WASHINGTON — The planned Sept. 15 launch of an upgraded Falcon 9 rocket is in question following the rocket’s prelaunch static fire test at Vandenberg Air Force Base, Calif., according to Elon Musk, founder and chief executive of Space Exploration Technologies Corp. (SpaceX).

“Full thrust achieved on 2 sec static fire,” Musk tweeted early Sept. 13. “Some anomalies to be investigated, so launch date [to be determined].”

Hours after Musk’s tweet, however, the Canadian Space Agency (CSA) — SpaceX’s customer for Falcon v1.1’s debut — issued a media advisory saying launch of the Cassiope space weather satellite was on for Sept. 15 and would lift off during a two-hour window that opens at 12:00 p.m. EDT. 

“The launch is still planned for Sunday (Sept. 15) however we will know for sure after the launch readiness review planned for tomorrow,” a CSA official told SpaceNews midday Sept. 13. 

SpaceX spokeswoman Emily Shanklin could not be immediately reached for comment.

Musk told SpaceNews in recent interview that SpaceX was being “extremely paranoid about the launch and trying to do everything we possibly can to improve the probability of success, but this is a new rocket.”

Falcon 9 v1.1 features upgraded engines installed in a new configuration and a larger payload fairing designed to accommodate a backlog of commercial customers that have contracted with SpaceX to haul their communications satellites to geostationary transfer orbit. 

If all goes well during the Cassiope launch, SpaceX plans to return to Cape Canaveral, Fla., to launch its first geostationary-orbit mission. The customer for that mission is satellite fleet operator SES of Luxembourg.

Brian Berger is editor in chief of SpaceNews.com and the SpaceNews magazine. He joined SpaceNews.com in 1998, spending his first decade with the publication covering NASA. He was named senior staff writer in 2004, a position he held...