Tutorial:How to get to Jool
Contents
- 1 Traveling to Jool
- 2 Steps
- 2.1 Step 1 - Build Your Rocket
- 2.2 Step 2 - Planetary Alignment
- 2.3 Step 3 - Launching into Kerbin Orbit
- 2.4 Step 4 - Fly from Kerbin to Jool
- 2.5 Step 5 - Arriving at Jool
- 2.6 After circulation
- 2.7 Step 6 - Traveling to its moons
- 2.8 on the moons
- 2.9 docking back together
- 2.10 the return
- 2.11 Final Word
- 3 Ideas
Traveling to Jool
Jool is the second most distant body in the Kerbol system, and one of the more time-consuming locations to reach. Getting to Jool is really the next step after Eve and Duna, and is an attractive target due to its large atmosphere and complex moon system.
Specifications
- Length: 1–3 hours
- Difficulty: Moderate/Hard
- For version: .17
Additionally, you will need a good understanding of orbital mechanics (see Tutorials section), angles, and a lot of patience.
Steps
Step 1 - Build Your Rocket
This rocket should be fully capable to reach Jool. To build this rocket, you will need at least 8,300 Delta-V. To save some Delta-V in your rocket, you could aerobrake around Jool or Lathe. Ideally, in Career mode, you should have a fully upgraded level 6 Technology tree to build this rocket. You could probably get away with a level 5 Technology tree but you will probably need to add more stages or more power to the bottom stage to make this design work.
Upper Stage
This stage should have enough fuel to get into Jool orbit and to travel around Jool's 5 moons. You can reduce the required fuel by aerobraking inside Jool's atmosphere. At a bare minimum, use a Rocketmax Jumbo-64 Fuel Tank and ether a RE-L10 "Poodle" Liquid Fuel Engine or a LV-N "Nerv" Atomic Rocket Motor on the end.
Middle Stage
The middle stage should be able to escape Kerbin's SOI and get an encounter with Jool. A Rocketmax Jumbo-64 Fuel Tank will do for most small rockets but it depends on the size of your upper stage.
Lower Stage
This is the launcher stage that will get the rocket into orbit. Make sure you use a lot of Solid rocket booster and powerful engines. The size of your lower stage greatly depends on the size and mass of the middle and upper stages.
Step 2 - Planetary Alignment
While not absolutely essential, the easiest and fastest way to reach Jool from Kerbin is ensuring that they are properly aligned. Otherwise, you may spend a lot of time (possibly years) and fuel drifting until they happen to match up. To do so, check your map and make sure that Jool is in front of Kerbin in its orbit around Kerbol, and if you were to draw a line from Jool to Kerbol to Kerbin, it would form a ~90 degree angle.
Alternatively, you can visit The Interplanetary Guide and Calculator to calculate your own path.
Step 3 - Launching into Kerbin Orbit
Start with normal launch from Kerbin by making a gravity turn at ~10km (or whatever you are familiar with). Get your apoapsis to ~70 to ~100km than make your orbital insertion. If you have extra fuel in your lower stage after your orbital insertion, make sure to save it for your interplanetary burn.
Step 4 - Fly from Kerbin to Jool
Once you are in orbit, and Kerbin and Jool are aligned properly, select Jool as your target, it makes things a lot easier. Next, make a manouver node about 45 degrees past sunset. Then, pull out your prograde vector until the dotted yellow line leaves the Kerbin system and crosses Jool's orbit. If you have done these steps correctly, you should see two white arrows near each other, one pointing up and one pointing down. If you do not see these arrows, you might have to tweak your orbit a bit. Play with the prograde and retrograde vectors a bit until you see the arrows. If you get the two white arrows close enough to each other, you will get an encounter with Jool. If you cannot get an encounter, try moving your manouver node around a little bit. Once you complete the burn, you will be on a course to Jool!
Step 5 - Arriving at Jool
When you get into Jool's SOI, you have two options for getting into orbit. 1- Play it save and burn retrograde periapsis, but risk running out of fuel 2- Aerobrake, save some fuel but risk burning up in the atmosphere
Option 1- When you arrive into Jool's SOI, make sure your periapsis is is above 200km. Simply point and burn retrograde until you get into a stable orbit.
Option 2- A few days before you arrive in Jool'a SOI, play with a manouver nose and get your periapsis under 200km, inside Jool's atmosphere. The height of the periapsis is totally up to you, but I recommend not to go under 160km. Once there, enter Jool's atmosphere pointing retrograde. Try to keep your ship as stable as possible and not flip around, or else you could burn up. Once you have exited the atmosphere, burn retrograde for a bit if you are not in a stable orbit. A safer alternative to option two is to aerobrake in Lathe's atmosphere and then transfer to an orbit around Jool.This does require more planning, and I will not explain how to do it.
Congratulations! You have now reached Jool!
After circulation
You should put your orbit in a moon unaffected region
Step 6 - Traveling to its moons
One by one you should deploy landers to go to each of the moons and do lots of science.
on the moons
When you have landed on each moon make sure you take and store all the data in your command pod as this will make your life easier in space. Then take off into jool orbit
docking back together
Dock ALL the landing devices back together to the main ship. transfer all fuel, electricity, xenon, ore and Monopropellant to the main ship and have your kerbals go on EVA and take the data and jet pack to your main ship crew quarters(I do know that crew transfer exists but this is for science purpose)and make sure no science or resources are stored on board the landing devices and then undock all of them or risk not getting to kerbin by taking them with you.
the return
Make sure kerbin is behind jool and now escape jool and then burn what you need to burn to make your periapsis one the orbit of kerbin and you should get an encounter. Put your periapsis at 30-20km and swiftly get rid of any engines or fuel tanks and start the re-entry procedure.
Final Word
You have successfully done a mission to the joolean system and now you have explored most of the kerbol system and now you can build bases, send rovers and more to the planets of kerbal space program. Have fun!
Ideas
Re do the Galileo probe entry to Jupiter
Try a low mass Jool ship using Ion engines.