The launch schedule in the past few weeks has been notably quieter than usual. Last week, a Chang Zheng 4B launched the latest set of Gaofen-11 high-resolution Earth observation satellites in the early hours of Friday, July 19 — the only launch of the week of July 14 through July 20.
Following a Falcon 9 second stage anomaly during the Starlink Group 9-3 mission on July 12, Falcon 9 has been grounded while SpaceX and the Federal Aviation Administration (FAA) conduct a mishap investigation. Falcon launches were anticipated to return as soon as this last weekend but are now expected to occur toward the end of this week while the investigation continues. Currently, three launches may take place this coming Wednesday through Friday if the FAA completes a public safety determination and confirms that the flights can proceed.
Rocket Lab was initially set to launch its next Electron on Saturday, July 20, but has since moved this launch to give its customer Capella Space sufficient time to complete testing of the payload. The mission, “A Sky Full Of SARs,” is expected to launch in August.
The first launch of a Chang Zheng 4B this year lifted off from LC-9 at the Taiyuan Satellite Launch Center in China on Friday, July 19, at 03:03 UTC.
Since 1999, Chang Zheng 4B has launched various Earth observation, weather, and experimental payloads, including several Shijian and Gaofen satellites. The rocket has launched from both LC-9 and Site 9401 at the Jiuquan Satellite Launch Center and flew only once last year, carrying a Fengyun-3G precipitation-measuring satellite to a low-Earth orbit.
Onboard was the latest in the Gaofen-11 group of satellites, the last of which launched in December 2022. The Gaofen satellites are a series of civilian high-resolution satellites for the state-sponsored China High-Definition Earth Observation, or CHEOS, program.
Chang Zheng 4B launches Gaofen-11 05 on July 19 from LC-9. (Credit: CCTV / CASC)
Falcon 9 Block 5 | Starlink Group 10-4
SpaceX plans to launch the Starlink Group 10-4 mission on Wednesday, July 24, at 12:14 AM EDT (04:14 UTC) from SLC-40 at the Cape Canaveral Space Force Station in Florida, pending confirmation from the FAA.
Assuming an on-time launch, this mission will be the first Falcon 9 to launch since the Starlink Group 9-3 mission nearly two weeks prior, during which an in-flight anomaly occurred. Additionally, the launch of Starlink Group 10-4 would occur while the SpaceX and FAA investigation is still ongoing.
Before the Starlink Group 9-3 anomaly, the drone ship A Shortfall of Gravitas had headed out northwest towards the landing zone for Starlink Group 10-4. Once Falcon 9 was grounded from all future flights, the droneship returned to port. While the booster for this mission has not yet been officially assigned, A Shortfall of Gravitas is still expected to support Starlink Group 10-4 and left Port Canaveral again on Sunday.
Falcon 9 Block 5 | Starlink Group 9-4
Starlink Group 9-4 is currently scheduled to launch from SLC-4E at the Vandenberg Space Force Base in California — the site of the most recent Falcon 9 to fly from two weeks before on July 12. Liftoff is expected at 1:34 AM PDT (08:34 UTC) on Thursday, July 25, at the start of a four-hour launch window.
Falcon 9 is expected to carry an unconfirmed number of Starlink v2 Mini satellites to low-Earth orbit. The booster has not yet been announced and is expected to land on the autonomous droneship Of Course I Still Love You.
Falcon 9 Block 5 | Starlink Group 10-9
SpaceX plans to launch another payload of Starlink v2 Mini satellites on Friday, July 26, from pad LC-39A at the Kennedy Space Center in Florida. The mission, Starlink Group 10-9, is expected to launch during a four-hour launch window that opens at 12:21 AM EDT (04:21 UTC).
This will be the first launch from LC-39A since the pad was reconfigured following the launch of the GOES-U satellite on a Falcon Heavy in June. The booster, which has not been announced, is expected to land on a currently unknown droneship stationed approximately 600 km downrange.
Booster B1063 atop a droneship after launching Starlink Group 9-3. (Credit: SpaceX)
Upper stage issues
Problems with rocket upper stages have been a recurring theme in recent weeks. The largely successful maiden launch of the Ariane 6 rocket on July 9 experienced a problem with the auxiliary propulsion unit (APU) that enables the second stage engine to be restarted multiple times. While the primary payload of 11 satellites was deployed successfully, the APU shut down almost immediately when trying to restart the engine for the second time. As a result, the stage could not perform a deorbit burn, and will likely remain in orbit for around 15 years. A secondary objective to release two final customer capsules that would test heat shields during reentry was also not achieved due to the issues with the APU.
The following day, on July 10, the Chinese Hyperbola-1, also known as the Shuang Quxian-1, experienced a malfunction on its fourth stage. This resulted in the loss of the payload of three Yunyao weather satellites.
Lastly, just two days later, Falcon 9’s second stage Merlin Vacuum engine failed to complete its second burn during the Starlink Group 9-3 mission. Unusual amounts of ice were seen near the engine on the live stream, which SpaceX later confirmed was due to a liquid oxygen leak that had developed on the second stage. The payload of 20 Starlink satellites was subsequently deployed in a lower-than-intentioned orbit with a perigee of only 135 km.
Liquid oxygen ice buildup near the upper stage Merlin Vacuum engine during the Starlink Group 9-3 mission. (Credit: SpaceX)
Despite the team’s efforts to command an early burn, the satellites were unable to generate sufficient thrust to raise their orbits. The onboard hall-effect thrusters are very efficient but low on thrust, which is why Starlink satellites can take months to reach their final target orbit. Of the 20 satellites launched, 18 have reentered Earth’s atmosphere, where they disintegrated.
The FAA deemed a mishap investigation necessary and will need to approve SpaceX’s final report, including any corrective actions that may emerge. In a statement to NSF, the FAA noted that, on July 15, SpaceX had requested that the FAA make a public safety determination as part of the ongoing investigation. It added that “when a public safety determination request is received, the agency evaluates safety-critical systems, the nature, and consequences of the anomaly, the adequacy of existing flight safety analysis, safety organization performance, and environmental factors”.
This approach is what enabled the fourth flight of SpaceX’s Starship to proceed while the investigation from the third flight continued. The FAA continued, saying, “If the FAA agrees no public safety issues were involved, the operator may return to flight while the investigation remains open, provided all other license requirements are met.” SpaceX requested several hazard notices for up to four Starlink missions, initially between July 19 and July 22, which have since been periodically revised.
SpaceX’s launch manifest had already been shuffled in the days before the Starlink 9-3 anomaly. The Transporter 11 rideshare mission, once anticipated to launch on Thursday, July 18, was initially delayed to a date later in the month. Additionally, the launch of the WorldView Legion 3 & 4 mission from the Cape had also been pushed out of last week’s schedule. These are two examples of commercial missions that will now be further delayed due to the grounding, which also delayed the Arctic Satellite Broadband Mission that had been due to launch last week in their place.
In addition to these commercial missions, the crewed Polaris Dawn and Crew-9 missions, as well as the CRS NG-21 cargo resupply mission, to the International Space Station are also likely to be affected. It is expected that the initial flights following the grounding will be Starlink missions to further prove the vehicle’s reliability before Falcon 9 returns to launching customer payloads and crew. In the meantime, SpaceX has continued to refurbish boosters in preparation for Falcon 9’s return to normal operations.
SpaceX has noted that it is “positioned to rapidly recover and continue our pace” in an official statement released following Starlink Group 9-3.
(Lead image: Falcon 9 launches a batch of Starlink satellites into orbit. Credit: Julia Bergeron for NSF)
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