Subj : Chang Zheng 2C lifts a pair of Earth observation satellites To : All From : NasaSpaceFlight Date : Fri Apr 29 2022 20:15:03 Chang Zheng 2C lifts a pair of Earth observation satellites Date: Fri, 29 Apr 2022 19:04:38 +0000 Description: China has successfully launched a pair of Commercial Earth observation satellites to a Sun-Synchronous Orbit The post Chang Zheng 2C lifts a pair of Earth observation satellites appeared first on NASASpaceFlight.com . FULL STORY ====================================================================== China has successfully launched a pair of Commercial Earth observation satellites to a Sun-Synchronous Orbit (SSO). Liftoff occurred at 04:11:33 UTC, from Launch Area 4 of the Jiuquan Satellite Launch Center. The rocket for todays payload was a Chang Zheng 2C. This was one of initially two planned launches for April 29, but a Chang Zheng 11 sea launch slipped to no earlier than April 30. The satellites are called Siwei-01/02 and are operated by the China Siwei Survey and Mapping Technology Co. Ltd. They are a company based in Beijing that produces and operates mapping technology and instruments. They are a subsidiary of the China Aerospace Science and Technology Corporation (CASC). The satellites were built by China Spacesat Co. Ltd., under the guidance of the China Association for Science and Technology (CAST). The English names of the satellites are SuperView Neo 1-01/02. Rendering of the Siwei satellite Both satellites mass about 540 kg individually and have a maximum optical resolution of 0.5 meters each. According to the satellite operator, they will serve the usual areas of satellite remote sensing service. This includes resource and environmental observation, agriculture and transportation service, emergency management, and urban planning. It is not clear if they will also serve a military purpose. The launch contract for this mission was finalized in January 2022 and the launch was initially planned for June 2022, but then was moved forward to April. This is the 417th of the Chang Zheng Family, and the 12th launch from China in 2022. In todays launch, the Chang Zheng 2C was used. It is a two-stage orbital rocket developed and manufactured by the China Academy of Launch Vehicle Technology (CALT). It is commonly used to launch small payloads and is the smallest and least powerful rocket of the early Chang Zheng generation. The payload fairing containing the two Siwei satellites is lifted for integration At liftoff, the rocket masses 233,000 kg. It stands 42 meters tall with a diameter of 3.35 meters. The rocket has the option to feature an optional third stage, however, this was not the case for todays launch. See Also Siwei-01/02 Updates China Forum Section L2 Resources Click here to Join L2 The first stage of the rocket stands 25.72 meters tall with a diameter of 3.35 meters. It is fueled with 162,706 kg of dinitrogen tetroxide and unsymmetrical dimethylhydrazine that power the four YF-21C engines at liftoff. The engines are part of the YF-20 family that powers a variety of launch vehicles in the early CZ generation. Depending on the configuration and variation, the name changes accordingly. The name 21-C refers to a module of four YF-20C engines. All four together provide a liftoff thrust of 2,961.6 kN with a specific impulse of 260.69 seconds. The engine masses about 700 kg and has a gimbal range of 10 degrees. It was developed by the Academy of Aerospace Liquid Propulsion Technology and utilizes the gas generator cycle. The first stage will perform its burn before separating and dropping over populated areas. In the past, China conducted experiments with grid finds on the CZ-2C to steer the rocket away from citizens, but it does not look like such an experiment was featured in todays mission. Above the first stage, the second stage is only 7.757 meters tall with the same diameter of 3.35 meters. It holds 54,667 kg of the same propellants and is powered by the same engine family as the first stage. The second stage of CZ-2C for todays launch is lifted for integration The variation of the engine on the second stage is called YF-24E, which features a YF-22E upper stage engine and four YF-23 vernier engines. Since the early days of the Feng Bao 1 rocket, the YF-23 has been a vernier engine on multiple Chinese rockets, including CZ-2, CZ-3, and CZ-4. It produces 47.1 kN of thrust with a specific impulse of 297 seconds. The vernier engines are used to steer the rocket in the second stage flight phase. Its partner, the YF-22E main engine, produces a thrust of 741.4 kN with a specific impulse of 289 seconds. The engine will conduct a single burn and can not relight after the initial ignition. If a launch requires it, there is an option to include a Yuanzheng upper stage that can function as a final orbital maneuvering stage. It only features a thrust of 6.5 kN with a specific impulse of 315.5 seconds and can operate over the time span of 6.5 hours with the ability to ignite multiple times. It was not used today. The Jiuquan Satellite Launch Center (JSLC) was founded in 1958 and is one of the oldest Chinese spaceports. It is a completely closed area that covers 2800 square kilometers and provides launch facilities and housing for employees. In the past, it launched Dong Fang family rockets, as well as multiple Chang Zheng rockets. It has also featured launches from Chinese private rocket startups such as OneSpace and i-Space. Jiuquan features three launch areas with six launch pads. (Lead photo: Chang Zheng 2C lifts off from Jiuquan with the Siwei satellites onboard.) The post Chang Zheng 2C lifts a pair of Earth observation satellites appeared first on NASASpaceFlight.com . ====================================================================== Link to news story: https://www.nasaspaceflight.com/2022/04/chang-zheng-2c-siwei/ --- Mystic BBS v1.12 A47 (Linux/64) * Origin: tqwNet Science News (1337:1/100) .