Space ain't what it used to be mainly because just like here on earth we are
slowly filling the most important part just above our heads with junk. Over 60 years
of space travel flight debris or space junk has accumulated around the earth to
the point where it's now becoming dangerous. With the amount of space junk
in orbit expected to triple up in the next 15 years
experts are beginning to take the problem very seriously indeed because if
they don't a theory known as the Kessler syndrome suggests that the space around
the earth could soon become so clogged with space junk but no vehicle will be
able to fly through it. That means no more missions to the Moon or Mars
no more deep-space probes and closer to home and more importantly for everyday
people like you and me, no more satellite communications
networks, weather satellites and research probes, live international news, stock
price updates, flight information or GPS services. We could imprison ourselves on
earth and make the world a lot smaller and more difficult to navigate and
understand while we do it. wWhen space exploration began there was no way of
dealing with the vehicles once they completed their jobs so they were just
left there floating around the earth but no further use to anyone but as the
pattern continued over the decades more and more debris built up and now it's a
real problem. objects from spacecraft to specks of dust
stay in orbit because they are traveling an incredibly high speed
normally in the order of around 17,000 miles an hour 27,000km it's not all that bad if they're all traveling in the same
direction like cars on the same side of a highway but if the orbits are
different and at different angles and directions then it's like a car driving
into oncoming traffic, the impact speeds are huge and so is the energy released
when they collide. A 1cm or 1/2 inch fleck paint around the size of
a fingernail traveling at a typical collision speed of 22,000 miles or
35,000 kilometers an hour has the same impact potential as an
object weighing 550 pounds or 250 kilograms traveling at 60 miles an hour
or 96 kilometers here on earth. A 10cm or 4 inch object has the
impact energy of around 7 kilograms of TNT. The Space Surveillance Network is
currently tracking more than 750,000 pieces of junk of which 16,000 are
10cm in diameter or larger whilst most of them are between 1 and 10cm
but there are thought to be more than 150 million pieces smaller
than a centimeter. Over the 5000 vehicle flights or so since 1957 rocket flights
have created clouds of aluminium dust from engines, nuclear powered satellites
have created droplets of fuel and liquid and radio experiments from the 1960s
have left strands of copper wire floating around. At the larger end of a
scale the junk includes defunct satellites, empty rocket stages, discarded
shields and even lens caps. The oldest known item still in orbit is NASA's
Vanguard 1 satellite and it's upper stage launch rocket which was launched
in 1958. In 2002 an unidentified item was found to be a burnt-out stage from the
Apollo 12 moon mission launched in 1969. It was identified by the paint pattern
on its exterior and paint as it turn it turns out is also a significant issue in the
space junk situation. Flecks of paint become detached from the dead vehicles
as a result of the extreme ultraviolet radiation, although they're tiny they're
traveling at around 5 miles per second and that means they can pack a serious
punch if they hit anything. Several Space Shuttle windows needed
replacing after being hit by what was later identified to be paint flecks. A
solar array removed from the Hubble Space Telescope in 1993
showed hundreds of tiny impact holes. Last year a piece of micro debris cut a
hole in the solar panel of a Copernicus sentinel 1A satellite
and in May 2017 astronaut Tim Peake revealed how a paint flakes believed to be
just a few thousandths of a millimeter in diameter made a serious dent in the
Coppola window of the International Space Station. The ISS can be moved out
of position if an impact is predicted. NASA flight rules include guidelines for
assessing the threat posed by space debris. They know that pieces of junk
moving up to 17,500 miles an hour pose a serious threat to vehicles in anyone
aboard, so an imaginary box known as the pizza box because the shape is projected
around the ISS and any other vehicles. It's a mile deep 30 miles wide and 30
miles long and if any pieces of space junk enter the pizza box area NASA and
its partners do what has to be done to protect the vehicle and its crew if
there are any onboard. There have actually been very few large-scale
collisions to date but for an idea of what does happen when they occur
consider this. In 2007 China tested an anti-satellite weapon by destroying a
defunct probe with a rocket that explosion created the largest breakup in
space history adding a further 3,000 new trackable pieces of space
junk around the planet. Two years later in 2009 a dead Russian probe struck and
destroyed at operating us commercial communication satellites creating a
further 2,000 more tiny bits of debris. The Kessler syndrome as defined by
Professor Don Kessler of NASA in 1978 predicts that these sorts of impacts
will become more and more common and create more and more tiny non trackable
bits of junk to clog up the space around the earth. The theory goes that as time
goes by large objects will smash into other large objects and break them into
smaller ones with so much junk for these smaller bits to hit a chain reaction
could be set off that ends up with billions of tiny pieces too small to be
tracked making it impossible to leave earth without encountering an impact. In
essence the Kessler syndrome warns that we
could lock ourselves into a world where we can't send out satellites or rockets
because there's no way through this invisible junkyard. So what is being done
government space agencies and corporate operators are working together in the
inter agency space debris Coordination Committee, they've developed guidelines
about limiting space junk. The current thinking is that the problem for micro
debris can't be solved so organizations must work to prevent the vehicles from
having the chance of smashing into other things and creating junk in first place.
Future satellite networks and space stations are expected to have a maximum
orbital last time of 25 years after which they are either sent into the
atmosphere to burn up or moved into a higher graveyard orbit well out of the
way but what about the current situation. Well the earth does have a self-cleaning
function to an extent. Every 11 years the solar cycle increases the
amount of energy received by the earth from the Sun. This heats up the lower parts of
the atmosphere which expand outwards creating higher air drag, which in turn
causes debris in the lower orbits to slow down and in fall back to earth to
burn up. Although this doesn't last for long as it's replaced by objects
descending from higher orbits. The problem here is that we are filling up space
faster than the earth can clean up our rubbish. In 2013 NASA said they aim to
concentrate on mitigation of the problem because there was no practical method of
debris removal. they posed a solution to the problem called space debris animation or "Spade".
This would shoot pulses of atmospheric gas at targets which would destabilize
their orbits and force them to re-enter the Earth's atmosphere and burn up. NASA
argued that the space system would be failsafe because the gas pulses would
just fade back into the atmosphere leaving no additional junk in the place
of the junk food just being removed. Meanwhile the European Space Agency is
working on its own solutions. Agreeing that the problem of the micro debris
can't be solved they're also going after the larger pieces. ESA are working on a
machine called the e-Deorbit which would use a net or robotic arm to capture
large bits of junk and drag them towards the atmosphere where
both the hunter machine and the piece-of-junk would burn up. The first
launch of e-Deorbit is expected to happen in 2023. If the chain reaction
predicted by the Kessler syndrome theory ever began we could find ourselves
trapped within the confines of the Earth's atmosphere until a way was found
to clean up the billions of tiny but deadly pieces of space junk. Human
ingenuity suggests that we would be able to solve a problem if we had to but it
makes much more sense to find a solution before the Kessler syndrome cascade
occurs. How long we've got to do this is anybody's guess and in the meantime with
more and more nations joining the space race and more than a hundred vehicle
launches every year and that figure is set to increase the problem is only
going to get worse. So as always thanks for watching them before I go I just
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