### SpaceX Halts Falcon 9 Launches After Deorbit Burn Anomaly

SpaceX has temporarily paused its Falcon 9 rocket launches following an unexpected issue with the deorbit burn of the rocket’s upper stage on the Crew-9 mission, launched on September 28. This incident marks the second upper stage anomaly with the Falcon 9 in less than three months.

In an early morning social media post on September 29, SpaceX confirmed that the upper stage experienced an "off-nominal deorbit burn." The result was the second stage landing safely in the ocean, but outside the intended targeted area. The company did not elaborate further but mentioned that Falcon 9 launches will be on hold until they thoroughly understand the cause of the anomaly.

The deorbit burn is a crucial procedure designed to guide the upper stage to reenter the Earth's atmosphere over an unpopulated region of the South Pacific Ocean. This step is necessary to avoid leaving the upper stage in orbit, which could pose a debris risk, and to prevent uncontrolled reentry. The planned reentry location, according to airspace and marine hazard notices, was east of New Zealand.

This recent malfunction follows another upper stage issue on a Starlink mission launched on July 11. During that mission, the upper stage's single Merlin engine failed upon reignition, leading to the premature reentry of the satellites due to their low orbits. An investigation uncovered a liquid oxygen leak caused by a crack in a pressure sensor's sense line, leading to excessive cooling of engine components and a hard start, which subsequently damaged the engine and led to a loss of attitude control.

On the recent Crew-9 launch, there was no indication of similar ice buildup or other unusual behavior observed during the upper stage’s initial burn. Both SpaceX and NASA did not report any concerns about the rocket post-launch during the conference.

The duration of this launch suspension remains uncertain. After the July incident, Falcon 9 launches were paused for 15 days, while SpaceX returned to flight on July 27. Additionally, SpaceX stopped launches for two days in late August after a booster tipped over and exploded on a droneship landing in the Atlantic Ocean. In both previous cases, SpaceX needed clearance from the Federal Aviation Administration (FAA) before resuming operations, either by completing a mishap investigation or ensuring the public’s safety.

The recent anomaly comes at a critical time for SpaceX, as the company prepares for two important launches in the coming weeks. A Falcon 9 is set to carry the European Space Agency’s Hera asteroid mission by October 7, and a Falcon Heavy is scheduled to launch NASA’s Europa Clipper spacecraft no earlier than October 10, with both mission’s launch windows extending through late October. The FAA has yet to respond to queries regarding the latest incident.