Cusps of superconducting strings can serve as GRB engines. A powerful beame
d pulse of electromagnetic radiation from a cusp produces a jet of accelera
ted particles. whose propagation is terminated by the shock responsible for
GRB. A single free parameter, the string scale of symmetry breaking eta si
milar to 10(14) GeV, together with reasonable assumptions about the magnitu
de of cosmic magnetic fields and the fraction of volume that they occupy, e
xplains the GRB rate, duration, and fluence, as well as the observed ranges
of these quantities. The wiggles on the string can drive the short-time st
ructures of GRB. This model predicts that GRBs are accompanied by strong bu
rsts of gravitational radiation which should be detectable by LIGO, VIRGO,
and LISA detectors. Another prediction is the diffuse x- and gamma-ray radi
ation at 8 MeV-100 GeV with a spectrum and flux comparable to the observed.
The weakness of the model is the prediction of too low a rate of GRBs from
galaxies, as compared with observations. This suggests that either the cap
ture rate of string loops by galaxies is underestimated in our model or tha
t GRBs from cusps are responsible for only a subset of the observed GRBs no
t associated with galaxies.