Prime Timeline
   | Year | Event | 
   | 1957 | 
       ● [1]
         Sputnik 1 is launched, Earth's first artificial satellite. The launch is observed by a Vulcan vessel which subsequently crashes on the planet, stranding the crew there for some months. [2] | 
   
Colour key
● - Shows the canon status and reference of the year for this event
References
| # | Series | Season | Source | Comment | 
| 1 |  |  | Speculative | Date is assumed to be the same as in the real world timeline | 
| 2 | ENT | 2 | Carbon Creek | It appears from the episode that this was indeed a real event and not just a story |