What happens if you skydive off the ISS?
The Burj Khalifa—standing tall at 2,717 feet—is the tallest building on the planet. Now,
imagine putting 50 Burj Khalifas one top of the other, and you will reach a height
of around 41.4 kilometers—the altitude from which Alan Eustace jumped in 2014,
setting the current world record for the highest and longest free fall jump.
Now, what if you were to jump from the International Space Station—the
artificial satellite inhabited by humans that continuously circles our planet?
Regular skydivers jump from a height of roughly 3.7 kilometers. But the highest
human jump in history was executed from a much greater height by Alan Eustace
Now, think even higher... let's talk about skydiving off the ISS.
The International Space Station or the ISS is a large manned artificial satellite that
orbits planet Earth at an altitude of between 330 and 435 kilometers.
Jumping off the ISS would be nothing like regular skydives, because in a normal skydive, the jumper
is instantly pulled down by Earth’s gravity the moment he jumps from the plane. However,
the gravitational pull up at the altitude of the ISS is much less, which is why the jumper would
actually fall into orbit and begin circling the Earth, just like any other satellite!
This would happen because the ISS is already in orbit, swinging around Earth at a blazing speed
of 27,680 kilometers per hour! It is essentially falling towards the ground at all times,
but it doesn't really hit the ground due to its sheer orbital speed. Similarly, a skydiver
from space won’t fall to the ground instantly, but will instead continue orbiting the Earth.
Then there’s the danger of space debris to consider. There are hundreds of thousands of
little pieces of space debris orbiting our planet at this very moment. They are all of different
shapes and sizes, and, and are often moving at speeds of up to 32,200 kilometers per hour.
In fact, the ISS itself is struck by tiny junk particles frequently,
but due to its excellent structural strength, those little particles don’t
do any serious damage to the ISS. A skydiver, therefore, will need to rely entirely on the
structural integrity of his space suit, if he were to be struck by space debris.
Assuming that the skydiver is completely unscathed by space debris, he would remain in orbit and keep
revolving around the Earth for a REALLY LONG time. In april 2018, China’s Tiangong-1 space
station burned up as it fell towards the ground after 2 years of spiralling ever closer to earth.
Since the ISS is much higher, it’s reasonable to assume that the skydiver would remain in
orbit for a little more than 2 years before he began falling more rapidly towards the ground.
How exactly would a man manage to remain in orbit around the planet for more than 2
years all by himself is, as you can imagine, an impossibly difficult question to answer.
But assuming that he manages to do that, then after a period of more than 2 years,
the jumper would eventually start falling towards the ground due to the resistance the minuscule
amount of air offers at that altitude. The ISS is in the same orbit as the jumper too, yet it
doesn't fall to the ground because the ISS has its own engines which keep compensating
for its gradual loss of altitude, thereby ensuring that it stays in the orbit for as
long as it wants. The jumper’s suit doesn't have any boosters to correct his trajectory,
so there’s nothing stopping him from falling towards the ground eventually.
Once the skydiver starts his reentry into Earth’s atmosphere, his suit’s structural integrity will
finally be put to test. Spacecraft returning to Earth face intense temperatures of about 1650
degrees Celsius due to air drag moving through Earth’s atmosphere. A skydiver would face similar
temperature conditions during reentry, which would make his suit incredibly hot and set it on fire.
If the jumper survives that, then the most difficult part is over. Now, all the skydiver
would need is some sort of mechanism in his suit to significantly slow his rapid free fall,
enabling the deployment of a parachute at a safe height above the ground. He would finally be able
to land on the ground safely after an extremely long, tiring and a humanly-impossible free fall.
All in all, a space jump off the ISS is practically impossible,
unless you are the Iron Man, and can don your super armor and jump off the ISS to land on
the ground with style amid a thunderous round of applause by the whole world!