SpaceX launching 2 European navigation satellites tonight

SpaceX will launch two European navigation satellites tonight (Sept. 17), weather permitting.

A Falcon 9 rocket carrying two spacecraft for Europe’s Galileo satnav constellation is scheduled to lift off from Cape Canaveral Space Force Station in Florida tonight at 6:50 p.m. EDT (1850 GMT).

SpaceX will webcast the action live via its X account, beginning about 15 minutes before liftoff. However, the company says it’s keeping its eye on the weather, which is frequently iffy on Florida’s Space Coast. If Mother Nature doesn’t cooperate tonight, there’s another opportunity tomorrow (Sept. 18) at around the same time.

If all goes according to plan tonight, the Falcon 9’s first stage will return to Earth safely, landing at sea on the SpaceX droneship “Just Read the Instructions” about 8.5 minutes after launch. According to a SpaceX mission description, it will be the 22nd liftoff and landing for this particular booster — one shy of the company’s reuse record.

Related: SpaceX launches 2 Galileo navigation satellites to orbit (video)

The Falcon 9’s upper stage, meanwhile will haul the two Galileo satellites toward medium Earth orbit, deploying them there about 3.5 hours after launch.

The Galileo constellation — Europe’s equivalent of the United States’ Global Positioning System (GPS) — resides at an altitude of 14,430 miles (23,222 kilometers). Thirty Galileo satellites have launched to date, all but two of them atop Russian-built Soyuz rockets or Europe’s Ariane 5 heavy lifter.

The two outliers launched this past April atop a Falcon 9. Europe signed a Galileo launch deal with SpaceX in late 2023 after its other options dried up: It cut most space ties with Russia following the February 2022 Ukraine invasion, and the Ariane 5 retired last summer. (The Ariane 5’s replacement, the Ariane 6, launched for the first time this past July.)

The SpaceX launch contract covers up to four Galileo spacecraft, so tonight’s liftoff will presumably fulfill it.

On the April Galileo launch, the Falcon 9’s first stage did not try to make a safe landing; rather, it ditched into the sea, lacking the fuel to steer itself back for a vertical touchdown.

Tonight’s mission will send the satellites to the same distant orbital destination. But SpaceX says it learned enough from the first Galileo liftoff to bring this Falcon 9 home in one piece.

“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 company wrote in mission description.

“This landing attempt will test the bounds of recovery, giving us valuable data on the design of the vehicle in these elevated entry conditions,” it added. “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.”