Post on 08-Sep-2014
description
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Space Debris
INTRODUCTION• Satellites are used for invaluable services, such as
o GPS
o Navigation systems
o DTH
o Telecommunications
o Weather forecasting
o climate monitoring
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Space Debris
SPACE DEBRIS Space debris is any human-origin object in space that no
longer serves a useful purpose
It may be
o Launcher
o Combustion residue
o Out of use satellites
o Fragmentation waste …
Launching of satellites is responsible for some of the debris
seen in those regions
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Space Debris
Debris in two main Regions
Lower Earth Orbit (LEO)
o The fastest growth of debris is in these orbits
o These appear to form a fuzzy shell around the
Earth
Geo-stationary Earth Orbit (GEO)
o Here satellites orbit the Earth in 24 hours
o These satellites form a circle around the
Earth rather than a shell
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Space Debris
Other regions Constellations of satellites used for
navigation, like the GSP satellites, lie midway
between LEO and GEO
Launching of these satellites is responsible
for some of the debris seen in that region
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Space Debris
History In 1957, Sputnik I, the first satellite, was
launched to orbit. With this, first pieces of Debris
are placed into space
In 1958, America’s 2nd satellite, Vanguard I
served only for 6 years
Collision of Iridium33 & Cosmos2251 on February
9th, 2009
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Space Debris
Debris is Dangerous... In LEO, space debris travels nearly at 8kmps
So, even small pieces of debris can cause
severe damage to a satellite on collision
An object of few inches in size could completely
destroy a satellite in a head-on collision
This could result in thousands of additional
pieces of deadly space debris
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Space Debris
Contd… Space debris can stay in orbit for a long time—
decades, near the Earth, and essentially forever
at very high altitudes
Over time, the amount of space debris has
increased dramatically
It has become dense enough in some parts of
space, which can damage or destroy satellites
on collision
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Space Debris
Fig: Delta 2 launcher tank near Bangkok
on 13 Jan 2005
Fig: Impact of a paint flake on the windshield of the space ship Endeavour
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Space Debris
The United States maintains list of tracked
active satellites and large debris in a
debris catalog
The following snapshots shows the debris
count giving the number of objects in the
catalog.
Today, only 5-6% of those objects are
active satellites—the rest are debris
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Debris count: <100
Debris count: 1,000
Debris count: 2,700
Debris count: 5,400
Debris count: 6,500
Debris count: 8,700
Debris count: 10,000
Debris count: >14,000
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Possible Solutions
Alternate OrbitTerminator Tether Other Expensive or Unrealistic Ideas
20Possible Solutions
Alternate Orbit It includes deorbiting of satellite from its
path
It would require too much fuel
Later the atmospheric drag would make it to fall back to earth
21Possible Solutions
Terminator Tether
This includes bringingback dis-functionalsatellites when they have completed the tasks
Later it could be properlydisposed off or recycled
This is also called “electro-dynamic tether”
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Other expensive or unrealistic ideaso Electro-Dynamic Debris Eliminator (for LEO)
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Other expensive or unrealistic ideaso Using laser brooms to Vaporize or nudge
particles into rapidly decaying orbits
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Contd…◦ Using Solar Sails in Satellites yet to be
launched to space
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Instead, NASA currently focuses on preventing collisions by keeping track of the larger debris, and preventing more debris from littering space
26Possible Solutions
ConclusionThe reduction of waste at the source in space is
possible if all launching states and satellite operators are aware of the seriousness and risks
To achieve this Laws on space must be cooperative, progressive and binding.
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Sources
•http://www.nasa.gov
•http://www.space.com/spacewatch/space_junk.html
•http://www.space.com/scienceastronomy/planetearth/space_junk_000901.html
•http://en.wikipedia.org/wiki/Space_debris
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Thank You