No deep space program challenge

Keep the human race from sending probes or ships beyond geosynchronous orbit until 2012 at least.
 
Cause some catastrophe in the late 19th or early 20th century that causes societa collapse and leads to technology not advancing for a few decades leadin the world to only be reaching 1950's level technology now.

Otherwise it's not possible, exploration and wanting to learn/know stuff is hardcoded into us on a primal level.
 
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