UPDATE – Launch was aborted just before liftoff. No word yet on a new date for the next launch attempt.
For the first time on Sunday, a five-times-used Falcon 9 booster will spear aloft from historic Pad 39A at the Kennedy Space Center (KSC) in Florida to kick off SpaceX’s sixth overall mission of 2020. Although a handful of boosters have flown four times, none have previously launched a fifth mission.
Laden with another 60 Starlink internet communications satellites—part of CEO Elon Musk’s pledge to emplace thousands of these low-orbiting platforms in space by mid-decade—the mission brings yet another piece of history-making to Pad 39A, which previously supported all but one of the Apollo lunar flights, 82 Space Shuttle launches and which has since 2014 been leased to SpaceX.
Sunday’s liftoff, timed to occur at 9:22 a.m. EDT, will also represent the 20th Falcon to rise from Pad 39A since February 2017, in a run of missions which has also seen the first voyage of the mammoth Falcon Heavy and last year’s maiden flight of Crew Dragon.
All told, this will be Pad 39A’s 113th launch in a little more than five decades of operational service. It also affords us a peculiar shift in focus for the complex, which back in January supported the long-awaited in-flight abort test of Crew Dragon and is expected to serve as the staging-point for the Demo-2 mission with NASA astronauts Doug Hurley and Bob Behnken as soon as May, which is confidently expected to see the return of U.S. human spaceflight capability aboard U.S.-built spacecraft, from U.S. soil and aboard U.S. rockets, for the first time since the end of the shuttle era. It is not expected that Saturday’s next batch of Starlinks will negatively impact the Demo-2 launch date.
Providing the first-stage muscle for this mission will be B1048, the first Falcon 9 core to support as many as five discrete launches. SpaceX has long declared that the Block 5 variant can fly up to ten times and, to date, 23 boosters have flown twice, six have launched on three occasions and only four have done so as many as four times. Of those four, only two remain in existence, following the intentional destruction of B1046 during January’s Crew Dragon in-flight abort test and the loss of B1056 last month, which missed the Autonomous Spaceport Drone Ship (ASDS) in part due to inaccurate wind data and was subsequently sunk in the Atlantic Ocean. Still raring to go for potential fifth missions are B1049, which last flew in January, and B1048, which is earmarked for Sunday’s launch.
Scarred and blackened from its four previous high-energy ascents and re-entries, B1048 has a chequered career to date. First used back in July 2018 to lift the second-to-last batch of Iridium NEXT low-orbiting communications satellites, it saw subsequent service to deliver Argentina’s SAOCOM-1A Earth-imaging platform the following October. In so doing, B1048 achieved the first-ever “land” landing at Vandenberg Air Force Base, Calif., touching down smoothly on Landing Zone (LZ)-4, the repurposed Space Launch Complex (SLC)-4W. A third launch in February 2019 saw it deliver Indonesia’s Nusantara Satu communications satellite to geostationary transfer orbit and Israel’s Beresheet lunar lander towards the Moon, whilst B1048 most recently carried a 60-strong batch of Starlinks into space last November. In doing so, this particular core became the first Falcon 9 to record a fourth launch. If Sunday’s flight goes ahead without a hitch, it will also be first to make a fifth.
And if you happen to think that seeing B1048 in action again has a touch of “Groundhog Day” about it, you would not be far wrong, for this will also be the fifth dedicated launch of Starlink satellites in less than four months. Batches of 60 of these low-orbiting internet communications satellites were despatched on B1048’s most recent launch, as well as twice in January 2020 and once just last month. Prior to those flights, a series of Starlink “test satellites” were launched in February 2018 and May of last year.
The $10 billion Starlink program, unveiled by SpaceX CEO Elon Musk in Seattle, Wash., in January 2015, has been described as a means of revolutionizing low-cost broadband provision. He identified it as a means of opening the way for competitively-priced services for urban regions and rural and underserved areas of the United States. Under the announced plan, an eventual constellation of 12,000 satellites could handle up to half of all backhaul communications traffic and a tenth of all local internet traffic in high-population-density cities by the mid-2020s.
Late in 2016, SpaceX described the concept as “non-geostationary” and revealed Starlink’s initial coverage would span the Ku-band and Ka-band regions, between 12-18 GHz and 26.5-40 GHz, respectively. By the late spring of the following year, plans were laid for a second orbital “shell” of satellites to utilize the V-band at 40-75 GHz, which is not routinely used for commercial communications purposes. Previously, the V-band has seen service for millimeter-wave radar research and scientific applications, but it reportedly also has promise for high-capacity terrestrial millimeter-wave communications networks.
SpaceX’s original intent was for 4,425 Ku-/Ka-band Starlinks to reside at an altitude of 710 miles (1,150 km) and 7,518 V-band birds to sit at 210 miles (340 km), producing a total population of these small satellites by the mid-2020s. However, in November 2018 SpaceX received licensing from the Federal Communications Commission (FCC) to operate a third of the Ku-/Ka-band complement—some 1,584 satellites—at just 340 miles (550 km), much lower than initially planned. This will produce a relatively short operational lifetime of around five years, before they are maneuvered into a disposal orbit for controlled re-entry. SpaceX has explained that all satellite components are “100-percent demisable” and exceed “all current safety standards”, but the sheer volume of Starlinks to be launched in a relatively short period has aroused lingering controversy, both in terms of the work of astronomers and adding to ongoing debate about the effect of space debris.
Two Starlink test satellites, Tintin-A and Tintin-B, were launched in February 2018 and successfully validated the phased-array broadband antenna from an orbital perch 320 miles (515 km) above Earth. Then, last May, the first 60 “production-design” Starlink satellites were launched atop B1049. Although three of the satellites failed shortly after reaching orbit, the remainder are still healthy. More recently, in November 2019 and on three occasions in January and February of this year, a further four batches of 60 Starlinks apiece were boosted to space on three veteran Falcon 9 rockets.
SpaceX President Gwynne Shotwell has already confirmed plans to launch further 60-strong sets of Starlinks approximately every two weeks throughout 2020, raising the likelihood that many hundreds of these small satellites will be in orbit by next New Year’s Eve. And that pledge looks set to be met not only with words, but also with the roar of rocket exhaust, too, for Sunday’s launch will come only a few weeks since the most recent Starlink flight.
As has become customary on these missions, the Falcon 9 was transported to the pad for its Static Fire Test with the Starlink payload “stack” already in place. This is quite different to other SpaceX customers, which are installed after the Static Fire Test, following a September 2016 anomaly in which the Amos-6 communications satellite was lost in a pre-flight explosion on the pad. One of the key benefits of hauling the Falcon 9 out to the pad with the Starlink payload pre-integrated is that the Static Fire Test of the nine Merlin 1D+ first-stage engines can be conducted only a day or two prior to launch. As such, B1048 was not transported out to Pad 39A until Friday, 13 March.
Assuming an on-time liftoff on Sunday morning, this will be SpaceX’s sixth launch of 2020 and the sixth Falcon 9 mission in a row to utilize a flight-proven core stage.