>If you try and send information between the 2 spaceships. If we use light or radio waves surely the data carried on those wavelengths are corrupt due to red shift.

you KNOW the transmission frequency. you know redshift. in theory you could correct for it.

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>Making it impossible for long distance data transfer in space between 2 objects that are moving away.

it's going to be "one way" both ways.. 20 light hour delay is not conducive to conversations.

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https://www.jpl.nasa.gov/news/engineers-investigating-nasas-voyager-1-telemetry-data

Voyager 1 is currently 14.5 billion miles (23.3 billion kilometers) from Earth, and it takes light 20 hours and 33 minutes to travel that difference.