NASA changes the rules of the game for commercial space stations

Aiming to shrink the post-ISS gap, but less orbit time for NASA astronauts?
NASA has moved the goalposts for companies seeking to replace the aging International Space Station (ISS) and changed the minimum capability required to four crew for one-month 'increments.' The change means that the permanent occupation of the ISS will be a thing of the past, at least as far as the US space agency is concerned.…