SpaceX will attempt to send a cargo spacecraft to the International Space Station on Friday morning, with an instantaneous launch window that opens at 10:36am ET. There are some clouds at the launch site, but overall weather conditions appear favorable for a liftoff today.

Perhaps the bigger question is whether the technical problems with the launch have been solved. Originally targeted for Tuesday, SpaceX delayed a day to Wednesday for additional pre-launch ground systems checks. Then the company delayed until Friday because it had detected “particles” in the fuel system of the rocket’s second stage. As a result, it needed to conduct “full inspections and cleanings.”

The rocket did go vertical on Space Launch Complex-40 early on Friday, increasing confidence that a flight will occur today. The Dragon spacecraft atop the rocket will carry 4,800 pounds of crew supplies and payloads, as well as more than 250 science and research payloads. About eight minutes after launch, the Falcon 9’s first stage will attempt to land at SpaceX’s Landing Zone 1.