TOKYO — SpaceX says it will not be able to recover the 20 Starlink satellites left in a very low orbit after a malfunction of a Falcon 9 upper stage on a July 11 launch.
In a statement July 12, the company said that the 20 satellites on the Group 9-3 launch have been unable to raise the orbit because the electric propulsion systems on the spacecraft cannot counteract the high atmospheric drag the satellites encounter in their very low orbits.
The rocket’s upper stage engine “experienced an anomaly and was unable to complete its second burn,” the company stated, which would have circularized the orbit of the stage before satellite deployment. While the stage was able to deploy the satellites, they were left in an orbit with a perigee, or low point, of just 135 kilometers.
That kept them in what SpaceX called an “enormously high-drag environment” that reduced the perigee by at least five kilometers per orbit. “At this level of drag, our maximum available thrust is unlikely to be enough to successfully raise the satellites. As such, the satellites will re-enter Earth’s atmosphere and fully demise.”
SpaceX Chief Executive Elon Musk posted a few hours after the anomaly that satellite controllers were trying to fire the spacecraft’s electric thrusters at maximum levels to overcome atmospheric drag. “We’re updating satellite software to run the ion thrusters at their equivalent of warp 9,” he stated. “Unlike a Star Trek episode, this will probably not work, but it’s worth a shot.”
The company added that the satellites “do not pose a threat to other satellites in orbit or to public safety” given their very low orbits and a design that is intended to break up completely on reentry.
Launch failure update and implications
The SpaceX statement provided few additional details about the problem with the upper stage. It noted that there was a liquid oxygen leak on the second stage noticed during the first burn of the single Merlin engine. That would explain the unusual ice buildup seen on parts of the engine.
The company did not elaborate on the nature of the anomaly during the planned one-second relight of the engine. Musk had stated that the engine suffered a “RUD” or “rapid unscheduled disassembly,” but SpaceX noted in its statement that “the stage survived and still deployed the satellites.” The stage also was able to “passivate itself,” a standard procedure at the end of its mission, removing energy sources from propellant tanks and batteries that could cause the stage to break up.
The incident will ground the rocket, the most active launch vehicle in service today, for an indefinite period while SpaceX investigates the root cause and determines what it must make to the upper stage.
The Federal Aviation Administration stated July 12 that it will require an investigation into the anomaly. “The FAA will be involved in every step of the investigation process and must approve SpaceX’s final report, including any corrective actions,” it stated. “A return to flight is based on the FAA determining that any system, process, or procedure related to the mishap does not affect public safety.”
The launch failure will affect a wide range of customers, ranging from SpaceX’s own Starlink satellites to NASA. The space industry has grown increasingly reliant on the Falcon 9, which had more than 300 consecutive successful launches before this incident, because of its high flight rate and lack of capacity on other vehicles.
Near-term missions facing delays include the Arctic Satellite Broadband Mission, a pair of communications satellites that had been expected to launch this month on a Falcon 9 from Vandenberg Space Force Base, along with the Transporter-11 rideshare mission on another Falcon 9 in July from Vandenberg.
Also on hold is Polaris Dawn, a private astronaut mission that will send four people on a Crew Dragon to test high-altitude operations and a new SpaceX-developed spacesuit. That mission was scheduled to launch as soon as July 31 from Florida.
“I have no doubt they will arrive at a cause quickly and ensure the most cost-effective and reliable launch vehicle keeps delivering payload to orbit,” Jared Isaacman, the billionaire backing the Polaris program of missions and who will command Polaris Dawn, stated. “As for Polaris Dawn, we will fly whenever SpaceX is ready and with complete confidence in the rocket, spaceship and operations.”
Others in the industry are less sanguine. One industry official, speaking on background, said the best-case scenario is that SpaceX is able to quickly identify and address the problem that caused the failure, allowing it to resume Starlink launches in a matter of a few weeks. That would provide other customers with confidence the problem had been rectified. Even that, though, may delay some customers’ missions by months as SpaceX reshuffles its manifest.
That official added that Falcon 9 is grounded for months, it would be “catastrophic” for much of the industry as their launch plans face lengthy delays with few options for alternative launches.
One of SpaceX’s biggest customers is NASA. Falcon 9 rockets were scheduled to launch a Northrop Grumman Cygnus cargo spacecraft to the International Space Station in early August, followed in mid-August by the Crew-9 Crew Dragon launch. NASA has not stated its criteria for allowing the Crew-9 mission in particular to proceed, such as how many Falcon 9 successful launches will be required.
Another major NASA mission is the Europa Clipper spacecraft, which will use a Falcon Heavy rocket with a similar upper stage as the Falcon 9. That mission has a three-week launch window that opens Oct. 10. That mission, though, is facing its own problems as NASA investigates problems with transistors on the spacecraft that may not be able to survive the radiation conditions around Jupiter as designed.
“Crew safety and mission assurance are top priorities for NASA. SpaceX has been forthcoming with information and is including NASA in the company’s ongoing anomaly investigation to understand the issue and path forward,” the agency said in a statement late July 12. “NASA will provide updates on agency missions including potential schedule impacts, if any, as more information becomes available.”
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source: spacenews.com