Depends on what you'd call a "machine", and how "raw" your raw materials are. Bob Freitas wrote an open-sourced book on this a decade ago: http://www.molecular

Depends on what you'd call a "machine", and how "raw" your raw materials are. Bob Freitas wrote an open-sourced book on this a decade ago: http://www.molecularassembler.com/KSRM.htm http://www.molecularassembler.com/KSRM.htm For simple tinkertoy-ish machines, floating in a sea of parts, and sitting on a shaker table, (to provide power) it's already been done. For anything with a microchip in it, full closure would require machine-phase nanotechnology. Partial replication should be possible with conventional technology, (a "clanking replicator" http://en.wikipedia.org/wiki/Clanking_replicator http://en.wikipedia.org/wiki/Clanking_replicator ) if you supply the replicators with "vitamin" parts they can't produce themselves. (Chips, stepper motors, anything made of rare minerals) A lot of work was put into this for the Advanced Automation for Space Missions study in 1980, a proposal for a solar panel factory on the Moon that would build more solar panel factories: http://www.islandone.org/MMSG/aasm/ http://www.islandone.org/MMSG/aasm/