KSP Tips: RemoteTech, MechJeb, and Flight Engineer

The first thing you need to do when using RemoteTech and you plan to get some probes usable in orbit and beyond is to set up a basically communications constellation with three satellites.

RemoteTech_Constellation

Ideally, in a 3-satellite constellation, you want to be at 777 km with identical velocities, and a separation of 120 degrees per sat. This allows simple Communotron-16 broadcast antennas to reach each other and the ground station without additional configuration.

Use resonant orbits to adjust your separation between Kerbin-orbiting communication relays.

For example:

  1. Select one of your satellites, and target the next comm relay “ahead” of you in orbit.
  2. In Flight Engineer/RDZV mode, look at the phase angle.
    Let’s say the angle is 232 degrees.
    The ideal Phase Angle for the target sat should be 240 degrees.
  3. The difference between your ideal angle and your current angle is 8 degrees.
    Calculate the difference from 360 (degrees), and input this as your orbital period ratio.
  4. In MechJeb, use the Maneuver Planner to adjust your resonant orbit.
    Set a new orbital period ratio of 352/360 at the next apoapsis.
  5. Execute the maneuver.
  6. Once the maneuver is complete, plan a new maneuver node to circularize at the apoapsis.
  7. Check your phase angle. It should now be 240 degrees.
  8. Be sure to check your apoapsis and periapsis, they should both be 777km. If not, fix that. 🙂 If you check the relative speed with your target, it should be in the mm/sec range. (As close to zero as you can get)

To move away, the number will be greater than 360 (ie, 372/360) and you will circularize at the periapsis instead of the apoapsis.

Fun note: In orbital mechanics, you burn retrograde (go slower) to catch up to something ahead of you in orbit.

(Yes, I know this is possible using only MechJeb, however this teaches players how to use two tools. 🙂