diff --git a/nav.py b/nav.py
index 71f9e2a..995a4a3 100644
--- a/nav.py
+++ b/nav.py
@@ -14,6 +14,7 @@ DISTANCES = {
     ("gateway", "mars"): 225.0,
     ("gateway", "venus"): 41.0,
     ("mars", "phobos"): 0.01,
+    ("mars", "deimos"): 0.02,
 }
 
 # Every route starts at Earth.
@@ -22,6 +23,7 @@ ROUTES = {
     "mars": ["earth", "gateway", "mars"],
     "venus": ["earth", "gateway", "venus"],
     "phobos": ["earth", "gateway", "mars", "phobos"],
+    "deimos": ["earth", "gateway", "mars", "deimos"],
 }
 
 NAMES = {
@@ -31,6 +33,7 @@ NAMES = {
     "mars": "Mars",
     "venus": "Venus",
     "phobos": "Phobos",
+    "deimos": "Deimos",
 }
 
 CRUISE_SPEED = 0.87  # million km per day