Soyuz launched to add two more satellites to the European Galileo navigation network – Spaceflight Now


EDITOR’S NOTE: Arianespace delayed the launch until 7:19 p.m. EST on Saturday, December 4 (0019 GMT on Sunday, December 5) after missing a launch attempt on Friday evening due to a lightning hazard. The mission had already been delayed from December 2 due to the unavailability of a downstream tracking station on a ship in the Atlantic Ocean.

The next two European Galileo navigation satellites are ready to be attached to their Russian-made Fregat upper stage at the Guyana Space Center. Credit: ESA / CNES / Arianespace – Photo Optical Video of CSG – P. Baudon

Two other Galileo navigation satellites should take off Thursday evening from French Guiana aboard a Soyuz rocket, the first mission in more than three years to be added to the European space positioning and synchronization network.

The two Galileo satellites, each weighing about 1,576 pounds (715 kilograms) fully powered, are mounted side-by-side inside the payload fairing of their Soyuz launcher.

Designed for 12-year missions, the new spacecraft will join 26 Galileo satellites already in orbit providing worldwide navigation services for the EU’s multibillion-euro flagship space program. Ten Soyuz and Ariane 5 rocket launches from French Guiana since October 2011 have deployed the operational Galileo satellites, which are distributed over three orbital planes approximately 23,200 kilometers above Earth.

The full constellation needs 30 satellites, including 24 active platforms and six spare.

“The aim of the upcoming Galileo launch is to complete the satellite and population deployments of the various orbital planes to ensure that the constellation is complete,” said Andrea Cotellessa, head of the Galileo space segment management office at the European Commission. Space agency. “Our constellation requires eight operational satellites and two spare air satellites, and this has yet to be achieved.”

The next two Galileo satellites will head into space on top of a Soyuz ST-B rocket. Liftoff from the Guyana Space Center, the European spaceport located on the northeast coast of South America, is scheduled for 7:27:25 p.m. EST Thursday (0027:25 GMT Friday), according to an Arianespace spokesperson, the launch service provider.

The launch is scheduled for 9:27 p.m. local time in French Guiana, a French overseas territory sandwiched between Suriname and Brazil.

The Soyuz launcher will head northeast from the Guyana Space Center over the Atlantic Ocean, lining up for a trajectory in an orbit tilted 57.1 degrees from the equator.

The rocket will lose its four first-stage boosters, main stage, and payload shroud during the first five minutes of the mission. A third-stage engine will place a Fregat upper stage and the two Galileo satellites on a suborbital path approximately nine minutes after take-off.

A first burn with the Fregat upper stage will first place the Galileo satellites in an elliptical transfer orbit. Another engine launched 3 hours and 42 minutes after the start of the mission will aim to position the satellites in a near-circular orbit about 14,615 miles (23,522 kilometers) above Earth.

The satellites will deploy from the Fregat upper floor at 11:19 PM EST (4:19 GMT).

Artist’s illustration of two Galileo navigation satellites inside the payload fairing of a Soyuz rocket. Credit: European Space Agency

Once the satellites are separated from the Fregat upper stage, ground crews from a Galileo control center in Oberpfaffenhofen, Germany, will take command of the spacecraft. The satellites will deploy their solar panels and begin a usual series of post-launch tests before entering operational service.

Galileo satellites are already transmitting navigation signals to users around the world. Over 2 billion smartphones have been sold with Galileo compatible chipsets, allowing users to locate themselves with navigation signals from Galileo satellites as well as data from the US Army’s Global Positioning System network.

Thursday night’s launch will be the last mission from the French Guiana spaceport before takeoff on December 22 of the James Webb Space Telescope, a $ 9.7 billion observatory developed by NASA, ESA and the Canadian Space Agency. .

Webb, the most expensive space science mission in history, will take off on top of an Ariane 5 rocket. Guiana Space Center officials need about two weeks to reconfigure the ground infrastructure between launches, which means the Soyuz flight is scheduled to take off around December 8 to ensure Webb’s launch stays on schedule.

Soyuz’s launch with the next two Galileo satellites was previously scheduled for Wednesday evening, but officials delayed the flight for a day due to poor weather forecasts.

The mission will mark the 26th flight of a Russian Soyuz rocket from French Guiana since 2011.

The two Galileo spacecraft launched Thursday evening were built by OHB in Bremen, Germany. L-band navigation payloads on each satellite were provided by SSTL in the UK.

The satellites are the first two of 12 Galileo spacecraft ordered under a third ESA batch contract in 2017. The “batch 3” satellites, with the same capacities as the previous 26, will support the Galileo constellation until ” that a new generation of spacecraft is ready. for the launch.

Over the next few years, three Soyuz launches and three flights of the new European Ariane 6 rocket will each carry two Galileo satellites into orbit.

Second-generation satellites are expected to start launching by the end of 2024, according to ESA, which manages spacecraft development for the Galileo system on behalf of the European Commission, the EU’s executive body.

“They will be more powerful,” said Paul Verhoef, ESA director of navigation. “They will therefore also be heavier, but they will have more capacity. In particular, they will be fully flexible, fully digital, so that we can reprogram them in orbit.

“At the moment, with the first generation, if we are to provide any important new services, we are going to have to put completely new satellites into orbit,” said Verhoef. “With the second generation, we decided to do things differently and allow this capability, de facto, to be on the satellites, so that we can change things as the markets demand it in a relatively quick way.”

Earlier this year, the European Commission and ESA awarded contracts to Airbus and Thales Alenia Space for 12 second-generation Galileo, or G2, satellites. Each company has won a contract for six spacecraft, which will carry navigation payloads built on the European continent, rather than by SSTL in the UK.

SSTL was excluded from the new generation of Galileo satellites after Brexit. EU officials have demanded that sensitive elements of the Galileo program come from EU member states.

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