hopper1.ks

@lazyglobal off.

function gravMag {
    parameter alt,bdy.
    return bdy:mu/(bdy:radius+altitude)^2.
}

function gravVec {
    parameter self is ship.
    return gravMag(self:altitude,self:obt:body)*-self:up:vector:normalized.
}

function thrustVec {
    parameter self is ship.
    return self:availableThrust*-self:facing:vector:normalized.
}

function maxMag {
    parameter vec, mag.
    if vec:mag<mag return vec.
    return mag*vec:normalized.
}

clearVecDraws().

local posVec is vecDraw(V(0,0,0),V(0,0,0),red,"POS",1,true,0.2).
local velVec is vecDraw(V(0,0,0),V(0,0,0),green,"VEL",1,true,0.2).
local accVec is vecDraw(V(0,0,0),V(0,0,0),blue,"ACC",1,true,0.2).

local launchPad is LatLng(-0.0971570496595165,-74.557757572037).
local landingPad is LatLng(-0.0967218940930756,-74.6173570891441).

lock throttle to 0.
if ship:availableThrust=0 stage.
sas off.
rcs on.

local waypt is 0.
until waypt>0 and status="LANDED"{
    local tgtPos is 0.
    if waypt=0 set tgtPos to launchPad:altitudePosition(landingPad:terrainHeight+100).
    else if waypt=1 set tgtPos to landingPad:altitudePosition(landingPad:terrainHeight+100).
    else if waypt=2 set tgtPos to landingPad:altitudePosition(landingPad:terrainHeight).

    local gAccV is gravVec().
    local tgtVel is maxMag(tgtPos,7.5).
    local tgtAcc is maxMag(tgtVel-ship:velocity:surface,7.5).

    local tAccV is thrustVec()/ship:mass.

    local netAcc is -tgtAcc+gAccV.

    print tgtPos:mag.
    //print netAcc:mag.

    lock steering to lookDirUp(-netAcc,-ship:north:vector).
    local x is vDot(tAccV,netAcc).
    if x<>0 lock throttle to netAcc:vec:mag^2/x. //vDot(tAccV,netAcc).

    //print throttle*thrust:mag/gAccV:mag.
    //print round(cos(vang(up:vector,facing:vector)),4).
    //print throttle*tAccV+gAccV.

    set posVec:vec to tgtPos.
    set velVec:vec to tgtVel.
    set accVec:vec to tgtAcc.

    wait 0.1.

    if tgtPos:mag<1 set waypt to waypt+1.
}
lock throttle to 0.
unlock steering.