[powera]

If every computer data on a Mars mission dies, I think all the colonists aree dead. We aren't anywhere close to the technology to support colonists on Mars without technology. Ergo, "physical books" are just a waste of weight.

[dvdfvo]

If every computer ... dies. Ironically this is also true for Earth. Therefore it is not a concern. :-)

[chongli]

How does that follow? There are billions of computers on Earth. On Mars there may be fewer than one hundred. The odds are not even remotely comparable.

Secondly, if all of the computers on Earth die we can still go outside and breathe the air, drink water from rivers and lakes, gather plants and hunt wild game for food. None of those options are available on Mars. If the computer controlling life support suddenly fails, what options are there to survive? All of this has to be planned for and taken into account. If there is nobody on Mars capable of repairing the life support system (including its software) then they are utterly dependent on the communication link back to Earth.