run gravity_calculator.
run suicide_burn_calculator.

clearscreen.

wait 1.
sas on.

set vLand to -4.
set runmode to 7.
set thrust to ship:maxthrust.
set counter to 0.

lock h to alt:radar.
lock vd to ship:verticalspeed.
lock vDiff to (vLand - vd).

lock TimeToBurn to ((suicide_burn_calculator(1.05)-h)/vd).
lock ZeroAccelThrust to ((Ship:mass*g)/thrust).

until runmode = 6 {
    set g to -gravity_calculator().

    if runmode = 7 {
        set TVAL to 0.
        if h > 5000 {
            lock steering to retrograde.
            }
        if h < 50000 {
            ag3 on.
            lock steering to srfretrograde.
            set runmode to 8.
            }
    }

    if runmode = 8 {
        if h < (suicide_burn_calculator(1.05) - vd) {
            set TVAL to 1.
            RCS on.
            }
        else {
            set TVAL to 0.
            }
        if h/-vd < 2 {
            brakes off.
            }
        if alt:radar < 400 {
            gear on.
            }
        if vd > -6 {
            lock steering to up.
            set runmode to 9.
            }
        }

    if runmode = 9 {
        if vDiff > 0 {
            set TVAL to (ZeroAccelThrust + 0.1).
            }
        if vDiff < 0 {
            set TVAL to (ZeroAccelThrust - 0.1).
            }
        if vd > -0.1 and h < 100 {
            set counter to counter + 1.
            wait 0.1.
            }
        if counter > 20 {
            set runmode to 6.
            }
        }

    lock throttle to TVAL.

    print "Vertical Velocity:               " + round(vd, 2) + "                " at (5,4).
    print "Required Burn Height:            " + round(suicide_burn_calculator(1.1), 2) + "                  " at (5,5).
    print "Time to Required Burn            " + round(TimeToBurn, 2) + "        " at (5,6).
    print "Runmode:                         " + runmode + "                     " at (5,7).
    print "Gravitational Acceleration:      " + round(g, 2) + "                 " at (5,8).

    }

if runmode = 6 {
    set TVAL to 0.
    unlock throttle.
    clearscreen.
    print "Landing Complete" at (5,4).
    wait 1.
    }