A cluster of space weather satellites blasted off Wednesday morning to cast fresh eyes on solar storms that can produce stunning auroras but also scramble communications and threaten astronauts in flight.

The three satellites soared from the Kennedy Space Centre shortly after sunrise on the same SpaceX rocket.

They aimed for a Sun-orbiting lookout 1.6 million kilometres from Earth, each on its own separate mission.

Altogether, the satellites from NASA and the National Oceanic and Atmospheric Administration (NOAA), plus related costs, are worth about $US1.6 billion ($2.4 billion).

NASA's director of Heliophysics, Joe Westlake, calls it "the ultimate cosmic carpool" by sharing a rocket to save money.

Heading the line-up is NASA's Interstellar Mapping and Acceleration Probe, the first to

See Full Page