SpaceX scrubs Falcon 9 launch today - NROL-108 postponed 24 hours

SpaceX has scrubbed today's Falcon 9 launch, postponing the NROL-108 mission that was due to be the company's last of 2020. The three hour launch window opened this morning at the NASA Kennedy Space Center in Florida, and was due to run for three hours, until noon EST.

Weather had been SpaceX's primary concern ahead of that window. Conditions were forecast to be 70-percent favorable for the launch, with NROL-108's initial blast-off time set for 9:45am EST – 45 minutes into the window – to allow some of that weather to pass.

In the end, though, it was a different reason that scrubbed the launch today. "Falcon 9 auto-abort called at T-1:53 due to a second stage sensor reading," SpaceX tweeted, with initial indications suggesting that the company still hoped to launch today. However that opportunity was quickly scrapped.

"Standing down from today's launch attempt of NROL-108 to take a closer look at the data," SpaceX confirmed. "Falcon 9 and NROL-108 remain healthy. Teams are working toward a backup launch opportunity of tomorrow with a three-hour window opening at 9:00 a.m. EST."

According to SpaceX's Elon Musk, the sensor issue concerned one of the fuel tanks. "Pressure is slightly high in upper stage liquid oxygen tank," he tweeted this morning. "Review underway."

SpaceX will now inspect the rocket, hopefully giving it the green-light for another attempt tomorrow, Friday, December 18.

NROL-108 is another mission by SpaceX for the U.S. National Reconnaissance Office (NRO). It'll eventually deploy a new satellite for the agency.

For SpaceX, it was to be the 31st launch of 2020, and indeed the third launch of December alone. It was also intended to once again demonstrate the Falcon 9 booster's flexibility. SpaceX planned to land it at Cape Canaveral Space Force Station, instead of on an autonomous drone-ship out at sea as is the usual method.

That opportunity to capture key parts of each launch and then reuse them has been instrumental to SpaceX's pitch of more affordable, sustainable space transportation. The company has inked deals with NASA to run supplies to and from the International Space Station, and will also act as a ferry for astronauts with its Dragon spacecraft. At the same time, it's offering commercial flights to companies like Sirius XM who want to launch their own satellites and other hardware, in addition to deploying SpaceX's own Starlink satellite constellation.

The new flight window for Friday's next attempt at the NROL-108 launch opens again at 9am EST.