Thunderstorms on Thursday scuttled an attempt by SpaceX to make an historic re-flight of its cargo Dragon spacecraft. SpaceX will now try again Saturday. Because of the orbital dynamics required to reach the International Space Station, today’s attempt has an instantaneous launch window, at 5:07pm ET (10:07pm BST).
That may pose a problem because today’s weather conditions at Kennedy Space Center are again iffy. Officially, there remains a 60-percent chance of favorable weather at launch time. However, by early Saturday afternoon, cumulus clouds had begun to develop near the launch site, which presages the formation of afternoon showers and thunderstorms—as is common in Florida during the summer.
This particular Dragon first flew to the International Space Station in September 2014 when it delivered nearly 2.5 tons of cargo. That was SpaceX’s fourth supply mission to the orbiting laboratory. Saturday’s is the company’s 11th, and it will carry three tons of supplies to the station. The spacecraft has undergone significant refurbishment and has a new heat shield. Even so, flying the vehicle again represents a major milestone for SpaceX, which has made reusability a hallmark of its efforts to lower the cost of spaceflight.