Raumfahrt - Start von Soyuz-2.1b mit 36 OneWeb Satelliten


Soyuz in position for liftoff Thursday with 36 OneWeb internet satellites


A Russian Soyuz booster and Fregat upper stage rode a specialized rail car to a launch pad at the Vostochny Cosmodrome Monday, moving into position for liftoff Thursday with the next 36 satellites for OneWeb’s growing global internet network.

The 15-story Soyuz-2.1b booster is set to take off from Vostochny, Russia’s newest spaceport in the far eastern part of the country, at 1:43 p.m. EDT (1743 GMT) Thursday. Liftoff is scheduled for 2:43 a.m. Friday local time at Vostochny.

The 36 new satellites will bring OneWeb’s fleet to 218 spacecraft, good enough to be the second-largest active satellite constellation orbiting Earth.

OneWeb’s spacecraft are built by in a factory just outside the gates of NASA’s Kennedy Space Center in Florida. A company named OneWeb Satellites — a joint venture between OneWeb and Airbus — manufactures the mini-fridge-size spacecraft on an assembly line.

The satellites beam broadband internet signals to users on the ground, at sea, or in the air, providing high-speed, low-latency connectivity for consumers, large companies, and governments. OneWeb is competing with SpaceX’s Starlink network, along with planned internet constellations from other companies.

The next batch of 60 Starlink satellites are scheduled to launch on a Falcon 9 rocket Wednesday from Cape Canaveral, pushing the total number of Starlink spacecraft SpaceX has deployed to more than 1,700.

SpaceX’s Starlink network and OneWeb’s internet system are the first two “mega-constellations” to become reality.

The Starlink network may eventually number 12,000 or more satellites, based on SpaceX’s filings with the Federal Communications Commission.

OneWeb, partially owned by the British government, is planning an initial fleet of 648 satellites, but could add more spacecraft if business opportunities grow. Other companies, such as Amazon and Telesat, are planning their own constellations with hundreds or thousands of small satellites to beam broadband internet service around the world. And there are firms in China eyeing the same capability.

Fifteen launches to Earth orbit so far this year have carried Starlink or OneWeb satellites, one-third of the worldwide total since Jan. 1.

Thursday’s launch is the fourth of a set of five Soyuz missions that will enable the network to provide initial connectivity to users north of 50 degrees latitude. The five launches began in December — after London-based OneWeb emerged from bankruptcy proceedings last year — followed by two more Soyuz flights March 25 and April 25. The next OneWeb launch after this week is tentatively scheduled for July 1 from Vostochny, according to Russian media reports.

“OneWeb’s ‘Five to 50’ program aims to connect broadband data users in the northern hemisphere, with services covering the United Kingdom, Alaska, Northern Europe, Greenland, Iceland, the Arctic Seas and Canada,” OneWeb said in a statement earlier this year. “Service will be ready to start by the end of year, with global service available in 2022.”

Four Soyuz launches for OneWeb are scheduled from the Baikonur Cosmodrome in Kazakhstan later this year — two in August, one in September, and one in December. Each mission will deploy more than 30 OneWeb satellites.

The launch Thursday will be the seventh dedicated Soyuz launch to build out OneWeb’s fleet. OneWeb’s contract with Arianespace, the French launch service provider, cover 19 Soyuz rocket launches from Vostochny, Baikonur, and the European-run Guiana Space Center in South America.

The first three launches for OneWeb occurred in 2019 and 2020, before the company’s bankruptcy.

OneWeb announced Monday it received more than £32 million, or $45 million, from the UK Space Agency and the European Space Agency to develop a spacecraft for launch in 2022 to demonstrate innovative “beam-hopping” technology, which allows satellites to direct their broadband teams to augment coverage in regions with high demand.

The capability will allow networks to respond to commercial demand surges and respond to emergencies, such as natural disasters, according to OneWeb.

The UK Space Agency said said OneWeb will demonstrate the technology for use in its second-generation satellite fleet, which could begin launching in 2025. OneWeb is partnering with SatixFy to develop the beam-hopping communications payload for the demo satellite, named “Joey-Sat.”

Celestia UK will develop ground station technology, and Astroscale UK received funding through the OneWeb deal to work on capabilities to remove space debris and unresponsive satellites from Earth orbit.

The Soyuz rocket preps for rollout to the launch pad Monday at Vostochny with the next 36 OneWeb satellites. Credit: Roscosmos

Russian managers will meet around five hours before launch Thursday to give the “go” to load kerosene and liquid oxygen propellants into the Soyuz rocket. The gantry will withdraw to a location near the launch pad, clearing the way for liftoff at 1:43 p.m. EDT (1743 GMT).

The four-hour mission will place the 36 OneWeb satellites into a polar orbit about 279 miles (450 kilometers) above Earth after launching toward the north from Vostochny. Each spacecraft will deploy power-generating solar panels and switch on xenon-fueled plasma thrusters to reach an operational altitude of 745 miles (1,200 kilometers) in the coming months.

After taking off from Vostochny, the Soyuz-1.b rocket will shed its four kerosene-fueled first stage boosters about two minutes after liftoff, then the payload shroud will jettison at T+plus 3 minutes, 35 seconds, after vehicle climbs above the thick, lower layers of the atmosphere. The Soyuz core stage will fire until just shy of the five-minute mark in the mission, then separate to fall back to the ground over Russian territory.

A third stage engine will light to propel the Fregat upper stage and stack of OneWeb satellites on a ballistic, suborbital trajectory. Then the Fregat main engine will ignite at T+plus 10 minutes, 22 seconds, for a five-minute burn to place the OneWeb satellites into a preliminary elongated orbit.

After soaring north over the Arctic Ocean and back south again, a second burn by the Fregat upper stage about 64 minutes after liftoff to finish the job of placing the OneWeb payloads into the proper 279-mile-high orbit for deployment.

The Fregat upper stage will release the OneWeb satellites into orbit four at a time, with pulses by the Fregat’s smaller control thrusters between each deployment to provide spacing between the spacecraft.

The first quartet of OneWeb satellites will separate at 3:01 p.m. EDT (1901 GMT), and the final four will fly free of the Fregat upper stage at about 5:34 p.m. EDT (2134 GMT), nearly four hours after liftoff.

We’ve posted additional photos below of the Soyuz-2.1b rocket’s rollout to the launch pad.

Credit: Roscosmos
Credit: Roscosmos
Credit: Roscosmos

Quelle: SN

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