SpaceX
SpaceX’s Falcon 9 rocket suffered an upper-stage engine failure after lifting off from California on Thursday night, ejecting its Starlink internet satellites into a dangerously low orbit, the first blemish on the rocket’s workhorse record in more than 300 missions since 2016.
Elon Musk, founder and CEO of SpaceX, Post to X About an hour after the Falcon 9 lifted off from Vandenberg Space Center in California at 7:35 p.m. PDT (2:35 a.m. UTC), the rocket’s upper stage engine failed while attempting to reignite.
Cold proof
After departing Vandenberg to begin SpaceX’s Starlink 9-3 mission, the rocket’s reusable first-stage booster launched the Starlink satellites into the upper atmosphere before returning to Earth and landing as scheduled on a recovery ship anchored in the Pacific Ocean. The rocket’s second stage’s single Merlin vacuum engine fired for about six minutes to reach the preliminary orbit.
Minutes after the launch of SpaceX’s Starlink 9-3 mission, longtime observers of SpaceX launches noticed an unusual buildup of ice on top of the Merlin Vacuum engine, which uses a fuel mix of cryogenic kerosene and cryogenic liquid oxygen, which is stored at temperatures hundreds of degrees below freezing.
As the upper stage engines reached orbit, numerous chunks of ice fell off the rocket, but the Merlin Vacuum (M-Vac) engine appears to have completed its first burn as scheduled. While a leak in the oxidizer system or insulation issues could have led to the ice buildup, the exact cause and its relationship to subsequent in-flight engine failures will be the focus of SpaceX’s investigation into the failure.
A second burn from the upper stage would raise the rocket’s perigee, or lowest point, of its orbit well above the atmosphere, after which it would release the 20 Starlink satellites, which would then use their momentum to continue the ascent to their operational altitude.
“We restarted the upper stage to raise the perigee, but for currently unknown reasons, the engine went into RUD,” Musk said in an update two hours after launch. RUD, or rapid unplanned disintegration, is rocket engineering jargon that usually means a catastrophic or explosive failure.
“The team is reviewing data tonight to determine the root cause,” Musk continued. “The Starlink satellites launched, but the perigee may be too low to raise their orbit. We will know more within the next few hours.”
Telemetry from the Falcon 9 rocket showed the Starlink satellites were launched into an orbit with a perigee just 86 miles (138 kilometers) above Earth, about 100 miles (150 kilometers) lower than expected. According to Jonathan McDowellan astrophysicist and a trusted tracker of spaceflight activity. Detailed orbital data from the U.S. Space Command was not immediately available.
Ripple effects
While ground controllers scrambled to recover the 20 Starlink satellites, SpaceX engineers began investigating what happened to the second-stage M-Vac engine, although the investigation into the rocket failure is likely a more pressing issue for SpaceX and its customers.
SpaceX would be able to absorb the loss of 20 Starlink satellites relatively easily. The company’s satellite assembly line can produce 20 Starlink spacecraft in a matter of days. But the Falcon 9 rocket’s reliability and high flight rate make it a workhorse for NASA, the U.S. military and the entire space industry. The investigation makes it likely that SpaceX will delay several upcoming flights.
This is the first in-flight failure for SpaceX’s Falcon rocket family since June 2015. Until tonight, the company had had 344 consecutive successful launches.
During tonight’s first burn, a large amount of unusual ice was observed on the Falcon 9’s upper stage, some of which fell into the engine smoke. https://t.co/1vc3P9EZjj pic.twitter.com/fHO73MYLms
— Stephen Clark (@StephenClark1) July 12, 2024
Depending on the cause of the problem and what SpaceX has to do to fix it, the company could recover from its upper stage failure and resume launching Starlink satellites soon. Most of SpaceX’s launches are not for external customers, but rather deploy satellites for the company’s own Starlink network. This gives SpaceX unique flexibility to resume flights with the Falcon 9 quickly without having to address customer concerns.
Ars asked the Federal Aviation Administration, which approves all commercial space launches in the United States, whether it would require SpaceX to complete an accident investigation before allowing the Falcon 9 to fly again.
Two crewed missions are scheduled to launch aboard SpaceX’s crew-certified Falcon 9 rocket within the next six weeks, although the launch dates are currently unclear.
The entirely civilian Polaris Dawn mission Directed by billionaire Jared Isaacmanis scheduled to launch on a Falcon 9 rocket on July 31 from NASA’s Kennedy Space Center in Florida. Isaacman and a crew of three private astronauts will spend five days in orbit wearing new pressure suits designed and built by SpaceX during the mission, which will mark the first private spacewalk outside of the Crew Dragon capsule.
NASA and SpaceX’s next crewed mission is scheduled to launch on a Falcon 9 rocket from Florida around August 19. This team of four astronauts will replace the four-person crew that has been aboard the International Space Station since March.
Some customers, particularly NASA’s Commercial Crew Program, are likely to demand that they see the results of a detailed investigation and approve their own launch missions after SpaceX has completed a series of successful flights of its Falcon 9 rockets carrying Starlink satellites. SpaceX has already conducted 70 flights with its Falcon rocket family since January 1, averaging one launch every 2.7 days, more than the number of orbital launches conducted by all other countries combined this year.
The rapid pace of launches allowed SpaceX to quickly validate any fixes its engineers recommend to resolve the issues that caused Thursday night’s failure. But investigations into rocket malfunctions often take weeks or months, and it was too early Friday to know what actual impact the upper stage failure would have on SpaceX’s launch schedule.
SpaceX said ground teams had contacted five of the 20 Starlink satellites shortly after the Falcon 9 upper stage failed and separated. Officials hope to quickly activate ion thrusters to overcome the effects of atmospheric drag. At their current altitude, the satellites would naturally be pulled back into the atmosphere and burn up within hours to days if their orbit isn’t raised.
“The satellite’s thrusters need to raise its orbit faster than the atmosphere can pull it down, or it’ll burn up,” Musk said, adding that efforts to save the satellite “probably won’t work, but it’s worth a try.”
By the numbers
At the start of Thursday’s mission, SpaceX’s current version of the Falcon 9 rocket, the Falcon 9 Block 5, was arguably the most reliable launch vehicle in history. The Falcon 9 Block 5, which is cleared by NASA to fly astronauts, had not experienced a single mission failure in 297 launches since its debut in May 2018, prior to the ill-fated Starlink 9-3 mission.
Even if the Starlink satellites aren’t saved and Thursday night’s launch is rated a complete failure, the Falcon 9 Block 5 still has a 99.7 percent success rate — a figure that any launch company would envy.
SpaceX has launched Falcon 9 rockets, including the retired version, 354 times since 2010. The more powerful Falcon Heavy, which uses three linked Falcon 9 rocket boosters, has flown 10 times.
The Falcon 9 rocket’s early days saw some failures: During the fourth Falcon 9 launch in 2012, the first stage engine failed and the rocket was unable to put its secondary payload into the correct orbit, but SpaceX was still able to complete its primary mission of delivering cargo to the International Space Station.
The Falcon 9’s only complete in-flight failure occurred on June 28, 2015, during its 19th flight, when an upper stage liquid oxygen tank ruptured minutes after liftoff from Cape Canaveral Space Station in Florida. The rocket broke apart in the upper atmosphere, and the Dragon cargo capsule crashed en route to the spaceport.
SpaceX resumed Falcon 9 launches six months later, in December 2015. On that flight, SpaceX landed a Falcon 9 first stage booster at Cape Canaveral for the first time, a historic feat and a precursor to the company’s later success in rejecting the rocket.
SpaceX’s nine missions had launched flawlessly until a Falcon 9 rocket exploded on the launch pad during a pre-launch test on September 3, 2016. While it wasn’t an in-flight malfunction, a fireball destroyed the Israeli Amos 6 communications satellite that was on board the Falcon 9. Engineers traced the cause to a failure of a helium tank in the upper stage.
Since then, SpaceX’s Falcon rocket series has been sailing smoothly, with 335 consecutive successful launches since the 2016 launch pad explosion, or 344 flights since the in-flight malfunction — both of which are industry records.
The first Falcon Heavy rocket launched in 2018, and SpaceX launched its first astronaut mission under a NASA contract in May 2020. SpaceX is increasing its flight rate from 18 launches in 2017 to 96 launches of its Falcon rocket in 2023. SpaceX aims to launch 144 Falcon rockets this year, but even a temporary launch pause could jeopardize that goal.
In that time, SpaceX has mastered recovering and reusing the Falcon 9’s boosters and payload fairings, maintaining a perfect launch success record. But the Falcon 9’s upper stage is still expendable, and every launch requires a brand new second-stage engine — which is what failed on Thursday night.
