Kerbin to Mun and Back

--
--         Kerbin to Mun and Back by B25Mich
--                    Version 1.0
--
--                 for MechJeb 1.9.1
--
--------------------------------------------------------
-- Usage: * save to KSP/PluginData/mumechlib/kerbintomun.lua
--        * in game, open autom8
--        * enter: dofile("kerbintomun.lua")
--        * and follow the instructions.
--------------------------------------------------------

function GoMunDriver(lat, lon)

    print "Launching..."
        mechjeb.launchTo(125000, 0)
        wait(mechjeb.free)
        mechjeb.autoStageActivate()
        print "TMI..."
        mechjeb.transfer("Mun", 200000)
        wait(mechjeb.free)
        print "Warping to SoI..."
        mechjeb.warpToEvent("soi")
        wait(mechjeb.free)
        print "Warping to Pe..."
        mechjeb.warpToEvent("pe", 30)
        wait(mechjeb.free)
        print "Circularizing orbit..."
        mechjeb.circularize()
        wait(mechjeb.free)
        print "Landing..."
        if (lat == nil or lon == nil) then
        mechjeb.landAt(0, 14)
     else
            mechjeb.landAt(lat, lon)
        end
        wait(mechjeb.free)
        mechjeb.autoStageDeactivate()
        print "Landed!"
end

function GoKerbinDriver(lat, lon)

    print "Lifting off..."
    mechjeb.attitudeTo("up", "SURFACE_NORTH") -- vertical ascent
    mechjeb.thrustActivate(100)
    while vessel.altitudeTrue < 300 do
        wait(0.25)
    end

    print "Escaping the Mun..."
    -- this needs to be optimized. figure out an escape vector
    -- that is as close as possible to the opposite of Mun's orbital velocity
    -- but not lower than 0° to the surface
    mechjeb.attitudeTo("right", "SURFACE_NORTH") -- heading east
    while vessel.orbitEccentricity < 1 do
        wait(0.25)
    end
    mechjeb.thrustDeactivate()

    print "Coasting to Mun escape, hang on."
    mechjeb.warpToEvent("soi")
    wait(mechjeb.free)

    print("Lowering Kerbin periapsis to 100 km...")
    mechjeb.changePe(100 * 1000)
    wait(mechjeb.free)

    print "Warping to Pe..."
        mechjeb.warpToEvent("pe", 30)
        wait(mechjeb.free)

        print "Circularizing orbit..."
        mechjeb.circularize()
        wait(mechjeb.free)

    print "Re-entry... hold onto something."
        mechjeb.landAt(-0.103, -74.575)
        wait(mechjeb.free)
        mechjeb.autoStageDeactivate()
        print "Landed!"
end

function WaitForLandingDriver(lat, lon)
    wait(30)
    while vessel.altitudeBottom > 5 do
        wait(5)
    end
    print "Prepare for launch."
    wait(30)
    local co = coroutine.create(GoKerbinDriver)
    coroutine.resume(co, lat, lon)
end

function GoKerbin(lat, lon)
    local co = coroutine.create(GoKerbinDriver)
        coroutine.resume(co, lat, lon)
end

function GoMun(lat, lon)
    local co = coroutine.create(GoMunDriver)
    coroutine.resume(co, lat, lon)
end

function RoundTrip(munlat, munlon, kerblat, kerblon)
    local co1 = coroutine.create(GoMunDriver)
    coroutine.resume(co1, munlat, munlon)
        local co2 = coroutine.create(WaitForLandingDriver)
    coroutine.resume(co2, kerblat, kerblon)
end

print "Usage: GoMun(lat, lon)"
print "Usage: GoKerbin(lat, lon)"
print "Usage: RoundTrip(munlat, munlon, kerbinlat, kerbinlon)"