Jul 20 1978
From The Space Library
NASA announced that an Ames Research Center scientific team led by Univ. of Chicago astronomer Dr. Richard Miller and ARC astrophysicist Dr. Bruce Smith had been pioneering in computer simulations of cosmic events that might alter traditional ideas of how galaxies formed, what shapes they assumed, and what happened when they collided.
Using ARC's ILLIAC IV, world's most powerful computer, the researchers had recreated the birth and evolution of stars and galaxies, compressing 200 million yr into several hr of computer time and reducing the distance light traveled in 100 000yr to the length of a television screen, to witness galaxies colliding and gas clouds begetting embryonic, stars. Computer simulations had shown elliptical galaxies, thought to be oblate (shaped like a frisbee), to have a 3-dimensional prolate shape (oblong); astronomers had found observational evidence confirming the computer discovery. The researchers had instructed the computer to create swirling systems of 100 000 computer points, each point representing the mass of about 1 million suns to give the simulated galaxy a realistic total mass. Each point had felt the gravitational pull of its neighbors and had absorbed energy from exploding supernova. Furnishing a computer with the power of ILLIAC IV with a detailed program on formation and dynamics of galaxies had proved computer simulation to be a useful approach to explaining basic astrophysical processes.
ARC scientists had filmed several computer simulations showing results unexpected in light of traditional astrophysical theories. For example, vast congregations of computer-generated stars had repeatedly evolved into stable prolate bars that rotated end over end to form what was perhaps the true shape of elliptical galaxies. When Miller and Smith had set two simulated 50 000-star galaxies on a collision course, the colliding galaxies had exhibited much greater interaction than was forecast. First they contracted, their gravitational fields reinforcing each other, then they bounced back in violent expansion flinging hundreds of stars out of the galaxies, resulting in merged galaxies containing considerably fewer stars. The two researchers' most recent efforts had centered on tracing simulated masses of gas as they coalesced and formed stars. (NASA Release 78-108)
NASA announced that officials from DOE, the U.S. Forest Service, and LeRC had gathered atop a 2392m (7684ft) peak to dedicate a pioneer solar-cell-powered lookout tower that would demonstrate applications of solar-electric technology in the foreseeable future. The lookout tower, on Antelope Peak in Calif.'s Lassen National Forest, would use a 300w solar-cell system to power the tower's refrigerator, water pump, lights, radio-communications equipment, and small appliances used by a fire lookout who would live round the clock in the tower. Electricity generated by the solar cells would charge eighteen 12-volt lead/acid batteries, storing up to 36kw-hr of electric energy and supplying normal amounts of power for about a mo before needing recharge.
The tower's solar electric power system had been designed to operate continuously for a yr without fuel or periodic maintenance. LeRC had built the solar electric-power system funded by DOE through the Test and Applications Project managed by the center as part of DOE's photovoltaic conversion program. LeRC officials noted that, at current prices, electricity generated by solar-cell power systems over a 20yr system life would cost about $1.73 per kw-hr, which compared favorably with the price of electricity generated in remote areas by alternate methods such as diesel generators. (NASA Release 78-110; DOE Release R-78-270)
The Naval Research Laboratory reported that a team of its space scientists had evaluated two new types of far-ultraviolet electrographic cameras. Designed for possible use in the Space Shuttle program to investigate radiation spectra of distant stars and other celestial objects, both cameras would use alkaline halide photocathodes having more sensitivity in the vacuum ultraviolet below 2000A, and higher angular resolution, than cameras previously used.
One camera, the internal-Schmidt-optics type, had an opaque photocathode like those NRL had used in previous sounding-rocket flights, in the lunar camera on the Apollo 16 mission, and on Skylab 4 . The new camera, flown on two sounding-rocket missions, had on the first flight obtained far-ultraviolet images of the Andromeda galaxy and on the second had recorded the North America nebula in Cygnus and far-ultraviolet spectra of stars in Cygnus. The other camera developed by NRL, a more conventional end-window type, had a semitransparent photocathode intended for possible use at the focus of a large telescope or for making spectrographs on the Spacelab. This large-format electrographic camera, instead of using a phosphor screen, would record directly on film the electrons emitted by the photocathode, allowing better resolution and photometric accuracy. NASA had supported development of the electrographic cameras. (NRL Release July 20/78)
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