China conducts three launches with Shiyan and Yaogan satellites

by Adrian Beil

China has launched three rockets, from two different launch sites, in under 50 hours. The first launch happened on Sunday, Sept. 24 at 22:55 UTC, with the Kuaizhou 1A rocket launching two Shiyan Weixing satellites. It was followed by two Chang Zheng missions, of which one also belongs to the Shiyan line, and one to the equally secretive Yaogan series.

Kuaizhou-1A Launches Shiyan 14 and 15

The KZ-1A rocket launched a double payload, consisting of the SY-14 and SY-15 satellites. The two payloads went to a Sun-synchronous orbit (SSO) with an inclination of 97.52 degrees and an altitude of 488 by 506 km. Both payloads are listed with different purposes.

The SY-14 payload is described as a scientific research and technology validation mission. This is similar to the usual labels that the Shiyan Weixing satellites receive, based on statements for the previous missions. It is not known which company or China Aerospace Science and Technology Corporation (CASC) subordinate built the payload.

The SY-15 payload was described as a land surveyor, city planning, and disaster monitoring satellite. This is the usual description for optical satellites, which also matches the payload’s orbit. An SSO will make sure that illumination remains constant during the observation of certain areas. Thus, this type of orbit is often used for optical satellites. The SY-15 satellite was built by the Shanghai Academy of Spaceflight Technology (SAST), which is also referred to as the “Eight Academy.”

Shiyan Weixing translates to “experimental satellites” in English. The spacecraft belong to a series of test satellites that launch on a variety of launch vehicles. Usually, neither the payload details nor the mass is given.

The first launch of a Shiyan technology satellite happened in April 2004 on a Chang Zheng 2C rocket from Xichang. The most recent one happened in January 2022, with the launch of Chang Zheng 2D from Taiyuan. 

KZ-1A on the launch truck, ahead of liftoff. (Credit: CASC)

For this launch, the Kuaizhou-1A (KZ-1A) was used. It is a mostly solid-fueled small launcher with three solid stages and one liquid stage. It is built and operated by ExPace, a government-owned subsidiary of the China Aerospace Science and Industry Corporation (CASIC). After the three solid stages did most of the lifting job for the payload, the final liquid stage took over and placed the payload in its final orbit.

KZ-1A had a busy few weeks, with the Chuangxin-16 A/B mission in August 2022, the Centispace 1-S3/S4 mission on Sept. 6, and now the Shiyan-14/15 mission on Sept. 24. This was launch number 18 for the rocket configuration, with 16 successes so far.

The launch site for this rocket was the Taiyuan Satellite Launch Center (TSLC). The spaceport was opened in 1966 and is home to a variety of China launch vehicles, such as the CZ-2, CZ-4, and CZ-6.

Chang Zheng 2D Launches Yaogan-36

Just a few hours later, the Yaogan 36 mission was launched, lifting off from the Xichang Satellite Launch Center (XSLC) on Sept. 26 at 13:38 UTC. It was yet another Yaogan triple, similar to the Yaogan 35 payloads. It also launched on a Chang Zheng 2D (CZ-2D). All three payloads went to a low Earth orbit (LEO).

Yaogan Weixing translates to “remote sensing satellite,” and they are often referred to as simply “Yaogan” satellites. They are classified military satellites, comparable to the US satellites designated “USA” and the Russian designated “Kosmos” missions.

They are launched for a wide range of surveillance, spy, and national security purposes, and are usually hidden behind the official designated purpose of agricultural and natural disaster prevention. However, for this launch, no purpose was given at all. 

Yaogan 36 on its way to the pad. (Credit: CASC)

The A and B payloads were developed by CASC, while payload C was developed by SAST. The exact purpose and mass of the payload remain unknown. The structure is the same as previously flown Yaogan-35 payloads, making it likely that it is related to the Yaogan-35 triplet missions. The exact purpose of these triplet missions is not known at this point.

This launch used the Chang Zheng 2D, which has already flown for the ninth time in 2022. This makes it the second most flown rocket configuration of the year, after SpaceX’s Falcon 9.

It is a two-stage orbital class rocket, manufactured by SAST. Of its 66 launches, 65 were successful, with the only failure being the SuperView-1 payloads in December 2016. Since then, the rocket has had 34 successful flights in a row. 

Down the line, these earlier Chang Zheng rockets will be phased out, instead using modern Chinese RP-1 fueled rockets, such as Chang Zheng 6 or Chang Zheng 8. This will put a stop to China’s use of dinitrogen tetroxide and unsymmetrical dimethylhydrazine, which is known to be harmful to breathe and dangerous to handle.

Chang Zheng 6 Launches Shiyan 16 and 17

The last launch of the recent three was the Shiyan 16 A/B and Shiyan 17 missions on board a Chang Zheng 6 on Sept. 26 at 23:50 UTC. The launch was conducted from Taiyuan, like the KZ-1A launch just days before.

In an unusual situation, the launch was accidentally published early on Chinese social media about eight hours before launch, which confirmed the payload. The post was deleted quickly after the initial publishing.

These are part of the same Shiyan Weixing satellites that are described above. For these, the payload mass and size are also unknown, however, since the capacity of the CZ-6 is smaller, these payloads are most likely lighter as well. The CZ-6 can lift up to 1,080 kg to a 700 km SSO. The purpose of the payloads remains unknown.

Liftoff of CZ-6. (Credit: CASC)

The launch vehicle for the mission was the Chang Zheng 6. It is a liquid-fueled launch vehicle, consisting of three stages. So far, it has only ever launched from Taiyuan and stands 29 meters tall at liftoff. 

In the CZ-6 family, an upgraded version exists, called the CZ-6A. It features four strap-on solid boosters, to increase the capability of the launch vehicle to about 4000 kg to orbit. This variant debuted in March of this year. More variants, such as a version with two solid boosters, have been teased in the past.

These three launches bring the launch count of China in 2022 up to 42 launches. With that, China is the country with the second most orbital launches worldwide, only trailing the US which sits currently at 62.

(Lead photo: CZ-2D lifts off with Yaogan-36. Credit: CASC)

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