Why is mariner 2 important

Regarded as both the evening and the morning star, Venus had long enchanted humans-and all the more so since astronomers had realized that it was shrouded in a mysterious cloak of clouds permanently hiding the surface from view. It was also the closest planet to Earth, and a near twin to this planet in terms of size, mass, and gravitation. These attributes brought myriad speculations about the nature of Venus and the possibility of life existing there in some form.

For instance, in the first half of the twentieth century a popular theory held that the sun had gradually been cooling for millennia and that as it did so, the terrestrial planets of the solar system had a turn as a haven for life of various types.

Although it was now Earth's turn to harbor life, the theory suggested that Mars had once been habitable and that life on Venus was now just beginning to evolve. Beneath the clouds of the planet, the theory offered, was a warm, watery world and the possibility of aquatic and amphibious life.

Mariner 2 helped to determine that none of these speculations were true. The second in a series of planetary exploration spacecraft, this was the world's first spacecraft to fly-by a planet. Both Mariner 1 and 2 were part of a NASA planetary exploration initiative that took some of its design from the Ranger program, Mariner 2 bears a striking resemblance to the basic framework, solar panels, and antennas of its Ranger predecessor. Although Mariner 1 was lost during launch on July 22, , Mariner 2 successfully took off on August 27, A pound vehicle, it carried six scientific instruments, a two-way radio, a solar-power system, and assorted electronic and mechanical devices.

Mariner 2 made its closest approach to Venus on December 14, , after a day journey from Earth, coming within 21, miles of the planet. It carried several scientific instruments that provided information about the nature of the venusian atmosphere and surface as well as interplanetary space. A microwave radiometer measured the temperatures of both the planet's surface and its upper atmosphere, and found that the surface of Venus was indeed very hot; some degrees F as measured by the microwave radiometer.

Mariner 2 also carried a high-energy radiation experiment and a magnetometer. These did not detect any noticeable differences in radiation from space once in the vicinity of Venus, nor did it seem likely that the planet had an appreciable magnetosphere.

Perhaps the most important observation these instruments made was that an astronaut would not be exposed to lethal doses of radiation even on a four month interplanetary voyage.

Contact with Mariner 2 was lost on January 2, , and it is now in orbit around the Sun. This object is a full scale engineering prototype and was constructed from flight spares by engineers at the Jet Propulsion Laboratory in Mariner 2 flew by Venus in , discovering its surface is extremely hot and unlikely to support life. The spacecraft on display is an engineering model. Ultimately three Mariner missions failed due to launch vehicle or payload shroud failures.

In each case, the duplicate spacecraft was able to complete the mission. Mariner spacecraft accomplished a number of important firsts, including the first mission to visit Venus Mariner 2 , the first successful Mars encounter Mariner 4 , and the first mission to visit Mercury Mariner Each spacecraft was launched on an Atlas Agena-B rocket right. The spacecraft's electronics were contained in a hexagonal base, measuring 1.

A pyramid shaped structure, supporting some of the scientific instruments, was mounted on top of the hexagonal base. Two solar panels,.

A high gain directional dish antenna, mounted below the hexagonal base, was used for communications with Earth. A cylindrical omni-directional antenna was mounted on top of the pyramid structure. A monopropellant propulsion system was used for midcourse maneuvers. Experiments included a microwave radiometer, an infrared radiometer, a magnetometer, a cosmic ray detector, a cosmic dust detector, a solar plasma spectrometer, a particle detector, and a celestial mechanics experiment.

Mariner 1 was destroyed in a launch vehicle failure on 22 July The Atlas-Agena rocket veered off course and had to be destroyed by the range safety officer. Launched on 27 August , Mariner 2 was the first spacecraft to visit Venus.

Closest approach to Venus, 34, km, occurred on 14 December These photos are of a replica, constructed from test components, on display at the National Air and Space Museum. Photos: Richard Kruse, Each spacecraft was launched on an Atlas-Agena D rocket right. Skip to main content. About JPL. Engage With JPL. Mariner 2 Mariner 2 Mariner 2 became the first successful mission to another planet when it flew by Venus on December 14, Mission Statistics.

Launch Date Aug 27, Type Flyby Spacecraft.