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U.S. military tracking unguided re-entry of large Chinese rocket

A Chinese rocket measuring around 100 feet long that launched earlier this month will likely plunge back into Earth’s atmosphere some time Monday, becoming the most massive object in decades to fall out of orbit in an uncontrolled manner.

The core stage of China’s Long March 5B rocket is expected to fall back to Earth unguided after nearly a week in orbit. The Long March 5B rocket launched May 5 with a prototype for a next-generation Chinese crew capsule.

As of Saturday, the rocket stage was circling Earth in an elliptical orbit ranging between 94 miles (152 kilometers) and 167 miles (270 kilometers) in altitude, according to U.S. military tracking data. A prediction issued Saturday by the U.S. military, which tracks objects in orbit, forecasts the rocket’s re-entry in a 24-hour period between 2335 GMT (7:35 p.m. EDT) Sunday and 2335 GMT (7:35 p.m. EDT) Monday.

But uncontrolled re-entries are difficult to predict, and the forecast could change as ground-based radars continue tracking the Long March 5B rocket body in orbit. Changes in atmospheric drag and solar activity could move the time of re-entry earlier or later.

A one-minute error in predicting the re-entry time changes the location of potential falling debris by nearly 300 miles, or about 500 kilometers, according to the Aerospace Corp.

The Long March 5B rocket body is in an orbit that flies between 41.1 degrees north and south latitude, meaning the re-entry could occur as far north as around New York City, or as far south as Wellington, New Zealand.

Maj. Cody Chiles, a Combined Force Space Component Command spokesperson, said Friday that the U.S. Space Force’s 18th Space Control Squadron is tracking the Chinese Long March 5B rocket body. The object is approximately 20 meters squared in size, Chiles said in response to an inquiry from Spaceflight Now.

The core stage of the Long March 5B rocket measures around 100 feet (30 meters) long and 16 feet (5 meters) wide.

This map illustrates some of the possible tracks the Long March 5B rocket body could take on Monday, the expected day of re-entry. An exact location of the re-entry cannot be predicted with certainty. Credit: Aerospace Corp.
During the May 5 launch, the core stage contained super-cold liquid hydrogen and liquid oxygen to feed the rocket’s two YF-77 engines. Four liquid-fueled boosters clustered around the core stage dropped off the rocket around three minutes after liftoff to call into the South China Sea.

With the tanks empty, the Long March 5B’s core stage stage has a mass of roughly 20 metric tons. An exact mass figure has not been released by Chinese officials.

That makes the Long March 5B core stage the most massive object to make an uncontrolled re-entry since the Soviet Union’s Salyut 7 space station in 1991, according to Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics who tracks global satellite and launch activity.

The core stage is more massive than other notable satellites that have plunged unguided back into Earth’s atmosphere in the last decade, such as China’s Tiangong 1 space lab, Russia’s failed Phobos-Grunt Mars probe, and NASA’s UARS atmospheric research satellite. It’s about one-quarter the mass of NASA’s Skylab space station, which made headlines when it fell to Earth over Australia in 1979.

Dead satellites and old rocket stages regularly re-enter the atmosphere, but re-entering objects with masses of more than a few tons are rare.

There have been no reported human injuries or deaths from falling space junk. NASA in 2011 calculated a 1-in-3,200 chance of someone being hit by debris from the UARS satellite, which was less than one-third the mass of the Long March 5B core stage. A casualty risk estimate for the Long March 5B was not available.

In 2016, an upper stage from a Chinese Long March 7 rocket — about one-third the mass and size of the Long March 5B core stage — streaked through the atmosphere over the Western United States. The re-entry was captured on video.

The Long March 5B rocket body is mostly comprised of hollow propellant tanks, and much of the rocket’s structure is expected to burn up during re-entry. But some pieces, such as denser parts of the rocket’s two main engines, could survive the fall to Earth and hit the ground.

A Long March 5B rocket lifts off from the Wenchang launch center May 5. Credit: CASC
Space agencies, launch operators and satellite companies often try to guide spent rocket stages and aging satellites toward re-entries over the ocean, reducing the risk that debris could fall over a populated area.

In the case of the Long March 5B, the core stage delivered its payload — a prototype Chinese crew capsule — into a low-altitude orbit. The heavy-lift Long March 5B is designed to directly inject payloads into low Earth orbit without an upper stage, meaning the core stage also ends up in orbit, instead of immediately falling back to Earth in a predetermined downrange drop zone.

China plans to launch at least three more Long March 5B rockets in 2021 and 2022 with modules for the country’s planned space station, so more uncontrolled rocket re-entries are expected in the next couple of years.

After the Tiangong 1 space lab re-entered the atmosphere unguided in 2018, China performed a controlled de-orbit of the follow-on Tiangong 2 spacecraft in 2019.

The most massive human-made object to re-enter the atmosphere from orbit was Russia’s Mir space station, which made a guided re-entry over the South Pacific Ocean in 2001. NASA and Russia’s space agency have plans to eventually execute a controlled re-entry of the International Space Station at the end of its service life.


品葱用户 王莽谦恭未篡时 评论于 2020-05-11


品葱用户 M36 评论于 2020-05-11

墙国应该还沉浸在发射成功的喜悦中 没了美国芯片就是一堆废铜烂铁

品葱用户 Acca0429 评论于 2020-05-12


品葱用户 tommy_lee 评论于 2020-05-12


品葱用户 hun 评论于 2020-05-11



品葱用户 uckfU 评论于 2020-05-11

re-entry could occur as far north around New York City, or as far south as Wellington, New Zealand.—你肯定不是故意的?

品葱用户 三零一小护士 评论于 2020-05-11


品葱用户 Knightstone 评论于 2020-05-11

結果最終太空垃圾墜落到悉尼, 第二次不列顛作戰正式開始(゜皿。)

土共的國旗顏色是紅色的, 自護的國旗也是紅色的。 因此土共是自護說成立(゜皿。)

品葱用户 **Hermione

uckfU** 评论于 2020-05-11


re-entry could occur as far north around New York …



品葱用户 pcfun 评论于 2020-05-11


品葱用户 **北美carl

Knightstone** 评论于 2020-05-12


結果最終太空垃圾墜落到悉尼, 第二次不列顛作戰正式開始(゜皿。)土共的國旗顏色是紅色的, 自護的國旗…

血色5月 澳洲:怎么tm老是我

品葱用户 **隼龙

Knightstone** 评论于 2020-05-11


結果最終太空垃圾墜落到悉尼, 第二次不列顛作戰正式開始(゜皿。)土共的國旗顏色是紅色的, 自護的國旗…


品葱用户 xhblxyz081 评论于 2020-05-12


品葱用户 grantyang 评论于 2020-05-12


品葱用户 **油膩的天堂

hun** 评论于 2020-05-12




品葱用户 **三零一小护士

xhblxyz081** 评论于 2020-05-11




品葱用户 **hun

油膩的天堂** 评论于 2020-05-11



所以全世界的衛星監測一致注意著中國的破銅爛鐵在哪兒自由落體? XD

品葱用户 cjmtsi 评论于 2020-05-12


品葱用户 nmff 评论于 2020-05-11


品葱用户 我就獨 评论于 2020-05-11


品葱用户 **小嘴抹蜜刁包子

北美carl** 评论于 2020-05-12


品葱用户 **华国锋

我就獨** 评论于 2020-05-11





品葱用户 Childhoodagain 评论于 2020-05-12


品葱用户 **Knightstone

北美carl** 评论于 2020-05-12


血色5月 澳洲:怎么tm老是我


品葱用户 **北美carl

小嘴抹蜜刁包子** 评论于 2020-05-11




品葱用户 戈培爾同志 评论于 2020-05-11

随 机 杀 人

品葱用户 **PaperPlane

戈培爾同志** 评论于 2020-05-12


随 机 杀 人

](https://pincong.rocks/article/item_id-374311#https://pincong.rocks/article/item_id-374311#")無 差 別 襲 擊

品葱用户 staff 评论于 2020-05-11


品葱用户 hkgusa 评论于 2020-05-12

中國一不輸出革命 二不輸出貧窮 三不輸出難民
只是輸出一下病毒跟太空垃圾而己 還有什麼好說的

品葱用户 Arti000 评论于 2020-05-12


品葱用户 汉娜怎么说 评论于 2020-05-12


结果搜了下发现其实大部分都会在re-entry的时候烧掉。。。= =

品葱用户 **扛麥子高手

staff** 评论于 2020-05-12




品葱用户 ppp111 评论于 2020-05-12


品葱用户 **U檸三文魚

北美carl** 评论于 2020-05-11


血色5月 澳洲:怎么tm老是我


品葱用户 **Charlemagne

我就獨** 评论于 2020-05-12




品葱用户 待明之时 评论于 2020-05-11


品葱用户 担麦人吃包子 评论于 2020-05-11


品葱用户 en010272 评论于 2020-05-12


品葱用户 **hun

en010272** 评论于 2020-05-12





品葱用户 adblocker 评论于 2020-05-12

贵支务必自作自受 贵支务必自作自受 贵支务必自作自受 贵支务必自作自受

品葱用户 萌萌哒 评论于 2020-05-12


品葱用户 **Alleria

待明之时** 评论于 2020-05-12




根据CNN: 已经落在大西洋内。 轨迹飞过了 LA 和 NYC.

品葱用户 **Deatholder

Alleria** 评论于 2020-05-11


根据CNN: 已经落在大西洋内。 轨迹飞过了 LA 和 NYC.


品葱用户 **三零一小护士

Alleria** 评论于 2020-05-11


根据CNN: 已经落在大西洋内。 轨迹飞过了 LA 和 NYC.





品葱用户 雙加不好的鴨語者 评论于 2020-05-11


品葱用户 **Maru

三零一小护士** 评论于 2020-05-12





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