Going to Jool

[Captain Sierra]

Jool is quite a profitable planetary system with it's 5 moons if you have kethane and(/or) extraplanetary launch pads. Getting there is obviously harder than it looks. So far, I've lost a total of 5 out of 6 probes I sent. All 6 are useless because I got them in the system with the wrong rotation and 5 are dead. Good thing I haven't sent kerbals! XD I still have not updated. Any help for going to Jool? I can get the phase angle set up but once in the SoI is when things go bad.

If it is of help, I've been swinging out wide and coming in on the dark side. is this one of my problems?

[SRV Ron]

Try coming in short of Jool's orbit. Play around for the best fuel efficient intercept. Halfway there, make a correction burn in order to line up on plane. When in Jool's sphere of influence, you can fine tune a burn to use its moon to slow down using a retrograde slingshot maneuver, use aerobraking from Lathye to slow into orbit, or even use Jool to areobrake. All will save fuel if done right to get orbital insertion and eventual landings.

[Captain Sierra]

My latest probe can get all the way there, with multiple correction burns without touching it;s main engine. It has ~6500 dV on it's engine. Fuel efficiency is not a problem for this mission.

[Mr Shifty]

If you find yourself going retrograde when you enter the SOI, you can do a +normal burn way out there and you should be able to rotate your orbit around until it's prograde for very little dv. What do you mean when you say that 5 of 6 are dead?

[Captain Sierra]

5 of six probes sent to Jool (thats a career total) have either been thrown off into space with too little fuel left to do anything effective or crashed into a planet. All 6 were useless as the last one alive is in a retrograde orbit with not enough fuel to reverse it.

[Tokay Gris]

Coming into Jools SOI with the wrong rotation should be easy to correct.

Once you are in its SOI, just burn radial to change it... While still far out this takes not that much delta-V.

You can also do it with Mechjeb and "Change inclination", but it works this way as well.

Also to save delta-V, aerobraking is suprisingly easy to do. Again MechJeb is usefull, even if you don't want to use the autopilots (docking autopilot seems to be broken anyway), because it can give you projected orbit after aerobraking.

[LoneRider]

My trip to Jool (or Laythe, to be correct) was made using the thermonuclear engines, because you have more than enough time to burn, and they have the best fuel efficiency in space. My ship had a science lander module (just a cone with science modules attached, solar panels, batteries, antennas and a parachute) and a relay satellite (solar panels, batteries, antennas and satellite dishes for long range communication to kerbin, RCS). Not much but enough for a good science mission. The big breaking burns took 4 to 6 minutes full-throttle, but you dont even see the fuel bar move. It worked on the second try, but you have to correct your course at several points. like on 1/4, 1/2 and 3/4 of the way to jool. Just watch and correct on and on with maneuver nodes, so you will get into jools area of infuence as close as possible.

[Tokay Gris]

You want to get to Laythe, see what I did here:

So ok, I was pretty lucky. Took some tinkering. And I am not talking some small vessel here. I am talking about a modular vessel, parts lifted into orbit, assembled there then send on to Jool.

This part was done by this one:

(Ok, so I AM damn proud of that mission....)