Curt Godwin

June 17th, 2017

Image Credit: Peoples Republic of China

China is preparing to launch theZhongxing-9A direct-to-home (DTH) television service satellite aboard the countrys Long March 3B/E carrier rocket. Although newsfrom the countrys tight-lipped space agency is difficult to come by, information fromtheGBTimes indicates the launch may occur as soon as June 18, 2017, from the Xichang Satellite Launch Center.

Tipping the scales at more than 11,200 pounds (5,100 kilograms) is the Zhongxing-9A satellite, also known as ChinaSat 9A. It will ride to space atop the 185-foot (56.3-meter) tall Long March 3B/E.

File photo of a Long March 3B being prepared for launch at the Xichang Satellite Launch Center. Photo credit: Chinanews.com

Built on the indigenous DFH-4bus, the spacecraft isChinas first domestically-produced DTH satellite. It will provide services to mainland China,the autonomous regions of Macau and Hong Kong, and the island of Taiwan via 24 Ku-band transponders.

ChinaSat 9A has a design lifetime of 15 years, and will be positioned at 101.4 degrees East in geostationary orbit.

One of Chinas workhorse rockets, the Long March 3B willdeliver the spacecraft into a geosynchronous transfer orbit (GTO). The boosterhas launched 39 times notching 37 successes, onepartial failure, and onetotal failure across both its standard (3B) and enhanced (3B/E) configurations.

Although it hasnt been confirmed, its assumed the rocket will be configured in its enhanced arrangement to support delivering the heavy payload to GTO.

The Long March 3B/Eis a three-stage rocket, with four supplemental liquid-fueled strap-on boosters. When outfitted in the enhanced configuration, the vehicle is capable of lofting 12,100 pounds (5,500 kilograms) into GTO, compared to the11,200 pounds (5,100 kilograms) in the standard configuration.

At liftoff, the firststages YF-21C engine and the supplemental power suppliedby a singleYF-25 on each of the four boostersprovide 1.3 million pounds (5,923.2 kilonewtons) of sea-level thrust. The boosters operate for 140 seconds before falling away, while the first stage burns for an addition 20 seconds.

The vehicles second stage is powered by a YF-24E propulsion unit comprised of a loneYF-22E engine and a quartet ofYF-23C vernier thrusters. In total, the YF-24E provides 177,419 pounds (789.2 kilonewtons) of thrust and operates for slightly more than three minutes.

Like its first stage and booster siblings, the second stages YF-24E burns a relatively inefficient mixture of nitrogen tetroxide and unsymmetrical dimethylhydrazine. Although this toxic mixture is significantly less efficient than either a kerosene/liquid oxygen or liquid hydrogen/liquid oxygen combination, it has the benefit of being able to be stored at room temperature.

The third stage is outfitted with a single YF-75 engine, producing 37,850 pounds (167 kilonewtons) of vacuum thrust and burning a mixture of liquid hydrogen and liquid oxygen. This stage can operate for nearly eight minutes across two ignitions.

This will mark Chinas sixth launch in 2017.

Tagged: China Lead Stories Long March 3B/E Xichang Satellite Launch Center Zhongxing-9A

Curt Godwin has been a fan of space exploration for as long as he can remember, keeping his eyes to the skies from an early age. Initially majoring in Nuclear Engineering, Curt later decided that computers would be a more interesting - and safer - career field. He's worked in education technology for more than 20 years, and has been published in industry and peer journals, and is a respected authority on wireless network engineering. Throughout this period of his life, he maintained his love for all things space and has written about his experiences at a variety of NASA events, both on his personal blog and as a freelance media representative.

Continued here:

Long March 3B to launch Zhongxing-9A television satellite - SpaceFlight Insider