Cheng Zhang 2D launches from Taiyuan with Jilin-1 satellites

by Justin Davenport

A Cheng Zhang 2D (also known as the Long March 2D) has successfully lifted off from Launch Pad 9 in Taiyuan, China at 10:38 AM Beijing time (02:38 UTC) Thursday, carrying a commercial Jilin-1 Wideband-01C spacecraft and seven other Jilin satellites (HR-03D) satellites into a sun-synchronous orbit.

The Jilin-1 constellation, now consisting of 54 Earth observation satellites since its first launch in 2015, is China’s first-ever commercial remote-sensing satellite system. The system is operated by Chang Guang Satellite Technology Corporation, also known as Charming Globe, a commercial spinoff of the Changchun Institute of Optics, Fine Mechanics, and Physics in the northeast Chinese city of Changchun.

The constellation is planned to consist of 138 satellites by 2025, and the satellites will be orbiting at 535 km altitude above Earth. The constellation, featuring types of satellites with different capabilities, will ultimately be capable of revisiting any point on Earth every ten minutes, with an interim thirty-minute capability being achieved with sixty satellites in orbit.

Today’s launch orbited the Wideband-01C satellite, also known as Kuanfu-01C, a 230 kg spacecraft featuring a high resolution (UHD/4K) video capability. The spacecraft is capable of a 0.5 meter resolution as well as a wide field of view and 2-meter resolution multi-spectral capability. The “push-broom” imager, so-called because there are multiple detectors perpendicular to the spacecraft’s flight path, has a swath width of greater than 150 kilometers.

Seven HR-03D, also known as Gaofen-03D, high-resolution imaging satellites were also flown on today’s launch. These satellites, numbered 27 to 33 in the series, are approximately 40 kg each and are capable of greater than 0.75 meter resolution, as well as 2-meter resolution in multiple spectral bands if using push-broom imaging. The Gaofen-03D series of satellites are capable of a swath width of greater than 17 kilometers.

Chang Zheng 2D on the pad in Taiyuan before Thursday’s launch

The CZ-2D is based on the CZ-4 series but typically uses only two stages. This vehicle, in service since 1992, is used for low Earth orbit and sun-synchronous polar orbit launches and has flown from Jiuquan, Xichang, and Taiyuan launch sites. It is capable of lifting 1300 kilograms to the sun-synchronous orbit flown today, or up to 3500 kg to a low earth orbit with an eastbound trajectory.

Like the ICBMs the initial Chang Zheng rocket families were based on, the CZ-2D uses storable but highly toxic dinitrogen tetroxide and unsymmetrical dihydrazine. These fuels require special handling including technicians wearing “moonscape” suits and are being phased out in favor of newer Chang Zheng vehicles from the CZ-5 onwards.

The CZ-2D’s first stage uses four YF-21C engines with a total of 665,800 lbf of thrust, while the second stage uses one YF-24C engine, made up of the YF-22C main engine and four YF-23C vernier engines for roll control. The main engine has a thrust of 166,820 lbf while the verniers have a total thrust of 10,600 lbf. Both stages use N2O4/UDMH fuel.

Today’s launch, known as Y79, is the 59th flight of the CZ-2D and the 58th complete success of the type. It is also the 14th orbital launch this year for the Chinese program and the 19th launch for the Jilin constellation, with 17 successes. In addition, today’s launch is the fourth flight out of Taiyuan in 2022.

Chang Zheng 2D ascends from Taiyuan

Taiyuan, like Xichang and Jiuquan, is an inland launch site. Taiyuan is located in Kelan County, in Shaanxi province in east-central China. It is 1500 meters above sea level, with a dry climate. The trajectories rockets take from this spaceport require them to also drop stages on land, potentially placing towns and other infrastructure at risk.

In this case, the drop zone for the first stage on this flight was in a mountainous region east of Chongqing, close to halfway between Chongqing and Wuhan. A number of flights have experimented with grid fins to control where the vehicle drops, though none appeared to have been installed on this flight.

Taiyuan hosts the CZ-2, CZ-4, and CZ-6 launch vehicle families. Like Vandenberg Space Force Base in the United States, Taiyuan hosts many launches to a polar sun-synchronous orbit as well as ICBM tests to a range thousands of kilometers away.

As the Chinese program gears up for upcoming space station-related launches, it also continues to fly a large number of Earth observation satellites. The events of early 2022 have only increased the demand for observations of our home planet from space, and the Jilin-1 constellation is one of several providers worldwide that will meet this demand over the coming months and years.

(Lead photo: Chang Zheng 2D lifts off with several Jilin-1 satellites on Thursday.)

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