NASA’s supply ships to the International Space Station are soon to fly again.

Orbital ATK, one of two companies that NASA has hired to ferry cargo, is set to launch 7,700 pounds of equipment, experiments and supplies, but bad weather delayed the launch until at least Friday.

Orbital’s last cargo run, in October last year, ended in a fireball when the rocket exploded 15 seconds after liftoff. Investigators blamed the failure of one of two refurbished 1970s-era Soviet engines that powered Orbital’s Antares rocket. The launchpad at Wallops Island, Va., was badly damaged.

This time, Orbital’s unmanned spacecraft, Cygnus, is flying on top of a competitor’s rocket, an Atlas 5 built by the United Launch Alliance.

“We’re very confident once we’re delivered into orbit, we’ll be able to get back in the groove and do what we’ve done before,” said Frank L. Culbertson Jr., president of the space systems group at Orbital ATK.