Video: Change of command aboard International Space Station

With Hurricane Isaias threatening Florida’s East Coast, astronauts Doug Hurley and Bob Behnken are awaiting a go-ahead on plans to undock from the International Space Station Saturday, setting up a fiery plunge to splashdown Sunday, presumably in the Gulf of Mexico, to close out a 64-day flight.

Physicists are gearing up to send a re-engineered science instrument originally designed for lofty balloon flights high in Earth’s atmosphere to the International Space Station next week to broaden their knowledge of cosmic rays, subatomic particles traveling on intergalactic routes that could hold the key to unlocking mysteries about supernovas, black holes, pulsars and dark matter.

An unmanned cargo freighter carrying nearly four tons of supplies and science, launched and operated commercially for NASA, blasted off from Cape Canaveral on Tuesday atop an Atlas 5 rocket bound for the International Space Station.