Hi guys. I just needed a little help with my first program for kOS (I assume this is the right place to post this?). I know it's a little rough... // ######################################### // ##### LAUNCH TO ORBIT. ##### // ######################################### clearscreen. // VARIABLE DECLARATION declare status. // program status declare mt. // mission time declare svel. // ship surface velocity declare alt. // ship altitude declare tlf. // total liquid fuel left declare slf. // current stage liquid fuel left declare steer. // the direction the ship is steering to declare thr. // throttle percentage declare tvel. // ship terminal velocity // INITIAL VARIABLE SETTING set mt to missiontime -11. set status to "Status: Idle.". set thr to 1. set tvel to 100.9. // MAIN LOOP until ship:altitude > 250000 { set mt to mt + 1. // Counting down. set svel to round(velocity:surface:mag). set alt to round(ship:altitude). set slf to round(stage:liquidfuel). set tlf to round(ship:liquidfuel). // ASCENTION INITIATION. if mt = -6 { set status to "Status: Throttled engines to 100%.". lock throttle to thr. }. if mt = -4 { set status to "Status: Locked steering to upwards direction". lock steering to up + R(0,0,-180). }. if mt = -2 or mt = -1 { set status to "Status: Ready to go in... " + abs(mt). }. if mt = 0 { set status to "Status: Lift off!". stage. }. // VERTICAL ASCENT if mt = 1 { set status to "Status: Vertical ascent.". }. // MAINTAIN TERMINAL VELOCITY lock throttle to thr. if tvel < svel { set thr to 0. } else { set thr to 1. }. if alt < 1000 { set tvel to 110.5. } else if alt > 1000 and alt < 2000 { set tvel to 121.9. } else if alt > 2000 and alt < 3000 { set tvel to 134.5. } else if alt > 3000 and alt < 4000 { set tvel to 148.4. } else if alt > 4000 and alt < 5000 { set tvel to 163.7. } else if alt > 5000 and alt < 6000 { set tvel to 180.6. } else if alt > 6000 and alt < 7000 { set tvel to 199.3. } else if alt > 7000 and alt < 8000 { set tvel to 219.9. } else if alt > 8000 and alt < 9000 { set tvel to 242.6. } else if alt > 9000 and alt < 10000 { set tvel to 267.7. } else if alt > 10000 and alt < 12500 { set tvel to 342.4. } else if alt > 12500 and alt < 15000 { set tvel to 437.8. } else if alt > 15000 and alt < 20000 { set tvel to 716. } else { set tvel to 2332. }. // STAGING // SCREEN PRINTING clearscreen. print "##### ASCENTION PROTOCOL v 0.1 #####" at (7,1). print "####################################" at (7,2). print "--------------------------------------------------" at (0,4). print "|" at (0,5). print status at (5,5). print "|" at (50,5). print "--------------------------------------------------" at (0,6). print " -----------------------------------" at (0,8). print "|" at (15,9). print "|" at (50,9). print " -----------------------------------" at (0,10). print "Mission time: " + mt at (19,9). print "--------------------DATA TRACK--------------------" at (0,16). print "|" at (0,17). print "|" at (50,17). print "|" at (0,18). print "Surface vel.: " + svel at (5,18). print "Terminal vel.: " + tvel at (25,18). print "|" at (50,18). print "|" at (0,19). print "|" at (50,19). print "|" at (0,20). print "Altitude: " + alt at (5,20). print "Thrust: " + thr at (25,20). print "|" at (50,20). print "|" at (0,21). print "|" at (50,21). print "|" at (0,22). print "Stage Fuel: " + slf at (5,22). print "Total Fuel: " + tlf at (25,22). print "|" at (50,22). print "--------------------------------------------------" at (0,23). wait 1. }. My problem is that I can't do the auto-staging cause kOS doesn't recognize the stage fuel left. It prints the total fuel left as the same amount as the stage fuel left. So I don't know what condition to give for it to work. Any help?