Space Exploration Technologies (SpaceX) has postponed the Falcon 9 v1.1’s first mission to geostationary transfer orbit until Nov. 28, as mission managers sort out a liquid-oxygen pressurization issue on the rocket’s first stage.

The planned Nov. 25 mission was to carry the Orbital Sciences Corp.-built SES-8 satellite to a supersynchronous transfer orbit of 295 km x 80,000 km altitude and an inclination of 20.75 deg. for Luxembourg-based SES, the world¹s second largest commercial fleet operator by revenue.

The first stage pressurization anomaly was among a series of what appeared to be minor technical setbacks during a 66-min. launch window that opened at 5:37 p.m. EST at SpaceX’s Launch Complex 40 at Cape Canaveral AFS, Fla.

The Falcon 9 v1.1 and its SES-8 payload are now slated to launch at 5:38 EST Nov. 28. If successful, the mission would give SpaceX entree to the commercial launch market and position the company to unseat United Launch Alliance (ULA), a Boeing-Lockheed Martin joint venture that holds a virtual monopoly on NASA, U.S. Air Force and intelligence community missions.

“We’re hoping to provide a forcing function for increased competitiveness in the launch vehicle industry and potentially for improving the technology across the board,” SpaceX founder and CEO Elon Musk stated in a pre-launch conference call with reporters Nov. 24, adding that SpaceX competitors will have to quickly catch up or risk losing “significant market share” to the Falcon 9.

“They are now going to need to improve their rocket technology in order to compete, and that¹s a good thing for the future of space,” Musk says.

About two minutes before the launch window opened at 5:37 p.m. EST, SpaceX said engineers were troubleshooting a first-stage liquid-oxygen vent anomaly, and the countdown was set to a launch target of 5:54 p.m. EST.

At T-6:11, mission managers stopped the clock as the vehicle’s first stage transitioned to an internal power supply. At 6 p.m. EST, the clock was once again reset to T-13 minutes as engineers changed telemetry limits on the power supply.

At 6:12 p.m., with the power-supply issue resolved, the launch was recycled to 6:30 p.m. It was then put on hold at T-3:41 owing to a problem raising the strongback support into position. Minutes later the launch was scrubbed owing to a liquid-oxygen ullage on the first stage.

SpaceX says despite the anomalies, the Falcon 9 v1.1 could launch SES-8 Nov. 26. But it says that the mission must be postponed until Nov. 28 due to FAA airspace restrictions associated with heavy traffic in the days leading up to the Thanksgiving holiday weekend.