SpaceX Calls Rare Last-Minute Abandon During California Launch Countdown – Spaceflight Now

SpaceX Calls Rare Last-Minute Abandon During California Launch Countdown – Spaceflight Now

File photo of a SpaceX Falcon 9 rocket on its launch pad in California before a previous mission. Credit: SpaceX

SpaceX canceled a Falcon 9 launch attempt on Thursday less than a minute before liftoff from Vandenberg Space Force Base in California, the company’s first terminal countdown in more than 18 months for reasons other than such as bad weather or range safety.

The Falcon 9 rocket was supposed to lift off for SpaceX’s Starlink 3-2 mission at 10:39 a.m. PDT (1:39 p.m. EDT; 5:39 p.m. GMT) Thursday from a foggy launch pad in Vandenberg, a military spaceport about 140 miles away. (225 kilometers). ) northwest of Los Angeles.

But the computer countdown sequencer interrupted the pre-launch sequence at T-minus 46 seconds. SpaceX did not identify a reason for the suspension, but weather parameters and military range at Vandenberg were “go” for the launch.

The company had two instant launch opportunities on Thursday to line up with orbital planes in the company’s Starlink internet constellation. There are 46 Starlink internet satellites awaiting launch from California on the Falcon 9 rocket.

Options for SpaceX’s launch team are also limited once the Falcon 9 rocket is loaded with propellants. The Falcon 9 uses supercooled, densified liquid oxygen and kerosene propellants, and the fluids can get too hot if the rocket sits on the ground too long before liftoff.

SpaceX’s launch director announced Thursday’s countdown has been canceled and teams have begun preparations to drain the boosters from the two-stage Falcon 9 rocket. Officials have tentatively set another launch attempt for Friday at the same time — 10:39 a.m. PDT.

The last time a technical issue forced SpaceX to halt a countdown in the final phase of countdown preparations was in December 2020 during a launch from Florida for the National Reconnaissance Office. During this launch attempt, SpaceX engineers identified an unexpected pressure reading in the Falcon 9’s upper stage liquid oxygen tank, lowered the rocket to horizontal for troubleshooting, then launched successfully completed the mission two days later.

SpaceX has erased several Falcon 9 countdowns since December 2020 due to poor weather conditions or range violations by ships or aircraft that ventured into restricted airspace or waters near the launch site. And there were a few launch delays caused by issues with the Falcon 9 rocket or ground systems, but none of those happened in the final countdown to liftoff sequence.

SpaceX has launched 62 Falcon 9 rocket missions since the NROL-108 launch was canceled by a technical issue more than 18 months ago.

The Starlink 3-2 mission aims to deploy 46 Internet satellites in polar orbit. Credit: Spaceflight Now

The launch of the next 46 Starlink satellites from California will mark the 32nd flight of a Falcon 9 rocket this year, breaking the record of 31 missions in a calendar year set for 2021.

And the year is barely halfway through, which means SpaceX is on track to nearly double the number of launches it has completed in 2021. SpaceX has launched more successful missions into orbit so far this year than the combined effort. of any other nation, and the company is far surpassing its major competitors in the commercial market.

United Launch Alliance, a rival in the competition for military launch activities in the United States, has successfully launched four times this year. Arianespace, the European commercial launch company, has already completed three missions in 2021.

SpaceX said its first 31 missions of the year delivered about 351 metric tons (about 774,000 pounds) of payload mass to orbit. The flights have carried astronauts to the International Space Station, launched hundreds of small satellites for the Starlink network and customer fleets, and deployed national security payloads for the US government’s spy satellite agency.

As SpaceX prepares for the launch of the Starlink 3-2 mission, Kennedy Space Center workers are preparing another Falcon 9 rocket for liftoff from pad 39A early Sunday along with another batch of Starlink internet satellites.

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Follow Stephen Clark on Twitter: @StephenClark1.

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