In what SpaceX expects to be a busy pre-Christmas week of launches, a record-setting Falcon 9 booster roared into the night from Vandenberg Space Force Base, Calif., early Saturday, laden with 52 Starlink internet communications satellites, bound for low-Earth orbit and an inclination of 53.2 degrees to the equator.
Liftoff of B1051—the first Falcon 9 core to record an 11th mission—occurred from Vandenberg’s storied Space Launch Complex (SLC)-4E at 4:41 a.m. PST and its payload was successfully deployed some 15 minutes later. With this 17th and last dedicated Starlink mission of 2021, SpaceX has placed 989 of these flat-packed satellites into orbit in the last year, including its first batch to near-polar orbit.
More than seven months since her most recent flight, B1051 was transported to the pad last week and underwent a customary Static Fire Test of her nine Merlin 1D+ engines early Friday. SpaceX announced shortly thereafter that it was targeting 1:24 a.m. PST Saturday for launch, but late Friday this T-0 was nudged to the backup opportunity a little more than three hours later at 4:41 a.m. PST.
The record-setting booster for last night’s flight first entered service in March 2019, when she delivered an unpiloted Crew Dragon to the International Space Station (ISS) for the critical Demo-1 mission in support of the Commercial Crew Program. She then lifted Canada’s three-spacecraft Radarsat Constellation Mission (RCM) the following June. Those two opening missions of her career saw B1051 fly both from historic Pad 39A at the Kennedy Space Center (KSC) in Florida and from SLC-4E at Vandenberg.
Following her brief stint on the West Coast for the Radarsat launch campaign, B1051 headed back east to fly eight missions between January 2020 and last May, delivering 417 Starlinks and SiriusXM’s high-powered SXM-7 radio broadcasting satellite to orbit.
In 2020, she became the first Falcon 9 core to launch four times and five times in a single calendar year. Just last January, she established a new record—now beaten—for the shortest launch-to-launch interval of an orbital-class booster. And in 2021, she became the first Falcon 9 core to record eighth, ninth, tenth and now 11th missions.
With tonight’s flight, B1051 pushed her personal Starlink tally to 469 satellites. And of those missions, her first seven Starlink batches were headed to orbital altitudes of about 340 miles (550 kilometers), inclined 53 degrees to the equator.
But tonight’s 52-strong batch were bound for a slightly lower 335 miles (540 kilometres), becoming become only the third group of Starlinks in the Group 4 “shell” at 53.2 degrees of inclination. Since last month, 153 Starlinks have been launched to 53.2 degrees over three missions, marking the first of over 1,500 satellites headed for this shell by 2027.
Eight minutes after tonight’s launch, B1051 smoothly alighted on the deck of the Autonomous Spaceport Drone Ship (ASDS), “Of Course I Still Love You”, located offshore in the Pacific Ocean. It marked the rocket’s tenth successful drone ship landing of her career, with one other touchdown having occurred on solid ground at Landing Zone (LZ)-4 at Vandenberg.
It was also the 75th fully successful landing of a booster on an ASDS since April 2016. In the meantime, the Merlin 1D+ Vacuum engine of the second stage executed a six-minute “burn” to position the Starlink stack for deployment at 15 minutes and 36 seconds after launch.
Last night’s success marked the 29th Falcon 9 launch of the year, with two more missions now primed to fly from the East Coast in the next few days. Up next, from storied Space Launch Complex (SLC)-40 at Cape Canaveral Space Force Station, Fla., a rocket which previously saw service as a Falcon Heavy side-booster will launch no sooner than 10:58 p.m. EST Saturday.
The B1067 core—making the third flight of its career—will lift Turkey’s powerful Türksat 5B communications satellite on the first leg of its trek to geostationary orbit.
Developed and built by Airbus Defence and Space and Turkish Aerospace Industries (TAI), the 9,900-pound (4,500-kilogram) Türksat 5B will provide Ku- and Ka-band communications and direct-broadcast television services across a broad swath of territory from Turkey and the Near East to Europe and Africa, on behalf of the Ankara-based provider, Türksat.
Its High Throughput Satellite (HTS) payload will provide more than 50 Gbps of capacity. Based on the all-electric variant of Airbus’ EuroStar E3000 “bus”, Türksat 5B will enter a geostationary orbital “slot” at 42 degrees East longitude for an expected 15 years of active operational service.
Contracts to build two satellites—including Türksat 5A, which rode another Falcon 9 to orbit last January—were awarded to Airbus back in November 2017 and both adhered with surprising closeness to their targeted launch dates. Right from the outset, Türksat 5B was scheduled to fly in 2021.
Also in November 2017 SpaceX was awarded the contract to launch both satellites. A year later, in October 2018, Mehmet Cahit Turhan, Turkey’s minister of transport and infrastructure, told delegates at the fourth Global Satellite Show at the Istanbul Exhibition Ceter that both satellites had passed their Preliminary Design Review (PDR) and were pressing into Critical Design Review (CDR).
“With the Türksat 5B satellite, especially the Ka-band capacity will increase to 15 times the current capacity,” explained Mr. Turhan. “With the Ka-band capacity planned on Türksat 5B, we will focus especially on the commercial ships and airlines market…thus, we will reach an important position in the sector by including the entire Middle East, the Persian Gulf, the Red Sea, the Mediterranean, North and East Africa, Nigeria, South Africa and nearby neighboring countries.”
By March 2020, physical construction of the satellite had been completed and the integration of Türksat 5B’s communications module was underway. By this time, and with the worldwide impact of the COVID-19 coronavirus pandemic beginning to be felt, the launch was targeted for the second quarter of 2021.
System-level testing of the satellite progressed into last fall, but by April 2021 launch had moved to no earlier than the fourth quarter and by mid-September had shifted again to “the end” of the year. Earlier this month, Türksat confirmed that it was targeting 19 December for launch.
In readiness for the Türksat 5B launch campaign, the East Coast ASDS, “A Shortfall of Gravitas”, departed Port Canaveral last Wednesday, bound for a position about 390 miles (630 kilometers) offshore, to await B1052’s return. Weather conditions for Saturday night are predicted to be around 80-percent favorable, deteriorating slightly to 60 percent in the event of a 24-hour slip to Sunday.
“A frontal boundary is forecast to approach from the northwest Saturday, with the onshore component to the wind becoming increasingly moist and unstable over the weekend,” noted the 45th Weather Squadron at Patrick Space Force Base in a Friday update. “Therefore, the primary weather concern for launch day is cumulus clouds potentially associated with showers in advance of this front. For the delay day, the front is expected to stall nearby, allowing additional moisture convergence and a greater potential for showers and layered thick clouds.”
Should B1067 launch on time tonight, she will establish a new record for the shortest interval between any two Falcon 9 missions, a little more than 18 hours. That will eclipse the previous record of slightly over 44 hours, set by the first Starlink batch out of Vandenberg last 14 September and the historic, all-civilian Inspiration4 from KSC on the 16th.
And following the return of B1067 from delivering Türksat 5B to orbit, the smoke will have barely cleared, before a third Falcon 9 lifts the next Cargo Dragon towards the International Space Station (ISS) from KSC’s Pad 39A at 5:06 a.m. EST Tuesday.
The CRS-24 mission represents the fourth cargo mission to the station under the second-round Commercial Resupply Services (CRS2) contract with NASA.
Laden with 6,500 pounds (2,590 kilograms) of payloads, equipment and supplies for the incumbent Expedition 66 crew, the Cargo Dragon will spend almost a day in transit, before conducting an autonomous docking at the space-facing (or “zenith”) port of the station’s Harmony node at about 4:30 a.m. EST Wednesday. Monitoring the cargo ship’s arrival from the station will be NASA astronauts Tom Marshburn and Raja Chari.
In anticipation of the CRS-24 mission, a Launch Readiness Review (LRR) was completed yesterday, although the weather outlook for Tuesday appears somewhat pessimistic, with only a 40-percent chance of acceptable conditions at T-0, improving only marginally to 60 percent in the event of a 24-hour scrub to Wednesday.
“An unsettled pattern will be in place across Central Florida and the Spaceport for the first half of the upcoming week as a frontal boundary arrives in the state on Sunday and stalls out by early Monday,” noted the 45th Weather Squadron. “Confidence in increased shower and storm coverage, along with extensive mid-level cloud cover bringing in less-than-favorable conditions for the primary launch attempt early Tuesday morning is high.”