How Can Dres Be Intercepted?

[Duxwing]

I want to send an unmanned rover to Dres. My plan, which worked before, was a burn from LKO and a mid-course plane-change. I come here because the plan left me with a nearest approach exceeding four gigameters. Any help?

• KAC tells me the interplanetary transfer window is open
  
• My tank is full
  
• I have Precise Node
  
• The game time is Year 14, Day 172, 0:35:21
  

-Duxwing

Edited April 19, 2014 by Duxwing

[Sirrobert]

2000km isn't actually that far

How is your accending/decending node? If that's a to high number, you'll be under/above the planet when you reach it

Other than that, just open a manouver node and try to fiddle around with all the directions to see if you can get it closer.

Also: If you find that each change you make has to much effect (so you can't be accurate), try again closer to the planet. The closer you are to the target, the more expencive manouvers become. But that also means that they are more precise.

[Duxwing]

2000km isn't actually that far

How is your accending/decending node? If that's a to high number, you'll be under/above the planet when you reach it

My plane-difference already is NaN.

Other than that, just open a manouver node and try to fiddle around with all the directions to see if you can get it closer.

Also: If you find that each change you make has to much effect (so you can't be accurate), try again closer to the planet. The closer you are to the target, the more expencive manouvers become. But that also means that they are more precise.

I already did both.

-Duxwing

[StrandedonEarth]

I've found you have to fiddle with one direction on the man. node to get as close as it will let you, then find another direction that will take you a bit closer, then alternate those 2 directions on the node until you reach the periapsis you want.

[cantab]

Chances are you just need a small course correction in some direction. Don't overlook radial burns when doing this either.

[Vanamonde]

Nevermind.

Edited April 19, 2014 by Vanamonde

[Nemecle]

If you are able to get an encounter or a close approach from LKO, it will be less expensive than doing it from interplanetary space : it's because of the Oberth effect. You will probably have to correct your orbit before getting to Dres anyway.

You can also try a gravity assist with the mun to have a less-expensive Dv escape from Kerbin

[Duxwing]

I changed the number to better reflect my data: I missed three orders of magnitude.

-Duxwing

[Sirrobert]

I changed the number to better reflect my data: I missed three orders of magnitude.

-Duxwing

It is definitly easy to get a closer encounter than 2 gigameters.

Just open a mode, and fiddle with all 6 axes. You WILL get closer with 1 of them

[Duxwing]

It is definitly easy to get a closer encounter than 2 gigameters.

Just open a mode, and fiddle with all 6 axes. You WILL get closer with 1 of them

I already tried that.

-Duxwing

[Sirrobert]

I already tried that.

-Duxwing

No you didn't, because if you do it right you WILL get closer. You can manipulate your orbit to go in ALL directions. Including 'closer to the planet'

You probably forgot radial. The blue circles

[Vanamonde]

No you didn't

I'm pretty sure he did, because I've found myself in the same situation. Obviously, some combination of axes will result in drawing your path closer, but since we can only move one at a time and they are at right angles to each other, it is not at all uncommon to find that moving every marker in every direction makes things worse. I know. It sounds counter-intuitive, and I was baffled by it as well, but it does happen.

[BudgetHedgehog]

You can also try a gravity assist with the mun to have a less-expensive Dv escape from Kerbin

You really don't want to do that. The Mun has such low gravity that to use it for what you want (an inexpensive Kerbin escape), you'll end up not too far from Kerbins orbit which means a very expensive manoeuvre later on. If you're planning inter planetary transfers, at the speed you need to be going, you'll be in and out the Muns gravity well far too quickly for it to have any major effect on you.

TL;DR - Munar gravity assist for planets is not a good idea. Is a very good idea for a Minmus transfer though, but I'd rather spend the extra 200 m/s dV than wait for the exact point they're in line for it.