June 14, 2017 - China Launches Communications Satellite Into Orbit

On June 18, 2017, China launched the ChinaSat 9A communications satellite aboard a Long March 3B rocket from Xichang Satellite Launch Center. The mission hit a serious snag when the rocket's third stage malfunctioned, leaving the satellite stranded in a far lower orbit than planned. Ground controllers pulled off a remarkable recovery using onboard thrusters, though the effort cost the satellite years of operational life. There's much more to this story than a simple launch.

Key Takeaways

• China launched the ChinaSat 9A communications satellite on June 18, 2017, from Xichang Satellite Launch Center at 16:11 UTC.
• The satellite was carried by a Long March 3B enhanced rocket, a medium-to-heavy lift vehicle standing 56.3 metres tall.
• A third-stage engine anomaly caused the satellite to reach a lower-than-planned orbit, with apogee at only 16,360 kilometres.
• Despite the malfunction, the satellite deployed its solar panels, established ground contact, and completed ten recovery maneuvers over two weeks.
• ChinaSat 9A supports TV broadcasting, digital broadband, and direct-to-home services across China and neighboring Asia-Pacific regions.

What Is Chinasat 9A and Who Is It Built For?

ChinaSat 9A, also known as Zhongxing 9A, ZX 9A, Sinosat 4, or Xinnuo 4, is a Chinese communications satellite built by the China Academy of Space Technology (CAST) and operated by China Satellite Communications Co. Ltd. (China Satcom). It's based on the DFH-4 bus and carries 18 Ku-band transponders at 36MHz and 4 at 54MHz, supporting direct broadcast services across China and neighboring regions.

You can think of it as a dedicated platform for commercial broadcasting, digital film distribution, and broadband multimedia transmission. With a designed orbital lifespan of 14-15 years, it serves information and entertainment markets throughout the region. China Satcom built this satellite to deliver TV broadcasting, DirectPC, and digital broadband services to both domestic and regional audiences. The satellite was originally developed by Sino Satellite Communications Co., Ltd. and was designated SinoSat 4 before being handed over to China Satcom in 2010 and renamed ChinaSat 9A. The satellite was launched from Xichang Satellite Launch Center aboard a Long March CZ-3B/E rocket in June 2017. The development of satellites like ChinaSat 9A reflects a broader evolution in space-based platforms, which were first established as essential tools for global monitoring following early milestones such as the launch of TIROS-1 in 1960.

Which Regions Rely on Chinasat 9A's TV and Data Services?

Positioned at 92.2°E in geostationary orbit, ChinaSat 9A covers almost all of China's territory, reaching densely populated inland regions and the southeast coast alike.

It delivers up to 98% TV coverage in remote areas, making rural broadcasting practical where ground infrastructure falls short.

Beyond China, the satellite extends its reach across low-latitude zones between 35°N and 35°S, touching Southeast Asia, Africa, and South America.

Southern China's 15 provincial-level regions depend on it most heavily for HD television and data services.

You'll also find it supporting disaster management operations, helping authorities coordinate resource allocation across vulnerable low-latitude areas. China's Wuyang Constellation project similarly targets this band, with its 1,008-satellite network planned to deliver real-time remote sensing and communication coverage across the same low-latitude regions by approximately 2035.

Its C-band and Ku-band transponders carry everything from 4K video to web services, strengthening connectivity for surrounding regions including Australia and parts of the South Pacific. Receiving dishes as small as 0.45 to 0.6 metres in diameter allow direct satellite reception, enabling households in underserved areas to access broadcasts without relying on ground-based relay infrastructure. This drive to connect remote communities echoes earlier efforts like Alfred Traeger's pedal-powered radio network, which linked over five million square kilometres of outback Australia to medical and educational services without mains electricity.

How the Long March 3B Rocket Was Configured for This Mission

Carrying ChinaSat 9A to geostationary transfer orbit, the Long March 3B rocket stood 56.3 meters tall, weighed 456 metric tons at liftoff, and stretched 3.35 meters in diameter.

Four liquid-fueled strap-on boosters surrounded the core first stage, generating roughly 3,120 kN of thrust at liftoff. Engineers configured the rocket in its enhanced 3B/E variant, pushing GTO payload capacity to 5,500 kg.

Propellant handling relied entirely on hypergolic UDMH fuel and nitrogen tetroxide oxidizer, enabling instant ignition without complex pre-ignition sequences.

The 4.2-meter fairing, standing 9.56 meters tall, protected the satellite during payload integration and ascent. A hydrogen-fueled third stage with YF-75 engines completed orbital insertion, delivering ChinaSat 9A precisely into geostationary transfer orbit from Xichang Satellite Launch Center's Launch Area 2. A roll control error on the third stage during this mission would later cause ChinaSat 9A to be deployed into a lower-than-planned orbit.

The Long March 3B was developed by the China Academy of Launch Vehicle Technology, which played a critical role in establishing China's presence in the competitive global commercial launch market. Similar to Axiom Space's approach of securing NASA institutional validation before operating independently, Chinese launch providers pursued commercial satellite contracts to establish credibility before competing more broadly on the global stage.

How the Chinasat 9A Launch Unfolded From Xichang

At Xichang Satellite Launch Center's Launch Area 2, the Long March 3B/E carrying ChinaSat 9A lifted off on June 18, 2017, at 16:11 UTC. Xichang operations proceeded smoothly through the first and second stages, with each burn executing nominally. The launch choreography followed a precise sequence, guiding the vehicle along its planned trajectory toward geostationary transfer orbit.

However, the third stage underperformed, failing to deliver ChinaSat 9A to its intended orbit. Xinhua confirmed the anomaly on June 19, 2017, though specific technical details weren't released. The satellite's onboard thrusters compensated through 10 correction maneuvers, ultimately positioning it at 101.4° E longitude. Despite the setback, ChinaSat 9A reached operational status, ready to deliver Ku-band broadcasting services across the Asia-Pacific region. The recovery effort came at a significant cost, as reaching geostationary orbit consumed ten years of lifespan. The satellite is designed to serve markets including radio and TV transmission, digital film, and broadband multimedia, carrying twenty-two transponders total across its Ku-band payload configuration.

What Caused the Chinasat 9A Third Stage Anomaly?

While ChinaSat 9A ultimately reached its operational orbit, the question of what went wrong during the third stage burn deserves a closer look.

According to CASC's post-launch technical examination team, a thruster malfunction in the third stage's rolling control system disrupted attitude control, preventing the rocket from achieving its planned geostationary transfer orbit apogee of 22,300 miles. Instead, the stage delivered the satellite into a far lower orbit with an apogee of only 16,360 km.

CASC hasn't released specifics on the malfunction's root mechanism, but the fault's impact was clear — the satellite consumed far more onboard propellant than planned during its recovery, shortening its operational lifespan. Much like Deep Blue's purpose-built hardware design, the Long March 3B relied on highly specialized components working in precise coordination, meaning a single point of failure could cascade into mission-wide consequences.

It marked China's first Long March 3-series orbital delivery failure since August 2009. The third stage relies on a dual-nozzle YF-75 engine burning liquid hydrogen and liquid oxygen to achieve the precision burns necessary for geostationary transfer orbit insertion.

The carrier vehicle involved in the failed attempt was specifically identified as the Long March 3B Y28 rocket, one of the workhorse variants of China's medium-to-heavy lift launch family.

How Far Off Was the Chinasat 9A Orbit?

The third stage shortfall left ChinaSat 9A well short of its intended geostationary transfer orbit, delivering the satellite to an apogee of just 16,360 km instead of the planned 22,300 miles.

This orbital deviation forced the satellite to rely entirely on its onboard thrusters to close the gap. Over two weeks, it executed 10 corrective maneuvers, burning through propellant reserves that were never meant for such extensive orbital raising.

The propellant consumption was severe enough to slash the satellite's operational lifespan from 15 years down to just 5. You can see the direct trade-off: every kilometer the rocket failed to deliver, the satellite paid for in fuel.

Despite reaching the correct 101.4° E geostationary position, ChinaSat 9A arrived there significantly compromised. The satellite is designated for live radio and television broadcasts, making its reduced operational lifespan a particularly costly outcome for Chinese broadcasting infrastructure. Canada's Anik A1 demonstrated in 1974 that a single geostationary communications satellite could simultaneously handle up to 11,520 telephone calls and 12 television channels across an entire nation, setting the standard for what platforms like ChinaSat 9A are ultimately built to achieve.

Why Chinasat 9A Survived the Failed Third Stage

Despite arriving at geostationary orbit as a shadow of its intended self, ChinaSat 9A survived at all because of one fortunate reality: the third stage failure happened at the right moment. The stage had already completed its first burn and entered the coast phase before the spin took hold. That timing meant the satellite separated cleanly, even from a spinning rocket.

You might wonder how a satellite survives separation from an out-of-control stage. ChinaSat 9A's redundant systems handled the stress of an irregular release, and the spinning third stage actually provided a form of spin stabilization during separation, keeping the trajectory predictable enough for a clean break. Once free, the satellite deployed its solar panels and antennas, established contact with ground controllers, and began the long recovery process. The satellite's small thrusters were fired ten times in total by flight controllers in Xi'an, Shaanxi province, to steer it toward its intended geostationary position above Southeast Asia.

The cost of that recovery, however, was severe: the propellant consumed during those maneuvers reduced ChinaSat 9A's designed operational life from fifteen years to five.

Can Ground Controllers Recover the Chinasat 9A Mission?

Once ChinaSat 9A settled into its dangerously low, misshapen orbit, ground controllers faced an urgent question: could the satellite's onboard thrusters do the job that the rocket's third stage had failed to complete?

Ground recovery wasn't guaranteed. The satellite's thrusters weren't designed to compensate for a failed upper stage, yet contingency planning kicked in fast. Controllers at Xi'an's satellite monitoring center established contact, confirmed the satellite's health, and immediately began calculating a series of corrective maneuvers.

You'd see ten orbit adjustments executed over roughly two weeks, each perigee kick nudging the apogee higher. By July 5, ChinaSat 9A reached its intended geostationary slot at 101.4 degrees east. The mission survived, though the extra propellant burned likely shortened the satellite's operational lifespan. In a separate milestone for remotely piloted systems, GA-ASI demonstrated that the MQ-9B could complete an entire mission, including automatic takeoff and landing, using SATCOM and XC2 without a forward-deployed ground control station.

Notably, ChinaSat 9A holds the distinction of being China's first satellite purpose-built for live radio and television broadcasts, making its successful recovery all the more significant for the nation's domestic broadcasting ambitions. The reliability of such broadcast infrastructure depends heavily on the underlying fiber optic networks that carry signals across continents before they ever reach a satellite uplink.

What It Takes to Reach Geostationary Orbit From a Bad Trajectory

Reaching geostationary orbit from a flawed trajectory demands far more from a satellite's onboard propulsion than mission planners ever intend.

When a launch vehicle delivers a satellite to the wrong orbit, you're relying entirely on the spacecraft's own thrusters to compensate. High-efficiency electric propulsion enables low thrust recovery, but the process takes months of continuous spiraling burns rather than days. Perigee raising maneuvers gradually reshape the elliptical path while simultaneous inclination corrections reduce the orbital tilt toward zero.

A supersynchronous apogee above 42,164 kilometers actually helps here, giving low-thrust systems extra margin to work with despite a poor initial injection. Prior to modern satellite navigation, military planners relied on ground-based systems like LORAN and TRANSIT that lacked the global coverage and precision necessary to support continuous, three-dimensional positioning from space.

You need both zero eccentricity and zero inclination to achieve true geostationary orbit, making every burn critical to the satellite's ultimate operational success. Unlike geostationary satellites, geosynchronous satellites with non-zero inclination trace a figure-eight pattern across the sky as seen from the ground, a constant reminder of what remains uncorrected until the final burn sequence is complete. Inclination changes are most efficiently performed at apogee, where orbital velocity is lowest, since the delta-v required for a plane change is proportional to instantaneous velocity.

How Chinasat 9A Advances China's Domestic Satellite Broadcasting Technology

The months-long orbital recovery effort that saved Chinasat 9A wasn't just a technical rescue mission—it preserved a satellite that meaningfully advances China's domestic broadcasting infrastructure.

Its payload integration combines 18 Ku-band transponders at 36 MHz with four wider 54 MHz units, delivering radio, TV, digital film, and broadband multimedia across China, including Hong Kong, Taiwan, and Macao.

These broadcast innovations support high-power direct-to-home services using circular polarization for stronger signal reception.

You'll also notice Chinasat 9A's role within a larger network—it operates alongside ChinaSat 9 at 92.2° E, expanding regional coverage. This regional approach reflects a broader industry lesson, as the fragility of low-orbit satellite systems demonstrated by early satellites like Telstar 1 showed that orbital configuration choices are critical to long-term system resilience.

As the replacement for SinoSat 2 and the predecessor to Chinasat 9B, which introduced 4K/8K Olympic broadcasting, Chinasat 9A clearly positioned China Satcom as a dominant force in domestic satellite broadcasting. The satellite was carried to orbit aboard the Long March 3B/E, one of the most successful medium-range heavy-lift launchers in China's space program. When Chinasat 9B eventually launched in September 2021, it was built on the DFH-4E satellite bus, developed by the China Academy of Space Technology to restore the full broadcasting capability that Chinasat 9A's shortened service life had compromised.