Transcript SPUTNIK 1

SPUTNIK 1
By,
S.Subhashini
M.Tech(COS)
1st year
INTRODUCTION
• Sputnik 1 was the first artificial Earth satellite.
• It was a 58 cm diameter polished metal
sphere, with four external radio antennas to
broadcast radio pulses.
• The Soviet Union launched it into an elliptical
low Earth orbit on 4 October 1957 at
19:28:34.
• It was visible all around the Earth and its radio
pulses were detectable.
Cont…
• Sputnik itself provided scientists with valuable
information.
• The density of the upper atmosphere could be
deduced from its drag on the orbit, and the
propagation of its radio signals gave
information about the ionosphere.
• The satellite travelled at about 29,000 kilometres per hour (18,000 mph), taking 96.2
minutes to complete each orbit.
Cont..
• It transmitted on 20.005 and 40.002 MHz which
were monitored by amateur radio operators
throughout the world.
• The signals continued for 22 days until the
transmitter batteries ran out on 26 October 1957.
• Sputnik 1 burned up on 4 January 1958, as it fell
from orbit upon reentering Earth's atmosphere,
after travelling about 70 million km and spending
3 months in orbit.
HISTORY
• 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.
Cont..
• In July 1955, the White House announced
plans to launch an Earth-orbiting 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.
Cont..
• As a technical achievement, Sputnik caught the
world's attention and the American public offguard.
• Its size was more impressive than 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.
Cont…
• 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.
DESIGN
• The satellite was a 585-millimetre (23.0 in)
diameter sphere, assembled from two
hemispheres which were hermetically sealed
using o-rings and connected using 36 bolts,
and had a mass of 83.6 kilograms.
Cont…
• The hemispheres were 2 mm thick, and were
covered with a highly polished 1 mm-thick
heat shield made of aluminium-magnesiumtitanium AMG6T alloy.
• ("AMG" is an abbreviation for "aluminiummagnesium" and "T" stands for "titanium",
the alloy contains 6% of magnesium and 0.2%
of titanium).
Cont…
• The satellite carried two pairs of antennas designed by
the Antenna Laboratory of OKB-1.
• Each antenna was made up of two whip-like parts: 2.4
and 2.9 meters (7.9 and 9.5 ft) in length, and had an
almost spherical radiation pattern, so that the satellite
beeps were transmitted with equal power in all
directions, making reception of the transmitted signal
independent of the satellite's rotation.
• The whip-like pairs of antennas resembled four long
"whiskers" pointing to one side, at equal 35 degree
angles with the longitudinal axis of the satellite.[
• The power supply, with a mass of 51 kg was in
the shape of an octagonal nut with the radio
transmitter in its hole.
• It consisted of three silver-zinc batteries,
developed at the All-Union Research Institute of
Current Sources (VNIIT).
• Two of them powered the radio transmitter and
one powered the temperature regulation system.
• They were expected to fade out in two weeks,
but ended up working for 22 days.
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