For the 106 days that Mariner was actually in Mode II (cruise), the telemetry data were processed twenty-four hours a day, seven days a week. Data were presented to the engineering and science analysis teams in quick-look format every three hours, except for short maintenance interruptions, one computer failure, and a major modification requiring three days, when a back-up data process mode of operation was used. The large computer performed full processing and analysis of engineering and science data seven days a week from launch until the Venus encounter. On encounter day, the secondary Station C computer processed telemetry data from the high-speed Goldstone line. Data on magnetic tapes produced by the computer were processed and analyzed by the large unit in near-real time every 30 minutes. The computer processing and delivery time during this operation varied from 4½ to 7 minutes. CHAPTER 8 THE SCIENTIFIC EXPERIMENTS After a year of concentrated effort, in which the resources of NASA, the Jet Propulsion Laboratory, and American science and industry had been marshalled, Mariner II had probed secrets of the solar system some billions of years old. Scientists and engineers had studied the miles of data processed in California from the tapes recorded at the five DSIF tracking stations around the world. Two and a half months of careful analysis and evaluation yielded a revised estimate of Venus and of the phenomena of space. As a result, the dynamics of the solar system were revealed in better perspective and the shrouded planet stood partially unmasked. When the Mariner data were correlated with the data gathered by JPL radar experiments at Goldstone in 1961 and 1962, the relationships between the Earth, Venus, and the Sun became far clearer than ever before. Two experiments were carried on the spacecraft for a close-up investigation of Venus’ atmosphere and temperature characteristics—a microwave radiometer and an infrared radiometer. They were designed to operate during the approximate 35-minute encounter period and at a distance varying from about 10,200 miles to 49,200 miles from the center of the planet.[2] [Illustration: _Cosmic dust detector._] [Illustration: _Solar plasma spectrometer._] COLLECTOR CUP PROGRAMMER ELECTROMETER DEFLECTION PLATES [Illustration: _Magnetometer._] [Illustration: _High-energy particle detector._] COLLECTOR SHIELD CAN QUARTZ FIBER [Illustration: _Microwave and infrared radiometers._] REFERENCE HORNS MICROWAVE RADIOMETER INFRARED RADIOMETER _Table 2. Mariner Experiments_ _Experiment_ _Description_ _Experimenters_