sejarah
estipg14 25/01/2007 09:13 pm Page 02
14
Januari
2007
THE Sputnik
launch also led
to the creation
of NASA.
The Explorer program continued as a
successful ongoing series of lightweight, scientifically useful spacecraft.
The Sputnik launch also led directly
to the creation of National Aeronautics
and Space Administration (NASA).
In July 1958, Congress passed the
National Aeronautics and Space Act
(commonly called the “Space Act”),
which created NASA as of October 1,
1958 from the National Advisory
Committee for Aeronautics (NACA)
LANDSAT data has been used in a variety of practical commercial applications.
The History of Satellites
Oleh KHAIRUNNISA SULAIMAN
H
istory changed on October 4,
1957, when the Soviet Union
successfully launched Sputnik
I. The world’s first artificial
satellite was about the size of a basketball, weighed only 183 pounds, and
took about 98 minutes to orbit the Earth
on its elliptical path.
That launch ushered in new political,
military, technological, and scientific
developments.
While the Sputnik launch was a single event, it marked the start of the
space age and the U.S.-U.S.S.R space
race.
The story begins in 1952, when the
International Council of Scientific
Unions decided to establish July 1,
1957, to December 31, 1958, as the
International Geophysical Year (IGY)
because the scientists knew that the
cycles of solar activity would be at a
high point then.
In October 1954, the council adopted a resolution calling for artificial
satellites to be launched during the
IGY to map the Earth’s surface.
In July 1955, the White House
announced plans to launch an Earthorbiting satellite for the IGY and solicited proposals from various Government research agencies to undertake
development.
In September 1955, the Naval
Research Laboratory’s Vanguard proposal was chosen to represent the U.S.
during the IGY.
The Sputnik launch changed everything. As a technical achievement,
Sputnik caught the world’s attention
and the American public off-guard.
Its size was more impressive than
SATELLITE carry a
small scientific
paywad that
eventually
discovered the
magnetic radiotion
belts around
the Earth.
Vanguard’s intended 3.5-pound payload.
In addition, the public feared that the
Soviets’ ability to launch satellites also
translated into the capability to launch
ballistic missiles that could carry
nuclear weapons from Europe to the
U.S.
Then the Soviets struck again; on
November 3, Sputnik II was launched,
carrying a much heavier payload,
including a dog named Laika.
Immediately after the
Sputnik I launch in October,
the U.S. Defense Department responded to the political furor by approving
funding for another U.S.
satellite project.
As a simultaneous alternative
to
Vanguard,
Wernher von Braun and his
Army Redstone Arsenal
team began work on the
Explorer project.
On January 31, 1958, the
tide changed, when the
United States successfully
launched Explorer I.
This satellite carried a
small scientific payload that
eventually discovered the
magnetic radiation belts
around the Earth, named
after principal investigator
James Van Allen.
and other government agencies.
Applications Satellites
NASA did pioneering work in space
applications such as communications
satellites in the 1960s.
The Echo, Telstar, Relay, and Syncom
satellites were built by NASA or by the
private sector based on significant
NASA advances.
In the 1970s, NASA’s Landsat program literally changed the way we look
at our planet Earth.
The first three Landsat satellites,
launched in 1972, 1975, and 1978,
transmitted back to Earth complex data
streams that could be converted into
colored pictures.
Landsat data has been used in a variety of practical commercial applica-
The Sputnik program was a
series of unmanned space missions launched by the Soviet Union
in the late 1950s to demonstrate
the viability of artificial satellites.
The Russian name Sputnik means
literally ‘fellow traveler’, i.e. ‘satellite’.
● Sputnik 1, the first artificial satellite, was launched on October 4,
1957. The world’s first artificial
satellite was about the size of a
basketball, weighed only 183
pounds, and took about 98 minutes
to orbit the Earth on its elliptical
path
● Sputnik 2 was launched on
November 3,1957 and carried the
first living passenger, a dog named
Laika. The mission planners did not
provide for the safe return of the
spacecraft or its passenger, making Laika the first space casualty.
● The first attempt to launch
Sputnik 3, on February 3, 1958,
failed, but the second on May 15
succeeded, and it carried a large
array of instruments for geophysical research. Its tape recorder
failed, however, making it unable to
measure the Van Allen radiation
belts.
● Sputnik 4 was launched two
years later, on May 15, 1960.
● Sputnik 5 was launched on
August 19, 1960 with the dogs
Belka and Strelka, 40 mice, two
rats and a variety of plants on
board. The spacecraft returned to
earth the next day and all animals
were recovered safely.
All Sputniks were carried to orbit by
the R-7 launch vehicle, originally
designed to carry nuclear warheads.
tions such as crop management and
fault line detection, and to track many
kinds of weather such as droughts, forest fires, and ice floes.
NASA has been involved in a variety
of other Earth science efforts such as
the Earth Observation System of
spacecraft and data processing that
have yielded important scientific
results in such areas as tropical
deforestation, global warming, and
climate change.
NASA has
been
involved in
a variety of
other Earth
science
efforts.
A Selective Communications Satellite Chronology
1945 Arthur C. Clarke Article: ‘Extra-Terrestrial Relays’
1955 John R. Pierce Article: ‘Orbital Radio Relays’
1956 First Trans-Atlantic Telephone Cable: TAT-1
1957 Sputnik: Russia launches the first earth satellite.
1960 1st Successful DELTA Launch Vehicle
1960 AT&T applies to FCC for experimental satellite communications license
1961 Formal start of TELSTAR, RELAY, and SYNCOM Programs
1962 TELSTAR and RELAY launched
1962 Communications Satellite Act (U.S.)
1963 SYNCOM launched
1964 INTELSAT formed
1965 COMSAT’s EARLY BIRD: 1st commercial communications satellite
1969 INTELSAT-III series provides global coverage
1972 ANIK: 1st Domestic Communications Satellite (Canada)
1974 WESTAR: 1st U.S. Domestic Communications Sate
llite
1975 INTELSAT-IVA: 1st use of
dual-polarization
1975 RCA SATCOM: 1st operational body-stabilized comm.
satellite
1976 MARISAT: 1st mobile
communications satellite
1976 PALAPA: 3rd country (Indonesia) to launch domestic
comm. satellite
1979 INMARSAT formed.
1988 TAT-8: 1st Fiber-Optic
Trans-Atlantic telephone cable
SPUTNIK programme was a series of
unmanned space mission launched by the
Soviet Union in the late 1950s.
15
Januari
2007