The mission: Hopkins and another astronaut will attempt to repair a faulty pump outside the International Space Station.
Spacewalks were suspended after an Italian astronaut nearly drowned when water from his suit's cooling system leaked into his helmet.
A snorkel has now been retrofitted into those helmets and astronauts can breathe through a tube if there's a water leak.
As an additional safety measure, pads are now velcro'd inside the back space helmets as an early warning system.
If the pads feel "squishy," astronauts are instructed to alert mission control.