Long March 3A - Fengyun 2G Launch

Stunning Photos Capture Descent & Wreckage of Chinese Rocket Stage

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All Photos - Credit: China News Agency

January 6, 2015

Photo: ChinaNews.com

It was not quite the landing SpaceX would be aiming for, but Chinese photographers were able to capture the descent and impact of a large expendable rocket booster in China's Guizhou province. The stunning images were captured back on December 31 when a Chinese Long March 3A rocket lofted the Fengyun 2G weather satellite into a Geostationary Transfer Orbit.

The 52.5-meter tall Long March 3A rocket blasted off from the Xichang Satellite Launch Center in the Sichuan Province at 1:02 UTC last Wednesday, embarking on a mission to boost the next in the Fengyun 2 series of Geostationary Weather Satellites into orbit. As the basic model of the CZ-3 series, the Long March 3A only consists of a three-stage stack while its larger sisters employ two (3C) or four (3B) strap-on boosters to achieve a higher payload capability.

Powered by its powerful first stage engine cluster, the 241,000-Kilogram Long March 3A rocket raced downrange from its launch site, heading to the south-east to reach an initial parking orbit. The first stage of the vehicle and its DaF-6-2 engine cluster delivering 302 metric ton-force of thrust burned for the first 146 seconds of the flight, providing the initial boost to get the vehicle on its path towards orbit.

Separating from the also hypergolic-fueled second stage, the first stage began its trip back to Earth. Unlike SpaceX that aims to re-use its first stages, China relies on fully expendable launch vehicles that are used only once. Making its ballistic trip back to Earth, the first stage of the launcher plummeted to the ground near the village of Gaopingsi, about 545 Kilometers from the launch site - in line with previous launches from Xichang, although the first and second stage drop zones were not identified in any pre-launch warnings which is common practice for Chinese launches.

After dropping its first stage, the Long March 3A headed on towards orbit, burning its second stage for for three minutes and conducting two burns of its cryogenic upper stage to deliver the Fengyun 2G satellite to its planned orbit.

Photo: ChinaNews.com

Photographers of the ChinaNews.com News Agency were present near the crash site, lucky enough to see the first stage fall back to the ground in a relatively upright position - a stable posture due to the low center of gravity caused by the heavy engine compartment in the aft. No casualties were reported as a result of the impact of the first stage and further images show the wreckage of the stage in a forest, still releasing toxic propellant fumes.

Photo: ChinaNews.com

Photos of Chinese rocket and fairing debris are not uncommon since most Chinese rocket stages end up on land due to the use of inland launch sites, however, published images of a large booster in the final stages of its descent are rarely available.

Pre-staged military teams and local authorities were present at the crash site - equipped with paper masks to provide a crude form of protection from the fumes. Villagers approached the rocket stage which contained over 172,000 Kilograms of toxic unsymmetrical dimethylhydrazine and nitrogen tetroxide propellants at launch.

Photos show the large, 3.35-meter diameter first stage largely intact, only with its engine section separated, presenting the inner workings of a space launch vehicle to curious villagers - including the thin outer shell of the rocket body, the main propellant feedlines, the external wire canal and the massive rocket engines. Images show a crowd of adults and children approaching the crash site and inspecting the individual engines that were once part of the four-engine cluster of the rocket.

Usually, rocket stages are retrieved from the crash sites by the Chinese military to become scrap metal. One of the peculiarities of the CZ-3A launcher is the low kinetic energy of its first stage when returning to Earth - a result of the three-stage design with a powerful cryogenic upper stage. Comparing with the two-stage Falcon 9, the Chinese stage has only about 65% the kinetic energy of that of the 1st stage of Falcon 9 returning in ballistic mode - further underlining the difficulty of SpaceX's current endeavor of making the stage re-usable by returning it to Earth in a controlled fashion.

The company plans to attempt a daring return of the Falcon 9 first stage when launching the Dragon SpX-5 mission, expected to perform a series of three propulsive maneuvers and use grid fins to navigate to a small floating platform station in the Ocean, downrange from the launch site for a pin-point touchdown.

Busy 2014 closes with China's Long March 3A lofting Fengyun 2G

December 31, 2014

Marking the final space launch in a busy year, China successfully launched its Fengyun 2G weather satellite atop a Long March 3A rocket. Launch from the Xichang Satellite Launch Center took place at 1:02 UTC on Wednesday and the Long March 3A rocket successfully carried the satellite into a Geostationary Transfer Orbit, official Chinese Media confirmed. Wednesday's launch was the 92nd orbital launch in 2014 - the most launches conducted in a calendar year since 1994.

Fengyun is China's Meteorological Satellite Program, consisting of at least one operational satellite in Geostationary Orbit and several satellites in polar orbits, creating a satellite constellation to monitor the Chinese and surrounding territory to deliver timely data relevant for weather forecasting and nowcasting. The program saw its first launch back in 1988 when the Fengyun 1A satellite was launched into a Sun-Synchronous Orbit - Fengyun 1B followed in 1990.

The development of the Fengyun 2 satellites as the Geostationary component of the constellation started in the 1980s and the first satellite was ready for launch in 1994, however, when being loaded with propellants for flight, the satellite exploded, killing one technician, injuring 20 more and setting back the entire program that went through a re-design of the satellite's propulsion system. As a result, the first Fengyun 2 satellite launched three years later than originally planned. A total of six FY-2 satellites have been launched to date, entering positions at 86.5 and 105° East in Geostationary Orbit. Of the FY-1 polar orbiting series, four satellites have been launched with FY-1C making the news in 2007 when it was destroyed as part of a anti-satellite test conducted by the Chinese, creating a large debris cloud in orbit.

*File Image* - Photo: Xinhua

The FY-1 generation of satellites were succeeded by the FY-3 satellites, the first of which launched in 2008 and was followed by two more in 2010 and 2013 to keep up a steady flow of meteorological data from a Low Earth Orbit. The most recent FY-2 launch took place in January 2012. The FY-4 series of Geostationary Satellites is currently being developed and will take over from FY-2 in the coming years with the first launch as early as 2015.

Image: CAST

FY-2C (above), 2C Color Composite (below)

Image: China Meteorological Administration

The FY-2 spacecraft are spin-stabilized satellites rotating at 100 RPM with a de-spun antenna unit and body-mounted solar panels for power generation. Developed by the Shanghai Academy of Space Flight Technology (SAST) and China Academy of Space Technology (CAST), the cylindrical satellite bus measures about 2.1 meters in diameter and 4.5 meters in length. Overall, the satellite has a launch mass around 1,380 Kilograms and an in-orbit mass of 680 Kilograms using a solid-fueled apogee kick motor to inject itself into Geostationary Orbit with a liquid-fueled propulsion system for orbital adjustments and stationkeeping.

Fengyun 2G's main instrument is the Stretched Visible and Infrared Spin Scan Radiometer that delivers daylight cloud imagery in the visible wavelengths, round the clock infrared cloud imagery which also allows the determination of cloud top temperature, sea surface temperature and wind field distribution. The instrument covers a visible band at 0.5 to 1.0 µm, a series of infrared bands around 3-5 and 10.5-12.5 µm and a dedicated water vapor channel at 6.2-7.6µm.

FY-2G's main instrument was designed to meet the data requirements by combining a favorable spectral coverage, spectral resolution, spatial resolution and radiometric accuracy. The satellite covers the entire disk of the Earth.

Data from FY-2 is used to determine atmospheric temperature profiles, cloud water content, precipitation rate, reflectance data for vegetation assessments, sea surface temperature, ocean imagery, land surface temperature and imagery. Image resolution reaches 1.25 and 5 Kilometers for the visible and infrared channels.

Additionally, the Fengyun 2G satellite carries a Space Environment Monitor, a miniaturized instrument that measures the radiation environment in near-Earth space and can be used for space weather assessments and research.

Also, the satellite sports a Solar X-Ray Monitor and a Data Collection Service Terminal that uses a UHF/S-Band Terminal that is operated to deliver acquired data to various users on the ground in real time via low data rate communications to enable a rapid distribution and processing of data by those who need it.

China's Long March 3A rocket is a three-stage launch vehicle, and currently one of the largest in the Long March Fleet, used to deliver satellites to high-energy orbits such as Geostationary Transfer Orbit.

China's Long March 3A rocket is a three-stage launch vehicle, and currently one of the largest in the Long March Fleet, used to deliver satellites to high-energy orbits such as Geostationary Transfer Orbit. The Long March 3A first flew in 1994 and builds the basis for the CZ-3B and CZ-3C vehicles and their enhanced versions that add boosters and/or stretch the stages of the original CZ-3A to increase payload performance.

Overall, Long March 3A stands 52.5 meters tall with a diameter of 3.35 meters and a launch mass of 241,000 Kilograms consisting of two lower stages that use hypergolic propellants and a cryogenic upper stage. The launcher can deliver payloads of up to 2,600 Kilograms into a Geostationary Transfer Orbit.

The large first stage of the Long March 3A is 23.27 meters long and 3.35 meters in diameter, following the basic design with the oxidizer tank located above the fuel tank. The tanks use individual bulkheads which creates a small inter-tank area that is used to facilitate equipment such as control units and avionics. Overall, the first stage holds 171,775 Kilograms of propellants at liftoff for consumption by a DaFY-6-2 engine which is a cluster of four DaFY-5-1 engines. Each of the engines delivers 740 Kilonewtons (75,500kgf) of thrust, operating at a chamber pressure of 71 bar with an engine diameter of 0.84 meters. The four engines provide a total sea level thrust of 2961.6 Kilonewtons (302,000 Kilogram-force). Vehicle control during first stage flight is accomplished by individually gimbaling the four engines. The first stage operates for 146 seconds using a hot-staging for separation that is accomplished by using 14 pyrotechnic bolts.

Stage 2 is 9.94 meters long and shares the first stage’s diameter of 3.35 meters. It has an empty mass of 3,850 Kilograms and is loaded with 49,605 Kilograms of propellants that are consumed by a single DaFY-20-1 main engine and a four-chamber DaFY-21-1 vernier engine. The main engine provides 742 Kilonewtons of thrust (75,660 Kilogram-force) while the four chambers of the vernier engine each provide 11.8 Kilonewtons of thrust (1,200 Kilogram-force). The nozzles can be gimbaled individually to provide vehicle control during flight. The second stage main engine burns for 178 seconds, the vernier burns six seconds longer. Staging is accomplished by pyrotechnic bolts.

The Cryogenic Upper Stage of the Long March 3A is 12.38 meters long with a reduced diameter of 3.0 meters having an inert mass of 2,740 Kilograms. The third stage carries a total propellant load of 18,193 Kilograms of Liquid Hydrogen and Liquid Oxygen. The third stage uses Propellant Utilization Technique to adjust the propellant mixture consumed by a YF-75 cluster of two cryogenic main engines providing a total vacuum thrust of 156.9 Kilonewtons (1,600 Kilogram-force) operating at a chamber pressure of 37.6 bar.

*File Image* - Photo: Xinhua

The engines are optimized for operation in vacuum conditions with an area ratio of 80:1. The third stage provides re-ignition capability to support a two-burn GTO mission profile – using the first burn to reach a parking orbit ahead of a plane-change and apogee boost as part of the second burn. The third stage is equipped with a monopropellant Propellant Management and Attitude Control System and the stage also includes the vehicle avionics. The payload fairing of the CZ-3A is 3.35 meters in diameter and 8.89 meters long capable of hosting large payloads.

Wednesday’s launch marked the 202nd flight of the Long March Rocket Family, the 215th overall orbital launch made by China and the 15th of 2014. On the books for the next year could be over two dozen Chinese launches including the debut missions of the Long March 6, 7 and 11 launch vehicles.