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Raumfahrt - China says it will put parachutes on its rocket boosters next year and heres why

17.10.2018

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An expended booster which landed in Guangxi Province following launch of a Long March 3B launch from Xichang on October 15, 2018. Sina Weibo/China航天

China says it will test parachute landings of its Long March 3B rocket boosters in 2019 in order to limit the threat of space debris from launches from the Xichang Satellite Launch Centre.

The latest launch from Xichang on Monday saw two Beidou navigation satellites sent into medium Earth orbits, but also saw the used up boosters from the first stage land near a populated area downrange.

Fortunately there were no injuries, and precautions including notification and evacuation of areas within the calculated drop zones help to prevent tragedy. As it stands the dangerous, uncontrolled events are all-too-common.

In January a booster from a similar launch exploded near a town in Guizhou Province and in June another fell from the sky and ignited over a different settlement.

Smoke rises after the spent first stage of a Long March 2C rocket impacts a town in China's Guizhou Province on June 27, 2018.

 

 

Smoke rises after the spent first stage of a Long March 2C rocket impacts a town in China's Guizhou Province on June 27, 2018. Framegrab/Sina Weibo

The powerful Long March 3B rocket, used to carry satellites to medium and geosynchronous Earth orbits, is almost 55 metres long, with a diameter of 3.35 metres on the core stage. The launcher has a mass at liftoff of 458,970 kg, or just over 1 million pounds.

The four 2.25 m diameter, 15 m long strap-on boosters are filled with unsymmetrical dimethylhydrazine (UDMH) and dinitrogen tetroxide (N2O4) hypergolic propellant, which is highly toxic.

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In a new effort to reduce risk, the China Academy of Launch Vehicle Technology (CALT), which developed the Long March 3B rocket, stated(Chinese) that the boosters for today's launch carried data logging and active tracking equipment for tests to determine the altitude and timing for future parachute landings.

The trial phase of parachute booster landings is expected in 2019. Rather than landing the components for potential reuse, the parachutes will be deployed to control the landing zone and reduce the chances of damaging people or property.

China is also working on reusability for its new generation rockets, looking to land first stages in a similar fashion to SpaceX's Falcon 9 and Falcon Heavy launch vehicles. The Long March 8 and Long March 6 may be the first to test powered descent and vertical landing.

Last month CALT also tested a parafoil on a payload fairing, again to control the debris from launches from its three inland launch sites.

 

First footage of China using a parafoil for payload fairing reentry after satellite launch

Rockets attempting to place satellites in orbit use a number of stages, which separate when spent, helping the spacecraft reduce mass to achieve the kilometres-per-second velocities required to reach various orbits.

While US and European rockets launch over water and first stages splash down safely, three of China's four launch sites were constructed inland during the Cold War due to the security concerns posed by both the US and Russia. Russia also launches over land but the 'drop zones' are in uninhabited areas.

A burning booster which fell to Earth in Guangxi from the Long March 3B launch on January 12, 2018.

 

 

A burning booster which fell to Earth in Guangxi from the Long March 3B launch on January 12, 2018. Sina Weibo

Quelle: gbtimes

 

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