In war, the 'high ground' refers to the most
strategic position available on a battlefield, and its occupation and exploitation gives
the force occupying it major military advantages. With the dawn of the space age, it quickly
became clear that the space around earth was the ultimate high ground, and whoever conquered
it first would put all other militaries at a severe disadvantage. So why hasn't it happened yet? That’s what we’ll find out today, in this
episode of The Infographics Show- why we can't put weapons on space stations. The first and most obvious answer is a simple
matter of physics. Newton's Third Law of Motion states that for
every action there is an equal, and opposite reaction. If you throw a ball, the ball pushes back
on you- but the friction between your feet and the ground keeps you in place. If you were to try throwing a ball on roller
skates though, the force of the ball pushing back on you would knock you backwards. Because space is a vacuum, there is no friction-
so basic physics tells us that if you tried to shoot a rocket or fire a big enough gun
from a space station, you would send that space station flying out of control. You would have to either counteract the force
of the firing weapon with reaction control thrusters, or make a station massive enough
that the force pushing back on the station is minimal- though of course you would still
need to adjust your orbit after every shot to make sure you didn't accidentally de-orbit
your entire space station! With an average cost of putting objects or
fuel into orbit resting at $1 million dollars per pound, either option makes for a very,
very expensive weapon. Gun are pretty much out of the question, but
you could potentially design a missile that's gently released with just a small puff of
accelerant before its rocket motor ignites and carries it away- similar to how the International
Space Station undocks visiting spacecraft. So why not do that? Well, basic physics is again the most obvious
answer- a missile re-entering the earth's atmosphere would experience the same extreme
heating that a returning space capsule does. In order to protect the chemical warhead from
accidentally blowing up, you would have to spend a lot of money on shielding materials
to keep the warhead cool during re-entry. Ultimately it's just not worth it- conventional
land, air and sea-fired missiles are much cheaper and less risky. But there is one type of missile that would
be worth the cost, risk, and difficulty of firing from orbit- a nuclear-tipped missile. The goal of a nuclear arsenal is not just
to respond to a nuclear attack- but ideally to be able to destroy an enemy's own nuclear
arsenal before they have a chance to retaliate. With nuclear weapons, speed is key- yet even
at a whopping 4 miles per second, an ICBM launched from Russia at the United States
would still need about 41 minutes to reach the East Coast. If we put nuclear weapons in orbit though,
that flight time would potentially shrink to mere minutes. The International Space Station (or ISS) orbits
the earth at 5 miles per second, making a complete orbit in just 92 minutes. If a nation where to build a constellation
of just six nuclear-armed orbital stations at the same altitude as the ISS - 250 miles
above earth- there would always be one station loaded with nuclear weapons flying over enemy
territory, and the next station with its nuclear payload would be a maximum of 15 minutes away. Most nuclear nations operate a nuclear launch
and detection system made up of a small fleet of satellites that are constantly scanning
the earth for the telltale massive heat signature of an ICBM being fired. Once detected, other satellites and ground
tracking stations use radar to track the ICBM. But a nuclear-tipped missile fired from orbit
wouldn't need a big rocket motor - instead each missile could simply be released, use
small RCS thrusters like those used on space capsules when docking to orient each missile
to a different target, and then let gravity pull them down to earth. Without a big, very hot rocket motor, an early
warning and detection system would be useless, and outfitting a missile with radar absorbent
materials like those used on modern stealth aircraft would make radar tracking extremely
difficult. Basically, a nation could launch a crippling
sneak attack against another nation, decimating its nuclear stockpiles and ICBM launch complexes,
and fifteen minutes later have another salvo ready to fire as a new orbital station moves
into position overhead. So why- especially during the heated rivalry
of the Cold War- hasn't any nation done this? The official reason is the UN's Outer Space
Treaty. Ratified on October 1st, 1967, by 107 countries-
including China, the United States, and the Soviet Union- the treaty served as the basic
legal framework upon which international space laws could be built upon. With the space race in full swing and humanity's
imagination picturing a near-future of space colonies and interplanetary travel, it became
clear to the UN that space itself would soon have to be regulated much the same way we
regulated the open seas with international maritime laws. Much more pressing though than a need for
basic laws governing the use of space, was the reality of potential conflict between
two very hostile nuclear powers- the Soviet Union and the United States. MAD- or Mutually Assured Destruction- had
for the moment maintained the peace and kept either nation from even flirting with the
possibility of nuclear war, as each nation knew it could never survive a retaliatory
strike. But with space technologies and capabilities
rapidly evolving in both nations, the possibility of one nation putting nuclear weapons into
space and thus circumventing the safeguards of the MAD doctrine became very real. Thus while the Outer Space Treaty governs
the use of space and prohibits nations from claiming sovereignty over any moon, planet,
or anything in between, the main goal of the treaty was to ban the use of nuclear weapons
in space and thus maintain the security of the MAD doctrine. This is the legal reason why no nation has
ever tried to put weapons into space- but the Outer Space Treaty only governs weapons
of mass destruction, and while as we saw before missiles or guns would do very little good
in space, other weapons known as kinetic impactors would be extremely effective. Basically nothing more than a very large and
very dense projectile, a kinetic impactor uses only its own mass, velocity and kinetic
energy to deliver incredible devastation. The impactor has no chemical explosive, and
relies on fundamental physics - because Force = Mass times Acceleration, by dropping something
very massive (or dense) from orbit and letting the force of gravity accelerate it to thousands
of miles an hour as it falls, you could potentially deliver a destructive blast on par with a
small, tactical nuclear weapon. In fact, the US military has used similar
weapons before in both the Korean and Vietnam war. Known as 'Lazy Dog' bombs, the projectiles
were nothing more than 2 inch-long pieces of steel outfitted with fins. When dropped from an aircraft, the projectiles
would reach 500 miles an hour and be capable of penetrating 9 inches of solid concrete
- not bad for having absolutely no explosive! So why then has no nation put kinetic impactor
weapons in space? The reason, it turns out, is a matter of simple
self-preservation. If any nation began such a program, every
other nation on earth would face three choices: A) Allow that nation to complete its orbital
weapon system program and be at their mercy forever.
B) Begin their own orbital weapon system program. C) Immediately go to war with that nation
before they can complete building their orbital weapon system. In order to avoid all-out war, or risk creating
an environment where even if it fields its own orbital weapons, a nation is still critically
vulnerable to hostile orbital weapons it cannot possibly counter, the United States, Russia,
and other space-faring nations have, to date, simply refused to build these weapons. In the best case scenario, putting orbital
weapons in space would simply force other nations to do the same, creating yet another
Mutually Assured Destruction scenario. Given how many close calls we've had already
with our earthbound nuclear arsenals, it's ultimately best we simply stay away from putting
any weapons in space- period. But, what do you think though? Should nations have the right to put anything
they want in space? Let us know your thoughts in the comments! Also, be sure to check out our other video
called What Happens When You Get Knocked Out! Thanks for watching, and, as always, don’t
forget to like, share, and subscribe. See you next time!
