Today at 4:43 PM Eastern, SpaceX will attempt its big comeback to the International Space Station, and it's carrying an extra safety precaution onboard.

Last summer, just two minutes after liftoff, the company's seemingly routine delivery to the station went up in flames, destroying the Dragon capsule and the several thousand pounds of supplies and science experiments it was hauling. No one was harmed, but the loss was undoubtedly in the millions of dollars.

SpaceX has since fixed the problem that caused the explosion—a faulty support strut was to blame—and they're flying on an upgraded version of the Falcon 9 that has already successfully launched two payloads. But if tonight's launch were to fail, some of the cargo might be saved this time around. That's because SpaceX is adding an abort option that's designed to carry the capsule to safety.