# Tutorial: Orbital Docking with the Kergena Target Vehicle

Docking is a relatively difficult task and can be a frustrating process. Strong familiarity with the navball is recommended prior to attempting a docking maneuver.

## Step 1: Establish Orbit

This tutorial is based on the Kergena Target Vehicle. What you want to achieve here is getting the first ship in a circular orbit (this is not necessary but will make your life a lot easier). To circularize your orbit you want to use your burn at periapsis and apoapsis and make the altitude of both as equal as possible. Now launch your second ship and get it into orbit. Try to launch a bit sooner than the time that the first ship passes over the KSC.

Now set the other craft as target (by clicking on it from map view and selecting "set as target"). It is very important that the ascending and descending nodes are 0.0; if they are not, you will need add maneuvers to fix this. To get your ships closer together, use a higher orbit if you are ahead of the target, and a lower orbit if you are behind. In either case, the ship in the lower orbit will catch up to the ship orbiting higher. Also, keep the orbit of the second ship elliptical, with an intersect along the first ship's orbit. It may take several orbits to catch up if the second launch was not very close; this can be offset by increasing the altitude between orbits, but be careful not to overdo it.

## Step 3: Orbital Rendezvous

Once your orbit is adjusted, you will need to add a maneuver that will match you with the other ship's orbit as shown. If you have done a good job on the launch, you should have an intercept of 4 km or less on the maneuver. Now you will need to burn until your relative speed to target reaches almost zero (make sure the velocity displayed by the navball is set to "Target" and not "Orbit" or "Surface"). So now aim your craft at the purple dot (the one with the 4 circular segments around it, not the 3 lines) that resembles the target and fire your engines! Make sure you're not going too fast:

• A relative speed of 20m/sec is a good speed for 2 km or more.
• When you reach 1 km decrease it to 10m/sec.
• As you are at 600m you should decrease your relative speed to 5 m/sec.

When getting close to the target, try not to use the engines because you may blow up the target ship ^_^ - use RCS for the remaining movements instead.

## Step 4: Maneuvering for the Final Approach

To maneuver while close to the target, you want to use the option docking mode at the lower left corner of the screen. Now enable RCS. Remember that while in docking mode, you cannot turn the ship, only rotate it. So before you move in to dock, stop about 50m away of the target by setting your relative speed to 0.00m/sec. Switch to the first ship and make sure its docking port is facing back at the second craft (use the bracket keys do this easily).

## Step 5: Docking

Now quick save so you don't screw it up ;)

Move toward the target port slowly, making sure both ships have SAS on. The ships may drift at a slightly different angle during your final approach. This can be corrected with RCS maneuvers, or, stop just a few meters from the target ship, reface each ship toward the other, and repeat the forward move. The ports are magnetic, which can aid in docking (just disable SAS at very close range). Ta-da, they are connected! After a short pause, the view will change, indicating the completed connection.

## Step 6: Controlling the Connected Craft

Congratulations! You've completed the docking maneuver. At this point, make sure you are aware which command module is "in control" (you can switch by right-clicking on a control unit and selecting "control from here"), as it will affect your navball indicators and heading. Since you likely have engines at opposite ends of the connected craft, make sure to activate the one that matches which command unit you've selected. The other can be temporarily deactivated by right clicking on it and selecting the action.