   }
   
   func drawText() {
-    guard let vars = data else {
+    guard let data = data else {
       return
     }
 //    text.draw(String(format: "%03.1f°", vars.Roll), size: 32,

    "v.altitude", "n.roll", "n.pitch", "n.heading",
    "rpm.RADARALTOCEAN", "v.surfaceSpeed", "v.verticalSpeed",
    "v.orbitalVelocity", "rpm.HORZVELOCITY", "v.sasValue", "v.rcsValue", "v.lightValue", "v.brakeValue", "v.gearValue", "f.throttle",
    "rpm.SPEEDDISPLAYMODE", ]
  
  /// Start communicating with the kerbal data store
  func connect(to : IKerbalDataStore){

  var Throttle : Float = 0
  var SpeedDisplay : SpeedDisplayMode = .Surface

  var NodeExists : Bool = false
  var NodeBurnTime : Float = 0
  var NodeTime : Float = 0
  var NodeDv : Float = 0
}

class NavBall : Instrument {
