The launch of NASA’s Dawn mission to two of the largest asteroids in the solar system has been delayed again, putting the space probe’s liftoff at no earlier than Monday afternoon.

NASA spokesperson D.C. Agle at the agency’s Kennedy Space Center spaceport in Florida said Dawn is now slated to launch no earlier than 3:56 p.m. EDT (1956 GMT) July 9.

“Monday is the earliest time,” Agle said via telephone.

Bound to visit the asteroids Vesta and Ceres, the Dawn spacecraft was slated to launch Saturday, but then postponed until Sunday after a lightning advisory prevented pad crews from fueling the second stage of the probe’s Delta 2 booster.

Engineers were slated to resume fueling the rocket today, but that operation has been postponed to Saturday, NASA officials said.

Dawn mission scientists are due to hold a press conference later today at 1:00 p.m. EDT (1700 GMT) to discuss the upcoming spaceflight and the new launch delay.

You can tune in to that status report on NASA TV by using SPACE.com’s feed, which is available by clicking here.