Pumps are now loading refined kerosene known as RP-1 into the fuel tanks of the Falcon 9 first stage. Liquid oxygen will be loaded into the first stage later this morning. The nine Merlin engines of the first stage burn a combination of kerosene fuel and oxygen to produce about 1.7 million pounds of thrust at liftoff. Launch remains on track for 9:39 a.m. EST.
‘Go’ for Propellant Loading
The SpaceX launch team is prepping to begin loading fuel and liquid oxygen into the Falcon 9 rocket standing at Launch Complex 39A for liftoff at 9:39 a.m. EST.
Forecast Remains 70 Percent ‘Go’
Launch Weather Officer Mike McAleenan informed the launch teams that today’s outlook forecasts a 70 percent chance of acceptable conditions at launch time. The concern is for cumulus clouds and the possibility of having to fly through precipitation. A light system of precipitation that is moving into the area is expected to clear away from the launch site by 9:20 a.m., about 20 minutes before launch time from Launch Complex 39A.
Next Potential Launch Opportunity: 9:39 a.m. Sunday
Next potential launch opportunity for SpaceX’s space station cargo mission is 9:39 a.m. EST Sunday. Live coverage starts at 8:45 a.m.
Potential Sunday Launch Opportunity: 9:38:59 a.m. EST
The next potential launch opportunity is Sunday at 9:38:59 a.m. EST. It would be an instantaneous launch window to allow the cargo-laden Dragon spacecraft to reach the International Space Station.
Launch Scrubbed
Today’s launch attempt has been scrubbed because of the thrust vector control system issue that developed late in today’s countdown, NASA Launch Commentator George Diller reports. The launch team is setting up for a 24-hour turnaround, meaning the team will try again tomorrow morning if the thrust vectoring issue is resolved. Like today, tomorrow’s weather forecast calls for a 70 percent chance of acceptable conditions.
HOLD!
The countdown has been held at T-13 seconds.
T-1 Minute
1 Minute to launch.
Strongback Retraction
The strongback support structure for the Falcon 9 rocket and Dragon spacecraft has been retracted to launch position.
Second Stage Thrust Vectoring Issue in Work
NASA Launch Commentator George Diller reports that the SpaceX launch team is watching a thrust vectoring system issue as the countdown continues toward a liftoff at 10:01 a.m. EST. All other countdown processes are continuing as planned.