“SpaceX launched 60 more Starlink internet satellites to orbit this morning (Feb. 4) on a mission that notched a booster-reusability milestone for the company.
A two-stage Falcon 9 rocket topped with the 60 broadband spacecraft lifted off from Space Launch Complex 40 here at Cape Canaveral Space Force Station today at 1:19 a.m. EST (0619 GMT).
Approximately nine minutes later, the rocket’s first stage returned to Earth, landing smoothly on one of SpaceX’s drone ships in the Atlantic Ocean. The massive ship, “Of Course I Still Love You,” is one of two SpaceX vessels that catch falling boosters and return them to port.
It was the fifth launch for this Falcon 9 first stage, which last flew just 27 days ago — the quickest turnaround between missions for any SpaceX booster. Today’s launch was also the first of two nearly back-to-back Starlink liftoffs; another 60 satellites are scheduled to take flight early Friday morning (Feb. 5) on a different Falcon 9.
Today’s launch, dubbed Starlink 18, leapfrogged that coming flight, known as Starlink 17. Starlink 17 was supposed to get off the ground on Monday (Feb. 1) but was delayed due to poor weather in the recovery zone and the need for extra pre-flight checks.
For a while, it looked like Starlink 17 would fly this morning as well. The Eastern Range, which oversees all launches from the U.S. East Coast, granted SpaceX approval to launch Starlink 17 today from NASA’s Kennedy Space Center, next door to Cape Canaveral Space Force Station, less than five hours after Starlink 18 took flight.
If that had happened, it would have been the first time since 1966 that two orbital missions had launched from the Eastern Range on the same day, officials with the 45th Space Wing said via Twitter yesterday (Feb. 3). On Nov. 11, 1966, a Gemini rocket and an Atlas Agena launched just 99 minutes apart.
This short turnaround time between Falcon 9 launches can happen because SpaceX operates from two different launch pads here in Florida and also because the Space Force has streamlined launch procedures. Such streamlining is possible partly because all Falcon 9 rockets are equipped with an automatic flight termination system (FTS), which reduces the amount of staff needed on console for any launch.
The FTS is a safety feature that will destroy a rocket in a controlled manner if something goes wrong during flight. Falcon 9 is currently the only American rocket that packs an automated FTS — meaning the rocket’s onboard computer can detect if there’s something wrong and, if so, either shut down the rocket’s engines before liftoff or destroy the vehicle in flight.
Other rockets rely on humans to make that call, but as a requirement set by the Space Wing, all future launchers (Blue Origin’s New Glenn and United Launch Alliance’s Vulcan Centaur, for example) will also have this key feature.
Double the launches
With today’s successful launch, SpaceX has now deposited more than 1,000 Starlink satellites into orbit. And there are more launches coming; SpaceX’s initial Starlink constellation will consist of 1,440 satellites, and there could eventually be tens of thousands of spacecraft in the network.
Starlink 17, the other part of the doubleheader, was originally set to blast off Monday (Feb. 1). It was initially pushed 24 hours to allow for improved weather conditions at the recovery zone, then delayed several more times, causing it to switch places with Starlink 18. SpaceX relies heavily on its fleet of reused rockets, so the company wants to make sure that its recovery efforts are successful.
Starlink 17 will mark just the second time that one of the company’s Falcon 9 first stages has flown eight times. The booster, known by the designation B1049, launched a Telstar communications satellite in September 2018, lofted an Iridium NEXT satellite in January 2019, and then flew five different Starlink missions.
A record launch
The Falcon 9 first stage for Starlink 18, booster B1060, set a new record today for the fastest turnaround time between flights: B1060 just ferried the Turksat 5A satellite into space for Turkey on Jan. 7. Before that, it had launched a GPS III satellite for the U.S. Space Force and lofted two other Starlink batches as well.
Today’s launch was the fourth of 2021 for SpaceX and the 17th overall Starlink mission. It was also the 107th flight overall for the workhorse Falcon 9, as well as the 73rd successful rocket landing for the company.
SpaceX flew a record 26 missions in 2020, with 22 of them on refurbished rockets.
The current Falcon 9 iteration, which entered service in 2018, features the ability to fly multiple times with few refurbishments in between. That’s thanks to a series of upgrades — including a more robust thermal protection system, titanium grid fins and a more durable interstage — that facilitate reuse.
As such, SpaceX has relied heavily on its fleet of veteran rockets, having now reflown a total of 53 first-stage boosters since the first one landed on terra firma at Cape Canaveral in December 2015.
SpaceX has its two drone-ship landing platforms — “Of Course I Still Love You” and “Just Read the Instructions” — in Florida, allowing it to launch (and land) more rockets. Both massive ships are stationed out at their respective recovery zones, awaiting action.
“Of Course I Still Love You” was recently refurbished following a busy 2020. It did its rocket-catching job today, and “Just Read the Instructions” will be called into action on Friday.”