  We present coordinated observations of GRB 170202A carried out by the Zadko
and the Virgin Island Robotic Telescopes. The observations started 59s after
the event trigger, and provided nearly continuous coverage for two days due to
the unique location of these telescopes. We clearly detected an early rise in
optical emission, followed by late optical flares. By complementing these data
with archival observations, we show GRB 170202A is well described by the
standard fireball model if multiple reverse shocks are taken into account. Its
fireball is evidenced to expand within a constant density interstellar medium,
with most burst parameters consistent with the usual ranges found in
literature. The electron and magnetic energy parameters (\epsilon_e,
\epsilon_B) are orders of magnitude smaller than commonly assumed values. We
argue that the global fit of the fireball model achieved by our study should be
possible for any burst, pending the availability of a sufficiently
comprehensive data set. This conclusion emphasizes the crucial importance of
coordinated observation campaigns of GRBs, such as the one central to this
work, to answer outstanding questions about the underlying physics driving
these phenomena.
