Mission Type: Flyby
Launch Vehicle: Atlas-Agena B (no. 5 / Atlas D no. 145 / Agena B no. 6901)
Launch Site: Cape Canaveral, United States ETR / launch complex 12
NASA Center: Jet Propulsion Laboratory
Spacecraft Mass: 202.8 kg
Spacecraft Instruments: 1) microwave radiometer 2) infrared radiometer 3) fluxgate magnetometer 4) cosmic dust detector 5) solar plasma spectrometer and 6) energetic particle detectors
Spacecraft Dimensions: 202.8 kg
Total Cost: Total research, development, launch, and support costs for the Mariner series of spacecraft (Mariners 1 through 10) was approximately $554 million.
References:
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi

National Space Science Data Center, http://nssdc.gsfc.nasa.gov/

After approval by NASA Headquarters in September 1961, JPL prepared three spacecraft based on the design of the Ranger Block I series (therefore named Mariner R) to fly by Venus in late 1962.

Each spacecraft carried a modest suite (9 kilograms) of scientific instrumentation but had no imaging capability. The spacecraft included 54,000 components and was designed to maintain contact with Earth for 2,500 hours -- an ambitious goal given that the (still unsuccessful) Ranger was designed for only 65 hours of contact.

Mariner 1 would have flown by Venus at a range of 29,000 kilometers on 8 December 1962, but due to an incorrect trajectory during launch, range safety had to destroy the booster and its payload at T+290 seconds.