good 8km/s. Even skimming the surface at just I ended up needing to go down to about 5km above the surface to slow down sufficiently.

Eve just about the same story, as my probe plunges towards the planet, it goes along at 8km/s, if not closer to 9km/s.

So far I've dipped into the atmosphere to about 90km altitude, but with little effect on my speed, or my final orbit.

I'd go lower, but I understand that doing so would most likely result in rapid unplanned disassembly due to the thick atmosphere.

Am I doing something wrong in my captures to get these speeds? Usually I leave notes of my missions, but unfortunately, I don't have anymore notes about my escape burn from Kerbin. An earlier safe did show my Duna Probe cruising in a Kerbol orbit towards Duna at 14,5km/s (If that helps.)

Many thanks for any feedback !

[UmbralRaptor]

Those are... really high speeds. Are you running a realism mod perchance? Failing that, can you show picture of your approach in map view? With stock KSP, those would be some seriously hyperbolic orbits. As for one last thing, what is the navball set to? (In terms of orbital/surface/target)

[Kip336]

Hey UmbralRaptor, thanks for your post! Navbal has been set to Orbit (Though, surface shows a speed that's not too different (Less then 1k/s)) No realism mods that change orbital physics.

Images attached.

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[Eric S]

Something to be aware of is that the redone aerodynamics in 1.0 will probably change the way aerocapture works, if only because there's less air resistance now. Unless those tutorials/examples where done in 1.0 (which has only been out for a few days), then they were done in the old aerodynamics system which provided a lot more drag.

[Kip336]

But this is 0.25 with the old aerodynamics.

[UmbralRaptor]

That's... ah... an interesting transfer. Why is your periapsis down at Moho? (That it's not a Hohmann ellipse is probably a big part of the high encounter speeds)

[cybersol]

Wow, your orbital speed seem really high and I suspect you may be brute forcing burns towards the planets. Can you do a transfer to an airless body (i.e. Duna) using only within say 1000 dV of what is listed in a DeltaV map (http://wiki.kerbalspaceprogram.com/w/images/7/73/KerbinDeltaVMap.png)? Are you waiting for optimal transfer windows using time acceleration and a planner like http://alexmoon.github.io/ksp/?

[Kip336]

I used the transfer window planner to determine the rough time, then used the porkchop planner in mechjeb for a node....I might've possibly quite maybe used a shorter travel time.

Obviously, not even Kerbals would trust me anywhere close to their mission control.