Oh? We don't even begin to have the technology to create a self-replicating, self-repairing machine that can be expected to last 70 years or so of active servi

Oh? We don't even begin to have the technology to create a self-replicating, self-repairing machine that can be expected to last 70 years or so of active service. One that slowly gets better over time as the error-prone replication turns up the odd improvement.