Initial import

boot/moon-impactor.ks

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+@lazyglobal off.
+wait until ship:unpacked.
+rcs off.
+lock throttle to 0.
+
+runoncepath("0:/lib/common.ks").
+runoncepath("0:/lib/moonmath.ks").
+runoncepath("0:/lib/stage/atlas.ks").
+runoncepath("0:/lib/stage/agena.ks").
+
+local state is lex().
+
+local function ship_volume {
+    return ship:rootpart:getmodule("kosprocessor"):volume.
+}
+
+local function phase {
+    switch to ship_volume().
+    if not ship_volume():exists("state.json") {
+        set_phase("prelaunch").
+    }
+    set state to readjson("state.json").
+    return state["phase"].
+}
+
+local function set_phase {
+    parameter new_phase.
+    switch to ship_volume().
+    set state["phase"] to new_phase.
+    writejson(state, "state.json").
+    kuniverse:quicksaveto("moon-impactor-"+new_phase).
+}
+
+if phase() = "prelaunch" {
+    local target_inclination is max(moon:obt:inclination,ship:latitude).
+    local target_alt is 500_000.
+    set state["azimuth"] to launch_azimuth(target_inclination, target_alt).
+
+    local launch_params is moonmath:calculate_launch(target_inclination, state["azimuth"], target_alt).
+    local launch_time is launch_params:launch_time.
+    set state["moon_altitude"] to launch_params:moon_altitude.
+    set state["burn_longitude"] to launch_params:burn_longitude.
+    print "Burning for moon at " + state["burn_longitude"] + " right ascension".
+
+    wait 2.
+
+    until launch_time - time:seconds < 10 {
+        print "Not ready to launch yet, warping...".
+        warpto(launch_time-9).
+        wait 0.
+        wait until warp = 0.
+        wait until kuniverse:timewarp:issettled.
+        print "Maybe done warping?".
+    }
+    wait until time:seconds > launch_time.
+
+    atlas:launch(state["azimuth"], target_alt, 4).
+    stage.
+    set_phase("circularize").
+}
+
+if phase() = "circularize" {
+    agena:orbit(state["azimuth"]).
+    agena:power_down().
+
+    wait 1.
+    set_phase("parkingorbit").
+}
+
+local function ship_longitude {
+    return mod(ship:longitude + ship:body:rotationangle + 360, 360).
+}
+
+local function transfer_lead_angle {
+    parameter moon_alt.
+    local moon_range is moon:apoapsis - moon:periapsis.
+    local moon_frac is (moon_alt - moon:periapsis) / moon_range.
+    local lead_angle_frac is 1.0 - moon_frac.
+    return 1.1 + 0.65 * lead_angle_frac.
+}
+
+if phase() = "parkingorbit" {
+    // Just in case our burn point is RIGHT HERE, we want to go around at least once.
+    set warpmode to "physics".
+    set warp to 3.
+    wait until abs(ship_longitude() - state["burn_longitude"]) > 10.
+    set warp to 0.
+    wait until kuniverse:timewarp:issettled.
+    wait 1.
+
+    // Rails warp until we're nearish to the burn point
+    print "Warping to dLongitude < 15".
+    set warpmode to "rails".
+    set warp to 2.
+    wait until abs(ship_longitude() - state["burn_longitude"]) < 15.
+    set warp to 0.
+    wait until kuniverse:timewarp:issettled.
+    wait 1.
+
+    // Physics warp until we're nearish-er
+    print "Warping to dLongitude < 7".
+    set warpmode to "physics".
+    set warp to 3.
+    wait until abs(ship_longitude() - state["burn_longitude"]) < 4.
+    set warp to 0.
+    wait until kuniverse:timewarp:issettled.
+    wait 1.
+
+    agena:power_up().
+    rcs on.
+    lock steering to ship:prograde.
+    local lead_angle is transfer_lead_angle(state["moon_altitude"]).
+    wait until abs(ship_longitude() - state["burn_longitude"]) < lead_angle. // Hand-picked rather than computing burn time & time to target longitude
+    local transfer_vel is circular_vel() + hohmann_transfer_dv(earth, ship:altitude, state["moon_altitude"]).
+    print "Moon altitude is: " + state["moon_altitude"].
+    print "Transfer DV is: " + (transfer_vel - ship:velocity:orbit:mag).
+    print "Burn lead angle is: " + lead_angle.
+    agena:transfer_burn(transfer_vel).
+    wait 1.
+    stage.
+
+    set_phase("adjust").
+}
+
+if phase() = "adjust" {
+    panels on.
+    rcs on.
+
+    lock throttle to 0.0.
+    lock steering to lookdirup(ship:prograde:forevector, ship:up:forevector).
+    local adjustment is 8_000_000. // 1.5%..2.0%?
+    print "Alt Adjustment is " + adjustment.
+
+    local target_alt is state["moon_altitude"] + adjustment.
+    local max_alt_delta is 1_000_000.
+    local threshold is 0.1.
+    until false {
+        local p is threshold / max_alt_delta.
+        local da is target_alt - ship:orbit:apoapsis.
+        local horz_factor is da * p.
+        if abs(horz_factor) < threshold {
+            set ship:control:fore to 0.
+            break.
+        }
+        set ship:control:fore to horz_factor.
+        wait 0.
+    }
+    set_phase("pretransfer").
+}
+
+if phase() = "pretransfer" {
+    rcs on.
+    lock steering to sun:direction.
+    wait 1.
+    wait until steering_locked().
+    wait 1.
+    local avi_mod is ship:rootpart:getmodule("ModuleProceduralAvionics").
+    avi_mod:doaction("shutdown avionics", true).
+    wait 1.
+
+    set_phase("transfer").
+}
+
+if phase() = "transfer" {
+    set warpmode to "rails".
+    warpto(eta:transition + time:seconds).
+    wait until ship:obt:body = moon.
+    wait until kuniverse:timewarp:issettled.
+
+    set_phase("done").
+}
+
+if phase() <> "done" {
+    print "Phase logic failed, expected to be in phase '" + phase() + "'".
+}
+
+print "Done".