Space debris in low-Earth orbit poses a serious and growing threat. There are over 22,000 pieces of debris larger than 10 cm currently orbiting Earth, traveling at speeds sufficient to damage satellites. If left unchecked, the amount of debris will continue to grow exponentially through collisions in a process known as the Kessler Syndrome, which could render space exploration and satellite use impossible for generations. Solutions require both mitigation efforts to limit further debris creation as well as active removal of existing debris through methods like lasers, electromagnets, or debris-capturing space structures. International cooperation will be needed to implement solutions and avoid a space debris disaster.

1. Nemesis of
Space exploration :
Space Debris
Disaster preparedness Rajat Tiwari
IIT
Source : getty images MADRAS

2. Breaking the myth…..
When Sputnik was launched in 1957, it was heralded as a paradigm shift in
technology.
Pictures started pouring up of space which was once only envisaged and read in sci-fi
novels. At that time space was seen as too vast to fill up.50 years on, this BIG SPACE
THEORY is being proved wrong.
Things are getting rather crowded in low-earth orbit (LEO’s,700-1000km up), the
region most desirable for artificial satellite. They are easy for launch rockets to get to,
they allow the planet’s surface to be scanned for both military and civilian
purposes(Google Earth), and can even catch/transmit signals of satellite equipment.
Debris in the orbit includes everything from
paint scrapped off space shuttle to massive
defunct satellites. It is the legacy of more
than half a century of space activity.
Today approximately 22,000 pieces of
debris is zooming at several km/s-sufficient
velocity for even the smallest piece to
damage a space mission.
Source : The Economist

3. Stats….
According to NASA there are about 3000 active satellites orbiting the earth out of
roughly 8000 man-made objects which includes the International Space Station and
Envisat.
Envisat is the largest earth observation satellite and will soon become a giant piece
of junk, one which will remain in the crowded orbit for next 150 years. Satellites have an
orbiting life span of 5-20 years.
Satellites in orbit(2008):
• Former soviet union and Russia- 1400
•USA- 1000
•Japan-more than 100
•China , France- about 60
•India , Germany-about 30
Source: The Economist and wisegeek.com

4. Timeline:
• 1991- Inactive Cosmos 1934 satellite hit by cataloged debris from Cosmos 296
satellite.
• 1996- Active French Cerise satellite hit by cataloged debris from Ariane rocket stage.
•1997-Inactive NOAA 7 satellite hit by uncataloged debris large enough to change its
orbit
and create additional debris.
•2005-US rocket body hit by cataloged debris from Chinese rocket stage.
•2007-Active Meteosat 8 satellite hit by uncataloged debris large enough to change its
orbit.
•2007-China’s anti-satellite weapon test ,estimated to have increased the known
existing
orbital debris population at that time by more than 15%,without question the
biggest
single debris generating event in space age.
•2009-Active Iridium satellite hit by Cosmos 2251.
•2011 June-Piece of debris narrowly missed International Space Station, forcing its six
Source: The Space Review

5. Kessler Syndrome
•Proposed by NASA scientist Donald J. Kessler in 1978
•Objects could cause a cascade- each collision generating debris which
increases the likelihood of further collisions .
•If not averted the debris in orbit could render space exploration and even the use
of satellites unfeasible for many generations.
Source : Wikipedia

6. The Solution !!!
This problem is slowly becoming a disaster like global warming and the nations
apparently are not attempting to avert it. It has become a classic example of a
free riders problem where in nations blame each other for the debris.
Steps to reduce space debris are :
•Mitigation
•Removal
Mitigation refers to reducing the creation of new debris, while removal refers to
removing the existing debris from the low earth orbits either natural or by man-
made systems.
Source : google images

7. Mitigation
Mitigation measures can be the following:
•An international treaty to bind the nations to stop creating debris
•Rockets should not be disposed off close to the leo’s and in cases
could be even pushed into the earth’s atmosphere where it will
burnout due to friction.
•Making it mandatory for the satellites to save fuel to move into
graveyard orbits after their life cycle.
•Designing satellites to withstand impacts by small debris
•Implementing operational procedures such as using orbital regimes
with less debris, adopting specific altitudes
•Making an international advanced debris tracking system
Graveyard orbit
Source : nasa.gov

8. Removal -
There are currently 30,000 pieces of debris, of few cms diameter and around
19,000 pieces of debris larger than ten cm, So there is a urgent need to remove
these particles from orbits.
Some removal techniques can be:
•High power lasers can be used to vaporize
a minuscule part of a piece of space junk,
resulting in slowing the object down enough to
bring it out of Earth orbit.
•Satellite with electromagnet could be placed
which will attract and incinerate the debris.
•Large aerosol ball could be used in which
the particles will get trapped and subsequently
would be pushed towards Earth.
Source : chaosmosis.net

9. Goals….
In the light of these threats, measures need to be taken to address these
issues so that it does not turn into a disaster.
Space is a world resource, no single nation has a right on it so it is a
collective responsibility to act in averting this disaster.
Nations should cooperate with each other
and
should aim towards a sustainable launch
process.
They can start acting by adopting mitigation
measures and in process should work
towards development of feasible removal
techniques. International Conference
The first-ever
on Orbital Debris Removal, held in
December 2009 and co-hosted by NASA
and DARPA
illustrated the growing concern.

10. Conclusion:
Satellites have a wide range of applications like
•Weather prediction
•Global positioning system (GPS)
•TV and Entertainment broadcasts
•Defense and many more….
That is why its very important now to start acting in this direction so that we
don’t end up encaging ourselves in a sea of debris and hamper our dreams of
conquering space.
Source : Wall-E