  Space weather observations and modeling at Mars have begun but they must be
significantly increased to support the future of Human Exploration on the Red
Planet. A comprehensive space weather understanding of a planet without a
global magnetosphere and a thin atmosphere is very different from our situation
at Earth so there is substantial fundamental research remaining. It is expected
that the development of suitable models will lead to a comprehensive
operational Mars space weather alert (MSWA) system that would provide rapid
dissemination of information to Earth controllers, astronauts in transit, and
those in the exploration zone (EZ) on the surface by producing alerts that are
delivered rapidly and are actionable. To illustrate the importance of such a
system, we use a magnetohydrodynamic code to model an extreme Carrington-type
coronal mass ejection (CME) event at Mars. The results show a significant
induced surface field of nearly 3000 nT on the dayside that could radically
affect unprotected electrical systems that would dramatically impact human
survival on Mars. Other associated problems include coronal mass ejection (CME)
shock-driven acceleration of solar energetic particles producing large doses of
ionizing radiation at the Martian surface. In summary, along with working more
closely with international partners, the next Heliophysics Decadal Survey must
include a new initiative to meet expected demands for space weather forecasting
in support of humans living and working on the surface of Mars. It will require
significant effort to coordinate NASA and the international community
contributions.
