Launch Roundup: Boeing Starliner delayed and China launches new rocket variant

by Martin Smith

This week was expected to see the maiden launches of two new spacecraft: Boeing’s crewed Starliner spacecraft and the first Chang Zheng 6C rocket from China.

The launch of Starliner’s Crewed Flight Test (CFT) mission will be the first crewed launch from Cape Canaveral Space Force Station since the Apollo era, as well as the 100th overall mission for the United Launch Alliance’s Atlas V rocket. After discovering an issue with an oxygen relief valve on the Centaur upper stage of the launch vehicle, the flight has been delayed until no earlier than May 17 to allow replacement of the misbehaving part.

The first Chang Zheng 6C, a dual-engine variant of the Chang Zheng 6 (CZ-6) rocket developed and launched by China, launched approximately an hour after Starliner was initially due to take to the skies on Monday, May 6. China will also launch a Chang Zheng 3B and a 4C later in the week. Other flights this week include up to four more Starlink missions from SpaceX launching from both coasts of the US.

The week was originally expected to begin with four of the six planned launches at that time, including the two maiden flights, launching within a 24-hour period. Following the scrub of Starliner’s first attempt on Monday, the highly anticipated flight was rescheduled for no earlier than Friday, May 10, after Launch Director Tom Heter III made the decision not to proceed with the launch under an abundance of caution. After performing further analysis, ULA made the decision to replace the valve and will now roll the launch vehicle back to the Vertical Integration Facility to perform the work. The next launch attempt will be no earlier than May 17 at 6:16 PM EDT (22:16 UTC).

The Starliner CFT mission will set new milestones beyond being the first crewed launch from Cape Canaveral Space Force Station since Apollo 7 in 1968 and the first from Space Launch Complex (SLC) 41. Astronaut Suni Williams will also become the first woman to fly on a maiden flight of a new orbital vehicle.

Stage separation shortly before SpaceX makes its 300th successful deployment of payload into orbit since Amos 6. The customer requested the deployment was not broadcast. (Credit: SpaceX)

Stage separation during the launch of the WorldView Legion 1 mission shortly before SpaceX makes its 300th successful deployment of a payload into orbit since AMOS-6. (Credit: SpaceX)

One Starlink mission launched on Monday, with two more scheduled for Wednesday and possibly another on Sunday. Three of these are for the Group 6 shell and will launch from the East Coast, with the other batch headed into the Group 8 shell from Vandenberg on the West Coast. SpaceX will close this week with the chance for up to six Falcon 9 missions having launched in just the first 12 days of May, with more Starlink missions and missions for the National Reconnaissance Office and the European and Japanese Space Agencies being prepared for launches later in the month. If this pace is maintained, the company could exceed the 12 launches per month seen in March and April.

The company continues to reach milestones, with last week’s WorldView Legion mission scoring the 300th successful deployment of payload into orbit since the AMOS-6 pad anomaly in September 2016, as well as the recovery of a fairing half from a record 16th flight. In an updated animation at the end of its livestream for the Gaileo L12 mission, the company noted that it had recovered 430 fairings to date and counting.

Falcon 9 Block 5 | Starlink Group 6-57

This mission was switched with Group 6-56 over the weekend and was the first of the two to launch this week. Falcon 9 launched on Monday, May 6, at 2:14 PM EDT (18:14 UTC) from SLC-40 at the Cape Canaveral Space Force Station in Florida. Booster B1069 landed downrange on the autonomous spaceport droneship Just Read the Instructions. This was the booster’s 15th flight, having previously supported seven other missions to this Group 6 shell, as well as earlier Starlink groups: Hotbird 13F, OneWeb 15, SES-18/19, and its maiden launch carrying the CRS-24 cargo mission to the International Space Station.

As the week began, the total number of Starlink satellites launched stood at 6,327, to which this mission adds 23. Currently, 5,919 are in operation, and 408 have deorbited.

Chang Zheng 6C | Haiwangxing 01 and others

This is the second CZ-6 mission of the year, but the maiden flight for the 6C variant of the rocket. The more powerful CZ-6A version has most recently launched satellites into Sun-synchronous orbits for the Yaogan-40 and Yunhai 3 satellite constellations.

Made by the Shanghai Academy of Spaceflight, the CZ-6C is a shorter, single-stick version of the CZ-6A, which was introduced in 2022, and a dual-engine variant of the original CZ-6, which has been active since 2015. Using the familiar mix of liquid oxygen and kerosene rocket propellants on both stages, the launcher has a payload capacity of 4,500 kilograms to low-Earth orbit (LEO) and 2,000 kilograms to a 700-kilometer altitude Sun-synchronous orbit.

The first stage is powered by two YF-100K engines with a maximum thrust of 2,376 kilonewtons while the second stage has one YF-115 engine with a maximum thrust of 180 kilonewtons. The rocket stands at 43 meters high, with a diameter of 3.35 meters and a total mass of 217 tons. It was transported from the final assembly plant to the Launch Complex (LC) 9A launch pad at Taiyuan in the Shanxi Province using a rocket transport vehicle. Liftoff took place on Tuesday, May 7, at 03:21 UTC during a 42-minute launch window.

One payload onboard was the Haiwangxing-01 (Neptune-01) satellite, the first of a planned 36-satellite constellation of synthetic aperture radar satellites that will observe the Earth once per hour. Three other satellites, including the Zhixing-1C radar satellite and two optical imaging satellites, were also deployed.

Falcon 9 Block 5 | Starlink Group 6-56

SpaceX launched at least one more Falcon 9 from LC-39A at the Kennedy Space Center before the pad is to be reconfigured for the upcoming Falcon Heavy launch of the GOES-U mission, which is currently targeting a launch on June 25. With pad conversion preparations for Falcon Heavy typically taking 40 to 50 days, it would be tight but not impossible to squeeze another mission in before conversion operations begin.

This Starlink Group 6 launch was scheduled for 2:42 PM EDT (18:42 UTC) on Wednesday, May 8, with a pad turnaround of approximately 10 days following the launch of the Galileo mission on April 27. Two years ago this week, another Starlink mission set a new turnaround record for this pad at 9 days, 1 hour, and 50 minutes. This time has been reduced further since then, with less than 6 days and 19 hours between Starlink 6-42 and Eutelsat 36D at the end of March.

As with other launches into this Group 6 shell, the mission carried 23 Starlink v2 Mini satellites but placed them into an initial orbit around 20 to 30 kilometers higher than the usual one, perhaps as part of performance improvement testing. Following the launch, Falcon 9 headed southeast, passing northeast of the Bahamas. This was the third flight for booster B1083, which previously supported Crew-8 and a Starlink mission.

The booster landed downrange in the Atlantic Ocean on the autonomous spaceport droneship A Shortfall of Gravitas and will be the fleet’s least flown booster once B1082 has launched for its fourth time on Thursday. It is now expected to be reserved for the upcoming Polaris Dawn mission which will launch no earlier than July. SpaceX passed their 300th successful Falcon 9 booster landing four missions ago during the Starlink 6-53 mission. This was the 231st consecutive landing for a Falcon booster.

The Bahamas Ministry of Tourism, Investments, and Aviation recently signed an agreement with SpaceX to allow droneship landings of boosters in the calmer waters east of The Exumas, offering locals and tourists a spectacular view of booster landings. These were initially anticipated to begin with the Group 8 missions after the initial plans to land the first during the Group 7-28 mission were canceled. With Group-8 missions beginning to be launched, these landings in The Exumas are expected to begin soon.

Chang Zheng 3B | ZHTW 1-01

This is the second mission flying on a CZ-3B this year. This vehicle type previously launched satellites for the Beidou-3 and ChinaSat constellations into medium-Earth and geostationary transfer orbits.

Lift-off occurred on Thursday, May 9, at 01:50 UTC from pad LC-2 at the Xichang Satellite Launch Center in China. Onboard were two experimental wideband communications satellites – China’s first to be deployed into medium-Earth orbit. These will conduct tests with other satellites in low-Earth orbit as well as the Chinese Antarctic research bases from an altitude of approximately 20,000 kilometers.

Falcon 9 Block 5 | Starlink Group 8-2

Group 8-2 was the second mission to launch Starlink v2 Mini satellites into the Group 8 shell, the first of which carried 20 satellites in early April to an initial orbit of 336 by 345 kilometers with a 53-degree inclination. This flight, the 75th Falcon 9 to launch from Vandenberg, carried 20 satellites, including 13 of the new, heavier, direct-to-cell variant.

Liftoff took place an hour into the three-hour window on May 9 at 9:30 PM PDT (04:30 UTC on May 10) from SLC-4E at the Vandenberg Space Force Base in California. This was the fourth flight for booster B1082, which previously launched USSF-62 and two Starlink missions. The booster landed on the autonomous spaceport droneship Of Course I Still Love You.

Chang Zheng 4C Y50 launches Shiyan-23 (Credit: CCTV)

Chang Zheng 4C | Shiyan 23

This launch took place at 23:43 UTC on Saturday, May 11 from Site 9401 at the Jiuquan Satellite Launch Center in China. The payload on board CZ-4 Y50 was the Shiyan 23 classified satellite for “space detection purposes”. This vehicle type has more typically lifted the Gaofen, Fengyun, and most recently Yaogan “remote sensing” satellites, and previously deployed Shiyan 20A & 20B in December 2022.

The last time a CZ-4C had launched was over six months ago in September 2023, however. This was the last of four flights by this vehicle type within 55 days, of which the Yaogan 33-03 mission also marked the 35th anniversary since the maiden flight of the CZ-4 series. This launch in 1988 demonstrated the country’s ability to place satellites into sun-synchronous orbit when it deployed the Fengyun-1 satellite.

Falcon 9 Block 5 | Starlink Group 6-58

This Starlink Group 6 launch took place on May 12 at 8:53 EDT (00:53 UTC on May 13) from SLC-40 at the CCSFS. As with other launches into the Group 6 shell, this mission carried 23 Starlink v2 Mini satellites into a 285 by 293-kilometer orbit with a 43-degree inclination.

The Falcon 9 headed southeast, passing northeast of the Bahamas. Booster B1073 supported this mission on its 15th flight, having flown six other missions for Group 6 as well as for the Group 4 and 5 shells. This stage was flying within a couple of days of its 2nd anniversary when it first lofted Group 4-15 on its maiden voyage in 2022. It has also launched the CRS-27 cargo resupply mission to the International Space Station and the launch of the lunar flashlight on the Hakuto-R mission.  It landed downrange on the autonomous spaceport droneship A Shortfall of Gravitas and was the 91st orbital launch attempt worldwide for the year.


(Lead image: Starliner before ISS docking on the OFT-2 flight. Credit: Bob Hines/NASA)

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