Editors note: China’s state-run Xinhua news agency has since confirmed the failure of a Long March 4 carrying the Yaogan-33 satellite. “The first and second stages of the rocket worked normally, while the third stage had abnormal operation,” Xinhua reported. “Based on monitoring data, the third stage of the rocket and satellite debris have fallen on the ground.”

HELSINKI — A planned launch of a remote sensing satellite from Taiyuan in north China may have ended in failure, with the lack of an official statement suggesting an issue with the mission.

Airspace closure notices issued days in advance indicated a launch of a Long March rocket from Taiyuan was due to take place between 6:45 and 7:06 p.m. Eastern Wednesday (6:45-7:06 a.m. local time Thursday).

Amateur footage and images posted on Chinese social media platforms apparently consistent with a morning launch from Taiyuan Satellite Launch Center suggest the launch of a Long March 4C three-stage hypergolic rocket took place around 6:49 p.m. Eastern.

A successful launch is usually announced by the main space contractor, the China Aerospace Science and Technology Corporation (CASC), as soon as the spacecraft have entered their intended orbits. Wednesday’s launch, to place a remote sensing satellite into sun-synchronous orbit, would likely have been followed with an announcement of success within the hour.

More than 12 hours after the apparent launch, no statements from CASC nor government space authorities had been released.

SpaceNews has contacted the U.S. Air Force’s 18th Space Control Squadron, responsible for space situational awareness including detecting, tracking, cataloging and identifying artificial objects orbiting the Earth for comment on any possible new objects correlating with the launch and is awaiting a reply.

The launch took place deep inland, meaning spent rocket stages will fall

With the exception of major events such as crewed or lunar exploration missions, Chinese launches are rarely openly announced. Indirect means such as NOTAMS — notices filed with aviation authorities to notify of aircraft of potential hazards — are often the only indication of imminent launches.

The payload was expected by amateur aerospace watchers within China to be a Yaogan remote sensing satellite, designated Yaogan-33. Chinese state media typically state that Yaogan series satellites are used for “electromagnetic environment surveys and other related technology tests,” but outside analysts understand the satellites to be optical and synthetic aperture radar satellites for military reconnaissance purposes.

A similar launch in August 2016, also using a Long March 4C launch vehicle, believed to be carrying the Gaofen-10 satellite, part of a civilian Earth observation constellation, ended in apparent failure and was also followed by official silence. Loss of the satellite was only confirmed two weeks later by the China Great Wall Industry Corp., a CASC subsidiary.

As the issue for the Gaofen-10 launch was confined to the third stage, used only on the Long March 4C, developed by CASC subsidiary, the Shanghai Academy of Spaceflight Technology (SAST), other Long March flights were not affected. The carrier rocket did not fly again until November 2017, and in May 2018 launched the Queqiao relay satellite as a necessary precursor to the Chang’e-4 lunar far side landing on Jan 2.

If confirmed, it would be the first Chinese government launch failure since July 2017, when the second Long March 5 suffered a first stage issue. The Long March 5 has been grounded ever since, and a planned return-to-flight in July, announced in January, appears to have slipped.

Cargo vessels specially designed to transport the components of the 5-meter-diameter, 56-meter-long heavy-lift launcher from a manufacturing site in Tianjin, north China, to the Wenchang Satellite Launch Center, on the southern island province of Hainan, remain moored on the Yangtze river. The two previous Long March 5 launches required two months of launch preparations at Wenchang, leaving a July launch very unlikely.

The third Long March 5 is expected to carry an experimental communications satellite before the fourth launch can launch the Chang’e-5 lunar sample return mission, previously slated for late 2019. The country’s first independent mission to Mars is also expected to launch on the Long March 5 in the next Hohmann transfer window, in July and August 2020, while the debut of the Long March 5B, a variant for low-Earth orbit launches, is also expected in the first half of 2020, before being able to launch the first module of the Chinese Space Station.

The above missions require a successful return-to-flight of the Long March 5, which has undergone a redesign of its liquid oxygen and liquid hydrogen YF-77 first stage engines following the 2017 failure. Another slip could place huge pressure on the schedule for China’s most ambitious space projects.

Wednesday’s launch was China’s ninth of 2019, including a first orbital launch attempt by private launch firm OneSpace, which ended in failure. It follows the failure of commercial counterpart Landspace to reach orbit in October 2018. The next attempt from the nascent Chinese private launch sector is expected from iSpace in early June.