Featured image credit: CASC/Ying Longfei
Lift-Off Time | December 16, 2022 – 6:17 UTC | 14:17 BJT |
|---|---|
Mission Name | Shiyan 21, an experimental satellite |
Launch Provider | China Aerospace Science and Technology Corporation (CASC) |
Customer | Shanghai Academy of Spaceflight Technology (SAST) |
Rocket | Long March 11 Y12 |
Launch Location | A mobile launcher at Xichang Satellite Launch Center, in the Sichuan province, China |
Payload mass | N/A |
Where did the spacecraft go? | Low-Earth orbit (LEO), 473 km x 493 km (294 mi x 306 mi) at 36.0 degrees inclination |
Did they attempt to recover the first stage? | No, this is not a capability of the Long March 11 |
Where did the first stage land? | The first stage crashed into the mountains close to the triple border between the provinces of Sichuan, Guizhou, and Yunnan; the second stage, into the South China Sea, just south of Taiwan Strait; the third, into the Coral Sea, northeast of Australia |
Did they attempt to recover the fairings? | No, this is not a capability of the Long March 11 |
Were these fairings new? | Yes |
This was the: | –178th orbital launch attempt of 2022 –62nd Chinese launch of 2022 –52th launch of 2022 provided by CASC –15th mission of a Long March 11 rocket –11th mission of a Long March 11 rocket from ground –15th successful mission of a Long March 11 rocket –4th mission in 2022 of a Long March 11 rocket –456th mission of a rocket from the Long March family |
Where to watch | Unofficial launch summary |
How Did It Go?
China Aerospace Science and Technology Corporation successfully launched the classified Shiyan 21 payload (also, SY-21) atop a Long March 11 rocket. The vehicle deployed the satellite into a low-Earth orbit (LEO) at approximately 480 km (~300 mi) altitude and 36 degrees inclination with respect to the equator. A mobile launcher at the Xichang Satellite Launch Center saw the rocket take to the skies, subsequently completing every milestone for the flight, including stage as well as fairing separation events.
What Are The Shiyan Payloads?
China’s aerospace industry has a number of prolific programs aimed at improving applied technologies in this field. Shiyan satellites are a series of spacecraft which certainly play a role in the mentioned search for progress. This particular fact is highlighted by the Chinese word used for their name — Shiyan, or SY for short — which, some experts point out, should be translated as “pilot” or “trial.” However, these satellites are more commonly mentioned as “experiment,” a more widely used translation.
Other series aiming to achieve similar goals are the Shijian, or SJ — best practice, put into practice — and the Chuangxin, or CX — innovation. Both SJ and SY payloads have been contributing for decades now to the China High-resolution Earth Observation System (CHEOS). Apparently, though, a distinction can be made between those last two, as the Shijian sats have favored more radar and infrared payloads. On the other hand, Shiyan have been more focused on Earth-observation satellites.
In order to further differentiate the SY from the SJ, the latter are probably testing, or putting into practice, more mature technologies. These could imply a lower failure ratio, when compared to the Shiyan more experimental spacecraft. Similarly, the Chuangxin might also find themselves in an early condition.
Shiyan 21
Not much has been disclosed about this payload, in resonance with all that is explained in the previous paragraphs. Official authorities have reported that this spacecraft has been developed by SAST. Additionally, it has been informed that this satellite will be mainly used for in-orbit verification of new space technologies. However, this is a kind of standard way of speaking when Chinese authorities mean it is a classified mission.
Other Shiyan Launches
As previously mentioned, these satellites are part of a larger group of “pilot” payloads. In the following table you can find some other Shiyan spacecraft that were launched in the recent past.
| Date | Launch Vehicle | Mission Name |
| April 8, 2021 – 23:01 UTC | Long March 4B | Shiyan 6-03 |
| November 24, 2021 – 23:41 UTC | Kuaizhou-1A | Shiyan 11 |
| December 23, 2021 – 10:12 UTC | Long March 7A | Shiyan 12-01 & 02 |
| January 17, 2022 – 02:35 UTC | Long March 2D | Shiyan 13 |
| September 24, 2022 – 22:55 UTC | Kuaizhou-1A | Shiyan 14 & 17 |
What Is The Long March 11?
Developed and manufactured by the China Academy of Launch Vehicle Technology (CALT), one of CASC’s subsidiaries, the Long March 11 — also known as Chang Zheng 11, or CZ-11 — is a small satellite launch vehicle. Its maiden flight happened on September 25, 2015.
Versatility
Because of its design and its specifications, this Chang Zheng is incredibly versatile, being capable of both launching on short notice, or from either land or sea. In the former case, the focus is on keeping short operational timelines, while in the latter, on mission’s cost. During normal operations, the launch can take place within ten days from receiving the order. In emergencies, this time can be drastically reduced to about 24 hours.
Operations
When launching from the sea, the rocket is identified as CZ-11H, where H probably stands for haiyang: ocean. Because of this, their flights are numbered separately, though the vehicle serial numbers are not. In this way, it becomes clear that they are identical from a manufacturing standpoint.
| Stages | 4 |
| Propellant | Solid (all stages) |
| Lift-off mass [kg (lb)] | 58,000 (~128,000) |
| Lift-off thrust [kN (lbf)] | 1,177 (~264,500) |
| Height [m (ft)] | 20.8 (~68) |
| Diameter [m (ft)] | 1.6 (~5.2) 2.0 (~6.5) (1st stage) |
| Fairing diameter [m (ft)] | 1.6 (~5.2), or 2.0 (~6.5) |
| Mass to LEO [kg (lb)] | 700 (~1,550) |
| Mass to SSO* [kg (lb)], at 700 km (~438 mi) altitude | 400 (~770) |
(*) SSO: Sun-synchronous orbit
Furthermore, a mobile launcher, basically a truck with an erectable strongback, provides the launch platform when it is from land. On the other hand, if it lifts off from the sea, the rocket uses different barges, namely the Tai Rui, the DeBo-3, and the DeFu-15002. However, in both cases — land and sea — the rocket’s first stage ignites in the air. This is due to the Long March 11 leaving the ground similarly to a missile, that is, carrying out a cold launch. When such a system is used, the rocket is propelled by gas from a launch tube. Only then it starts generating its own thrust.
Chang Zheng 11 Yao 12
Twelve is the number that identifies this flight (Y12), and before which the rocket received some upgrades. In the first place, officials disclosed the solid rocket motor was selected to better fit the performance needed for this mission. That is to say, that there are probably a few different designs from which the launch provider chooses according to mission requirements.
On a different note, some satellite mount supports were 3D printed. This helped in decreasing both production times, and structural weight. In turn, the capabilities of the rocket in terms of mass to orbit see a rise.
Previous CZ-11 And CZ-11H Launches
| Date | Vehicle Variant | Mission Name | Flight ID | Launch Site |
| September 15, 2020 – 1:23 UTC | CZ-11H | Jilin-1 Gaofen 03B-01 to 06 & 03D-01 to 03 | Y2 | DeBo-3, Yellow Sea |
| December 09, 2020 – 20:14 UTC | CZ-11 | GECAM | Y9 | Mobile launcher, Xichang SLC* |
| March 30, 2022 – 02:29 UTC | CZ-11 | Tianping-2 A/B/C | Y10 | Mobile launcher, Jiuquan SLC* |
| April 30, 2022 – 03:30 UTC | CZ-11H | Jilin-1 Gaofen 03D-04 to 07 & 04A | Y3 | Tai Rui, Yellow Sea |
| October 7, 2022 – 13:10 UTC | CZ-11H | CentiSpace-1 S5 & S6 | Y4 | DeFu-15002, Yellow Sea |
