A miniature 'smart dust' craft to forecast space storms

American mechanical engineers have invented a one-
centimetre-square "smart dust" spacecraft that could provide an early warning of dangerous space storms.
The spacecraft, designed by Mason Peck and Justin Atchison from the Cornell University in Ithaca, New York, is modelled on the dust particles that orbit the sun and could alert about the approaching space storms well before a conventional craft can. The prototypes of the machine that is 25 micrometres thick and weighs less than 7.5
milligrams, are due to be launched into low-Earth orbit this year, journal New Scientist reported. "The craft is modelled on the dust particles that orbit the sun and are propelled by the photons streaming out from the sun," Peck said. He said, "This solar radiation pressure would have a negligible effect on normal-sized spacecraft but is significant at the millimetre scale. The grooved edges of the spacecraft-on-a chip deflect incoming photons in such a way as to ensure it always faces the sun". Peck estimates that its miniature size could give an extra 13 minutes' notice of a storm compared with larger solar monitoring craft such as Nasa's Advanced Composition Explorer. The craft's miniature size would let it hitch a ride into space on the back of another satellite mission headed for the Lagrange point between the earth and the sun.