Humanity Creates a Cloud of Space Garbage, Again

With the destruction of the Microsat-R reconnaissance satellite on March 27th, India became the fourth country in history to successfully hit an orbiting satellite with a surface-launched weapon. While Microsat-R was indeed a military satellite, there was no hostile intent; the spacecraft was one of India’s own, launched earlier in the year. This follows the examples of previous anti-satellite (ASAT) weapons tests performed by the United States, Russia, and China, all of which targeted domestic spacecraft.

Yet despite the long history of ASAT weapon development among space-fairing nations, India’s recent test has come under considerable scrutiny. Historically, the peak of such testing was during the 1970’s as part of the Cold War rivalry between the United States and then Soviet Union. Humanity’s utilization of space in that era was limited, and the clouds of debris created by the destruction of the target spacecraft were of limited consequence. But today, with a permanently manned outpost in low Earth orbit and rapid commercial launches, space is simply too congested to risk similar experiments. The international community has strongly condemned the recent test as irresponsible.

For their part, India believes they have the right to develop their own defensive capabilities as other nations have before them, especially in light of their increasingly active space program. Prime Minister Narendra Modi released a statement reiterating that the test was not meant to be a provocative act:

Today’s anti-satellite missile will give a new strength to the country in terms of India’s security and a vision of developed journey. I want to assure the world today that it was not directed against anybody.

India has always been against arms race in space and there has been no change in this policy. This test of today does not violate any kind of international law or treaty agreements. We want to use modern technology for the protection and welfare of 130 million [1.3 Billion] citizens of the country.

Further, the Indian Space Research Organisation (ISRO) rejects claims that the test caused any serious danger to other spacecraft. They maintain that the test was carefully orchestrated to that any debris created would renter the Earth’s atmosphere within a matter of months; an assertion that’s been met with criticism by NASA.

So was the Indian ASAT test, known as Mission Shakti, really a danger to international space interests? How does it differ from the earlier tests carried out by other countries? Perhaps most importantly, why do we seem so fascinated with blowing stuff up in space?

Learning from the 2007 Chinese Anti-Satellite Test

In 2007, China tested an ASAT missile against one of their own weather satellites in a polar orbit at an altitude of approximately 865 kilometers. It was the first time a satellite had been destroyed in orbit since 1985, and to this day represents the largest debris cloud ever created in space. More than 2,000 objects large enough to be tracked by ground radar were created in the impact, in addition to potentially hundreds of thousands of smaller particles which can’t be detected.

Model of satellite destroyed in 2007. Image credit Jakub Hałun.

Due to the high altitude of the impact, the debris field from the Chinese satellite will remain a hazard to navigation for years to come. With little atmospheric drag to slow them down, it’s estimated that some of the smaller pieces might not burn up for centuries. According to a report released by NASA, even relatively large pieces are estimated to remain in orbit until at least 2035. As recently as April 2011, debris from that 2007 ASAT test passed within 6 km of the International Space Station.

So how does this compare to the recent Indian ASAT test? Both weapons used what’s known as a “kinetic kill vehicle”, which is to say that the missile had no explosive payload. Much like the hypersonic weapon systems currently in development, the energy released upon impact is itself enough to destroy or disable the target. Indian authorities were quick to point out that such a weapon theoretically results in a smaller and denser debris cloud than would be created by an explosive warhead, though that came as little consolation during the Chinese test.

The biggest difference between the two events is the altitude at which the target was destroyed. Two weeks ago Microsat-R was flying at only 270 km when the impact occurred, putting the debris cloud fairly low within the Earth’s thermosphere. Objects orbiting within this regime will begin to slow down and lose altitude quickly, burning up once they hit the thicker parts of the atmosphere. Depending on how large the individual pieces are, they should completely burn up within weeks to months. Between the short time the debris will remain in orbit and their relatively low altitude (for comparison, the ISS orbits at an average of 400 km), ISRO officials say the cloud should pose little risk to other spacecraft.

High Flying Fragments

NASA agrees with the IRSOs assessment that the destruction of Microsat-R has resulted in far fewer debris than the 2007 Chinese test. Current estimates from the agency show the impact created around 400 objects which could pose a danger to other spacecraft, with as many as 60 of them large enough to track with radar. They also acknowledge that the majority of these pieces are in a low enough orbit that they should burn up in the near future. But recent statements from NASA Administrator Jim Bridenstine indicate the agency believes these facts don’t completely preclude the possibility of fragments being ejected into a higher orbit.

The issue is perhaps best understood through an animation produced by Analytical Graphics, which illustrates the moment of impact and the resulting debris cloud based on standard breakup model simulations used by the ESA and NASA:

While the majority of debris remain more or less on Microsat-R’s original orbit, some are blown farther out into space. The higher orbit of these fragments not only means they’ll remain in space longer than the ISRO’s estimates, but that they could pose an impact risk for the International Space Station. Administrator Bridenstine stopped short of saying the Station needed to perform any evasive maneuvers, only that the agency determined there was an elevated risk of impact for the two weeks following the satellite’s destruction.

Low Orbit Saber Rattling

India’s ASAT missile

As is often the case, the truth in this matter is likely somewhere in the middle. ISRO’s claim that the destruction of Microsat-R posed no danger to other spacecraft is likely reductive, but at the same time, Administrator Bridenstine’s description of the test as a “terrible thing” is obvious hyperbole. If there was even a chance that the debris posed a credible threat to the International Space Station or the crew members aboard it, evasive maneuvers would have been performed as a matter of course.

It’s unlikely Mission Shakti will have any long term effects on other craft in Earth orbit, and it’s even less likely there will be any punitive measures against India for carrying it out. History is full of nations scrambling to show each other they are on equal technological footing, and the development and successful deployment of an ASAT weapon is a milestone to strive for. India’s test was not in violation of any international law, and was less invasive than previous tests carried out by other countries. Aside from the fact they didn’t notify other countries before launching the weapon, India carried out Mission Shakti in about as responsible a manner as possible.

In the end, the chances of any nation actually shooting down a rival’s satellite is slim to none. The concept of mutually assured destruction (MAD) kept the nuclear weapons in their silos during the Cold War, and the same idea applies here. Shoot down their satellite, and you’re likely endangering one of your own. Make a habit of it, and pretty soon there’s no safe orbits left.

The true purpose of tests such as these is to demonstrate to the world that your country has the ability to destroy fast moving objects traveling at extreme altitudes. Landing a direct hit on an old weather or reconnaissance satellite is the least provocative way to indicate your country can defend itself against incoming ballistic missiles should the need ever arise. It’s an ability all countries hope they will never have to put into practice.

75 thoughts on “Humanity Creates a Cloud of Space Garbage, Again

  1. Destroying one satellite in predictable orbit and destroying hundreds of ICBMs and decoys on a short notice are completely different things.

    Let us hope that nobody is ever crazy enough to press the red button and thinks he or she can escape the consequences.

    Peace on Earth should be guaranteed even (and especially for) nations that don’t have advanced nuclear weapons. Otherwise, everyone is scrambling to get nukes. This is why attacking small countries under bogus pretexts was, and is, such an incredibly st.pid idea.

      1. This is usually based on a misconception of how ridonkulously big Earth orbit is, often accompanied by a graphic showing what all the man-made satellites would look like if they were each the size of Delaware. That looks pretty bad. You’ve all seen that graphic I’m sure. But technically it might be feasible in the future. It’s not gonna happen anytime soon, we have orders of magnitude too few bits of stuff up there to spark a Kessler syndrome. But maybe eventually…

        Fifty bucks says it happens the day we realize we’re way far past the point of no return on Global Warming and need to build a space colony ASAP. That’ll be the ideal moment.

        1. Here’s my naive comment by a non-scientist:
          Possibly putting “space junk” in a semi-permanent orbit that reduces the Sun rays hitting the Earth, if well planned, would be a good way to reduce global warming. I bet NASA is thinking about this.

    1. Oh yeah, any Star Wars concept of ICBM defense is total fantasy. We are still aaaages away from effective nuclear defense, nobody should ever be fooled by these little concepts and publicity stunts into thinking we could avoid even an OG missile from the fifties. If those things ever go up, they’re definitely coming down on everybody.

      Agreed on the last point too–MAD has basically just made us shift gears from going to war with people who actually pose a threat and could defend themselves to defenseless poor people who could never pose a real threat to us, that we pat ourselves on the back for curb-stomping for decades on end. It’s craven and disgusting. So we get to ramp up the military industrial complex for eternity without risking annihilation at least. Hmm.

    2. Well, during the 1980’s a plane (747) carried an IR sensor and computers on board that could determine the orbits of 3000 incoming warheads and tell them apart from the boosters and dummies. It was meant to be the director of other planes with chemical lasers. It worked fine. Finding the elements of ballistic trajectories is not so hard – they are all on ellipses. And what is the accusation that “humanity” blew up a satellite? As opposed to the Edorians?

      1. Cool tech for the 80’s and no doubt they are way more advance now with tracking tech but to my understanding it’s still considered a near impossible task because you have things like MIRV’s in play with decoy’s, dummy warheads with ECM and warheads that can perform evasive manoeuvres. Being able to see them is one thing, knowing which ones have the deadly payload and tracking a kill vehicle on to it are another thing. The technology still means that you are going to have to throw as much sh*t at the wall as possible in the hope that some will stick and accept you’re only going to stop a few.

          1. Sure it’s difficult to dodge light but I was thinking of an anti-missile missile targeting the warheads in the decent phase as the airborne laser was never an operational or effective weapon system. A nice proof of concept but too short a range, very expensive to maintain, low endurance and operationally ineffective in poor weather. Considering that it was designed to target the rocket in the boost phase the range was the real limiting factor.
            The U.S. has plans to use the knowledge gained to put a electrically powered laser on a UAV which would have near round the clock endurance with aerial refuelling but to get over the range issue they are talking about needed a laser with the power of a MW. From my understanding of current laser tech that’s going to be one massive UAV to fit such a high power laser on.

    3. Ballistic missile interceptors are not seen as an impenetrable shield against a full scale nuclear attack – it acts as a safety net for rouge attacks and can deter sudden first strikes by making your own arsenal more survivable to ensure retaliation.

      Destroying one satellite in a predictable orbit is just a stepping stone away from destroying a maneuvering warhead in space along with its decoys .

      Peace on Earth is a utopian ideal peddled by idealists in the 40s after WW2. There can be no peace even if there is no war. And it is more often the weaker states/actors with no nukes, no armies and no flag that are more eager to engage in violence for a wide variety of excuses.

      The realization that nuclear powers are not going to be using their nuclear weapons against small anonymous actors causing widespread mayhem has resulted in even nuclear powers being attacked repeatedly by small and supposedly “weak” states.

  2. PM Modi is full of shit, any development of weapons is an act of provocation, especially among the world powers. Ask the Americans how they feel about the Russians developing new age weapons. The other thing is that the entire excersize was meant to convey power to other countries, after-all if you can launch a satellite into orbit then you can easily use a non explosive projectile to bring one down.

    One can also not claim to be against the arms race in space while developing arms to be used in space. The point is that while this test may not have been directed at anybody else as he says, in the future it very well could be. Especially given that the country is currently engaged in some limited conflict with Pakistan, we should understand that this was all about politics and the threat of power. Essentially this is India saying to the world “be careful we can disrupt your communication and reconnaissance satellites”

      1. really? i mean they knew the exact orbit that the satellite was traveling on and they just got another satellite traveling the opposite direction along the same path. Sure it probably required finer control loops to get the timing right but all they did was put another satellite in conflicting orbit. It may be rocket science but it still isnt that complicated.

        Also who is to say that the actual weapon doesn’t have explosives to send a cloud of chaff at the satellite which would rip it to shreds?

        The whole point is that this is analogous to nukes and mutually assured destruction and this is India beating its chest among the other super powers and showing that it can destroy orbits like the other super powers which is dumb because anyone who can put up satellites can do the exact same thing through multiple means.

        1. No, they shoot it pretty much straight up and let the sat run into something. Much easier than orbit. Velocity of the intercept can be (should be) zero for the collision.

          1. NOPE – its not like throwing down a log on a busy road and expecting a truck to hit it.

            Anti-satellite weapons have to actively track and guide themselves to their targets – only the region of tracking and guidance is narrowed by radars on the ground which limit the area of search and track. Also, the intercept has to be pre-planned at a particular point in space and the missile has to be launched at exactly the right time and the right speed to make the intercept with enough velocity to destroy the satellite – otherwise they will just float along together.

        2. LOL…hitting a stationary billiard ball across the table reliably every single time requires lots of practice – yet you imagine hitting a 700 kg object 1mX1m at Mach23 orbiting 270 kms above is easy just because you “know” its orbit ?

          Even hitting a 1 meter stationary object on earth from just 10 kms away is a very sophisticated and difficult thing to do – so much so, that maybe 10 countries in the world have missiles that can do it reliably each time ?

          Now multiply that problem by a 100 times and you begin to appreciate the complexity of hitting an object in a “known” orbit outside the atmosphere in a precise window of a few hundreths of a second travelling more than 20 times the speed of sound and you can perhaps appreciate the complexity.

          1. The billiard ball comparison is fine, as long as by “shoot a billiard ball across the table” we mean that I can build a mechanical contraption to aim the ball and apply a predictable amount of force.

            I doubt I’ll get any better at pressing the button by practicing, though.

            We can scale it up 100 times, it only really changes the specifications of the parts, not the difficulty of the control loop. Also, increments of the speed of sound don’t really matter. More important, what is the response time of your tracking system compared to the speed of the tracked item and the acceleration of the interceptor.

            Getting the absolute numbers to sound big doesn’t seem to give any sort of picture of the complexity at all. It might even be easy, depending on the component values. But building the parts is going to be the hard part.

          1. Micheal, yes it’s quite easy to say afterwards: “I did not want to hit it anyway”. But this still leaves the question:”Would you really have been able to hit it, if you wanted?”

          2. @Martin I was answering the question, how to test non destructively, not how to be believed by others.
            I believe an announcement ahead of the test with the details of the fake satellite being targeted would allow everybody to see if your weapon would have intercepted the stated orbit, or failed.

          3. Just remember to write down where you were pretending that it was, and you don’t have to worry about forgetting if you were really trying to hit something or not.

            Surely the existence of genuine “want” doesn’t change any of the orbital variables. In sports, sure, if it was really the Big Game then chances are your hands would be shaking and you’d drop the ball. But when you’re using electronic control systems, that might not be a real issue.

      1. i think you missed my point: Anyone who can launch a satellite has that power, This has been a given since the first satellites were put up in space.

        This exercise was political chest beating for India to threaten other countries. The US, Russia and China all know that India had that power already, the same as any other country developing rockets to put stuff into space.

        1. @Mike
          There is a significant difference between getting something into orbit and getting something to intersect a specific orbit at a specific time with adequate precision/accuracy to hit a small target. To gain a better understanding of these difficulties I suggest reading about how rendevous for docking are done

          1. The US did it in the 1980’s in several ways like spreading a 15 meter wire mesh net in the path of the target or a bucket of marbles. The tests were more complicated using ballistic missiles instead of orbital objects, a minor difference with big consequences for debris. I would guess the Indians chose an orbital object because they had one, and coordination of a functional ballistic launch and the intercept is much more complicated. We don’t know how many times they had to call it off and reset for another orbit. The US used Kwajalein Island and the Pacific Test Range and submarines – 40 years ago.

    1. >>>” after-all if you can launch a satellite into orbit then you can easily use a non explosive projectile to bring one down.”

      That’s not how it works. Launching a satellite requires a very different set of requirements for a launch vehicle compared to one designed to bring one down. Even the most sophisticated countries with decades of experience in space can only place objects in space with a few meters of accuracy in their orbits – so its not 100% precise . Further, the challenge in bringing “one down” is not merely in colliding with the satellite but being able to do so rapidly – in India’s case , about 3 minutes from launch to strike.

      >>>”Essentially this is India saying to the world “be careful we can disrupt your communication and reconnaissance satellites””

      That is totally meaningless – Even North Korea can “disrupt global communications” – they have missiles and nuclear weapons. India doesn’t need to “announce” once again what is already well known. And the world is neither hounding it or sanctioning it like it has been doing with North Korea for obvious differences between the two nations.
      What India did is quite rightly represented in the article as a demonstration of technological ability to serve as a deterrence measure against any threat to its own space infrastructure. A nuclear state doesn’t need to “threaten” reconnaissance or communication satellites for “attention” – those are utterly meaningless compared to the threat to real human lives on Earth.

      >>>>”One can also not claim to be against the arms race in space while developing arms to be used in space. ”
      Actually, that seemingly contradictory stance is a very logical and popular stance in the global community. The US, USSR, France, GB etc were all “against” nuclear weapons and their use – yet they all went on to build vast arsenals just to compete and deter adversaries. They even co-operated to create international treaties or organizations to limit the spread of nuclear technologies even while building up their own arsenals uninterrupted. So it is the norm now to be against nuclear proliferation while still maintaining a nuclear arsenal – by justifying this position under the maxim of MAD and strategic deterrence.
      India’s position on ASAT weapons is no different and its perceptions about maintaining deterrence no different.

  3. “…possibility of fragments being ejected into a higher orbit.” – How can that happen without imparting delta-v? Atmospheric bounce? But that itself would introduce more drag than delta-v? Also simulation showing difference in velocity of particles wont that means, slower particles would fall down also faster? Add to it, solar radiation pressure’s effect on smaller particles. (Disclaimer: My views would be biased, I am from India)

    1. Perhaps by elastic collisions in the cloud of fragments? Something large hits something small and the something small can gain a relatively huge amount of momentum as velocity.

    2. the imparting of delta v happens through the impact as the ballistic hits the satellite, this causes the satellite to break up and all of kinetic energy from both the satellite and the ballistic are passed on to the broken up pieces. Due to the shape and complex structure of the satellite it is quite possible that the disintegration of the satellite imparted delta-v on to the resulting pieces in such a way to send some parts into a higher orbit. The problem in itself is that the satellite breaks apart upon impact, if the weapon was designed to keep the satellite together while robbing it of its kinetic energy then there wouldn’t be a debris field to deal with. They could have used a giant net or some sort of bolo type device, as once the satellites kinetic energy level is off balanced from its potential energy level then it changes orbit (ie, rob it of kinetic energy and the gravitational potential energy will drag it to the earth)

      1. Any delta-v you impart during the impact will change the orbit, but if the orbit becomes higher on one side, it will get lower on the other side (the new orbit will still pass through the “explosion” point). So any piece moving to a significantly higher altitude on the apoapsis would sink into the atmosphere on the periapsis, ensuring quick reentry.

        On the other hand, if the fragment hits a different one on its way up, then you get your missing delta-v, and the fragment might end up on a stable higher orbit. I can’t guess if that’s very likely.

        1. If the piece is ejected prograde during the impact, then that is going to raise apoapsis while leaving the periapsis essentially the same. On the other hand if it’s ejected retrograde it might lower the apoapsis to the point they actually switch.

          In either event, raising the periapsis shouldn’t have any substantial change to the opposite side.

      2. That would be the momentum that is transferred. Kinetic energy is not conserved and a lot becomes heat energy (which is technically kinetic at the atomic level) and radiant energy.

  4. Unfortunately for up and comers the first ever test was a challenge that had to be repeated. Similar to the bad ol’ days of the 50s where everyone and their wives were testing nukes.

  5. Anyone can go and blow something up. If you want to demonstrate real skill, you take an existing thing and make it even more capable. That should be the basic requirement for showing technological achievement. (And no, just making a bigger, fancier blower-upper doesn’t count.)

  6. It should be noted that such an impact can only raise the apogee of the orbit and cannot raise the perigee of the orbit. AFAIK orbit “height” is not a technical term and could mean several different things.

  7. > another satellite
    Wrong, the KKV was not a satellite.
    > traveling the opposite direction along the same path
    Wrong, the KKV hit the satellite from above on a downward trajectory, not on the same path.
    > anyone who can put up satellites can do the exact same thing
    There is a significant difference between getting something into orbit and getting something to intersect a specific orbit at a specific with adequate precision/accuracy to hit a small target. To gain a better understanding of these difficulties I suggest reading about how rendevous for docking are done.

    1. “To gain a better understanding of these difficulties I suggest reading about how rendevous for docking are done.”

      getting two objects on the same path at the same velocity for something such as docking is exceptionally complicated but they still manage to do it. The point i was making is that if you are a country that is significantly technically advanced to put up satellites in very specific orbits then you also have the capability to put up other objects into intersecting paths. The amount of computational power that we as a species have is mind boggling if only it wasn’t mostly used for showing other human beings advertisements. Then consider that we are a huge leap from when we were when we first tarted launching satellites, so how different is it really? sure its a more complicated problem but the major difference is just in the timing. They knew the orbit of the satellite and they knew the trajectory they wanted the projectile to travel on, Its just a matter of timing the launch of the projectile to be within the tolerance that the projectiles control loops could adjust for. There is no magic involved, just alot of work and money invested which is all in the realm of scope for any space capable nation.

      1. @mike
        > getting two objects on the same path at the same velocity for something such as docking is exceptionally complicated but they still manage to do it.
        It took a long time for that to happen after the first orbit was achieved.
        First you said:
        > if you can launch a satellite into orbit
        now you say:
        > if you are a country that is significantly technically advanced to put up satellites in very specific orbits

        > the major difference is just in the timing
        Yeah, about that, the target sat in this case was moving at about 8000 meters per second, so, if you’re off by an 8000th of a second you’re off by a meter. That is some pretty tight timing.

  8. My fear is “What if the test failed?”. What if the weapon missed and now you have this high-energy block of mass of mass that isn’t going to be slowing down anytime soon.

    Astrophysics is very complicated, there are millions of ways something could go wrong, yet so many nations and organizations seem to be so cavalier about it. And in this case we are dealing with a lot of unknowns. There is no possible way they could accurately predict every element of the resultant debris cloud. Even the original plan is reckless, you are sending two controlled objects to intersect and intentionally create a cloud of tens of thousands of uncontrolled and unpredictable objects.

    1. > What if the weapon missed and now you have this high-energy block of mass of mass that isn’t going to be slowing down anytime soon.
      Actually, since it was non orbital and relatively low energy, it would fall back down to the earth and stop in quite short order.

  9. Isn’t this the entire plot to the movie Gravity with Sandra Bullock and George Clooney? A foreign nation shoots down one of their own satellites and the debris cloud destroys the shuttle/space station? Maybe the Indian space agency should get out more and see a movie :-)

  10. Oh, in perspective of the planned projects – Amazon’s Kuiper (3260 satellites), OneWeb (650), StarLink (4425) this seems like a completely unimportant incident. Plus, no important radio spectrum chunks are going into private monopolist’s hands as result. Thank you for a news bit from what shall soon be regarded as an good, old, free world era :-)

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