Manual/Ascent Guidance

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Mechjeb makes it easy to get a rocket into a stable, circular orbit with a variety of options on the way up. Launches can be timed to rendezvous with a specific target or can simply be launched when ready.

Launch process

There are four main parts to the launch process, and the exact altitudes at which they occur are customizable:

  • Initial ascent
  • Gravity turn
  • Coast to the edge of the atmosphere (if applicable)
  • Circularization burn at apoapsis

Main Options

  • Show navball ascent path guidance - Creates a targeting reticle on the navball display to point towards while launching (NOTE: this creates a virtual target which will unset any target you currently have set)
  • Engage/Disengage autopilot - Engages the autopilot or (if engaged) disengages the autopilot
  • Orbit altitude (km) - The desired altitude in kilometers for the final circular orbit
  • Orbit inclination - The desired inclination in degrees for the final circular orbit
  • Prevent overheats - Limits the throttle to prevent parts from overheating
  • Limit to terminal velocity - Use this option to automatically throttle down the craft once the terminal velocity is reached
  • Corrective steering - Will cause the craft to steer based on the more accurate velocity vector rather than positional vector (large craft may actually perform better with this box unchecked)
  • Auto-stage - The autopilot will automatically stage when the current stage has run out of fuel
  • Delays - Allows for delays to the beginning and the end of each automatic stage
  • Stop at stage - Staging will not occur beyond this stage number
  • Autopilot status - A description of the current status of the autopilot

Edit Ascent Path

When checked, the Edit Ascent Path button will open a small window with diagram of the rocket's idealized ascent. The following options can be edited, and the diagram will update as their values change:

  • Turn Start Altitude - The altitude at which the gravity turn should begin
  • Turn End Altitude - The altitude at which the gravity turn should end
  • Final Flight Path Angle - The final angle with respect to the prograde direction
  • Turn Shape - Varies the parabolic part of the trajectory

Target Options

Further options are only available when a target is selected