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China’s satellites may have pulled off world’s first in-orbit fuel refill, beating US
Interesting Engineering ^ | July 14, 2025 | Chris Young

Posted on 07/15/2025 9:12:13 AM PDT by Red Badger

US-based COMSPOC and Swiss firm s2a systems tracked close proximity maneuvers between Shijian-21 and Shijian-25 from June to early July.

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China has reportedly performed a historic refueling mission in Earth’s orbit.

During the mission, two Chinese satellites appear to have docked in geostationary orbit, a report from the South China Morning Post reveals. One then refueled the other, marking an impressive milestone that no other nation has achieved.

While China’s space administration has not officially confirmed the operation was a success, a US space observation company observed the two satellites coming together.

Refueling technologies are a key evolution for orbital operations as well as human spaceflight. As crewed rockets use most of their fuel to reach orbit, these complex operations will be required to power these spacecraft out into deep space.

Shijan-21 and Shijan-25’s refueling operation

Between July 2 and July 6, China’s Shijian-21 and Shijian-25 satellites “appeared visually merged in optical sensor data”, US situational awareness software provider COMSPOC explained in a social media post.

“Given the prolonged RPO time, SJ-21 and SJ-25 may have docked,” it said, using the acronym for “rendezvous and proximity operations”.

Throughout June and July, COMSPOC observed the two satellites performing several close approaches in geosynchronous orbit. The first of these occurred on June 13, when Shijan-25 and Shijan-21 came with 1 km (0-6 miles) of each other after starting their close approach on June. They stayed in that position for roughly 90 minutes.

During the maneuver, two US surveillance satellites, USA 270 and USA 271, were positioned on either side of the Chinese satellites.

The two Chinese satellites performed another close-proximity operation on June 30, according to optical tracking images from Swiss space surveillance firm s2a systems. Both satellites were orbiting at an altitude of 35,786km (22,236 miles) above the equator at the time.

“After a day with small but relatively constant distance yesterday, the two objects came closer again today and can no longer be separated by our instrument since about 11:00 UTC (7pm Beijing time),” s2a systems said on July 2.

The importance of orbital refueling

Shijan-25 was launched in January this year, while Shijian-21 has been in space since 2021. The Shanghai Academy of Spaceflight Technology designed Shijan-25 satellites to test on-orbit refueling capabilities as well as operations that could extend a satellite’s life span.

In 2022, Shijan-21 was involved in a complex orbital operation. That year, the satellite docked with Beidou-2 G2, a defunct Chinese navigation satellite. Shijan-21 then towed the satellite to a “graveyard orbit” above GEO. The satellite used up most of its fuel in that operation. Now, it has reportedly been refueled by Shijan-25 in a historic world first.

The world’s leading space powers see in-orbit refueling is a key technology, crucial for future orbital operations as well as human space travel. The technology is a cornerstone of SpaceX and the US’ Starship program, which eventually aims to send humans to Mars. To fly humans to the Red Planet, a crewed Starship rocket will have to refuel in orbit to carry enough fuel for the long journey.


TOPICS: Astronomy; Military/Veterans; Science; Travel
KEYWORDS: ccp; china; comspoc; s2asystems; shijan21; shijan25
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1 posted on 07/15/2025 9:12:13 AM PDT by Red Badger
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To: 04-Bravo; 1FASTGLOCK45; 1stFreedom; 2ndDivisionVet; 2sheds; 60Gunner; 6AL-4V; A.A. Cunningham; ...

PING!......................


2 posted on 07/15/2025 9:12:58 AM PDT by Red Badger (Homeless veterans camp in the streets while illegals are put up in 5 Star hotels....................)
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To: Red Badger
Whooptie do! Katie bar the door! Chinamen refill rice bins on their hoopty satellite.

3 posted on 07/15/2025 9:14:39 AM PDT by Governor Dinwiddie ( O give thanks unto the Lord, for He is gracious, and his mercy endures forever. — Psalm 106)
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To: Red Badger

Yeah, but do the Muslim residents of China feel valued by their space agency? That’s what’s important.


4 posted on 07/15/2025 9:15:40 AM PDT by redangus ( )
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To: All

The article misses the most important point.

The lifetime of satellites, particularly recon satellites, is determined NOT buy solar panel degradation or even gamma particle impacts on memory.

Rather, it is fuel for the attitude thrusters. They correct for gravity (lunar) perturbations and solar wind perturbations. This is what keeps the cameras precisely pointed.

If you can refuel the thrusters in space, that is one hell of a lot of launch requirement for replacements that reduces.


5 posted on 07/15/2025 9:19:31 AM PDT by Owen
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To: Governor Dinwiddie

This is actually just as important to future combat as aerial refueling is to modern air combat. A surveillance satellite that can be autonomously refueled can be retasked and moved far more frequently, without having an hard per-unit limit on how many moves it can make.

A *combat* satellite could be reloaded and resupplied by almost the same method.


6 posted on 07/15/2025 9:23:16 AM PDT by Spktyr (Overwhelmingly superior firepower and the willingness to use it is the only proven peace solution.)
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To: Red Badger

How long has NASA been in existence, since the late 1950s? Just goes to show NASA isn’t about space anymore.


7 posted on 07/15/2025 9:25:00 AM PDT by DownInFlames (P)
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To: Red Badger

I’ll worry when the Chinese figure out how to give out Green Stamps when refueling….. 😂😂😂😂


8 posted on 07/15/2025 9:29:10 AM PDT by Lockbox (politicians, they all seemed like game show host to me.... Sting)
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To: Spktyr
Got it! Thanks for the explanation. I guess I'm jaded from growing up with all the Russian cold war
propaganda. "TASS has revealed that the Soviets have launched an ant into orbit around Planet X …
yadda yadda."
I'm still mad at the commies for letting Laika die.


9 posted on 07/15/2025 9:31:15 AM PDT by Governor Dinwiddie ( O give thanks unto the Lord, for He is gracious, and his mercy endures forever. — Psalm 106)
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To: Spktyr; MtnClimber; Red Badger; SunkenCiv

Future combat in space. And present combat in space too - since one of two satellites was designed and built and then launched 5 years ago.

But.

A stable, close robot-controlled remote rendezvous is necessary for refueling rendezvous and hookup, but is not necessarily a successful refueling. Yet.


10 posted on 07/15/2025 9:31:17 AM PDT by Robert A Cook PE (Method, motive, and opportunity: No morals, shear madness and hatred by those who cheat.)
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To: DownInFlames

It is hard to believe NASA does not have this capability already.

Any experts here that can confirm one way or the other?


11 posted on 07/15/2025 9:32:59 AM PDT by cgbg (It was not us. It was them--all along.)
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To: Red Badger

Well, NASA has been real good at not getting much done lately.


12 posted on 07/15/2025 9:33:03 AM PDT by rktman (Destroy America from within? Check! WTH? Enlisted USN 1967 to end up with this💩? 🚫💉! 🇮🇱👍!)
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To: DownInFlames

NASA *might* not trumpet such a capability. But the USAF, which has it’s own separate space program, would definitely classify any such re-fueling missions. Look at how long the X-37B has been flying long-duration missions? The USAF still has not clarified what that unmanned spacecraft does.


13 posted on 07/15/2025 9:33:30 AM PDT by Tallguy
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To: Lockbox

OMG loved doing those books and going to that funny store


14 posted on 07/15/2025 9:34:37 AM PDT by al baby (Whoopie Cushion Goldberg )
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To: Owen; cgbg
The article misses the most important point.

Yes it does, but its not what you wrote.

Being able to conduct RPO (rendezvous and prox ops) and docking is a required skill if you want to go up and do mischievous activities to other nations assets.

Most satellites have design life between 5 and 15 years and the fuel to do that, for the most part, is not a large mass issue. This is certainly the case in GEO. And most satellites would be obsolete 15 years after launch, which means 18-20 years after design and hardware build. The refueling case is largely an outlier.

15 posted on 07/15/2025 9:40:48 AM PDT by Magnum44 (...against all enemies, foreign and domestic... )
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To: All

Ban red China from American universities


16 posted on 07/15/2025 9:54:55 AM PDT by escapefromboston (Peace, commerce and honest friendship with all nations, entangling alliances with none.)
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To: Tallguy

I was just thinking about the x-37b. I haven’t heard anything about it for quite a while.


17 posted on 07/15/2025 9:55:42 AM PDT by Pocketdoor
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To: Red Badger

The Boeing X-37 only does propaganda and never is used for anything useful - or so China would like everyone to believe. No one in the USAF would even dream of refueling US spy satellites!

Refueling satellites is a far cry from refueling an orbiting rocket.


18 posted on 07/15/2025 9:56:46 AM PDT by PIF (They came for me and mine ... now its your turn)
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To: Red Badger

I wonder what that little space shuttle thing we have has been doing in orbit. I would not be shocked to hear it was a little satellite gas station.


19 posted on 07/15/2025 9:58:10 AM PDT by Vermont Lt
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To: DownInFlames

NASA is not tasked with such operations - it would be a DIA, DOD etc task.


20 posted on 07/15/2025 9:58:25 AM PDT by PIF (They came for me and mine ... now its your turn)
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