Engineering:Shijian-18
| Mission type | Technology demonstration and communications |
|---|---|
| Operator | CAST |
| Mission duration | ~45 minutes |
| Spacecraft properties | |
| Bus | DHF-5[1] |
| Manufacturer | CAST |
| Launch mass | >7,600 kg (16,800 lb)[2] |
| Power | 18kW[3] |
| Start of mission | |
| Launch date | 2 July 2017 11:23 GMT[3] |
| Rocket | Long March 5 Y-2 |
| Launch site | Wenchang Space Launch Site |
| Contractor | CAST |
| End of mission | |
| Disposal | Failure |
| Declared | 2 July 2017 |
| Destroyed | 2 July 2017 |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Geostationary (planned) |
| Period | 1 day (planned) |
| Transponders | |
| Band | Ka band |
| Capacity | 70 Gb/s |
| Coverage area | China |
Shijian-18 (Chinese: 实践十八号; transliteration: Practice-18) was a Chinese communications and technology demonstration satellite developed and launched by the China Academy of Space Technology on 2 July 2017. It was the median flight of the DHF-5 satellite bus, which is designed with 16-year lifespan. Shijian-18 carried 18 experiments on board involving communications and space telescopes. It was lost after a malfunction on the Long March 5 rocket carrying the satellite.
Design
Shijian-18 was the maiden flight of the DH-5 satellite bus, which is designed for a payload with a launch mass between 6,000 kg (13,000 lb) to 9,000 kg (20,000 lb). It would have been the heaviest geostationary satellite at the time of its launch,[4] with a launch mass of 7,600 kg (16,800 lb)[2]
The satellite incorporated a high-thrust ion propulsion system, a large trussed structure and a higher payload capacity.[4] More specifically, it used the LIPS-300 xenon thruster for orbit keeping, developed by the Lanzhou Institute of Physics. It was planned for the LIPS-300 system to be fully certified in this mission so that it could be used for geostationary and deep-space operations.[4] The satellite would operate at the Ka band with 70 Gb/s capacity, capable of providing broadband internet to whole mainland China.[4]
Launch
Shijian-18 launched from the Wenchang Space Launch Site on 2 July 2017 at 11:23 UTC on board a Long March 5 rocket to a geostationary orbit. It was the rocket's second flight,[3] the first being to launch Shijian-17.[5]
The rocket encountered an anomaly shortly after launch, causing it to switch into a gentler trajectory. However, 45 minutes into the flight, it was declared a failure, with the loss of the payload.[6][5] The cause of the failure was later determined to be a faulty oxidizer turbopump, which has now been redesigned twice.[7] The rocket and payload crashed in the Pacific Ocean somewhere at the Philippine Sea.[5]
References
- ↑ "China to launch first high-throughput communications satellite in April". http://www.cnsa.gov.cn/english/n6465652/n6465653/c6778858/content.html.
- ↑ 2.0 2.1 "SJ 18" (in en). https://space.skyrocket.de/doc_sdat/sj-18.htm.
- ↑ 3.0 3.1 3.2 Barbosa, Rui C. (2017-07-02). "Long March 5 suffers failure with Shijian-18 launch" (in en-US). https://www.nasaspaceflight.com/2017/07/long-march-5-lofts-shijian-18/.
- ↑ 4.0 4.1 4.2 4.3 "Shijian-18 – CZ-5 – Shijian-18 | Spaceflight101" (in en-US). https://spaceflight101.com/long-march-5-shijian-18/shijian-18/.
- ↑ 5.0 5.1 5.2 Clark, Stephen. "China launches Long March 5, one of the world’s most powerful rockets – Spaceflight Now" (in en-US). https://spaceflightnow.com/2016/11/03/china-launches-long-march-5-one-of-the-worlds-most-powerful-rockets/.
- ↑ Goh, Deyana (2017-07-03). "Long March 5-Y2 fails, Shijian-18 satellite lost" (in en-US). https://www.spacetechasia.com/long-march-5-y2-fails-shijian-18-satellite-lost/.
- ↑ "Successful Long March 5 launch opens way for China's major space plans" (in en-US). 2019-12-27. https://spacenews.com/successful-long-march-5-launch-opens-way-for-chinas-major-space-plans/.
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