posted 02-19-2020 10:44 AM               

But, along the way I run across questions that I just can't seem to find the answer to. One of them is how the International Space Station commander is selected. It seems to me that each member nation/organization gets time to command the station (to a certain degree) with the USA and Russia getting the majority of the share as they are the larger partners in the project.

During the three-person (and two-person "caretaker" crew) era (ISS Expeditions 1-20) the station commander basically alternated back and forth between USA and Russia. There were a couple exceptions to this during which Russian commanders had consecutive missions, but for the most part it alternated.

Once the station became a six-person crew, it seemed to change. For part of the time, USA and Russia alternated after two expeditions (for example Expeditions 27/28 had Russia commanders, 29/30 had USA commanders, 31/32 had Russian commanders) and other times long stretches occurred where one country dominated the "commander seat" (examples: USA astronauts commanded every expedition from 45-51 except 49 and then Russian cosmonauts commanded every expedition from 58-62 expect 61).

I assume that part of this is based on experience, but I'm certain part of it is also political. With so many different countries and organizations involved, there has got to be some negotiation and politics involved in this process.

So, my question is, how is the commander selected?

For reference, here is a list of each ISS Expedition to date with the nationality of then mission commander:

• Expedition 1: USA
  
• Expedition 2: Russia
  
• Expedition 3: USA
  
• Expedition 4: Russia
  
• Expedition 5: Russia
  
• Expedition 6: USA
  
• Expedition 7: Russia
  
• Expedition 8: USA
  
• Expedition 9: Russia
  
• Expedition 10: USA
  
• Expedition 11: Russia
  
• Expedition 12: USA
  
• Expedition 13: Russia
  
• Expedition 14: USA
  
• Expedition 15: Russia
  
• Expedition 16: USA
  
• Expedition 17: Russia
  
• Expedition 18: USA
  
• Expedition 19: Russia
  
• Expedition 20: Russia
  
• Expedition 21: Belgium
  
• Expedition 22: USA
  
• Expedition 23: Russia
  
• Expedition 24: Russia
  
• Expedition 25: USA
  
• Expedition 26: USA
  
• Expedition 27: Russia
  
• Expedition 28: Russia
  
• Expedition 29: USA
  
• Expedition 30: USA
  
• Expedition 31: Russia
  
• Expedition 32: Russia
  
• Expedition 33: USA
  
• Expedition 34: USA
  
• Expedition 35: Canada
  
• Expedition 36: Russia
  
• Expedition 37: Russia
  
• Expedition 38: Russia
  
• Expedition 39: Japan
  
• Expedition 40: USA
  
• Expedition 41: Russia
  
• Expedition 42: USA
  
• Expedition 43: USA
  
• Expedition 44: Russia
  
• Expedition 45: USA
  
• Expedition 46: USA
  
• Expedition 47: USA
  
• Expedition 48: USA
  
• Expedition 49: Russia
  
• Expedition 50: USA
  
• Expedition 51: USA
  
• Expedition 52: Russia
  
• Expedition 53: USA
  
• Expedition 54: Russia
  
• Expedition 55: Russia
  
• Expedition 56: USA
  
• Expedition 57: Germany
  
• Expedition 58: Russia
  
• Expedition 59: Russia
  
• Expedition 60: Russia
  
• Expedition 61: Italy
  
• Expedition 62: Russia