Phoning home from 93 billion miles away–only E.T. and other science fiction characters can do that. But with the help of National Institute of Standards and Technology (NIST) know-how, reality soon may catch up with imagination.
Conceptual designs for a “realistic interstellar explorer,” or RISE–a highly autonomous craft that would travel far beyond this solar system to collect scientific data–call for a laser-based communications link to Earth that relies in part on a recent NIST invention called a Parallel Cantilever Bi-axial Micro-Positioner. The prototype NIST device acts as a mechanical filter that generates very straight lines by screening out all other motions. Primarily intended for use in the delicate assembly and alignment of optoelectronic devices and applications in micro- and nano-manufacturing, the micro-positioner in a different application offers a promising means for meeting the demanding range, mass and power requirements for the RISE.
In its interstellar role, the micro-positioner would be used to position a lens that steers a laser beam communication link toward Earth. The beam must be pointed precisely because the distances would be, well, astronomical. The RISE is envisioned as having a range up to 1,000 Astronomical Units (AU)–1,000 times the distance from the Earth to the sun, or 93 billion miles.
A recent paper by researchers at NIST and Johns Hopkins University Applied Physics Laboratory (which is designing the RISE) concluded that an optical communications downlink spanning 1,000 AU is technically feasible in the next decade if these new technologies can be sufficiently refined. For example, the current range of the NIST micro-positioner would have to be improved by a factor of nearly 10.
