diff --git a/GameData/RP-1/Tree/ECM-Engines.cfg b/GameData/RP-1/Tree/ECM-Engines.cfg
index 2a6b4187e2..d1c4e36497 100644
--- a/GameData/RP-1/Tree/ECM-Engines.cfg
+++ b/GameData/RP-1/Tree/ECM-Engines.cfg
@@ -869,6 +869,7 @@
     X3-HV = 50000,X3
     X3-HV-K = 5000,X3-HV
     XASR-1 = 1000
+    XASR-2 = 1000, XASR-1
     XIPS25cm = 23000
     XLR10-RM-2 = 2500,Navaho-PhaseI-TP
     XLR11-RM-13-10K = 5000, XLR11-RM-13-8K
diff --git a/GameData/RP-1/Tree/TREE-Engines.cfg b/GameData/RP-1/Tree/TREE-Engines.cfg
index 559659d9d4..e8527d49e4 100644
--- a/GameData/RP-1/Tree/TREE-Engines.cfg
+++ b/GameData/RP-1/Tree/TREE-Engines.cfg
@@ -5682,6 +5682,13 @@
                 *@PARTUPGRADE[RFUpgrade_XASR-1]/deleteme -= 1
             }
 
+            @CONFIG[XASR-2]
+            {
+                %techRequired = earlyRocketry
+                %cost = 4
+                *@PARTUPGRADE[RFUpgrade_XASR-2]/deleteme -= 1
+            }
+
             @CONFIG[XIPS25cm]
             {
                 %techRequired = elecPropulsion1998
@@ -24151,6 +24158,46 @@ PART
 {
 }
 
+PARTUPGRADE
+{
+        name = RFUpgrade_XASR-2
+        partIcon = RO-H1-RS27 // FIXME Once we get dedicated model
+        techRequired = earlyRocketry
+        entryCost = 0
+        cost = 0      
+        title = Aerobee Engine Upgrade: XASR-2 Config
+        basicInfo = Engine Performance Upgrade
+        manufacturer = Engine Upgrade
+        deleteme = 1
+        description = The Aerobee Engine now supports the XASR-2 configuration for increased performance. Unlock it in the VAB/SPH through the engine configs interface.\n\n
+}
+
+PART
+{
+    name = RFUpgrade_engineConfigSource_XASR-2
+    engineType = Aerobee
+}
+
+@PART[RFUpgrade_engineConfigSource_XASR-2]:AFTER[RealismOverhaulEngines]
+{
+    %MODULE[Module*EngineConfigs] {
+        @name = ModuleEngineConfigs
+        %CONFIG[XASR-2] {
+            &specLevel = operational
+        }
+    }
+}
+
+@PARTUPGRADE[RFUpgrade_XASR-2]:AFTER[RealismOverhaulEngines]
+{
+    %description = #$description$\nAvailable at specLevel $@PART[RFUpgrade_engineConfigSource_XASR-2]/MODULE[ModuleEngineConfigs]/CONFIG[XASR-2]/specLevel$
+    // TODO: could add any number of other useful fields from the CONFIG here. cost? description?
+}
+
+!PART[RFUpgrade_engineConfigSource_XASR-2]:AFTER[RealismOverhaulEngines]
+{
+}
+
 PARTUPGRADE
 {
         name = RFUpgrade_XLR11-RM-13-10K
diff --git a/Source/Tech Tree/Parts Browser/data/Engine_Config.json b/Source/Tech Tree/Parts Browser/data/Engine_Config.json
index bdafa717e8..c130feb708 100644
--- a/Source/Tech Tree/Parts Browser/data/Engine_Config.json	
+++ b/Source/Tech Tree/Parts Browser/data/Engine_Config.json	
@@ -18884,6 +18884,27 @@
         "identical_part_name": "",
         "module_tags": []
     },
+    {
+        "name": "XASR-2",
+        "title": "XASR-2",
+        "description": "",
+        "mod": "Engine_Config",
+        "cost": 4,
+        "entry_cost": "0",
+        "category": "ORBITAL",
+        "info": "",
+        "year": "1950",
+        "technology": "earlyRocketry",
+        "ro": true,
+        "orphan": false,
+        "rp0_conf": true,
+        "spacecraft": "",
+        "engine_config": "Aerobee",
+        "upgrade": true,
+        "entry_cost_mods": "1000, XASR-1",
+        "identical_part_name": "",
+        "module_tags": []
+    },
     {
         "name": "XIPS25cm",
         "title": "XIPS25cm",