After a few days of delays pushed the missions closer together, SpaceX is now preparing to launch two batches of 53 Starlink satellites just eight hours apart – one from Florida and the other from California.
Originally scheduled to launch as early May 10th, which would have tied SpaceX’s Vandenberg Space Force Base (VSFB) SLC-4E launch pad turnaround record, Starlink 4-13 slipped to May 12th within the last few days. 2400 miles (~3900 km) to the east, SpaceX’s Starlink 4-15 mission – preparing to launch from the company’s Cape Canaveral Space Force Station (CCSFS) LC-40 pad – recently found itself on the opposite boat.
On April 22nd, Spaceflight Now reported that Starlink 4-15 was scheduled to launch no earlier than (NET) May 8th. At the time, Starlink 4-13 was also scheduled to launch on the 8th, placing the two Starlink missions just a few hours apart. On April 28th, Spaceflight Now updated its well-sourced launch calendar, revealing that Starlink 4-13 had slipped to May 10th and Starlink 4-15 to May 16th, ending their concurrence. Finally, on May 7th and May 8th, photographer Ben Cooper reported that Starlink 4-15 had moved up to 2:08 am EDT (06:08 UTC), May 13th and FAA documents revealed that Starlink 4-13 had slipped again to 3:29 pm PDT (22:29 UTC), May 12th.
In other words, the missions have again found themselves just a handful of hours apart after weeks of unrelated juggling and delays. Barring additional issues, Starlink 4-13 and Starlink 4-15 are scheduled to launch just 7 hours and 41 minutes apart. Set in late 2021, the shortest time between two Falcon launches is currently 15 hours and 17 minutes. But above all else, the constant back and forth – only to end up with both launches again just hours apart – demonstrates just how agonizing and unforgiving the planning behind every rocket launch schedule truly is.
Fittingly, Starlink 4-13’s drone ship headed to sea just ~60 hours before the scheduled launch and Starlink 4-15’s drone ship has yet to depart, keeping the launch dates of both missions about as uncertain as they can be without guaranteeing that delays are coming. Both drone ships must be towed about 400 miles downrange at speeds that almost never exceed 8-10 mph, translating to a minimum two-day journey even with zero stops, slowdowns, or detours.
Beyond the record-breaking potential, Starlink 4-13 is an otherwise ordinary mission that will launch another 53 Starlink V1.5 satellites to an ordinary 53.2-degree inclination, which simply means that they’ll end up in the same ‘shell’ as the other satellites in Starlink’s ‘Group 4’ shell. Despite launching from the opposite coast of the US, Starlink 4-15 will be almost identical and is expected to deploy another 53 Starlink V1.5 satellites to the same orbital shell. However, it appears that Starlink 4-15 will have a few highly unusual features.
Instead of performing a hockey stick-like ‘dogleg’ maneuver to avoid overflying any populated islands in the Bahamas, Falcon 9 will directly overfly the country’s largest western island and attempt to land right in the middle of the archipelago, potentially touching down on a drone ship just 5-15 miles away from Nassau and a couple other islands. The fact alone that SpaceX was able to convince both the Bahamas and the US’ FAA to allow it to fly the trajectory shown above is extremely impressive and belies a deep trust in SpaceX’s expertise and Falcon 9’s safety and reliability. At the same time, SpaceX may be taking some degree of risk, as the trajectory’s minuscule margins for error probably mean that Falcon 9’s automatic flight termination system will be programmed to destroy the rocket at the slightest hint of deviation from the planned trajectory.
Adding to the oddity, Starlink 4-15 will be the first in a long line of Four. Five dedicated Starlink launches to debut a new Falcon 9 booster. According to Next Spaceflight, Falcon 9 B1073 will claim that unusual first, almost entirely flipping the table on the precedent of conservative government customers – still timid about SpaceX reusability – scrambling to secure increasingly rare launch opportunities on new Falcon 9 boosters. Alternatively, it’s possible – but unlikely – that SpaceX implemented significant changes to Falcon 9 B1073 that it wants to verify independently before risking customer payloads.
With any luck, the new rocket will perform flawlessly and give some nearby Bahamians a truly one-of-a-kind experience: the ability to watch a SpaceX Falcon 9 booster land at sea… from the comfort of their own homes.