Probably not right now, but I don't see why it wouldn't be possible. Anyhow, a laser propelled solar sail would make the journey to, say, alpha centuri in more

Probably not right now, but I don't see why it wouldn't be possible. Anyhow, a laser propelled solar sail would make the journey to, say, alpha centuri in more like 20-40 years. There's really not much point in slow travel if you can, instead, launch a self-replicator, wait a few decades for it to get there, and then just cast on over.