Oct 4 1985
From The Space Library
As part of the continuing Lewis Advanced Turboprop Project (ATP), supported by some 50 contracts and 15 grants, two advanced propeller propulsion systems recently underwent testing, the Lewis News reported. Lewis Research Center's (LeRC) Advanced Turboprop Project Office was directing development of the new highly loaded, multi-bladed propellers for use at speeds up to Mach 0.85 and at altitudes compatible with commercial air support system requirements. Advanced turboprop engines offered the potential of 15 to 30% savings in aircraft fuel burned relative to advanced turbofan engines (50 to 60% savings over the current turbofan fleet). Investigators were developing both single- and counter-rotation propeller systems.
Researchers at Wright Patterson Air Force Base were testing in a static propeller test rig the first Large-Scale Advanced Propfan (LAP), designed and built by Hamilton Standard Div. of United Technologies Corp. under a NASA/ LeRC contract. Testing of the nine-foot diameter propfan, powered by an electric drive motor in the rig test, began in late August.
At approximately the same time, the General Electric Co. began static proof-of-concept tests of its Unducted Fan (UDF) demonstrator engine at the GE Peebles, Ohio, test site. LeRC partially funded development of this advanced counter-rotating pusher propellers propulsion system.
After completing a series of ground tests, both advanced propeller propulsion systems would undergo flight tests starting in mid-to-late 1986. The propfan would be tested in a wing-mount installation on a modified Gulf-stream II testbed aircraft under a NASA-contracted program with Lockheed; the UDF would be tested as an aft-mounted pusher on a Boeing 727 as part of a GE/Boeing cooperative program.
The propfan of the LAP program was an example of the application of single-rotation tractor propulsion technology, whereas the UDF was a unique example of counter-rotation pusher propulsion technology. The UDF was unique in that its propellers were directly driven by the multi-stage power turbine without the need for gearbox speed reduction. Normal procedure in propeller installations was to drive the propeller through a reduction gearbox so that both the propeller and its driving turbine operated at close to their optimum speedsfor peak efficiency.
The APT effort was also addressing more conventional counter-rotation propfan configurations, as well as associated gearbox designs. (LeRC News, Oct 4/85, 1)
Department of Defense scientists the previous week sent concentrated laser beams adjusted for atmospheric distortion from an Air Force facility on Maui, Hawaii, to a retroreflector on a Terrier-Malemute sounding rocket launched from the Navy Pacific Missile Range Facility in Hawaii, the Los Angeles Times reported. The test demonstrated for the first time that the U.S. could fire such a beam through the atmosphere and prevent air molecules from distorting and weakening it. The test appeared to be a significant technical achievement because distortion, or “blooming,” of a laser as it passed through air could totally block the beam.
To correct beam distortion, engineers developed a flexible mirror that, taking orders from computers, distorted the beam at the start of its journey to compensate, or correct, in advance the dispersing effects of the air molecules.
The sounding rocket reached an altitude of over 350 nautical miles with a flight time of 10 minutes, Defense Daily reported. Return of telemetry data from the diagnostic array aboard the rocket confirmed test success.
Defense Secretary Caspar Weinberger announced the test during a speech at a Philadelphia World Affairs Council luncheon for what appeared to be the start of a Reagan Administration campaign to justify continuing its $26-billion Strategic Defense Initiative (SDI) research effort in the face of intensified USSR protests over the program. (LA Times, Oct 4/85, A5; D/D, Oct 18/85, 251)
NASA announced today that Rep. Bill Nelson (D-Fla.), chairman of the subcommittee on space science and applications, would fly as a payload specialist aboard Space Shuttle mission 61-C scheduled for launch no earlier than December 20.
NASA said it was willing to schedule flights for the chairmen of its four Congressional appropriations and authorization subcommittees in connection with their NASA oversight duties. Sen. Jake Garn (R-Utah), chairman of the subcommittee on HUD/independent agencies, was a payload specialist the previous April aboard mission 51-D.
NASA assigned Nelson to mission 61-C after reassigning Gregory Jarvis, a Hughes Communications, Inc. payload specialist, from that flight to mission 51-L which was scheduled for launch January 22,1986. Hughes's decision not to launch its Syncom IV-5 spacecraft on the December mission eliminated the need for a company payload specialist on that flight. Jarvis would conduct experiments in fluid dynamics on the January flight. (NASA Release 85-141)
The military crew of the Space Shuttle Atlantis on mission 51-J deployed today two communications satellites for Department of Defense, the NY Times reported, citing reliable sources. After release from the Space Shuttle, the satellites, known as Defense Satellite Communications System (DSCS Ill) and weighing a ton each and measuring 38 feet long with solar panels extended, rocket engines boosted them to a point 22,300 miles above the earth.
According to General Electric Co., which built the satellites but would not confirm their presence on the Space Shuttle, both satellites were strengthened to withstand radiation from distant nuclear blasts and had a device to send emergency action messages from the President to the nation's nuclear forces.
The Department of Defense (DOD) scheduled Atlantis to land at Edwards Air Force Base on a date that was classified; NASA and DOD said they would announce the time of landing 24 hours in advance. (NY Times, Oct 5/85, A46)
University of Chicago scientists Edward Anders, Wendy Wolbach, and Roy Lewis found evidence that continent-sized firestorms 65 million years ago raged across much of the earth, blackening the skies with soot and possibly triggering a sudden global freeze that wiped out the dinosaurs, the Washington Post reported. The event occurred at the time that other scientists said a giant asteroid collided with earth, which may have generated enough heat to start the fires.
It was the asteroid theory that led the University of Chicago researchers to ask whether a nuclear war could trigger a similar freeze, a phenomenon now known as nuclear winter. Their findings suggested that nuclear winter theorists had greatly underestimated the amount of soot that would enter the atmosphere from wildfires.
The researchers found some of the soot, which eventually settled to the ground, in the same geologic layers that five years previously gave evidence of the asteroid impact. The layer, sampled in regions as far apart as Europe and New Zealand, contained an amount of soot, which was pure carbon, equal to about 10% of the carbon currently incorporated into all forms of life on earth.
The original impact theory held that an asteroid, probably at least six miles wide, hit earth, blasting enough rock dust into the atmosphere to darken the sky for weeks. Deprived of sunlight, the ground would have cooled, bringing on a global freeze that exterminated not only the dinosaurs but many other species all over the world. Paleontologists knew that the dinosaurs died out in the most wide-ranging mass extinction the earth had even seen. Scientists working on the asteroid impact theory already had calculated that airborne rock dust alone would have been thick enough to bring on a devastating freeze.
The discovery that vast quantities of soot might also have been in the upper atmosphere indicated that the period of darkness and freezing would have lasted longer, perhaps months, because soot washed out of the atmosphere more slowly than did rock dust, although it would have been no darker or colder than originally thought.
The finding added two more factors that might have contributed to the extinction-concentrations of fire-produced toxic substances, such as carbon monoxide, and the destruction of plants and animals by fire.
The researchers said the discovery was an accident, resulting fromexamination of ancient sediments while looking for traces of gases that had been part of the asteroid. Instead, they found that the sediments contained about 10,000 times as much carbon as would have been expected.
The layer, sampled in Denmark, Spain, and New Zealand, was the one in which other scientists previously found unusually high concentrations of iridium, an element that is rare on earth but abundant in meteorites and asteroids. The scientists thought that when the asteroid hit the earth, the impact would have generated enough heat to vaporize the asteroid, sending its iridium into the atmosphere where it spread around the world.
Anders said the impact would have scattered white-hot particles of rock dust as far as 800 and possibly 1,200 miles, igniting forest fires over the entire area. “Once started,” he noted, “such a fire could spread over an entire continent, and the resulting winds may disperse the soot worldwide.” The impact, other scientists calculated, would have left a crater 85 miles wide and 20 miles deep. Since no such crater had been found, many scientists assumed the asteroid hit the ocean, vaporizing the water before it hit the sea floor. (W Post, Oct 4/85, A2)
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