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Aviation History
1964
1964 - 2247.PDF
266 FLIGHT International, 13 August 19- The flight of Ranger 7 was the first to be controlled from the Jet Propulsion Laboratory's new Space Flight Operations Facility at Pasadena. Photo- graph shows the mission control area of the facility, which is designed to enable two spaceflight missions to be controlled and a third to be monitored concurrently Spaceflight and missiles of RCA, forms a truncated cone 59in high, 27in wide at the base and 16in wide at the top, mounted on the hexagonal base of the spacecraft bus. It is covered by a shroud of polished aluminium with a 13in opening near the top for the cameras. Of the two full-scan (wide-angle) cameras, one has a 25mm, f/1 lens with a field view of 25°. The other has a 75mm, f/2 lens with a field of 8.4°. The four partial-scan (narrow-angle) cameras comprise two with 75mm, f/2 lenses with a 2.1° field of view, and two with 25mm, f/1 lenses with a 6.3° field. Exposure time is l/500sec for the narrow-angle cameras and l/200sec for the wide-angle cameras. The six-camera assembly weighs 591b, and is mounted so that the cameras are pointed at an angle of 38° from the roll axis of the spacecraft. Behind each of the camera shutters is a vidicon tube lin in diameter and 4.5in long, on the face-plate of which an image is formed when a picture is taken. The image is scanned by an electron beam; the scan lines are converted to electrical signals which are amplified 1,000 times and sent to one of two video combiners in the television subsystem. The output of the video combiners is con- verted to a frequency modulated signal and passed to one of the two 60-watt transmitters. One transmitter sends pictures to Earth from the wide-angle cameras on 959.52 Mc/s, and the narrow-angle pictures are sent on 960.58 Mc/s. The cameras are controlled by camera sequencers which send instructions to the cameras to take a picture, read-out the vidicon face-plate, and erase face-plate and prepare for the next picture. Pictures were taken for about 17min as Ranger 7 approached the Moon, beginning when the spacecraft was approximately 1,300 miles from the lunar surface, until the craft was destroyed on impact. The transmitted pictures were recorded on magnetic tape and 35mm film at NASA's Goldstone deep-space tracking station in California. Nerve-centre of NASA's deep space network during the Ranger 7 flight was the recently opened spaceflight operations facility at JPL headquarters in Pasadena. The complete network includes in addition three permanent tracking stations at Goldstone, Woomera and near Johannesburg; a mobile tracking station which for this flight was also based near Johannesburg; a launch tracking station at Cape Kennedy; and a communications network linking all the individual units. At the JPL facility (illustrated above) some 250 personnel are employed during a mission such as that of the Ranger craft. The mission control team is supported by three specialized groups concerned respectively with space science analysis, flight path analysis, and spacecraft performance and analysis. MORE SOVIET ROCKET TESTS On July 31 the following official communique was issued by the Soviet news agency Tass: "Tests of new variants of carrier rockets for space purposes are u_ be conducted by the Soviet Union in accordance with its programme] of further space studies. These rockets will be launched into are of the Pacific Ocean within a radius of 65 nautical miles from th following points: (1) 0= 37' N, 165° 40' W; (2) 7° 15' N, 172° 35' W.l Measurements in the target areas will be conducted by special! vessels of the Soviet Navy equipped with the necessary measurement! apparatus. "The test programme will last to the end of 1964. The area centred on 0: 37' N, 165° 40' W will be used from August 4 to November 1 this year. The area centred on 7° 15' N, 172° 35'' will be used from October 1 to December 30 this year. "With the object of ensuring safety, Tass has been authorized to state that the Government of the Soviet Union asks the governments of other countries which use sea and air routes in the Pacific to instruct their appropriate agencies that ships and aircraft should not enter these regions of the ocean and airspace daily after noon between noon and midnight local time. Possible changes in the schedule of the launchings and the co-ordinates of the centres, and also the complete opening of the areas for free navigation and aircraft flights, will be announced by Tass later." ALTERED ORBITS The effect of solar radiation pressure on the orbits of lightweight balloon satellites is already widely appreciated, but two other forces—the gravitational fields of the Sun and Moon—are now becoming noticeable as they distort the eccentric trajectories of certain spacecraft. High circular orbits, such as those of Midas at 3,500km and especially Syncom at 35,OOOkm, are almost perfectly stable for dense satellites. Even fairly eccentric orbits with periods less than 1 .OOOmin and apogees below 50,000km behave predictably, the perigee staying almost constant and the apogee and period falling as the spacecraft decays. This is the case with Explorer 15 and the Syncom 1 and 2 rocket stages, which will probably remain in space for a century or more. Orbits with perigees inside the Earth's atmosphere and apogees which reach over one-tenth of the distance to the Moon, however, are greatly perturbed by this body, the perigee height often rising several hundred kilometres—a result opposite to that produced by atmospheric drag. This was first noticed with Explorer 12, whose Test pilot E. P. Hetzel tries out the paraglider system of spacecraft recovery, under consideration for Project Gemini flights, in the first manned test of the system at NASA's Flight Research Center at Edwards, California
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