Thursday, September 28, 2017

Proton-M Blasts Off from Baikonur with AsiaSat 9 Communications Satellite

Proton-M launch with AsiaSat 9. Credit: Roscosmos

International Launch Services (ILS) successfully conducted its third mission this year, launching its workhorse Proton-M rocket with AsiaSat 9 communications satellite into orbit. The launcher lifted off at exactly 18:52 UTC (14:52 EDT) on Thursday, September 28 from Site 200/39 at the Baikonur Cosmodrome in Kazakhstan.

The launch was initially scheduled for November 2016, however delays with the manufacturing of the satellite resulted in the postponement of the liftoff for almost one year. 

Preparations for the mission entered the decisive phase with the arrival of the AsiaSat 9 spacecraft at Baikonur on August 30. During first days of September the satellite was unpacked and the engineers performed initial tests and checkouts. Meanwhile, the Proton-M rocket and the Briz-M upper stage were transported to Baikonur for their assembly at the space center.

In mid-September the teams commenced the assembly process of the Proton-M rocket to ready it for the installation of the spacecraft encapsulated in the payload fairing. The launch vehicle was then rolled out to the pad on September 25 and erected vertically in order to start the final processing for the upcoming liftoff.

Pre-launch preparations culminated during the scheduled countdown, which started some 11 and a half hours before the ignition of the rocket’s engines. This phase included the fueling process of the launch vehicle and the removal of the launch pad’s service structure what cleared the way for the initiation of the automated countdown sequence five minutes prior to liftoff.

Proton-M rocket ignited its six RD-275M engines and some two and a half seconds later it thundered off the pad, starting a short vertical climb. The rocket’s first stage, consisting of these six boosters, powered the launch vehicle for the first two minutes of the flight and were then jettisoned.

Afterward, the second stage took control over the flight for three minutes and 27 seconds. Next, when the mission clock hit T+5:27 minutes, the second stage was also detached, leaving the stack consisting of the third stage, Briz-M and the payload. Shortly after, at T+5:47, the payload fairing protecting the satellite from the dense atmosphere was separated, uncovering AsiaSat 9 for the rest of the flight.

The launch vehicle flew in this configuration for nearly four minutes until the planned separation of the third stage that occurred nine minutes and 42 seconds into the flight. This was an important milestone of the mission as it released the Briz-M upper stage with the attached payload, starting a lengthy nine-hour journey that will end in the separation of the satellite.

During the nine-hour flight, the upper stage will perform five planned engine burns, meanwhile jettisoning its auxiliary propellant tank (APT) at T+3:40 hours. All these commands will be necessary to align the spacecraft with the nominal flight trajectory and to place it into a desired geostationary orbit at an altitude of 22,236 by 2,513 miles (35,786 by 4,045 kilometers), inclined 23.4 degrees.

AsiaSat 9 is a communications satellite built by Space Systems Loral (SSL) and based on the company’s well known SSL 1300 platform. The spacecraft weighs around 6.14 metric tons and is designed to be operational for at least 15 years. 

According to the manufacturer, the satellite features 28 C-band and 32 Ku-band transponders, and a regional Ka-band payload. Moreover, it carries the world’s first dedicated Ku-band Myanmar beam, new Ku-band beams for Indonesia and Mongolia, in addition to two enhanced Ku-band beams serving Australasia and East Asia and a wider high-power C-band coverage across the Asia-Pacific region.

AsiaSat 9 will be operated by Asia Satellite Telecommunications Co. Ltd. (AsiaSat) and is the most powerful spacecraft in the company’s fleet. It will provide additional capacity, enhanced power and coverage for DTH, video distribution, private networks and broadband services across the Asia-Pacific region. The new satellite will replace AsiaSat 4 operating at 122°E.

“We are committed to providing high quality service to both our existing customers and new users as we reach a new milestone for higher-performance, higher-efficiency and greater flexibility with our new AsiaSat 9,” said Andrew Jordan, President and CEO of AsiaSat.

The Proton-M booster that was used for Thursday’s launch is 190 feet (58 meters) tall, measures some 13.5 feet (4.1 meters) in diameter along its second and third stages. Its first stage has a diameter of 24.3 feet (7.4 meters). The total overall height of the rocket’s three stages is about 138.8 feet (42.3 meters).

The first stage consists of a central tank containing the oxidizer surrounded by six outboard fuel tanks. Each fuel tank also carries one of the six RD 275M engines that provide power for the first phase of flight. The cylindrical second stage is powered by three RD-0210 engines along with a single RD 0211 engine.

A single RD-0213 engine and a four-nozzle vernier engine powers the third stage. Guidance, navigation, and control of the Proton-M during operation of the first three stages is carried out by a triple-redundant closed-loop digital avionics system mounted in the third stage.

Topping off the rocket is the Breeze-M upper stage. It is powered by a pump-fed gimbaled main engine. This stage consists of a central core and the APT that is jettisoned in flight after the depletion of its fuel. The stage’s control system includes an onboard computer, a three-axis gyro stabilized platform, and a navigation system.

Thursday’s launch was the third and last ILS Proton mission in 2017 as well as the 96th Proton launch conducted by this company overall. It was also the 10th orbital mission that lifted off from Baikonur this year. When it comes to AsiaSat 9, it was the fifth satellite of this operated launched by ILS.

1 comment:

  1. one just can not get these kind of updates from anywhere and now i dont even have to look up different space articles i can just find them under one roof. thank you for posting

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