A two-week launch hiatus for SpaceX came to an end after midnight Saturday with the Starlink 10-9 mission returning the Falcon 9 to flight after an upper stage accident on July 11 grounded the rocket.
The Falcon 9 rocket lifted off from Launch Complex 39A at NASA's Kennedy Space Center at 1:45 a.m. EDT (0545 UTC). The mission marked Starlink's 50th dedicated launch in 2024. A successful payload deployment was confirmed just over an hour after launch.
The Federal Aviation Administration, the agency that oversees commercial space activities in the United States, has given SpaceX permission to resume launches of its Falcon 9 rocket before a formal investigation into the accident is completed.
The FAA has approved a public safety determination requested by SpaceX, one of two routes a launch provider that experiences a mishap during a mission can use to relaunch its rockets.
“Following a thorough review, the FAA determined that there were no public safety concerns associated with the anomaly that occurred during the SpaceX Starlink Group 9-3 launch on July 11,” the FAA said in a statement Thursday. “This public safety determination means that the Falcon 9 vehicle can return to flight operations while the overall investigation remains ongoing, provided all other licensing requirements are met.”
SpaceX’s Falcon 9 rocket, the most widely flown space launch vehicle, encountered a liquid oxygen leak in its upper stage during the Starlink 9-3 mission, which launched from Vandenberg Space Force Base in California on July 11. During its initial burn, viewers of the launch broadcast could see large amounts of ice building up around the rocket’s engine section.
“The cause of the leak was identified as a crack in a pressure sensor sensing line connected to the vehicle’s oxygen system,” SpaceX wrote in a blog post Thursday. “This line cracked due to fatigue caused by the high load from engine vibration and slack in the clamp that normally restrains the line.
“Despite the leak, the second stage engine continued to operate through its first burn and completed its shutdown, where it entered the coast phase of the mission in the planned elliptical parking orbit.”
During a briefing Friday at NASA's Johnson Space Center about the upcoming launch of the Crew-9 spacecraft, Sarah Walker, SpaceX's director of Dragon Mission Management, said the FAA has given them clearance to fly again. She added that NASA was involved throughout the process.
“In all the briefings and data analysis that we did with the FAA, NASA had an official seat at the table to participate in all of that,” Walker said. “We had a question-and-answer period where we exchanged more data and (the FAA) gave us the final determination yesterday that they agreed with our conclusions and we’re ready to fly again.”
He said freezing around the engine section caused by the liquid oxygen leak caused the Merlin Vacuum engine to have a “hard start” due to a slow delivery of ignition fluid to the chamber.
“That damaged the engine hardware and caused the upper stage to lose steering capability,” Walker said.
Steve Stich, NASA's Commercial Crew Program manager, said they watched video of the difficult launch with SpaceX and it was instrumental in their investigation into the mishap.
SpaceX said in a blog post Thursday that neither the upper stage nor the Starlink satellites posed a danger to the public. It also stressed that the first stage booster, tail number B1063, performed without issue and landed safely on the unmanned spacecraft, Of Course I Still Love You, just over eight minutes after liftoff.
The solution involves removing the problematic sensor, which was left in that configuration from a previous customer mission. Stich said this is a learning moment about “the attention to detail that is required in spaceflight.”
“Small changes matter. And we looked at the change and we didn’t see any issues on NASA’s part,” Stich said. “So SpaceX has done a great job of re-examining this area and any other areas of the vehicle that might have had the same issue, where they did a qualification that was a little bit similar to what they had before, but maybe without having done the extensive testing that they should have done.
“And so I think it was a great lesson learned for all of us.”
To avoid a similar problem in the future, SpaceX decided to remove the problematic sensor, which Walker described as redundant with other engine sensors. It tested the upgrade at its facility in McGregor, Texas.
The Falcon 9 upper stage, which will support the Crew-9 mission, will soon undergo testing there.
“It will undergo a second stage of hot testing around July 30 and that's really to verify some of the new modifications that that vehicle will have as a result of the anomaly,” Stich said.
Back to the launch
The FAA’s decision paves the way for the company to resume launching its battle rocket. Starting last weekend, SpaceX deployed multiple marine assets that would support launch operations. Its two Florida-based drone ships were deployed alongside recovery vessels to pick up payload fairings.
The return-to-flight mission could be followed by two more launches: the Starlink 10-4 mission scheduled for Space Launch Complex 40 (SLC-40), as well as the Starlink 9-4 mission from Vandenberg.
The resumption of launches is critical not only for SpaceX’s Starlink constellation, but also for customers like NASA and the Polaris program. NASA is looking forward to launching a Northrop Grumman Cygnus spacecraft on the NG-21 cargo resupply mission to the International Space Station, followed by the flight of Crew 9 astronauts to the orbiting outpost.
Jared Isaacman and three other private astronauts are also awaiting their turn to lift off aboard Crew Dragon Resilience for the roughly five-day Polaris Dawn mission, which will be highlighted by the first commercial spacewalk in history.
On Friday, NASA announced that the mission will launch from the LC-39A pad no earlier than Aug. 18, with a window of opportunity extending into early September. Stich said the date is determined by the time needed to convert that pad from a Falcon 9 configuration to a Falcon Heavy and allow its Europa Clipper to launch on time in October.
SpaceX has several major missions planned for the second half of 2024, including the launch of the CRS-31 Cargo Dragon mission to the ISS around September.
Leave feedback about this