  The HETE-2 mission has been highly productive. It has observed more than 250
GRBs so far. It is currently localizing 25 - 30 GRBs per year, and has
localized 43 GRBs to date. Twenty-one of these localizations have led to the
detection of X-ray, optical, or radio afterglows, and as of now, 11 of the
bursts with afterglows have redshift determinations. HETE-2 has also observed
more than 45 bursts from soft gamma-ray repeaters, and more than 700 X-ray
bursts. HETE-2 has confirmed the connection between GRBs and Type Ic
supernovae, a singular achievement and certainly one of the scientific
highlights of the mission so far. It has provided evidence that the
isotropic-equivalent energies and luminosities of GRBs may be correlated with
redshift; such a correlation would imply that GRBs and their progenitors evolve
strongly with redshift. Both of these results have profound implications for
the nature of GRB progenitors and for the use of GRBs as a probe of cosmology
and the early universe. HETE-2 has placed severe constraints on any X-ray or
optical afterglow of a short GRB. It has made it possible to explore the
previously unknown behavior optical afterglows at very early times, and has
opened up the era of high-resolution spectroscopy of GRB optical afterglows. It
is also solving the mystery of "optically dark" GRBs, and revealing the nature
of X-ray flashes (XRFs).
