diff --git a/lisainstrument/instrument.py b/lisainstrument/instrument.py
index 78016f6cfd90e9517bc21990d9c94602bc10271f..7607e3ba10bd6856450461dfecc3281583824a81 100755
--- a/lisainstrument/instrument.py
+++ b/lisainstrument/instrument.py
@@ -64,7 +64,7 @@ class Instrument:
 
     def __init__(self,
                  # Sampling parameters
-                 size=2592000, dt=1/4, t0='orbits',
+                 size=1200, dt=1/4, t0='orbits',
                  # Physics simulation sampling and filtering
                  physics_upsampling=4, aafilter=('kaiser', 240, 1.1, 2.9),
                  # Telemetry sampling