Why keep a close eye on nanotechnology? The Foresight Institute’s Conference on Advanced Nanotechnology, closing tomorrow at the Crystal City Marriott in Washington DC, is loaded with reasons, but for interstellar theorists, the answer is mass. Ponder this: the Project Daedalus multi-stage starship, designed by the British Interplanetary Society and the first complete theoretical study of an interstellar probe, carried 50,000 tons of fuel to push a 500 ton payload. And Daedalus used nuclear-pulse propulsion; the fuel to payload ratio gets far worse with utterly inadequate chemical rockets.

Nanotechnology offers the bright promise of interstellar probes so small as to dwarf the imagination, with corresponding savings in propulsion systems, yet capable of assembling full-scale observation platforms at their target star. One of the major speakers at the Foresignt Institute conference is Robert Freitas, a giant in the field of nanotechnology and a senior research fellow at the Institute for Molecular Manufacturing. He is also the author of the Nanomedicine book series.

I relied heavily on Freitas’ extrapolations of tiny ‘needle’ probes in the last chapter of Centauri Dreams, a concept that has now replaced in his thinking his older REPRO probe, which was a kind of super-Daedalus with the ability to reproduce itself at each target star system and thus continue the human wave of exploration ever outward. Chances are we’ll never see probes the size of REPRO, but take a look at Freitas’ A Self-Reproducing Interstellar Probe for a still fascinating look at how we viewed space exploration before the nano-revolution began.

Freitas has been having a running argument with Nobel laureate Richard Smalley over how feasible molecular manufacturing actually is (or will be), but whatever his topic, his work is worth studying. Be aware that both Adam Keiper (editor of The New Atlantis ) and Howard Lovy at Nanobot are reporting on this meeting with live blog entries. Being able to participate ‘virtually’ through their work is powerfully instructive, and keeps those of us unable to attend abreast of the most recent developments. What an extraordinary contribution the weblog community can make in covering such events.