May 11 1985
From The Space Library
France's Centre National d’Etudes Spatiales (CNES) space agency was planning to select by midyear a prime contractor for the Hermes manned shuttle and would open the program to participation by other European countries before the end of 1985, Aviation Week reported. CNES had established a competition between Aerospatiale and Dassault-Breguet for the Hermes leadership role, and the two companies would make technical presentations in April. After review of the data, CNES would make a selection within several months.
Normally the two companies had their separate niches in the aerospace field, but CNES had forced them into head-to-head competition over Hermes. In the competition, Dassault-Breguet would draw on expertise gained from its Mirage, Jaguar, and Alpha Jet military aircraft and related electronics/ avionics systems; Aerospatiale would emphasize its work on military missiles, reentry vehicles/nuclear warheads, the Ariane launcher, communications satellites, and civil aircraft such as the Concorde and Airbus Industrie A300/A310/A320.
CNES Director General Frederic d'Allest said several countries had shown interest in joining the Hermes program following the European Space Agency's (ESA) council meeting at which ministers approved Phase B definition work for the Ariane 5 launcher [see Feb. 4]. Ariane 5 would be capable of orbiting Hermes. France planned to retain a 50% share in the Hermes program and open the rest to participation by other European nations.
The 1985 and 1986 budgets for Hermes totaled $12 million, followed by about $20 million in study work in 1987. France would supply most of this money in 1985, because other European countries wouldn't be involved until at least October.
Hermes would carry two to six crew members and be about half the size of the U.S. Space Shuttle. Its approximate length would be 59 ft. and wingspan, about 33 ft. Payload bay volume would be 377 sq. ft.; diameter of the bay, 9.8 ft. A typical mission would carry 7,700 to 9,900 lb. of useful load to a 248.5-mile circular orbit inclined 0-30°. Mission duration with four to six crew members would be eight days, extending to 30 days with a reduced crew.
Start of full-scale Hermes development in mid-1988 would permit a first flight in 1997, according to CNES scheduling. (Av Wk, Mar 11/85, 19)
Dr. George Wetherill, director of the department of terrestrial magnetism at the Carnegie Institution of Washington, said in an interview with the New York Times that his report to appear in the May 17 issue of Science discussed his hypothesis that the inner planets of the solar system appeared to have been formed when a number of planets, some of them three times larger than Mars, repeatedly collided with one another until only one survived in each of the present planetary orbits.
Wetherill believed the present planets had "lots of brothers and sisters" not much smaller than themselves, which collided to form "trial" planets, the NY Times reported. "The four we see today [Mercury, Venus, Earth, and Mars]," he said, "are the survivors. One of the final collisions;' he added, "probably increased the spin of earth sufficiently to throw off materials that consolidated to form the moon." Wetherill derived his hypothesis from a computer simulation of what probably happened after the solar system began to take shape from a rotating cloud of dust and gas about 4.5 billion years ago. The analysis took into consideration various factors affecting the formation process once some 500 bodies, each one-third the size of the moon, had formed in the region around the sun now occupied by the four planets mentioned above. These factors included the gravitational fields around each object, the frequency of near misses that would throw the objects into eccentric orbits, and the collisions that may have canceled the eccentricity.
Collisions would have generated enough heat within the earth to melt most, if not all, of its interior, allowing heavy material to sink and form earth's metallic core.
Wetherill's calculations assumed that not enough gas was present to affect motions of the objects as they sped past one another; many scientists concurred that a violent "wind" blowing out from the sun swept the inner solar system clear of gas.
Each collision would have driven off most of any planetary atmosphere that had begun to accumulate, and since impact histories of Earth and Venus were different, this could account for the differences in their atmospheric abundances of such inert gasses as argon.
Initially, material destined to form the planets was so uniformly spread around the sun that their motions were determined by multiple collisions much like those of molecules in a hot gas. By the time this material had formed into larger bodies, Wetherill said, their mutual gravitational attractions would have become a significant factor. During the ensuing collisions, Wetherill believed, the existing planets had acquired 50% of their present material; after 100 million years the process was 99% completed.
Age determinations of moon rocks indicated that the last great crashes, enough to produce the lunar seas, did not end until 3.8 billion years ago, or several hundred million years after the formative process began. By then, however, the impacting bodies were "quite small," Wetherill said, "about 30 miles in diameter." What remained in the form of asteroids and meteorites was far less than that needed to produce even a small planet.
Jupiter and the large planets beyond it were not in a region swept clear of gas, making their formation histories very different, Wetherill concluded. (NY Times, May 11/85, 12)
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