SATELLITE – A PREVENTIVE MEASURE TO
CYBERWAR
BY
HAMPO, JOHNPAUL ANENECHUKWU
CHUKWUNONSO
A GRADUATE OF COMPUTER SCIENCE,
MATHEMATICS AND COMPUTER SCIENCE
DEPARTMENT OF DELTA STATE UNIVERSITY,
ABRAKA – NIGERIA
OCTOBER, 2012
1
Table of Contents
DEDICATION .................................................................................................................................... 3
ACKNOWLEDGEMENT .................................................................................................................. 4
SATELLITE: A PREVENTIVE MEASURE TO CYBERWAR ....................................................... 5
ABSTRACT........................................................................................................................................ 5
INTRODUCTION .............................................................................................................................. 6
AIMS .................................................................................................................................................. 9
SCOPE ................................................................................................................................................ 9
SIGNIFICANCE OF THE STUDY.................................................................................................... 9
MOTIVATION OF STUDY............................................................................................................... 9
SATELLITE: .................................................................................................................................... 10
HISTORY ......................................................................................................................................... 10
CLASSIFICATION OF SATELLITES ............................................................................................ 12
CATEGORIZATION ....................................................................................................................... 12
TYPES AND FUNCTIONS OF SATELLITES ............................................................................... 13
SIMILARITIES BETWEEN SATLLITES ...................................................................................... 14
HOW SATELLITES WORK............................................................................................................ 16
SATELLITE NAVIGATION ........................................................................................................... 21
SATELLITE INTERNET ACCESS ................................................................................................. 21
SATELLITE TELEVISION ............................................................................................................. 21
SATELLITE COMMUNICATION .................................................................................................. 22
CYBERWAR (CYBERTERRORISM) ............................................................................................ 22
HOW SATELLITES HELP TO FIGHT CYBERWAR ................................................................... 25
ADVANTAGES OF SATELLITES ................................................................................................. 26
DISADVANTAGES/LIMITATIONS OF SATELLITES ................................................................ 27
CONCLUSION ................................................................................................................................. 29
SUMMARY ...................................................................................................................................... 29
RECOMMENDATION .................................................................................................................... 29
REFERENCE.................................................................................................................................... 30
2
DEDICATION
This research work is dedicated first to Jehovah God and humanity especially those in
computing and ICT, and related fields.
3
ACKNOWLEDGEMENT
I appreciate and gratefully acknowledge God Almighty for making me who I am today. Also
for the intuition, life, Peace and every good thing God has been giving me; Lord you’re indeed
wonderful.
I salute my relatives, past and present friends (foes inclusive), lecturers back in school, bosses
at past times and opponents for all their support and otherwise.
More thanks to you, my readers. Continue the voyage on this work for better discoveries.
4
SATELLITE: A PREVENTIVE MEASURE TO CYBERWAR
ABSTRACT
In the context of spaceflight, a satellite is an object which has been placed
into orbit by human endeavour. Satellites are sometimes called artificial
satellites in order to distinguish them from natural satellites such as the Moon
which is the earth original satellite. Spaceflight or space flight is a ballistic
flight into or through outer space. Spaceflight can occur with spacecraft with or
without humans on board. Artificial satellites which are also called man-made
satellite and are usually closer to the earth; originate from more than 50
countries and have used the satellite launching capabilities of ten nations. A few
hundred satellites are currently operational, whereas thousands of unused
satellites and satellite fragments orbit the Earth as space debris. Satellites are
used for a large number of purposes, notably military and civilian Earth
observation satellites, communications satellites, navigation satellites, weather
satellites, and research satellites. Space stations and human spacecraft in orbit
are also satellites. Satellites are usually semi-independent computer-controlled
systems. Satellite subsystems attend many tasks, such as power generation,
thermal control, telemetry, attitude control and orbit control. Cyberwar (also
known
as
Cyberterrorism
motivated hacking to
or
Cyberwarfare) refers
conduct sabotage and
espionage.
to
It
is
politically
a
form
of information warfare sometimes seen as analogous to conventional warfare,
and in 2013 was, for the first time, considered a larger threat than Al Qaeda or
terrorism, by many U.S. intelligence officials. This seminar work, outline the
benefits of satellite and how it can be used (or how it is used) to prevent, track
and monitor the activities of cyberterrorist.
5
INTRODUCTION
Satellites which are semi- independent computer-controlled systems and
used for a large number of purposes, remarkably military and civilian Earth
observation, communications, navigation, weather monitoring and forecasting,
and research, have been a big plus to technology and has simplified many
complex areas of profession. These satellites are put in place in the orbit or
space by human efforts, hence they are termed artificial satellites against natural
satellites – Sun, Moon and so on; that are naturally in the orbit, (among the orbit
system). An orbit is the path which a satellite follows.
Although anything that is in orbit around Earth is technically a satellite,
the term "satellite" is typically used to describe a useful object placed in orbit
purposely to perform some specific mission or task. We commonly hear about
weather satellites, communication satellites and scientific satellites.
According to Wikipedia.org via www.en.wikipedia.org/Satellite, “The
world's first artificial satellite, the Sputnik 1, was launched by the Soviet Union
in 1957. Since then, thousands of satellites have been launched into orbit around
the Earth. Some satellites, notably space stations, have been launched in parts
and assembled in orbit. A few space probes have been placed into orbit around
other
bodies
and
become
artificial
satellites
to
the
Moon, Mercury, Venus, Mars, Jupiter, Saturn, and the Sun.” Satellite orbits
vary greatly, depending on the purpose of the satellite, and are classified in a
number of ways. Well-known (overlapping) classes include low Earth
orbit, polar orbit, and geostationary orbit.
 Geostationary orbit - A geostationary orbit, or Geostationary Earth
Orbit (GEO), is a circular orbit 35,786 kilometres (22,236 mi) above the
Earth's equator and following the direction of the Earth's rotation.
(Source: A geostationary Earth orbit satellite model using Easy Java
6
Simulation Loo Kang Wee and Giam Hwee Goh 2013 Phys. Educ. 48 72
in http://en.wikipedia.org/wiki/Geostationary_orbit#cite_ref-1).
 Polar orbit - A polar orbit is an orbit in which a satellite passes above or
nearly above both poles of the body being orbited (usually a planet such
as the Earth, but possibly another body such as the Sun) on each
revolution. It therefore has an inclination of (or very close to)
90 degrees to the equator.
(Source: http://en.wikipedia.org/wiki/Polar_orbit)
 Low Earth orbit - A low Earth orbit (LEO) is generally defined as
an orbit below an altitude of approximately 2,000 kilometres (1,200 mi)
said, http://en.wikipedia.org/wiki/Low_Earth_orbit.
Fig 1: An animation depicting the orbits of GPS satellites
in medium Earth orbit. (Source:
en.wikipedia.org/satellite)
Fig 2: A full-size model of the Earth observation
satellite ERS 2. (Source: en.wikipedia.org/satellite)
7
According to Wikipedia.org, Richard A. Clarke, in his book Cyber
War (May 2010), defines "cyberwarfare" as "actions by a nation-state to
penetrate another nation's computers or networks for the purposes of causing
damage or disruption." (See; www.en.wikipedia.org/cyberwarfare). Cyberwar,
consist of different attacks done on a computer system or network. This attack
can be averted, monitored and tracked done using surveillance satellites and
earth monitoring satellites. Cyberterrorism can also be checked by the aid of
communication satellites. Of latest, terrorist has evolved to using the cyberspace
for their activities, for instance, the Al Qaeda treat to the United States of
America this year, 2013. This makes the cyberwar a big issue that has to be
tamed as neglecting it might result to normal war and terrorism.
In
www.en.wikipedia.org/cyberwarfare,
‘The Economist describes cyberspace as
"the
fifth
domain
of
warfare,”
and William J. Lynn, U.S. Deputy Secretary of Defense, states that "as a
doctrinal matter, the Pentagon has formally recognized cyberspace as a new
domain in warfare which has become just as critical to military operations as
land, sea, air, and space.” Also on the aforementioned website, In February
2010, a top American lawmakers warned that the "threat of a crippling attack on
telecommunications
and
computer
networks
was
sharply
on
the
rise.” According to The Lipman Report, numerous key sectors of the U.S.
economy along with that of other nations, are currently at risk, including cyber
threats to public and private facilities, banking and finance, transportation,
manufacturing, medical, education and government, all of which are now
dependent on computers for daily operations. Moreover, President Obama in
2009 confessed by stating that "cyber intruders have probed our electrical
grids."
With the advancement of technology is used by the ‘black mind
technocrats’ for cyberwar and like crimes. This phenomenon – cyberwar; is o
8
the rise as it is done not only by individuals or terrorist but also nation indulge
in it.
Sadly, satellites that were lunched at the low earth orbit have been
destroyed by ballistic missiles launched from earth by some countries
conspicuously
Russia,
the
United
States
and
China.
“In
2007
the Chinese military shot down an aging weather satellite, followed by the US
Navy shooting down a defunct spy satellite in February 2008.
”, reports www.en.wikipedia.org/Satellite.
AIMS AND OBJECTIVES
SCOPE OF THE STUDY
This work is limited to the satellites as an aid to prevent cyberwar. The
literatures gotten are well utilized and the point of discussion is not satellites but
the way they help to prevent cyberwar, through their mode of communication.
The basis of this work would be on the information technological aspect of
satellites and not its mechanical or electrical mode of operation.
SIGNIFICANCE OF THE STUDY
MOTIVATION OF STUDY
9
SATELLITE: AN OVERVIEW
According to http://www.howstuffworks.com/satellite.htm, a satellite is
basically any object that revolves around a planet in a circular or elliptical path.
Satellites are objects that are placed or seen in the space – a vacuum or void that
is not necessary empty but it’s outside the planet. There are natural and artificial
satellites. The sun, moon and stars are classified under the natural satellites or
mostly called the Celestine bodies. Others satellites that are place in the space
by human’s endeavour are artificial satellites or just called satellites. There
various types of artificial satellites and they are classified according to their
usage, such as communication, weather forecasting, broadcasting and television
programming, earth surveillance and so on.
HISTORY OF SATELLITES
The desire and inquisitiveness of human to break into space, have a space
station and to bridge the gap of communication between the space and the
ground prompt many into research as to having a geostationary orbit. The idea
of
geostationary
satellites
was
first
put
forward
by
Tsiolkovsky.
Mathematically, calculations were done by Konstantin Tsiolkovsky (1857–
1935), In 1903, who published Means of Reaction Devices - a plan for a
breakthrough into space and a permanent human presence there. In 1928
Slovenian Herman Potočnik (1892–1929) published his sole book, The Problem
of Space Travel — The Rocket Moto. In a 1945 Wireless World article the
English science fiction writer Arthur C. Clarke (1917–2008) described in detail
the possible use of communications satellites for mass communications.
10
Fig 3: Sputnik 1: The first artificial satellite to orbit
Earth. (Source: en.wikipedia.org/satellite)
The first artificial satellite was Sputnik 1, launched by the Soviet Union
on October 4, 1957, and initiating the Soviet Sputnik program, with Sergei
Korolev as chief designer (there is a crater on the lunar far side which bears his
name). This in turn triggered the Space Race between the Soviet Union and the
United States. Sputnik 1 helped to identify the density of high atmospheric
layers through measurement of its orbital change and provided data on radiosignal distribution in the ionosphere. Sputnik 2 was launched on November 3,
1957 and carried the first living passenger into orbit, a dog named Laika. Early
satellites were constructed as "one-off" designs. Explorer 1 became the United
States'
first
artificial
satellite on
January 31,
1958.
With
growth
in geosynchronous (GEO) satellite communication, multiple satellites began to
be built on single model platforms called satellite buses. The first standardized
satellite bus design was the HS-333 GEO commsat, launched in 1972. (History
source
is
gotten
from:
www.en.wikipedia.org/satellites,
accessed
on:
13/06/2013)
Fig 4: CubeSat ESTCube-1, developed mainly by the
students from the University of Tartu, carries out a tether
deployment experiment on the low Earth orbit. (Source:
en.wikipedia.org/satellite)
11
CLASSIFICATION OF SATELLITES
Satellites are broadly classified into two, which are military satellite and
non military satellites. Here, the latter will be discussed in details.
 Military satellites are purely and specifically used for military purposes
and functions.
 Non military satellites are used for mainly for non military functions and
purposes but for other purposes.
CATEGORIZATION OF NON SATELLITES
These class of satellites are categorized into three (3). They are:
Fixed satellite services
Fixed satellite services handle hundreds of billions of voice, data, and video
transmission tasks across all countries and continents between certain points on
the Earth's surface.
Mobile satellite systems
Mobile satellite systems help connect remote regions, vehicles, ships, people
and aircraft to other parts of the world and/or other mobile or stationary
communications units, in addition to serving as navigation systems.
Scientific research satellites (commercial and non-commercial)
Fig 5: MILSTAR: A communication satellite. (Source:
en.wikipedia.org/satellite)
Scientific research satellites provide us with meteorological information, land
survey data (e.g. remote sensing), Amateur (HAM) Radio, and other different
12
scientific research applications such as earth science, marine science, and
atmospheric research.
TYPES AND FUNCTIONS OF SATELLITES

Anti-Satellite weapons/"Killer Satellites" are satellites that are designed to
destroy enemy warheads, satellites, and other space assets.

Astronomical satellites are satellites used for observation of distant planets,
galaxies, and other outer space objects.

Biosatellites are satellites designed to carry living organisms, generally for
scientific experimentation.

Communications satellites are satellites stationed in space for the purpose
of telecommunications. Modern communications satellites typically
use geosynchronous orbits, Molniya orbits or Low Earth orbits.

Miniaturized satellites are satellites of unusually low masses and small
sizes. New classifications are used to categorize these satellites: minisatellite (500–100 kg), microsatellite (below 100 kg), nanosatellite (below
10 kg).

Navigational satellites are satellites which use radio time signals transmitted
to enable mobile receivers on the ground to determine their exact location.
The relatively clear line of sight between the satellites and receivers on the
ground, combined with ever-improving electronics, allows satellite
navigation systems to measure location to accuracies on the order of a few
meters in real time.

Reconnaissance satellites are Earth observation satellite or communications
satellite deployed for military or intelligence applications. Very little is
known about the full power of these satellites, as governments who operate
them usually keep information pertaining to their reconnaissance satellites
classified.
13

Earth observation satellites are satellites intended for non-military uses such
as environmental monitoring, meteorology, map making etc. (See
especially Earth Observing System.)

Tether satellites are satellites which are connected to another satellite by a
thin cable called a tether.

Weather satellites are primarily used to monitor Earth's weather and climate.

Recovery satellites are satellites that provide a recovery of reconnaissance,
biological, space-production and other payloads from orbit to Earth.

Manned spacecraft (spaceships) are large satellites able to put humans into
(and beyond) an orbit, and return them to Earth. Spacecraft including space
planes of reusable systems have major propulsion or landing facilities. They
can be used as transport to and from the orbital stations.

Space stations are man-made orbital structures that are designed for human
beings to live on in outer space. A space station is distinguished from other
manned spacecraft by its lack of major propulsion or landing facilities.
Space stations are designed for medium-term living in orbit, for periods of
weeks, months, or even years.
SIMILARITIES BETWEEN SATLLITES
Not so long ago, satellites were exotic, top-secret devices. They were
used primarily in a military capacity, for activities such as navigation and
espionage. Now they are an essential part of our daily lives. We see and
recognize their use in weather reports, television transmission by DIRECTV
and the DISH Network, and everyday telephone calls. In many other instances,
satellites play a background role that escapes our notice:

Some newspapers and magazines are timelier because they transmit their
text and images to multiple printing sites via satellite to speed local
distribution.
14

Before
sending
signals
down
the
wire
into
our
houses, cable
television depends on satellites to distribute its transmissions.

The most reliable taxi and limousine drivers are sometimes using the
satellite-based Global Positioning System (GPS) to take us to the proper
destination.

The goods we buy often reach distributors and retailers more efficiently and
safely because trucking firms track the progress of their vehicles with the
same GPS. Sometimes firms will even tell their drivers that they are driving
too fast.

Emergency radio beacons from downed aircraft and distressed ships may
reach search-and-rescue teams when satellites relay the signal.
Despite the significant differences between all of these satellites, they have
several things in common. For example:

All of them have a metal or composite frame and body, usually known as
the bus. The bus holds everything together in space and provides enough
strength to survive the launch.

All of them have a source of power (usually solar cells) and batteries for
storage. Arrays of solar cells provide power to charge rechargeable batteries.
Newer designs include the use of fuel cells. Power on most satellites is precious
and very limited. Nuclear power has been used on space probes to other planets.
Power systems are constantly monitored, and data on power and all other
onboard systems is sent to Earth stations in the form of telemetry signals.

All of them have an onboard computer to control and monitor the different
systems.

All of them have a radio system and antenna. At the very least, most satellites
have a radio transmitter/receiver so that the ground-control crew can request
status information from the satellite and monitor its health. Many satellites can
15
be controlled in various ways from the ground to do anything from change the
orbit to reprogram the computer system.

All of them have an attitude control system. The ACS keeps the satellite pointed
in the right direction.
The Hubble Space Telescope has a very elaborate control system so that
the telescope can point at the same position in space for hours or days at a time
(despite the fact that the telescope travels at 17,000 mph/27,359 kph!). The
system contains gyroscopes, accelerometers, a reaction wheel stabilization
system, thrusters and a set of sensors that watch guide stars to determine
position.
HOW SATELLITES WORK
Satellite Internet generally relies on three primary components: a satellite
in geostationary orbit (sometimes referred to as a geosynchronous Earth orbit,
or GEO), a number of ground stations known as gateways that relay Internet
data to and from the satellite via radio waves (microwave), and a VSAT (verysmall-aperture terminal) dish antenna with a transceiver, located at the
subscriber's premesis. Other components of a satellite Internet system include
a modem at the user end which links the user's network with the transceiver, and
a centralized network operations centre (NOC) for monitoring the entire system.
Working in concert with a broadband gateway, the satellite operates a Star
network topology where all network communication passes through the
network's hub processor, which is at the centre of the star. With this
configuration, the number of remote VSATs that can be connected to the hub is
virtually limitless.
Satellite
At the centre of the new broadband satellite networks are a new generation of
high-powered GEO satellites positioned 35,786 kilometres (22,236 mi) above
16
the equator, operating in Ka-band (18.3–30 GHz) mode. These new purposebuilt satellites are designed and optimized for broadband applications,
employing many narrow spot beams, which target a much smaller area than the
broad beams used by earlier communication satellites. This spot beam
technology allows satellites to reuse assigned bandwidth multiple times,
enabling them to achieve much higher capacity than conventional broad beam
satellites. The spot beams also increase performance and consequential capacity
by focusing more power and increased receiver sensitivity into concentrated
areas. Spot beams are designated as one of two types: subscriber spot beams,
which transmit to/from the subscriber-side terminal, and gateway spot beams,
which transmit to/from a service provider ground station.
In
conjunction
with
the
satellite’s
spot-beam
technology,
a bent-
pipe architecture is employed in the network in which the satellite functions as a
bridge in space, connecting two communication points on the ground. The term
“bent-pipe” is used to describe the shape of the data path between sending and
receiving antennas, with the satellite positioned at the point of the bend. Simply
put, the satellite’s role in this network arrangement is to relay signals from the
end user’s terminal, to the ISP’s gateways, and back again. The satellite
receives, amplifies, and redirects signals carried on a specific radio frequency
through a signal path called a transponder.
The satellite has its own set of antennas to receive communication signals from
Earth and to transmit signals to their target location. These antennas and
transponders are part of the satellite’s “payload”, which is designed to receive
and transmit signals to and from various places on Earth. What enables this
transmission and reception in the payload transponders is a repeater subsystem
(RF (radio frequency) equipment) used to change frequencies, filter, separate,
amplify and group signals before routing them to their destination address on
Earth. The satellite’s high-gain receiving antenna passes the transmitted data to
17
the transponder which filters, translates and amplifies them, then redirects them
to the transmitting antenna on-board. The signal is then routed to a specific
ground location through a channel known as a carrier. Beside the payload, the
other main component of a communications satellite is called the bus, which
comprises all equipment required to move the satellite into position, supply
power, regulate equipment temperatures, provide health and tracking
information, and perform numerous other operational tasks.
Gateways
Along with dramatic advances in satellite technology over the past decade,
ground equipment has similarly evolved, benefiting from higher levels of
integration and increasing processing power, expanding both capacity and
performance boundaries. The Gateway—or Gateway Earth Station (its full
name)—is also referred to as a ground station, teleport or hub. The term is
sometimes used to describe just the antenna dish portion, or it can refer to the
complete system with all associated components. In short, the gateway receives
radio wave signals from the satellite on the last leg of the return or upstream
payload, carrying the request originating from the end-user’s site. The satellite
modem at the gateway location demodulates the incoming signal from the
outdoor antenna into IP packets and sends the packets to the local network.
Access server/gateways manage traffic transported to/from the Internet. Once
the initial request has been processed by the gateway’s servers, sent to and
returned from the Internet, the requested information is sent back as a forward
or downstream payload to the end-user via the satellite, which directs the signal
to the subscriber terminal. Each Gateway provides the connection to the Internet
backbone for the gateway spot-beam(s) it serves. The system of gateways
comprising the satellite ground system provides all network services for satellite
and corresponding terrestrial connectivity. Each gateway provides a
multiservice access network for subscriber terminal connections to the Internet.
18
In the continental United States, because it is north of the equator, all gateway
and subscriber dish antenna must have an unobstructed view of the southern
sky. Because of the satellite’s geostationary orbit, the gateway antenna can stay
pointed at a fixed position.
Antenna dish/modem
For the Customer Provided Equipment (i.e. PC, router) to access the broadband
satellite network, the customer must have additional physical components
installed:
Outdoor Unit (ODU)
At the far-end of the outdoor unit is a small (2–3 foot diameter), reflective dishtype radio antenna constructed from and coated with a variety of materials. As
indicated earlier, like the antenna used by the gateway, the VSAT antenna must
also have an unobstructed view of the southern sky to allow for proper Line-ofsight (L-O-S) to the satellite. There are four characteristic settings used to
ensure that the antenna is configured correctly at the satellite, which
are: Azimuth, Elevation, Polarization, and Skew. The combination of these
settings gives the outdoor unit a L-O-S to the chosen satellite and makes data
transmission possible. These parameters are generally set at the time the
equipment is installed, along with a beam assignment (Ka-band only); these
steps must all be taken prior to the actual activation of service. Transmit and
receive components are mounted at the focal point of the antenna which
receives/sends data from/to the satellite. The main parts are:

Feed – This assembly is part of the VSAT receive and transmit chain, which
consists of several components with different functions, including the feed
horn at the front of the unit, which resembles a funnel and has the task of
focusing the satellite microwave signals across the surface of the dish
19
reflector. The feed horn both receives signals reflected off the dish’s surface
and transmits outbound signals back to the satellite.

Block upconverter (BUC) – This unit sits behind the feed horn and may be
part of the same unit, but a larger (higher wattage) BUC could be a separate
piece attached to the base of the antenna. Its job is to convert the signal from
the modem to a higher frequency and amplify it before it is reflected off the
dish and towards the satellite.

Low-noise block downconverter (LNB) – This is the receiving element of
the terminal. The LNB’s job is to amplify the received satellite radio signal
bouncing off the dish and filter out the noise, which is any signal not
carrying valid information. The LNB passes the amplified, filtered signal to
the satellite modem at the user’s location.
Indoor Unit (IDU)
The Satellite Modem serves as an interface between the outdoor unit and
customer provided equipment (i.e. PC, router) and controls satellite
transmission and reception. From the sending device (computer, router, etc.) it
receives an input Bitstream and converts or modulates it into radio waves,
reversing that order for incoming transmissions, which is called Demodulation.
It provides two types of connectivity:

Coaxial cable (COAX) connectivity to the satellite antenna. The cable
carrying electromagnetic satellite signals between the modem and the
antenna generally is limited to be no more than 150 feet in length.

Ethernet connectivity to the computer, carrying the customer’s data packets
to and from the Internet content servers.
Satellite modems employ either the DOCSIS (Data Over Cable Service
Interface Specification) or WiMAX (World Interoperability for Microwave
Access) telecommunication standard to communicate with the assigned
gateway.
20
SATELLITE NAVIGATION
A satellite navigation or sat nav system is a system of satellites that
provide autonomous geo-spatial positioning with global coverage. It allows
small electronic receivers to determine their location (longitude, latitude,
and altitude) to within a few metres using time signals transmitted along alineof-sight by radio from satellites. Receivers calculate the precise time as well as
position, which can be used as a reference for scientific experiments. A satellite
navigation system with global coverage may be termed a global navigation
satellite system or GNSS.
SATELLITE INTERNET ACCESS
Satellite Internet access is Internet access provided through satellites.
Modern satellite Internet service is typically provided to users world-wide
through geostationary satellites that can offer high data speeds, with the latest
satellites achieving speeds up to 18 Mbps.
SATELLITE TELEVISION
Satellite
television is television
programming delivered
by
the
means
of communications satellite and received by an outdoor antenna, usually a
parabolic reflector generally referred to as a satellite dish, and as far as
household usage is concerned, a satellite receiver either in the form of an
external set-top box or a satellite tuner module built into a TV set. Satellite TV
tuners are also available as a card or a USB peripheral to be attached to
a personal computer. In many areas of the world satellite television provides a
wide range of channels and services, often to areas that are not serviced
by terrestrial or cable providers.
Direct-broadcast satellite television comes to the general public in two distinct
flavors - analog and digital. This necessitates either having an analog satellite
receiver or a digital satellite receiver. Analog satellite television is being
21
replaced by digital satellite television and the latter is becoming available in a
better quality known as high-definition television.
SATELLITE COMMUNICATION
A communications satellite or comsat is an artificial satellite sent to space
for the purpose of telecommunications. Modern communications satellites use a
variety of orbits including geostationary orbits, Molniya orbits, elliptical
orbits and low (polar and non-polar Earth orbits).
For fixed (point-to-point) services, communications satellites provide
a microwave radio relay technology complementary to that of communication
cables. They are also used for mobile applications such as communications to
ships, vehicles, planes and hand-held terminals, and for TV and radio
broadcasting.
CYBERWAR (CYBERTERRORISM)
Actions by a nation-state, an individual or group of persons to penetrate
another nation’s or human’s computers or networks for the purposes of causing
damage or disruption are termed cyberwar. Moreover, according to
Wikipedia.org, U.S. government security expert Richard A. Clarke, in his
book Cyber War (May 2010), defines "cyberwarfare (also known as cyberwar)"
as “actions by a nation-state to penetrate another nation's computers or networks
for the purposes of causing damage or disruption.” Richard A. Clarke
streamlined his definition to a nation. Cyberspace is recognised as a new
domain in warfare which has become just as critical to military operations as on
land, sea, air, and space.
According to The Lipman Report in www.en.wikipedia.org/cyberwarfare,
numerous key sectors of the U.S. economy along with that of other nations, are
currently at risk, including cyber threats to public and private facilities, banking
and finance, transportation, manufacturing, medical, education and government,
all of which are now dependent on computers for daily operations. The
22
aforementioned education/research, Wikipedia.org, also states that, The
Economist writes that China has plans of "winning informationised wars by the
mid-21st century". They note that other countries are likewise organizing for
cyberwar, among them Russia, Israel and North Korea. Iran boasts of having the
world's second-largest cyber-army. It is the duty of every nation and individual
to protect themselves from cyberwar as Michael Hayden - former deputy
director of national intelligence on July 2010 Black Hat computer security
conference, challenged thousands of attendees to help devise ways to "reshape
the Internet's security architecture’.
Methods of satellites attack
Cyberwarfare consists of many different threats: Clapper divides these into
cyber espionage and cyberattacks, the latter of which he defines as the top
security threat to the United States.
1. Espionage and national security breaches
Cyber espionage is the act or practice of obtaining secrets (sensitive, proprietary
or classified information) from individuals, competitors, rivals, groups,
governments and enemies also for military, political, or economic advantage
using illegal exploitation methods on internet, networks, software and or
computers. Classified information that is not handled securely can be
intercepted and even modified, making espionage possible from the other side
of the world. Specific attacks on the United States have been given codenames
like Titan Rain and Moonlight Maze. General Alexander notes that the recently
established Cyber Command is currently trying to determine whether such
activities as commercial espionage or theft of intellectual property are criminal
activities or actual "breaches of national security."
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2. Sabotage
Computers and satellites that coordinate other activities are vulnerable
components of a system and could lead to the disruption of equipment.
Compromisation of military systems, such asC4ISTAR components that are
responsible for orders and communications could lead to their interception or
malicious replacement. Power, water, fuel, communications, and transportation
infrastructure all may be vulnerable to disruption. According to Clarke, the
civilian realm is also at risk, noting that the security breaches have already gone
beyond stolen credit card numbers, and that potential targets can also include
the electric power grid, trains, or the stock market.
In mid July 2010, security experts discovered a malicious software program
called Stuxnet that had infiltrated factory computers and had spread to plants
around the world. It is considered "the first attack on critical industrial
infrastructure that sits at the foundation of modern economies," notes The New
York Times.
 Denial-of-service attack
In computing, a denial-of-service attack (DoS attack) or distributed denial-ofservice attack (DDoS attack) is an attempt to make a machine or network
resource unavailable to its intended users. Perpetrators of DoS attacks typically
target sites or services hosted on high-profile web servers such as banks, credit
card payment gateways, and even root nameservers. DoS attacks may not be
limited to computer-based methods, as strategic physical attacks against
infrastructure can be just as devastating. For example, cutting undersea
communication cables may severely cripple some regions and countries with
regards to their information warfare ability.
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 Electrical power grid
The federal government of the United States admits that the electric power
transmission is susceptible to cyberwarfare. The United States Department of
Homeland Security works with industry to identify vulnerabilities and to help
industry enhance the security of control system networks, the federal
government is also working to ensure that security is built in as the next
generation of "smart grid" networks are developed. In April 2009, reports
surfaced that China and Russia had infiltrated the U.S. electrical grid and left
behind software programs that could be used to disrupt the system, according to
current and former national security officials. The North American Electric
Reliability Corporation (NERC) has issued a public notice that warns that the
electrical grid is not adequately protected from cyber attack. China denies
intruding into the U.S. electrical grid. One countermeasure would be to
disconnect the power grid from the Internet and run the net with droop speed
control only. Massive power outages caused by a cyber attack could disrupt the
economy, distract from a simultaneous military attack, or create a national
trauma.
Howard Schmidt, Cyber-Security Coordinator of the US, commented on those
possibilities:
It’s possible that hackers have gotten into administrative computer systems of
utility companies, but says those aren’t linked to the equipment controlling the
grid, at least not in developed countries. [Schmidt] has never heard that the grid
itself has been hacked.
HOW SATELLITES HELP TO FIGHT CYBERWAR
From the aforementioned, the functions of satellites help to combat
cyberwar. As said earlier, satellites that helps in communication and earth
surveillance, reports through their signals any noticeable activities of
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cyberterrorist. This calls for a strong space policing and a strong anti-cyberwar
team.
Also, anti-Satellite weapons/"Killer Satellites" are designed to destroy
enemy warheads, satellites, and other space assets.
Moreover, Space Surveillance Network is required. According to
Wikipedia.org, ‘The United States Space Surveillance Network (SSN), a
division of The United States Strategic Command, has been tracking objects in
Earth's orbit since 1957 when the Soviets opened the space age with the launch
of Sputnik I. Since then, the SSN has tracked more than 26,000 objects. The
SSN currently tracks more than 8,000 man-made orbiting objects. The rest have
re-entered Earth's atmosphere and disintegrated, or survived re-entry and
impacted the Earth. The SSN tracks objects that are 10 centimetres in diameter
or larger; those now orbiting Earth range from satellites weighing several tons
to pieces of spent rocket bodies weighing only 10 pounds. About seven percent
are operational satellites (i.e. ~560 satellites), the rest are space debris. The
United States Strategic Command is primarily interested in the active satellites,
but also tracks space debris which upon re-entry might otherwise be mistaken
for incoming missiles.
A search of the NSSDC Master Catalog at the end of October 2010 listed 6,578
satellites launched into orbit since 1957, the latest being Chang'e 2, on 1
October 2010.’
ADVANTAGES OF SATELLITES
Below are a summary of the advantages of satellites as they have been
explained in the preceding sub-topic – functions of satellite. They are:
1. Security – anti-satellite weapon and military satellites amongst others
help to provide security to many nations as well as individuals and
organisations.
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2. Observation – the earth, other planets and every orbital object are
monitored by earth observation/surveillance satellites.
3. Communication – internet, digital television and internet radio are aided
by communication satellites.
4. Investigation – crime done by terrorist and criminals are checked by
satellites, notably the recent bomb blast in the U.S. (Boston precisely).
5. Navigation – navigation on the globe, instant locating of a place and GPS
are facilitated by satellites.
6. Forecasting – earth quake forecasting as well as weather forecasting are
done comfortably with the aid of satellites.
7. Research – most research are aided by the use of satellites.
8. Business – business and on line transactions are done by satellites. It
provides a vast representation of firms and products.
DISADVANTAGES/LIMITATIONS OF SATELLITES
The limitations and/or disadvantages of satellites are highlighted below:
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1. Signal latency - Latency is the delay between requesting data and the
receipt of a response, or in the case of one-way communication, between
the actual moment of a signal's broadcast and the time it is received at its
destination. Latency is the main difference between a standard terrestrial
based network and a geostationary satellite network.
2. Geostationary unsuitable for low-latency applications - All geostationary
satellite communications experience high latency due to the signal having
to travel 35,786 km (22,236 mi) to a satellite in geostationary orbit and
back to Earth again. Even at the speed of light (about 300,000 km/s or
186,000 miles per second), this delay can be significant. If all other
signalling delays could be eliminated, it still takes a radio signal about
250 milliseconds (ms), or about a quarter of a second, to travel to the
satellite and back to the ground.
3. Acceptable latencies, but lower speeds, of lower orbits - Unlike
geostationary satellites, low and medium Earth orbit satellites do not stay
in a fixed position in the sky. Consequently, ground based antennas
cannot be easily locked into communication with any one specific
satellite. Communications may involve more diffuse or completely omnidirectional ground antennas capable of communicating with one or more
satellites visible in the sky at the same time, but at significantly higher
transmit power than fixed geostationary dish antennas, and with much
poorer signal to noise ratios for receiving the signal.
4. Rain fade - Satellite communications are affected by moisture and various
forms of precipitation (such as rain or snow) in the signal path between
end users or ground stations and the satellite being utilized. This
interference with the signal is known as rain fade.
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5. Line of sight - Typically a completely clear line of sight between the dish
and the satellite is required for the system to work. In addition to the
signal being susceptible to absorption and scattering by moisture, the
signal is similarly impacted by the presence of trees and other vegetation
in the path of the signal. As the radio frequency decreases, to below
900 MHz, penetration through vegetation increases, but most satellite
communications operate above 2 GHz making them sensitive to even
minor obstructions such as tree foliage. A dish installation in the winter
must factor in plant foliage growth that will appear in the spring and
summer.
CONCLUSION
SUMMARY
RECOMMENDATION
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REFERENCE
http://www.howstuffworks.com/satellite.htm, accessed on 16/06/2013
http://science.howstuffworks.com/satellite1.htm, accessed on 15/06/2013
http://en.wikipedia.org/wiki/Satellite_navigation, accessed on 16/06/13
http://en.wikipedia.org/wiki/Satellite_Internet_access, accessed on 16/06/13
http://en.wikipedia.org/wiki/Satellite_television, accessed on 16/06/13
http://en.wikipedia.org/wiki/Communications_satellite, accessed on 16/06/13
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