Jul 16 1984

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ESA's Director, R. Bonnet, and Director General of Arianespace C. Bigot signed a contract for the launch of ESA's scientific spacecraft Giotto, which was designed for observations of Halley’s Comet, aboard an Ariane 1 launcher. They scheduled the launch for the first day of the July 1985 launch window.

Giotto would go into a heliocentric transfer trajectory that would be very close to the ecliptic plane (the plane in which the planets orbit the Sun). During its flight, which would last eight months, Giotto would be under the command of the European Space Operations Centre in Darmstadt, Germany. Ground-based telescopes would track Giotto, and course corrections would be made with the on-board propulsion system to ensure that the spacecraft passed as close as possible to the comet nucleus during the encounter phase, planned to last four hours. It was expected that the most important data from the mission would come from 10 scientific experiments on board Giotto within a few minutes before and after Giotto's closest approach to the comet's nucleus. It would be during that period that the spacecraft's camera would photograph the comet's nucleus in color, resolving surface structure down to 50 meters (150 feet). (ESA Release, July 16/84)

NASA and NOAA announced that the NOAA-8 environmental monitoring satellite appeared to have lost it latitude control system and was tumbling in orbit unable to relay its signal effectively to Earth. Launched board an Atlas E launch vehicle in 1983, the 1,700-kilometer (3,775-pound) satellite had six environmental monitoring instruments and a search-and-rescue payload, provided by Canada and France under an international cooperative space project with NASA known as SARSAT (search-and-rescue satellite-aided tracking).

Much of the environmental monitoring lost by NOAA-8 could be conducted by NOAA-6, launched in 1979. And although the SARSAT capability, which permitted the satellite to relay emergency signals from downed aircraft and ships in distress, was out of service, the SARSAT project would continue operations through use of three Soviet COSPAS search-and-rescue satellites in orbit.

NOAA-8 first showed signs of problems on June 12, when it experienced a "clock interrupt" that caused the spacecraft's gyros to desynchronize. Continued clock disturbances interfered with the meteorological instruments, preventing scientists and engineers from obtaining good data.

The satellite was the first in a series of three Advanced Tiros-N (ATN). NASA planned the next launch of a Tiros-N, NOAA-F, for October 1984. (NASA Release 84-93; NY Times, July 14/84, 46)

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