Mariner 1, 2

Part of the Mariner program

Mariner 2 was the world's first successful interplanetary spacecraft. It became the first spacecraft to flyby another planet on December 14, 1962 when it passed within 34,833 kilometers from the surface of Venus. During its flyby, Mariner 2 measured the temperatures of the clouds and surface of Venus as well as fields and particles near the planet and in interplanetary space. It discovered that Venus lacks a strong magnetic field and radiation belts, and that Venus' surface temperature was over 400 deg C. Contact was lost January 3, 1963 when the spacecraft was 86.9 million kilometers from Earth. An identical sister vehicle, Mariner 1, was lost in a launch failure prior to the launch of Mariner 2.

Spacecraft
Based on Ranger lunar spacecraft. Octagonal bus structure. Power provided by two deployed solar panels. 3-axis stabilized using cold gas jets. S-Band communications using LGA or HGA. Hydrazine main engine.

Payload
Geiger tubes, ion chamber, cosmic dust detector, microwave radiometer, magnetometers.

Country of Origin	United States
Customer/User	NASA
Manufacturer(s)	JPL
Orbit	Solar orbit - Direct trajectory, Venus flyby on December 12, 1962
Related Sites	JPL Mariner 2 Summary

Launch Facts

Name	Int'l Desig.	Date	Site	Vehicle	Orbit	Mass(kg)
Notes
Mariner 1	none	7/22/62	ESMC	Atlas Agena B	FTO	200
Destroyed by range safety; Venus probe
Mariner 2	1962-A[Rho]1	8/27/62	ESMC	Atlas Agena B	Solar	201
Venus flyby at 34745 km