In a rare surprise for Starlink launches, a SpaceX Falcon 9 booster has failed to successfully land after kicking off the first of two Starlink missions planned in a 25-hour period.

Some nine minutes after liftoff, Falcon 9 booster B1059 suffered an unknown failure that cut short its sixth landing attempt a second or two after landing burn. With no sign of a sustained burn, the booster most likely impacted the ocean at supersonic or high-subsonic speeds, unfortunately ending a record streak of 24 consecutively successful Falcon landings.

Thankfully, Falcon 9 B1059 had already supported five orbital-class launches since its December 2019 debut and, as always, booster recovery is always a secondary objective for SpaceX launches. The primary objective, deploying another batch of 60 Starlink satellites, is on its way to completion as Falcon 9’s upper stage orbits the Earth in preparation for a second small burn and payload deployment around 65 minutes after liftoff.

Update: Falcon 9’s upper stage performed flawlessly, igniting for a brief one-second orbit-raising burn and ultimately deploying a batch of 60 Starlink satellites without issue.

Known as Starlink V1 L19 or Starlink-19, the February 15th mission will be SpaceX’s 19th Starlink launch since operational ‘v1.0’ satellites first began flying in November 2019 and the 20th Starlink launch overall. Earlier this month, SpaceX’s Starlink-18 launch pushed the vast satellite broadband constellation past the 1000-satellite mark, making it the first constellation in history to grow to four digits strong.

Starlink-19 continues that growth just days after SpaceX quietly opened Starlink internet signups to almost anyone on Earth. According to SpaceX, the company expects the growing Starlink constellation to offer connectivity almost anywhere on Earth by the end of 2021.

Starlink-19’s landing failure serves as a bittersweet reminder that SpaceX’s ambitions of a broadband constellation several thousand (to several tens of thousands of) satellites strong is almost intrinsically contingent upon routine, reliable booster reusability. If SpaceX lost boosters on even a small fraction of the one or several hundred Falcon 9 launches needed to launch that constellation, the cost of getting Starlink into orbit would likely balloon by a factor of 5-10, if not more.

Ultimately, SpaceX will almost certainly determine the root cause of Falcon 9 B1059’s landing failure and use any lessons learned – however painfully acquired – to benefit all future Falcon launches and landings. There is a limited chance that this could impact SpaceX’s upcoming Crew Dragon Crew-2 mission in April, which is scheduled to be the first crewed launch ever to use a privately-developed flight-proven booster, but any knowledge gained will ultimately make Falcon 9 a safer rocket in ways that no other existing launch provider can match.

Barring delays caused by B1059’s landing failure, Starlink-17 – delayed roughly ten times by weather and technical bugs over the last month – is scheduled to launch no earlier than 12:55 am EST (5:55 UTC) on Wednesday, February 17th, a few minutes less than 26 hours after Starlink-19. Stay tuned for SpaceX’s official webcast!