The danger of Chinese nuclear activity in space


The Chinese intent is to create a temporary cloud of radiation that could quickly damage or destroy a large number of Low Earth Orbit Satellites.

A recent article in the SCMP indicates that Chinese scientists are experimenting to detonate a 10 MT atomic warhead near the edge of space. Technically this area is widely known as near space. The Chinese intent is to create a temporary cloud of radiation that could quickly damage or destroy a large number of Low Earth Orbit Satellites.  There are many questions about this anti-satellite (ASAT) thought process even if it is practical. With increasing militarisation of space, such ideas, proposals and debates are dangerous. Such
maverick actions have serious ramifications beyond the normal and we need to understand them in detail to tackle them. The proposal is ostensibly to destroy satellites which are considered as threats to the PRC. This article talks of destroying Elon Musk’s Starlink constellations but such action could be easily applied against Indian and all other satellites too. In my opinion, even Chinese satellites are not exempt from being affected.

Atmosphere Layers Diagram

What is Near Space?

Near Space is that region of Earth’s atmosphere that extends from 20 to 100 km above sea level. It encompasses the stratosphere, mesosphere, and the lower thermosphere. It extends roughly from the Armstrong limit (above which humans need a pressure suit to survive) up to the Kármán line where Earth’s atmosphere ends and gravity is near zero. In simpler and understandable terms, near space is above heights where commercial airliners fly but below orbiting satellites. In technical terms, near space begins above the
internationally accepted ceiling of controlled airspace. The air becomes too thin above this for most air-breathing aircraft. Its upper limit ends where air friction becomes too strong for low earth satellites to maintain an orbit. Near space is also referred to as the Death Zone. It is the least explored and resultantly the least exploited zone of the Atmosphere. It is also largely an unknown zone and the Chinese want to carry out a nuclear blast there!

The High Altitude Burst : Non Kinetic Effect
As per the SCMP, the Chinese intend to detonate a 10-megaton warhead at an altitude of 80 km (50 miles) so as to pose a serious threat to satellites. In effect, this is a high altitude nuclear airburst in space and not in near space as reported. Hence the whole issue is being smoke screened and fishy. The last high altitude nuclear bursts were carried out in Nov 1962(by the USSR and USA). Earlier in Jul 62, a 1.45 MT high altitude burst was carried out at a height of 250 miles. The result was widespread. “Almost immediately, an electromagnetic pulse knocked out electrical service in Hawaii, nearly 1,000 miles away. Telephone service was disrupted, streetlights were down and burglar alarms were set off by a pulse that was much larger than scientists expected”. Many satellites were affected. In fact when the USSR carried out a similar test in Oct 62, similar effects were noticed. This was a time when most transistors were analog in nature.
The current Chinese intent is to carry out a 10 MT burst at 80 miles altitude. What will be the effect of a bomb 6-7 times of that carried out in 1962? The EMP from the bomb will knock out communications farther and wider. The effect will be far more disastrous in a world which is far more dependent on delicate digitalisation and semiconductor based electronic equipment being the norm for IT and communication networks. Next, most passenger aircraft cruise at about 12-15 km above earth. All these are likely to get affected resulting in the death of many innocent people  since the jet aircraft  controls will just go awry. Imagine the catastrophe. The Ozone layer could get affected. The disastrous effect of a hole in the ozone layer is known but remains
uncalibrated. The radiation and fallout effects of a 10 MT bomb from a 80 km airburst on the Ozone hole is a completely unknown quantity. Last but not least. Satellites in the near vicinity will get knocked out physically. Electronics of low earth satellites which are even far away from the place of burst will get simply fried out due to the EMP. Further all satellites which pass through this area (which will be huge one and difficult to avoid) will get affected. I simply fail to understand as to how the Chinese intend to safeguard their own satellite constellations from evading the large danger zones resulting from a 10 MT atomic blast.   

The SCMP has reported the team of Chinese scientists also reportedly concluded that the cloud would dissipate quickly, reducing the risk to satellites outside of those caught in the initial products of the blast. That is simply not true. In fact the International Space Station which is on a low earth orbit at about 260 miles above the earth could be affected. We are talking of a 10 MT bomb and not an unreliable Diwali Chinese firecracker!

The High Altitude Burst : Kinetic Effect

There are huge unintended kinetic outcomes in space. Currently there are more than 3500 LEO satellites of all varieties in orbit. This number is increasing by the day. They are all hurtling around in different orbits. Most LEO satellites orbit the earth at an average speed of 7.12 Km to 7.8 Km/ sec (28080 kmph) depending upon their altitude. That is a staggering speed. They could be at altitudes varying between 300-1500 km. Each of them circumvents the earth once in 90-120 mins. It means that a LEO satellite circumvents the earth 16-12
times a day depending upon the height at which it is placed.  In such a scenario, the 10 MT nuclear blast could have two effects. Firstly it could physically destroy a few satellites. Each satellite destroyed will form part of space debris. Each space debris particle, immaterial of its size, is thereafter hurtling uncontrolled, at a speed upward of 7 km /hr. It is a lethal object in space. It is said that the Chinese ASAT test of 2007 and the accidental collision of two satellites (Cosmos 2251 and Iridium 33) in 2009 ‘represent the worst satellite break ups in history’. The space junk created by them accounted for more than 1/3 rd of the catalogued satellites in LEO at that time. Imagine the chaos of space debris if multiple satellites or a constellation is knocked out due
to a nuclear blast in space. All remaining satellite systems including Chinese will be at risk for a long time. Why? There will be large cumulative collision risk of debris to other satellites well into the future. Which means apart from everything else, satellite based navigation and communications systems could go down any time and unpredictably. Why unpredictably? Lethal debris could be floating in an uncontrolled orbit in space for any length of time; even beyond a year to cause collisions unpredictably. At higher altitudes (say at
about 800 km),  the decay rates of debris will be low. Implying that a chance of space debris collision with a functional satellite is much higher (estimated at 10 times higher). This will affect airline operations, data networks, met systems and so on. In fact our day to day life which we have got used to, will be altered
forever. A space based nuclear blast  is like a blind shot on a snooker table after a couple of stiff drinks with the snooker balls never slowing down. The outcomes will be most unpredictable and bizarrely unthinkable. If one wants to have an idea of this chaos, all one must do is see the popular Hollywood movie “Gravity”.

The second effect is of those satellites which may not be physically destroyed. However, many of them will be decapitated and no longer controllable. Many of them would have been nudged away from their original course due to the blast effect. Which means we will truly have a set of uncontrolled snooker balls in space which are never going to slow down? These are in addition to the space debris created. It will be a total catastrophe. Just to highlight the issue.

When we conducted the ASAT test in 2019, there was a lot of hue and cry about space debris endangering the manned International Space Station(ISS). Most of it came from you know where? China! The same China
wants to conduct a nuclear test in space and endanger humanity as a whole!


One wonders at the real intent of the Chinese. Is it all part of their psychological ops or is it a real threat? In any case, it reinforces one issue. The Chinese cannot be trusted. Next. Do the Chinese know what they are doing at all? Such an article coming out in international media cannot be ignored. There must be a plan behind this story. So much power concentrated in one person, who in my opinion, is the most ambitious on earth today, is dangerous. If such a man has the power to destroy mankind to achieve his personal goals, he relegates Hitler to the side-lines. We are dealing with Xitler and we should have no doubt about it. He presented us with one pandemic and brought misery to earth. We might have to endure a pandemic of a different kind in future. We need to wake up and do something about him.

 Lt Gen P R Shankar (R)

The author is a retired Director General of Artillery. He is currently a Professor in the Aerospace Department of IIT Madras. He writes extensively on defence & strategic affairs