diff --git a/lignumis/locale/en/strings.cfg b/lignumis/locale/en/strings.cfg
index 9c81d4a..4abc56b 100644
--- a/lignumis/locale/en/strings.cfg
+++ b/lignumis/locale/en/strings.cfg
@@ -185,5 +185,6 @@ quality-catalyst=Quality catalyst
 [lignumis]
 start-new-game=Lignumis is meant to be played in a fresh game as it extends the early game before Nauvis.
 provisional-rocket-silo-button=Escape to Nauvis
-provisional-rocket-silo-button-tooltip=Your personal inventory must be empty!
+provisional-rocket-silo-button-tooltip-inventory=Your personal inventory must be empty!
+provisional-rocket-silo-button-tooltip-nauvis=You don't know yet where to go!
 provisional-rocket-silo-description=Fill the rocket inventory and launch the rocket to escape to Nauvis.\nBe sure to take material to jumpstart your iron, copper and wood production.
diff --git a/lignumis/scripts/wooden-rocket-silo.lua b/lignumis/scripts/wooden-rocket-silo.lua
index 1d0f6bd..0693d13 100644
--- a/lignumis/scripts/wooden-rocket-silo.lua
+++ b/lignumis/scripts/wooden-rocket-silo.lua
@@ -15,11 +15,16 @@ local function build_gui(player, rocket_silo)
     local launch_button = { type = "button", name = "provisional-rocket-silo-launch-button", caption = { "lignumis.provisional-rocket-silo-button" } }
 
     local inventory = player.get_main_inventory()
-    launch_button.enabled = inventory.is_empty()
-    if not launch_button.enabled then
-        launch_button.tooltip = { "lignumis.provisional-rocket-silo-button-tooltip" }
+    local is_inventory_empty = inventory.is_empty()
+    local is_nauvis_researched = player.force.technologies["planet-discovery-nauvis"].researched
+    launch_button.enabled = is_inventory_empty and is_nauvis_researched
+    if not is_inventory_empty then
+        launch_button.tooltip = { "lignumis.provisional-rocket-silo-button-tooltip-inventory" }
+    elseif not is_nauvis_researched then
+        launch_button.tooltip = { "lignumis.provisional-rocket-silo-button-tooltip-nauvis" }
     end
 
+
     storage.rocket_silo_guis = storage.rocket_silo_guis or {}
     storage.rocket_silo_guis[player.index] = {
         fake_silo = rocket_silo,