Something sinister is going on above our heads - several somethings, in fact.

Satellites are chasing each other. Secret spaceplanes are doing strange things. Dead objects are coming back to life.

A Russian “chaser” satellite has been sitting hot on the tail of a secret US military surveillance satellite since August, a Chinese spaceplane is shifting orbit with a strange ‘tethered’ device dangling behind it and a supposedly “dead” Saudi Arabian satellite has suddenly, without explanation, moved.

Why? Satellites have long been critical components for communications and surveillance.

But now, they’re everywhere – all the time. They’ve become essential to every aspect of modern-day life, from financial transactions to tracking submarines. That makes them targets.

A satellite image of the six reactors at the Zaporizhzhia Nuclear Power Plant in Russian-occupied Ukraine. Photo / Maxar Technologies via The New York Times

Space, however, isn’t like any other battlefield. The consequences of a single shot can echo through the centuries and several already are because the wreckage can cannon about in orbit, posing a threat to space travel for decades – and millennia – to come.

“Some space experts have called the war in Ukraine the first commercial space war,” says international affairs analyst Mariel Borowitz.

“The conflict has clearly shown the national security value of commercial satellite imagery, the ability of commercial satellite images to promote transparency and the importance of not only national space power, but also the space capabilities of allies.”

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Russia and China see such space-source material as a clear and present danger to their territorial ambitions and both have issued barely veiled threats that they are doing something about it.

Australia’s Defence Space Command (DSpC) is barely a year old but it’s already been – unintentionally – in the thick of the action.

In August, it participated in a global hook-up of civilian and military space awareness organisations to learn what this new theatre entails.

“As well as the simulated exercise, Russia launched a satellite during the exercise, in real-time,” DSpC participant Corporal Jackson Smart said shortly after the Sprint Advanced Concept Training exercise wrapped up.

The January 15 eruption at the underwater Hunga Tonga Hunga Ha'apai volcano - observed in this satellite image - was the largest in nearly 140 years. Photo / JMA

“We were able to plot the trajectory of the Russian launch using commercial sensors and quickly identify its initial orbit.”

It wasn’t just any satellite, Kosmos-2558 was on an orbital path tailing that of a US spy satellite (USA-326).

That hints it could be an “inspector” or an assassin - Russia is known to have both.

The only official comment relating to Kosmos-2558 has been by US Space Command’s General James Dickinson. He said its tailgating behaviour was “really irresponsible”.

Russia has previously tested “chaser” satellites that can pass close to an object of interest for detailed photographs and electronic emissions analysis. But it’s also deployed small satellites armed with projectiles.

In July 2020, Kosmos-2543 was also stalking a US spy satellite. As it passed close by, it reportedly deployed a sub-satellite that seemed to fire a single shot.

The projectile was not aimed at anything, raising speculation that it was an overt threat.

“It’s very worrying, and you can be sure the Pentagon is tracking Kosmos-2558 closely,” says Belgian satellite security expert Bart Hendrickx. “[Russian] seem to be waiting for the right moment to deploy that subsatellite. It hasn’t separated yet, but once it does, it could move next to the US satellite and do the unthinkable.”

Satellites in Low Earth Orbit (LEO) orbit as low as 160km. Bigger, more significant satellites, such as GPS beacons, have Geostationary Orbits some 36,000km high.

An artist's impression of Starlink satellites in low Earth orbit. Image / Space X

Neither is easy to observe clearly from the ground and that makes it easy for satellites, and even rocket debris, to be more than they seem.

Others, reported to have passed their expiry dates, can remain very much alive, even unintentionally.

Hackers revived a decommissioned Canadian telecommunications satellite annual Def Con hacker convention in August. Using roughly $500 of commercially available equipment, Karl Kosher revived it to broadcast live streams of the event worldwide.

Other unusual activity doesn’t have such an innocent explanation.

In September, a supposedly dead Saudi-owned communications satellite suddenly moved. ARABSAT 1A (15560) is now on a course that will pass through a densely populated patch of Geostationary Orbit.

It wasn’t supposed to have thrusters but this cannot be confirmed and it doesn’t appear to have been hit by debris but many are too small to track.

It could have been the accidental venting of a storage tank. But there is no way of checking.

Satellites can be moved and it’s getting easier to do so. It used to be very expensive and rare to fit chemical manoeuvring thrusters. But new technology, such as Australia’s Neumann Space’s metal-fuelled drive, has dramatically slashed their size and cost.

A Rocket Lab Electron rocket takes off from the launch pad at the launch of the NASA Capstone lunar-orbiting satellite from the Wairoa Peninsula. Photo / Supplied, File

Others are pursuing the idea of “space tugs” to clean up – and recycle – space junk.

In January, China’s Shijian-21 space tug “towed” a defunct Chinese communications satellite out of its valuable Geostationary Orbit and into a deeper orbital “graveyard”.

But such a space tug can’t be stopped from interfering with vital infrastructure.

Both China and the United States are operating robotic spaceplanes, similar to the old Space Shuttle in looks and capabilities but not size.

Their cargo bays make them immensely flexible. Their thrusters give them the ability to move about in orbit. Their wings and heat-shield tiles allow them to return to Earth.

China’s second “reusable experimental spacecraft” launch was from the Gobi Desert on August 4. It’s since “flown” to a 608km high orbit.

Then, in late October, civilian and military ground-based sensors saw the spacecraft (NORAD ID 53357) had a companion. This is now sitting in space just 200m away.

But China’s not the only one doing mysterious things in orbit with its robot spaceplanes.

The Boeing X-37 has been operational for a dozen years although much of what it has been doing has not been disclosed. Photo / Nasa Press Centre

Boeing’s X-37 has been operational since 2010 and its latest secret mission has lasted more than 900 days in orbit. One of its four mission payloads is a NASA experiment looking at the effects of space radiation on seeds. The remainder is top secret.

“The fact that most space assets are dual-purpose and owned and operated by civilians and military alike highlights that it’s virtually impossible to separate the two uses,” argues Royal Australian Air Force Wing Commander Ulas Yildirim.

“This is because the security and prosperity of the state and its people are not mutually exclusive.”

As the access to space gets easier, and new technologies introduce new capabilities, orbital confrontations will continue to rise.

Space News reported in June that two Chinese companion satellites, Shiyan-12-01 and Shiyan-12-02, were approached by a US surveillance satellite. The two craft quickly separated – but not before one manoeuvred into an ideal position for close-up photos of its pursuer.

“The laws of armed conflict for the terrestrial domains evolved over many centuries, but that’s a luxury we don’t have in developing equivalent frameworks for space,” says Yildirim. “Settling these issues will remove any ambiguities on the role of defence space organisations upfront. And it will allow the argument to be framed by what nations seek to achieve rather than the means available to do so.”

Nuclear weapons in orbit are a real threat. The flash of electromagnetic radiation (EMP) can fry electronics on the ground but it can do the same in space.

China thinks this may be an answer to the constellations of small, cheap satellites now swarming across the skies.

A People’s Liberation Army study published in May identified SpaceX and its Starlink communications constellation as a threat. It has been crucial for Ukrainian soldiers to bypass Russia’s efforts to jam and destroy ground-based phone and radio networks.

The US had been discussing payments with Starlink to ensure connectivity for Ukrainian forces. Photo / Supplied

So China has simulated the effects of a near-space nuclear blast.

The Northwest Institute of Nuclear Technology calculated the impact of a 10-megaton explosion at an altitude of 80km. It found a cloud of radioactive atmospheric particles would balloon up to 500km high and cover a 140,000sq/km area.

“The strong residual radiation of the debris cloud may cause failures of spacecraft moving in it, such as satellites, or even cause direct damage that can lead to destruction,” the study reportedly reads.

“Due to the high concentration of fission products inside the debris cloud, the released gamma rays and beta particles are strong, making their effects on spacecraft and communications within the affected area stronger.”

While space conflict remains, for the moment, in the realm of spying, hacking and jamming, kinetic conflict is a real possibility.

“If competition continues, it is not inconceivable that it could lead to conflict,” warns Kings College London defence studies expert Mark Hilborne.

Especially over Ukraine.

“While the use of kinetic weapons, which destroy satellites by running into them at high speeds and which Russia tested recently, seems unthinkable, we cannot be sure what Putin will do next,” he adds.

It’s a threat recognised by Australia’s embryonic Space Command.

At the foundation of the command earlier this year, Air Vice-Marshal Catherine Roberts said Chinese and Russian space activities were her greatest concern. And establishing the ability to track, monitor and observe what’s going on over our heads is crucial.

“I think the activities by China and Russia, which have been fairly well documented in the public domain, scare me,” Air Vice-Marshal Roberts said. “We need to accelerate the capabilities so we can deal with the threats.”

- Jamie Seidel, news.com.au