You might be forgiven for thinking a touch of déjà vu hit the Space Coast on Friday, as a six-times-flown Falcon 9 roared uphill from storied Space Launch Complex (SLC)-40 at Cape Canaveral Space Force Station at 7:38 p.m. EDT, right on the opening of its 38-minute “launch window”. Laden with a pair of geostationary-bound satellites for Luxembourg-based telecommunications provider SES, it was SpaceX’s second mission of St. Patrick’s Day, establishing a new record of only four hours between a pair of Falcon 9 flights.
Earlier today, another booster—the eight-times-used B1071—rose from Space Launch Complex (SLC)-4E at Vandenberg Space Force Base, Calif., carrying a “batch” of Starlink internet communications satellites. Launched at 12:26 p.m. PDT, B1071 powered the 230-foot-tall (70-meter) Falcon 9 uphill for the opening 2.5 minutes of the mission, before separating and pirouetting to an on-point touchdown on the expansive deck of the West Coast-based Autonomous Spaceport Drone Ship (ASDS), “Of Course I Still Love You”, situated offshore in the Pacific Ocean.
With B1071 gone, the Falcon 9’s second stage executed a standard six-minute “burn” of its Merlin 1D+ Vacuum engine to deliver the 52-satellite Starlink payload—totaling around 35,500 pounds (16,100 kilograms)—into orbit. Deployment occurred some 15 minutes after liftoff and the satellites will be positioned at an orbital inclination of 70 degrees, at an altitude of 350 miles (570 kilometers).
It marked the ninth Starlink mission of 2023, which has seen 440 of these flat-packed internet communications satellites emplaced into orbit this year. All told, 4,103 “production-design” Starlinks have flown on 76 dedicated flights since May 2019.
Starlink now facilitates high-speed and low-latency internet provision across 50 sovereign nations and international markets, spanning North and South America, Europe, Asia, Oceania and Africa. Last month alone, Iceland, Rwanda and the Philippines—Starlink’s first client in South East Asia—officially signed up to the network.
Attention then turned to Florida and the Cape’s SLC-40, which was gearing up to host its tenth Falcon 9 launch of 2023. The five-times-used B1069 core, which flew most recently last month, was laden with the dual-stacked SES-18 and SES-19 geostationary satellites, flying on behalf of Luxembourg-based telecommunications provider SES.
B1069 entered SpaceX’s burgeoning booster fleet back in December 2021. Almost lost after her first flight in a hair-raising ASDS touchdown, she underwent substantial repairs—including a brand-new suite of Merlin 1D+ first-stage engines—and went on to fly three more missions in 2022.
She lofted 54 Starlinks to orbit in August, followed by Eutelsat’s Hotbird 13F geostationary-bound communications satellite in mid-October and 40 broadband satellites early in December for London, England-based OneWeb. A fifth flight just last month saw her deliver another Starlink batch on the Falcon 9 fleet’s 200th fully successful launch.
Friday’s opening “launch window” was set to open at 7:38 p.m. EDT and last 38 minutes, with a backup opportunity opening at the same time Saturday evening and extending for 37 minutes. A launch at the start of Friday’s first opportunity thus promised to set a new SpaceX record of four hours and 12 minutes between two Falcon 9 flights, eclipsing the current “personal best”, set last 5 October, between the Florida launch of Dragon Endurance and Crew-5’s Nicole Mann, Josh Cassada, Koichi Wakata and Anna Kikina—heading uphill for a five-month stay on the International Space Station (ISS)—and a Vandenberg Starlink mission, seven hours and ten minutes later.
Efforts to break this record have already been attempted earlier in 2023. Hopes of launching pairs of back-to-back missions 35 minutes apart in January and 53 minutes apart last month ultimately came to nought, thanks to schedule difficulties, technical troubles and poor weather.
In readiness for tonight’s launch, the Autonomous Spaceport Drone Ship (ASDS), “Just Read the Instructions”, put to sea out of Port Canaveral last Sunday and was positioned about 410 miles (660 kilometers) offshore in the Atlantic Ocean. Weather conditions for Friday were expected to be around 80-percent-favorable, according to the 45th Weather Squadron at Patrick Space Force Base, but were predicted to deteriorate markedly to only 35-percent-favorable for Saturday’s backup launch attempts.
As the next cold front approaches Florida from the west, high pressure will retreat into the Atlantic. “The front will be draped over the Florida Panhandle by the evening,” noted the 45th. “This set up will bring southerly winds, shifting southeasterly and becoming gusty in the late afternoon and evening behind the sea breeze.”
Potential showstoppers on Friday night included a risk posed by near-surface liftoff winds. But as the cold front makes its way into East Central Florida on Saturday, the 45th explained that weather conditions “will deteriorate”, with a high likelihood of showers, storms and increased cloud cover.
Yet Mother Nature was not one to be trifled with. “Falcon 9 vertical at SLC-40,” SpaceX tweeted at 5 p.m. EDT, then cautioned: “Teams are keeping an eye on winds at the launch site.”
Taking full advantage of this favorable weather, B1069 roared aloft at 7:38 p.m. EDT, snatching a new launch-to-launch record by flying only four hours and 12 minutes after her predecessor B1071 had left Vandenberg. Eight minutes later, blackened and scorched from her sixth ascent and high-energy re-entry, she alighted smoothly on the deck of the drone ship, wrapping up SpaceX’s sixth launch of March and 18th mission of 2023.
In the meantime, the Falcon 9’s second stage continued the push uphill, her Merlin 1D+ Vacuum engine executing a pair of “burns” to deliver the SES-18 and SES-19 twins to their dropoff point for Geosynchronous Transfer Orbit (GTO). The satellites were set to be deployed five minutes apart, with the upper satellite in the stack (SES-18) expected to drift off into the inky blackness of space at 32 minutes after launch and the lower satellite (SES-19) due to do likewise at 37 minutes.
They will employ their on-board propulsion assets to position themselves in their operational orbits, with SES-18 targeting 103.05 degrees West longitude by June and SES-19 some 134.9 degrees West. Built by Northrop Grumman Corp., the near-identical satellites will leverage the capabilities of the GeoStar-3 “bus” and carry ten C-band transponders to furnish digital television broadcasting to nearly 120 million homes.
These two satellites are part of a group of four SES birds—of which the first pair, SES-20 and SES-21, rode a United Launch Alliance (ULA) Atlas V to orbit early last fall—to spearhead an ongoing campaign to accelerate SES’ C-band clearing plan and meet a Federal Communications Commission (FCC) objective to free up spectrum for 5G terrestrial wireless services. SpaceX was selected back in June 2020 as the launch services provider for the SES-18 and SES-19 mission.
With six launches completed in the last two weeks, SpaceX looks ahead to as many as three more flights in the days ahead. This might possibly wind up March as its first eight-launch (or even nine-launch) month on record.
A pair of East Coast Starlink missions are provisionally slated a week or so apart in the final ten days of the month, followed by the first launch of “Tranche 0” of the Transport and Tracking Layer for the Space Development Agency (SDA) from Vandenberg. That may see March also become the first month to see three Falcon 9 launches from the West Coast.
Tranche 0 will form the basis of an eventual “constellation” of 300-500 low-orbiting experimental satellites to furnish ground-based warfighters with “assured, resilient, low-latency military data and connectivity worldwide”, together with Wide Field of View (WFOV) infrared sensors for infrared missile tracking. Contracts for Tranche 0 were signed with SpaceX in January 2021 for an estimated total value of $150.45 million.