to: Mariner 2, Soviet Crafts
and the Mariner 5 and Pioneer Venus, Magellan
The first spacecraft to study Venus
or any other planet up close was the U.S. Mariner 2. Launched on August
27, 1962. It flew by the planet on Dec. 14, 1962 after traveling for 3
1/2 months. It was designed to take measurements of the magnetic fields
in the inner solar system, solar wind and cosmic dust. It was also
equipped with a microwave radiometer to find if the massive amounts of
microwaves emanating from the planet was actually from the surface of
Venus. It was finally concluded through the Mariner 2 that Venus'
surface was as hot as 900 degrees Fahrenheit
(735 degrees Kelvin). The
Venera 1 was launched before the Mariner 2, but was unsuccessful and
SOVIET CRAFTS AND THE
MARINER 5 AND PIONEER VENUS
Later, the Soviet spacecraft,
Venera 2 flew by Venus on Feb 27, 1966. The Venera 3 launched 4 days
after the Venera 2 reached Venus on March 1, 1966, but crashed into it.
The Venera 3 was actually designed to be the first spacecraft to land on
a planet but it never got to do that. Then came a series of spacecraft
from both the Soviet Union and the U.S.A.. The Soviet Venera 4 capsule
was parachuted down into the atmosphere of Venus on Oct. 18, 1967.
Venera 4 was the first spacecraft to enter another planet's atmosphere.
It was a success until the atmospheric pressure was too great, at 18
atmospheres (8 time the atmospheric pressure of Earth on the surface).
The temperature was also getting too hot at 500 degrees Fahrenheit.
Venera 4 confirmed that the atmosphere was made mostly of carbon
dioxide, the temperatures were very hot and atmospheric pressure was
great. The next day the U.S. Mariner 5 (launched 2 days after the Venera
4) passed within 2,480 miles of Venus and was more successful at
collecting information about Venus. It was loaded with the most up to
date equipment of that time. It found out that the surface temperature
was about 980 degrees Fahrenheit and the atmospheric pressure was 100 atmospheres.
|An artist drew this
picture of the Pioneer Venus to show what it's supposed to look
like. The Pioneer Venus 1 was launched on May 20, 1978.
few years later, the Venera 7 landed on Venus on Dec. 15, 1970, which
made it through but fell over on impact, so no data could be sent. This
came after the Soviets had launched the Venera 5 and 6 on Jan 5 and 10
of 1969. The Venera 8 was more successful, which landed on July 22, 1972
and was able to transport data about the ground conditions, like
illumination level and rock properties on the surface. The Venera 9 and
Venera 10, also followed and landed on Venus. The U.S., in December 1978
sent the crafts Pioneer Venus 1 to orbit the planet and Pioneer Venus
Bus and the 4 probes it carried entered Venus' atmosphere. More Soviet
Venera crafts, the 11 and 12 also landed on Venus in December 1978, and
the 13 and 14 in March.
||This picture was taken
from the Venera 13 spacecraft that landed on the Venus. The
right side of the spacecraft is shown here.
In 1990, many years later the U.S.
spacecraft, the Magellan, began orbiting Venus on Aug. 10. Magellan was
equipped with modern instruments that provided radar images detailed
enough to make maps of many features. The Magellan was launched May 1989
on the shuttle Atlantis. The Magellan sent back to us more than 1
trillion bytes of data during its 5 year mission. Also Magellan
increased the number of named Venusian features from 300 to 1,000. It's
mission ended in October 1994. Even though it's dead now, Magellan
mapped 99 percent of Venus. It used radar mapping in its first phase and
collected gravity data in its second phase. The radar mapping was done
by bouncing thousands of pulses of radio energy each second, and then receiving
the radar signals that bounced off the surface. It also
collected altimetry data, data about how tall each feature was. The
Magellan also collected radiometry data so that scientists could have an
idea what the chemistry of the surface was. A much clearer picture of
what Venus was like became known to us after Magellan. Scientists have
analyzed the data and discovered that Venus may have a core that allows
plate tectonics to come into play. Still, Venus is very far from being
twins with Earth.
|The Gula Mons is shown
in this computer generated and false colored image. This was made
from the Magellan data.