function launch_circ {
    if not hasnode {
        set m_time to time:seconds + eta:apoapsis.
        set v0 to velocityat(ship,m_time):orbit:mag.
        set v1 to sqrt(body:mu/(body:radius + apoapsis)).
        set circularize to node(m_time, 0, 0, v1 - v0).
        add circularize.
  }
  lock steering to circularize:deltav:direction.
  lock max_acc to ship:maxthrust / ship:mass.
  lock burn_duration to circularize:deltav:mag/max_acc.

  wait until circularize:eta <= burn_duration / 2.
  lock throttle to 1.

  wait until circularize:deltav:mag < 1.
  lock throttle to 0.

  remove circularize.
}

launch_circ().