- 注册
- 2005-12-07
- 消息
- 21,734
- 荣誉分数
- 5,834
- 声望点数
- 373
这是个大新闻。 证明中国已经具备轨道无人维护和清理太空目标的能力。 这就是太空战的能力。
- SJ-21 有迅速转移能力，观察网确认此卫星失踪几个小时
- 用机械装置捕获失效北斗卫星，脱离原来轨道，拖着北斗卫星去几百公里外的轨道，
- 然后SJ-21释放北北卫星到安眠轨道后又准确回到SJ-21原有轨道。
中国以往的宣传很含糊，并有很夸张的模拟视频用网捕获，但美国观察的结果是用机器手控制。这难度比网兜捕获又上了一个台阶，美国民间太空检测网呼吁美国，俄罗斯和中国应该谈判制定未来太空物体靠近或规避国际协议
breakingdefense.com
A virtual dashboard created in partnership by CSIS, the Secure World Foundation and the University of Texas at Austin allows users to track real-time and predicted movements of satellites and space junk. (Screengrab satellitedashboard.org)
Updated Jan. 26, 2022 at 5:00 pm ET to include latest tracking data showing the coupled SJ-21 and Compass G2 separating.
WASHINGTON: China’s SJ-21 satellite now “appears to be functioning as a space tug,” pulling a dead CompassG2, or Beidou, navigation satellite out of the way of other satellites operating in the heavily populated Geosynchronous Orbit, according to a new analysis by commercial space monitoring firm ExoAnalytic Solutions.
The observations were reported today by Brien Flewelling, who serves as the firm’s chief architect for space situational awareness (SSA), during a webinar hosted by the Center for Strategic and International Studies (CSIS) and Secure World Foundation (SWF).
According to Flewelling’s video presentation, the SJ-21 on Jan. 22 went “missing” from its orbital slot for a few hours, after performing what are known as “close proximity operations,” moving closer and closer around the Compass G2. The “gap” in observations was caused by the fact that when it then docked with the defunct satellite, it was daytime — when telescopes cannot image. ExoAnalytics tracked it down after it had subsequently performed “a large maneuver” pulling the dead satellite out of GEO.
“We continue to track SJ-21 and monitor it for conjunctions with all known space objects. The ability to maintain custody of SJ-21 after this large daytime maneuver is an important and unique capability of Exo’s commercial SSA network,” the video reported.
Space Command, which via the 18th Space Control Squadron monitors space objects, did not respond to a request for comment by press time.
The SJ-21 is the same satellite that this past November caused a bit of a kerfuffle when the 18th Space Squadron reported that it was moving around either a sub-satellite or its kick motor (AKM) in a way that suggested Beijing was testing how to spoof space monitoring networks.
AIR WARFARE, SPONSORED
From BREAKING DEFENSE
EXCLUSIVE: US, China, Russia sats buzzing, spoofing, spying on each other
The Chinese satellite’s maneuvers are consistent with the capabilities needed to conduct On-Orbit Servicing, Assembly, and Manufacturing (OSAM) — capabilities that the US and Europe also are pursuing.
Beijing has a national goal to develop OSAM capabilities, according to a Dec. 13, 2021, study by Air University’s China Aerospace Studies Institute.
“An investigation into China’s stated OSAM goals and activities helps contextualize SJ-21 as a satellite to further test on-orbit debris mitigation technologies. On-orbit services to mitigate debris come in many forms, such as through refueling or relocation, and could eventually support a range of customers, including Chinese military, government and emerging commercial players, which would be consistent with OSAM activities globally,” wrote author Kristin Burke.
Recommended
By THERESA HITCHENS and JASPREET GILL
Led by NASA, the Trump administration in November 2020 launched a US national OSAM initiative, and since then the Defense Department has been pursuing a number of technology development projects.
In particular, the Air Force Research Laboratory is working closely with Northrop Grumman subsidiary SpaceLogistics on research projects designed to build OSAM capabilities. SpaceLogistics in April 2021 successfully docked its second Mission Extension Vehicle (MEV) with an Intelsat satellite to provide extra power to keep the communications satellite functional.
However, the SJ-21’s current orbit is “unusual” if the aim is to dispose of the defunct Compass G2 in what is known as the “graveyard” orbit, said Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics who keeps tabs on satellites. The Chinese satellite’s orbit is highly elliptical, he said, ranging from 36,076 km in altitude to 38,886 km, “so 290 x 3,100 km above GEO.”
Graveyard orbit is usually defined as 300 kilometers above GEO, which is at about 36,000 km.
“Usually GEO graveyard raising is done more symmetrically,” McDowell explained.
In an email to Breaking Defense this afternoon, Flewelling said the latest tracking data gathered earlier today from ExoAnalytic’s telescopes show the SJ-21 separating from the Compass G2, leaving the latter in the eccentric “super-graveyard drift orbit.” SJ-21 now has moved back to a near-GEO orbit.
Todd Harrison, director of CSIS’s Aerospace Project, told Breaking Defense that SJ-21’s movements have prompted “more questions than answers.”
“What we know for sure is what we can observe by its actions in space — the intent behind it and what China plans to do with this technology is a more subjective assessment,” he said.
He added that the Chinese sat “clearly is capable of close proximity operations, docking, and maneuver, much like Northrop’s MEV satellites. Beyond that, we will have to wait and see how they continue to use this satellite and others that come after it.”
Aaron Bateman, a former Air Force intelligence officer now at John Hopkins University, said that it is high time for nations to improve transparency about such satellite maneuvers.
“This is more evidence that there needs to be a greater effort to establish confidence-building measures for space, with a special focus on GEO,” he told Breaking Defense. “Now is the time for the US to work with China, Russia, and other countries to establish norms of behavior aimed at reducing the risk of escalation due to uncoordinated and unannounced close approaches in the GEO belt.”
With the aim of spurring improved transparency about close approaches on orbit, CSIS, the Secure World Foundation and the University of Texas at Austin today launched a new web-based project to track real-time and predicted movements of satellites and space junk.
“The Satellite Dashboard is a web-based tool that will collate and analyze” SSA data and “present it in an accessible format, while also providing a queuing function for further technical analysis,” the new website explains. The site “collates data from multiple sources, including publicly-available data provided by the U.S. military, commercial SSA providers, and data provided by international, scientific, and academic sources.”
- SJ-21 有迅速转移能力，观察网确认此卫星失踪几个小时
- 用机械装置捕获失效北斗卫星，脱离原来轨道，拖着北斗卫星去几百公里外的轨道，
- 然后SJ-21释放北北卫星到安眠轨道后又准确回到SJ-21原有轨道。
中国以往的宣传很含糊，并有很夸张的模拟视频用网捕获，但美国观察的结果是用机器手控制。这难度比网兜捕获又上了一个台阶，美国民间太空检测网呼吁美国，俄罗斯和中国应该谈判制定未来太空物体靠近或规避国际协议
China's SJ-21 'tugs' dead satellite out of GEO belt: Trackers - Breaking Defense
"I think there are more questions than answers right now when it comes to SJ-21," Todd Harrison, director of CSIS's Aerospace Project, told Breaking Defense.
China’s SJ-21 ‘tugs’ dead satellite out of GEO belt: Trackers
"I think there are more questions than answers right now when it comes to SJ-21," Todd Harrison, director of CSIS's Aerospace Project, told Breaking Defense.
By THERESA HITCHENSon January 26, 2022 at 3:26 PM
A virtual dashboard created in partnership by CSIS, the Secure World Foundation and the University of Texas at Austin allows users to track real-time and predicted movements of satellites and space junk. (Screengrab satellitedashboard.org)
Updated Jan. 26, 2022 at 5:00 pm ET to include latest tracking data showing the coupled SJ-21 and Compass G2 separating.
WASHINGTON: China’s SJ-21 satellite now “appears to be functioning as a space tug,” pulling a dead CompassG2, or Beidou, navigation satellite out of the way of other satellites operating in the heavily populated Geosynchronous Orbit, according to a new analysis by commercial space monitoring firm ExoAnalytic Solutions.
The observations were reported today by Brien Flewelling, who serves as the firm’s chief architect for space situational awareness (SSA), during a webinar hosted by the Center for Strategic and International Studies (CSIS) and Secure World Foundation (SWF).
According to Flewelling’s video presentation, the SJ-21 on Jan. 22 went “missing” from its orbital slot for a few hours, after performing what are known as “close proximity operations,” moving closer and closer around the Compass G2. The “gap” in observations was caused by the fact that when it then docked with the defunct satellite, it was daytime — when telescopes cannot image. ExoAnalytics tracked it down after it had subsequently performed “a large maneuver” pulling the dead satellite out of GEO.
“We continue to track SJ-21 and monitor it for conjunctions with all known space objects. The ability to maintain custody of SJ-21 after this large daytime maneuver is an important and unique capability of Exo’s commercial SSA network,” the video reported.
Space Command, which via the 18th Space Control Squadron monitors space objects, did not respond to a request for comment by press time.
The SJ-21 is the same satellite that this past November caused a bit of a kerfuffle when the 18th Space Squadron reported that it was moving around either a sub-satellite or its kick motor (AKM) in a way that suggested Beijing was testing how to spoof space monitoring networks.
AIR WARFARE, SPONSORED
Game Changer: The key to Army FVL weapons-systems development is modular open systems
Bell’s methodology to meet the Army’s Modular Open Systems Approach requirement is enabled by a common digital backbone that will be instantiated on both the V-280 Valor for FLRAA and the Bell 360 Invictus for FARA.From BREAKING DEFENSE
EXCLUSIVE: US, China, Russia sats buzzing, spoofing, spying on each other
The Chinese satellite’s maneuvers are consistent with the capabilities needed to conduct On-Orbit Servicing, Assembly, and Manufacturing (OSAM) — capabilities that the US and Europe also are pursuing.
Beijing has a national goal to develop OSAM capabilities, according to a Dec. 13, 2021, study by Air University’s China Aerospace Studies Institute.
“An investigation into China’s stated OSAM goals and activities helps contextualize SJ-21 as a satellite to further test on-orbit debris mitigation technologies. On-orbit services to mitigate debris come in many forms, such as through refueling or relocation, and could eventually support a range of customers, including Chinese military, government and emerging commercial players, which would be consistent with OSAM activities globally,” wrote author Kristin Burke.
Recommended
DARPA’s ‘ROCkN’ laser-based clocks will know what time it really is, to the sub-picosecond
Optical clocks in labs today “fill out a huge room, a big room with a very complex, very sophisticated apparatus that takes multiple PhDs to run,” Tatjana Curcic, who manages DARPA’s Robust Optical Clock Network project, told Breaking Defense.By THERESA HITCHENS and JASPREET GILL
Led by NASA, the Trump administration in November 2020 launched a US national OSAM initiative, and since then the Defense Department has been pursuing a number of technology development projects.
In particular, the Air Force Research Laboratory is working closely with Northrop Grumman subsidiary SpaceLogistics on research projects designed to build OSAM capabilities. SpaceLogistics in April 2021 successfully docked its second Mission Extension Vehicle (MEV) with an Intelsat satellite to provide extra power to keep the communications satellite functional.
However, the SJ-21’s current orbit is “unusual” if the aim is to dispose of the defunct Compass G2 in what is known as the “graveyard” orbit, said Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics who keeps tabs on satellites. The Chinese satellite’s orbit is highly elliptical, he said, ranging from 36,076 km in altitude to 38,886 km, “so 290 x 3,100 km above GEO.”
Graveyard orbit is usually defined as 300 kilometers above GEO, which is at about 36,000 km.
“Usually GEO graveyard raising is done more symmetrically,” McDowell explained.
In an email to Breaking Defense this afternoon, Flewelling said the latest tracking data gathered earlier today from ExoAnalytic’s telescopes show the SJ-21 separating from the Compass G2, leaving the latter in the eccentric “super-graveyard drift orbit.” SJ-21 now has moved back to a near-GEO orbit.
Todd Harrison, director of CSIS’s Aerospace Project, told Breaking Defense that SJ-21’s movements have prompted “more questions than answers.”
“What we know for sure is what we can observe by its actions in space — the intent behind it and what China plans to do with this technology is a more subjective assessment,” he said.
He added that the Chinese sat “clearly is capable of close proximity operations, docking, and maneuver, much like Northrop’s MEV satellites. Beyond that, we will have to wait and see how they continue to use this satellite and others that come after it.”
Aaron Bateman, a former Air Force intelligence officer now at John Hopkins University, said that it is high time for nations to improve transparency about such satellite maneuvers.
“This is more evidence that there needs to be a greater effort to establish confidence-building measures for space, with a special focus on GEO,” he told Breaking Defense. “Now is the time for the US to work with China, Russia, and other countries to establish norms of behavior aimed at reducing the risk of escalation due to uncoordinated and unannounced close approaches in the GEO belt.”
With the aim of spurring improved transparency about close approaches on orbit, CSIS, the Secure World Foundation and the University of Texas at Austin today launched a new web-based project to track real-time and predicted movements of satellites and space junk.
“The Satellite Dashboard is a web-based tool that will collate and analyze” SSA data and “present it in an accessible format, while also providing a queuing function for further technical analysis,” the new website explains. The site “collates data from multiple sources, including publicly-available data provided by the U.S. military, commercial SSA providers, and data provided by international, scientific, and academic sources.”
