Featured image credit: Qin Yingjian
Lift-Off Time | December 29, 2022 – 4:43 UTC | 12:43 BJT |
|---|---|
Mission Name | Shiyan 10-02, an experimental satellite |
Launch Provider | China Aerospace Science and Technology Corporation (CASC) |
Customer | Shanghai Academy of Spaceflight Technology (SAST) |
Rocket | Long March 3B/E Y88 |
Launch Location | LC-2, Xichang Satellite Launch Center, in the Sichuan province, China |
Payload mass | N/A |
Where did the spacecraft go? | Molniya orbit, 187 km x 40,090 km (116 mi x 24,900 mi) at 50.9 degrees inclination |
Did they attempt to recover the first stage? | No, this is not a capability of the Long March 3B/E |
Where did the first stage land? | The boosters of the Long March 3B/E crashed into the mountains of Guangxi |
Did they attempt to recover the fairings? | No, this is not a capability of the Long March 3B/E |
Were these fairings new? | Yes |
This was the: | – 185th orbital launch of 2022 – 64th Chinese launch of 2022 – 54th launch of 2022 provided by CASC – 145th mission of the Long March 3 rocket family – 137th successful mission of the Long March 3 rocket family – 4th mission in 2022 of a Long March 3 rocket |
Where to watch | Unofficial replay with great quality image and sound |
How Did It Go?
Using a Long March 3B/E rocket, the China Aerospace Science and Technology Corporation successfully launched the secretive Shiyan 10-02 payload (also, SY-10-02). The vehicle deployed the satellite into a Molniya orbit, where it will operate. This is a highly elliptical orbit with a higher apogee than the geostationary one. Xichang Satellite Launch Center’s Launch Complex 2 saw the rocket take to the skies, nominally completing every milestone for the flight.
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 10-02
Not much has been disclosed about this payload, in resonance with all that is explained in the previous paragraphs. The analysts believe this spacecraft has been developed by SAST. This satellite will be mainly used for in-orbit verification of new space technologies, such as space environment monitoring. However, this official statement is contested by analysts who argue the selected Molniya orbit could very well imply uses such as communications, missile warning, and signal intelligence.
The present mission could be a repeat of a previous launch carrying a spacecraft of the same name: Shiyan 10. This one reached orbit on September 27, 2021, but experienced an anomalous behavior at that point, and therefore it was believed a failure. Nevertheless, a few weeks later the satellite became active again and rose its orbit. Another possibility would be that Shiyan 10-02 will operate together with the older experimental craft.
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 3B?
Despite the Chinese rockets having different heritages, most of China’s orbital launch vehicles use the “Long March” (Chang Zheng) naming scheme. Thus, the Long March 3B is a three-stage rocket, with an optional fourth stage. Four liquid-fueled side boosters stand strapped to the first stage, and the launcher’s maiden flight took place in 1996.
The Long March 3B/E, the enhanced version of the Long March 3B, was first launched in 2007, and has greater Geostationary Transfer Orbit (GTO) payload capacity. The enhanced 3B/E’s have a larger first stage and larger side boosters, compared to the original Long March 3B. As a result, its payload capacity to GTO was increased from 5,100 kg (~11,300 lb) to 5,500 kg (~12,200 lb).
The Long March 3B series features the following sections or stages:
Side Boosters
There are four side boosters that each use one YF-25 engine, which runs on unsymmetrical di-methyl hydrazine (UDMH), the fuel, and nitrogen tetroxide (N2O4), the oxidizer. Although the regular Long March 3B’s side boosters are 15.33 m (50.3 ft) long, the enhanced versions are 16.1 m (52.3 ft) long, producing 740 kN of thrust for both versions. The YF-25 engine has a specific impulse (ISP) of 260 s, and burns for 140 s on the 3B/E variant.
First (Center) Stage
The first stage has four YF-20C engines (this group forms a YF-21C engine), which also use UDMH/N2O4 for propellant. The first stage has an ISP of 260 s and produces 2,960 kN of thrust. In the LM-3B’s case, its length is 23.27 m (76.35 ft) tall, but the 3B/E’s version is 24.76 m (81.23 ft) tall.
Second Stage
The second stage is powered by a single YF-22E engine, which is a vacuum-adapted version of the YF-20E. However, a single YF-23C vernier engine with four nozzles provides attitude control, which combined with the main one forms a YF-24E engine. The engine runs on UDMH and N2O4, and produces 742 kN of thrust. The second stage is 12.9 m (42.3 ft) tall and burns for 185 s.
Third Stage
The third stage is 12.4 m (40.7 ft) long and two YF-75 engines power it. Unlike the other stages, this stage runs on liquid hydrogen (LH2) and liquid oxygen (LOx).
The third stage will ignite its engine after the second stage is jettisoned, in order to continue to raise the orbital apogee (maximum altitude). Once the target apogee has been achieved, it shuts down. The vehicle will then coast to apogee, where the stage relights and burns to raise the perigee (lowest altitude) of the orbit.
Optional Fourth Stage
The fourth stage runs on UDMH / N2O4, and has a singular YF-50D engine.
