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Soyuz ST-B launcher lofts O3b quartet to orbit

Arianespace launched a Soyuz ST-B rocket from Kourou, French Guiana with a quartet of O3B communications satellites. Archive Photo Credit: Arianespace

Arianespace launched a Soyuz ST-B rocket from Kourou, French Guiana with a quartet of O3B communications satellites. Archive Photo Credit: Arianespace

Arianespace successfully conducted its second launch this year on Friday, March 9 lofting four O3b communications satellites to orbit.

The mission, designated VS18, employed a Russian-built Soyuz ST-B rocket which lifted off from the Soyuz Launch Complex (ELS) at 16:37 GMT (11:37 a.m. EST) on Friday, March 9.

The Soyuz ST-B was rolled out to the launch pad a few days earlier, on March 2 as the VS18 mission was initially scheduled to be launched March 6. However, Arianespace decided to postpone the launch in order to “…enable additional checks as part of the resumption of launches from the Spaceport in French Guiana.”

The countdown campaign commenced approximately five hours ahead of the scheduled liftoff when it was decided that the launch vehicle was ready for fueling operations. The conclusive phase of the campaign started some five minutes before the launch, when the rocket’s Fregat upper stage was switched to onboard power.

The O3b Satellites in the clean room. Photo Credit: Arianespace

The O3b Satellites in the clean room. Photo Credit: Arianespace

Sixteen seconds after the ignition of its four strap-on boosters (affixed to the rocket’s first stage) the Soyuz ST-B thundered off the launch pad and completed a short vertical ascent. The first phase of the flight lasted almost two minutes, until about T+1:58 minutes when the strap-on boosters were jettisoned, leaving the launch vehicle powered by its second stage alone.

About two minutes later, the protective payload fairing was detached from the Ariane 5, unveiling the mission’s four passengers.

The central core separated from the assembly some four minutes and 47 seconds into the flight and the propulsion for the flight was provided by the third stage, which burned for about four and half minutes.

After the separation of the third stage, the rocket’s Fregat upper stage was ignited, this marked the start of a two-hour trek to deliver the payload into targeted circular orbit at an altitude of 4,865 miles (7,830 kilometers).

The Fregat upper stage conducted three engine burns in order to deploy the first two O3b satellites into orbit about two hours and one minute into the flight.

Afterward, the upper stage completed one more burn and released the remaining two satellites two hours and 22 minutes after liftoff.

Built by Thales Alenia Space, each O3b satellite weighs around 1,543 lbs. (700 kilograms) and has dimensions of 25.3 x 10.5 x 5.57 feet (7.72 x 3.2 x 1.7 meters). The spacecraft is based on the ELiTeBus-1000 platform and has two deployable solar arrays capable of generating up to 2,482 W of power during its planned operational lifetime of 10 years.

“We are very excited to have four more O3b satellites in orbit, and we look forward to them joining the constellation in May and serving our customers around the globe. The demand for high performance bandwidth and networks continues to grow and, as the only successful non-geostationary broadband system, we need these new satellites to fulfill demand across a wide range of verticals and applications. From connecting underserved communities and meaningfully transforming lives through improved broadband access, to delivering state of the art satellite-enabled network services to ships, planes and government platforms, our O3b fleet offers unique and differentiated performance and is driving our customers’ businesses forward,” said Steve Collar, Chief Executive Officer at SES Networks, and CEO designate of SES via a company-issued release.

The quartet of the newly launched O3b satellites will be operated by O3b Networks, a subsidiary of the Luxembourg-based satellite operator SES. The four new spacecraft will reside in a medium-Earth orbit (MEO) from this vantage point they should provide high-speed connectivity to people and businesses in growing mobility, fixed data and government markets. For this purpose, each satellite of the quartet is fitted with 12 Ka-band transponders designed to enable the high speed flow of data between locations on the ground.

If everything goes as envisioned, the VS18 mission should expanded the constellation of O3b satellites currently in orbit from 12 to 16 spacecraft. The new quarter are designed to generally focus on providing more capacity, enhanced coverage, increased efficiency and greater reliability while delivering carrier-grade services including MEF Carrier Ethernet 2.0 certified services to telecommunications operators, mobile network operators, enterprises, Internet service providers and government customers.

“In addition to the O3b satellites’ throughput capabilities and low latency, a unique feature of the O3b constellation is that it is easily scalable and is designed to be expanded in response to demand. Demand for reliable fiber-like connectivity has never been higher, and we are excited that our satellites can play a key role in connecting people, communities, and improving their lives,” said Martin Halliwell, Chief Technology Officer at SES.

The first batch of four O3b satellites was delivered into space on June 25, 2013 by another Soyuz ST-B rocket.

The Soyuz ST-B launcher that was employed for Friday’s mission is a four-stage launch vehicle that is composed of four boosters affixed to its first stage, a central core (second stage), a third stage, and a restartable Fregat upper stage. It also includes a payload adapter/dispenser and fairing.

Friday’s mission was Arianespace’s second launch of 2018 as well as the second mission that got its start from Kourou this year. The company’s next planned flight is currently scheduled for March 21 when the Superbird-B3/DSN-1 and HYLAS-4 communications satellites are slated to be send aloft atop an Ariane 5 rocket.

For their part, SES stated that they were focused on customer service and highlighted the flexibility of their constellation.

“This was the fourth launch performed by Arianespace for our O3b fleet and we have yet another batch of O3b satellites planned for 2019 on their Soyuz rocket as well. This is the beauty of our MEO constellation: it can easily be scaled to respond to demand in an agile manner while beams can be allocated dynamically to where the demand is, and thus deliver low-latency connectivity where our customers need it. By augmenting our fleet, we will offer more throughput, more coverage, and more capabilities to our customers,” Halliwell stated via an SES-issued release.







Tomasz Nowakowski is the owner of Astro Watch, one of the premier astronomy and science-related blogs on the internet. Nowakowski reached out to SpaceFlight Insider in an effort to have the two space-related websites collaborate. Nowakowski's generous offer was gratefully received with the two organizations now working to better relay important developments as they pertain to space exploration.

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Oh no! We’re missing the ‘countdown to next launch’ window>

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