A SpaceX Falcon 9 rocket, carrying two spacecraft for Europe's Galileo satellite navigation constellation, lifted off at 2250 UTC, Sept. 17, from Cape Canaveral Space Force Station in Florida.
About 8.5 minutes after launch of the Galileo L13 mission, the Falcon 9's first stage returned to Earth as expected, landing at sea on the SpaceX droneship "Just Read the Instructions"(JRTI). The rocket's upper stage, meanwhile continued skywards, hauling the two Galileo satellites to be deployed in medium Earth orbit(MEO), about 3.5 hours after launch.
This was the 22nd landing for this particular Falcon 9 first stage -- one shy of the company's reuse record, according to a SpaceX mission description.
During SpaceX Galileo launch last April, the Falcon 9's first stage did not try to make a safe landing; rather, lacking the fuel to steer itself back for a vertical touchdown, it ditched into the sea.
Commenting on Tuesday's launch, SpaceX wrote on X: "During the Galileo L12 mission earlier this year, the Falcon 9 booster was expended to provide the additional performance needed to deliver the payload to its orbit. Data from that mission informed subtle design and operational changes, including mass reductions and trajectory adjustments, that will allow us to safely recover and reuse this booster. The booster reentry trajectory will result in higher heating and dynamic pressure on the booster than many of our historical landings. Although the reentry conditions are on the higher end of past missions, they are still acceptable. This landing attempt will test the bounds of recovery, giving us valuable data on the design of the vehicle in these elevated entry conditions. This in turn will help us innovate on future vehicle designs to make our vehicles more robust and rapidly reusable while expanding into more challenging reentry conditions."
The Galileo constellation -- Europe's equivalent of the United States' Global Positioning System (GPS) -- resides at an altitude of 23,222 kilometers. Thirty-two Galileo satellites have now launched to date, all but four of them atop Russian-built Soyuz rockets or Europe's Ariane 5 heavy lifter.
However after Europe's other options dried up -- it cut most space ties with Russia following the February 2022 Ukraine invasion, and the Ariane 5 retired last summer -- it signed a Galileo launch deal with SpaceX in late 2023. The Elon Musk company has launched two missions this past April. And Tuesday's launch fulfils the contract which covers up to four Galileo spacecraft.
