Early on Friday morning, within minutes of the opening—and closing—of an instantaneous launch window, SpaceX scrubbed the launch of its Falcon 9 rocket and Cargo Dragon supply mission to the International Space Station.
The company said it made the decision to stand down due to an “electrical issue” on its droneship, positioned just offshore for the Falcon 9 rocket’s first stage to land on.
This is the first time SpaceX has stood down a launch attempt due to a problem related to recovering a first-stage booster. The company can probably thank NASA for being an understanding customer.
After the scrub, SpaceX also said there was a ground-based helium leak it wanted to check out before the rocket’s next launch attempt. This leak was located in a “quick-disconnect” interface on the rocket’s second stage, where helium is used to pressurize fuel tanks.
Weather had been a concern for Friday morning’s launch attempt, but near the launch time at 3:11am ET (07:11 UTC), the rains had remained well offshore and SpaceX had proceeded with fueling the rocket. If Dragon launches on Saturday morning, it will arrive at the station on Monday.
The instantaneous launch window opens at 2:48am ET (06:48 UTC) Saturday morning. Weather is forecast to be favorable, with a 70 percent chance of “go” conditions. If the Falcon 9 rocket cannot make this launch attempt for some reason, officials said at a news conference Thursday that the Cape Canaveral launch range would enter into a week of maintenance, and stand down from launches during that time.
SpaceX will use a new Falcon 9 rocket for this launch attempt, but the Cargo Dragon spacecraft previously flew to the International Space Station in August 2017. For this mission, it will ferry about 2.5 tons of supplies to the station, including more than 700kg of science experiments, as well as transporting NASA’s Orbiting Carbon Observatory 3 and Space Test Program-Houston 6 in its unpressurized trunk. As part of a contract for 20 missions in total, this will be SpaceX’s 17th supply mission to the space station for NASA.
Overall, this will be the company’s fifth launch of 2019, and SpaceX’s 70th launch of the Falcon 9 rocket. This story will be updated with webcast information, and other pertinent details, as they become available later day.