Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/DAILY_1/930324A.DFC

Text File | 1993-04-01 | 49KB | 994 lines

Paula Cleggett-Haleim
 Headquarters, Washington, D.C.                      March 24, 1993
 (Phone:  [phone])

Peter Waller
 Ames Research Center, Mountain View, Calif.
 (Phone:  [phone])

RELEASE:  93-51

EVIDENCE POINTS TO OCEANS, LIGHTNING ON EARLY VENUS

The last findings by the Pioneer Venus Orbiter spacecraft have provided strong
new evidence that planet Venus once had three and a half times more water as
thought earlier -- enough water to cover the entire surface between 25 and 75
feet deep (762 and 2286 centimeters).

These findings also give new support for the presence of lightning on Venus
and discoveries about the ionosphere and top of the atmosphere of Venus.
Considered Earth's twin planet, Venus today is very dry and searing hot.

Pioneer entered Venus' atmosphere on Oct. 8, 1992, and burned up soon after,
ending 14 years of exploration.

"Many of us have long thought that early in its history Venus had temperate
conditions and oceans like Earth's," said Dr. Thomas Donahue, University of
Michigan, head of the Pioneer Venus science steering group.

"Findings that Venus was once fairly wet does not prove that major oceans
existed, but make their existence far more likely," he said. "The new Pioneer
data provides evidence that large amounts of water were definitely there,"
said Donahue.

"Most scientists think Venus' early oceans vaporized and 'blew off' 3 billion
years ago in a runaway greenhouse effect when the cool early sun increased its
luminosity and heated the planet very hot," he said.  "The oceans evaporated.
Solar ultraviolet radiation split the water molecules into hydrogen and
oxygen, and the hydrogen was lost to space.

"Pioneer Venus Probe and Orbiter data showed early in the mission," Donahue
said, "that on Venus heavy hydrogen abundant relative to ordinary hydrogen
than on Earth and everywhere else we've looked in the solar system --Mars,
Comet Halley, meteorites, Jupiter and Saturn."  Venus' remarkable
hydrogen/deuterium ratio has since been confirmed by independent measurements.

Abundant deuterium is taken as clear evidence that Venus once had 150 times as
much water in its atmosphere as today, he said.  This is because the water's
ordinary hydrogen has escaped.  But most of the water's heavy hydrogen
(deuterium - twice as heavy as hydrogen) stayed behind because of its weight.

When the Orbiter made its final descent to unexplored regions only 80 miles
(129 kilometers) above Venus' surface, it found evidence for 3.5 times as much
water as previously suggested by the deuterium ratio.

"We found a new and important easy-escape mechanism, which
 accelerates hydrogen and deuterium away from the planet," he said. "This
means that much more hydrogen had to escape to build up the present high
deuterium concentration.  A lot more hydrogen lost means a lot more water
early on," he said.  "This also rules out theories of a dry-from-the-beginning
Venus, whose present meager supply of water comes from an occasional comet
impact."

The data also show that at Pioneer's lowest altitude 80 miles (129 kilometers)
"whistler" radio signals, believed generated by Venus' lightning, were the
strongest ever detected.  Pioneer has long measured such "lightning" signals.
They are the same as the radio signals used in most lightning studies on
Earth.

In its final orbits, Pioneer penetrated 7 miles (11 kilometers) below the peak
of Venus' ionosphere, which tends to block these radio signals.  Here also,
the magnetic fields which channel the signals were the strongest ever seen on
Venus' night side.

"These results are best explained by a strong and persistent source of
lightning in the Venus atmosphere," said Robert Strangeway of UCLA, Pioneer
electric field investigator.

 Some scientists continue to doubt Venus lightning.  They say only optical
sightings can prove lightning.  A Russian spacecraft has reported visible-
light sightings of lightning.  Four Russian spacecraft and the U.S. Galileo
craft also have observed radio signals believed from lightning.

Pioneer found the peak density of Venus' ionosphere for the first time - at 87
miles (139 kilometers).  The ionosphere was much different between solar
maximum and minimum, which are high and low periods of storm activity on the
sun and in the solar wind.  At minimum, it was far smaller.  It was gone
altogether above 85 miles (136 kilometers), and its lower layer was half as
dense.  It was more variable, much cooler, and full of small structures (1-60
miles in size (1.6-96 kilometers).

For the ionosphere on the night side, at solar minimum, hydrogen ions were
reduced 20 times.  Its lower layer was half as dense as at maximum.

Over 3 months, Pioneer provided data from 80 to 210 miles (129 to 336
kilometers) altitude.  It found the beginning of Venus' real, mixed atmosphere
(transition from oxygen to carbon dioxide) at 80 miles (129 kilometers).
Below 85 miles (136 kilometers), it identified various waves and a 4-day
oscillation of Venus' atmosphere top.  The neutral atmosphere above 185 miles
(296 kilometers) was more than 10 times denser and 2120 F (1,000 degrees
Celsius) hotter than thought.

Working with Donahue were Drs. Richard Hartle and Joseph Grebowsky of NASA's
Goddard Space Flight Center, Greenbelt, Md.  Ames Research Center manages the
Pioneer project for the Office of Space Science, NASA Headquarters,
Washington, D.C.

 -END OF FILE-
----------

3/24/93:  DIAZ NAMED TO SPACE SCIENCE POST

Paula Cleggett-Haleim
 Headquarters, Washington, D.C.          March 24, 1993

RELEASE:  93-53

Alphonso V. Diaz was named today as the Deputy Associate Administrator for
NASA's new Office of Space Science, effective immediately.

In making the announcement, NASA Administrator Daniel S. Goldin said, "Al is
widely recognized as an accomplished manager.  His leadership ability and
technical expertise are vital as we reestablish the focus of NASA's science
and exploration programs."

During his extensive career at NASA, Diaz served as Deputy Associate
Administrator for Space Science and Applications, managed the Galileo and
Ulysses programs in the Solar System Exploration Division and developed space
science programs for Space Station Freedom.

Diaz began his NASA career at the Langley Research Center, Hampton, Va., in
1964 as a cooperative education student.  Later at Langley, he worked on the
technical development of one of the Viking Mars exploration experiments.

Diaz received a B.S. degree from St. Joseph's University, Philadelphia, in
1966; a M.S. degree in physics from Old Dominion University, Norfolk, in 1970;
and a M.S. degree in management from Massachusetts Institute of Technology,
Cambridge, as a NASA- sponsored Sloan Fellow in 1986.  He was awarded the NASA
Medal for Outstanding Scientific Achievement in 1977 for his work on the
Viking experiment.

 -END OF FILE-
----------
Contact: John Thom
         Douglas Aircraft Company
         [phone]
 93-71

MCDONNELL DOUGLAS FORECASTS AIR PASSENGER TRAFFIC GROWTH
 ---------------------------------------------------------

     LONG BEACH, Calif., March 15, 1993 -- McDonnell Douglas
 forecasts world air passenger traffic will brow at a 6.7
 percent annual rate over the next 20 years, which will
 require a fleet of more than 17,000 jetliners by the year
 2011 to serve air travel needs.

     David P. Shube, deputy general manager of market
 development at the Douglas Aircraft division of McDonnell
 Douglas, says, "Between 1992 and 2011, the forecast
 indicates that 14,072 new passenger aircraft deliveries will
 be required to satisfy projected traffic levels."

     Expressed in 1992 U.S. dollars, these planes will cost
 just over one trillion dollars.

     The company said that 9,200 aircraft, or 65 percent,
 will be needed ot accommodate traffic growth, while nearly
 4,900 of these deliveries, or about 35 percent, will be for
 replacement purposes.

     Shube said the open market, or the difference between
 the forecast of new deliveries and airlines' existing
 orders, will be more than 11,000 aircraft. The value of
 these airplanes is more than $800 billion.

     Despite the current airline recession and the
 expectation of future slumps from time to time in the
 industry, McDonnell Douglas, a leading manufacturer of
 commercial jetliners, sees substantial long-term growth in
 both air traffic and aircraft manufacturing in the next two
 decades. The company published its findings in its annual
 "Outlook for Commercial Aircraft."

     In a companion publication, called "World Economic and
 Traffic Outlook," McDonnell Douglas describes the recent
 economic environment as a "weak recession" and a "weak
 recovery." The recession followed the longest peacetime
 expansion on record, which lasted 92 months.

     The expectation for strong growth in aircraft
 manufacturing is based on McDonnell Douglas' forecast for
 moderate economic expansion in North America and Europe and
 strong expansion in the Asia/Pacific region.

     For the next two decades, the Asia/Pacific economies
 are expected to grow at an average annual rate of 5.1
 percent, outpacing growth in other parts of the world. Rapid
 economic growth in Asia will provide the base for higher
 increases in both domestic and international air traffic
 growth, Shube says. This, in turn, will mean the need for
 expansion of airline fleets domiciled in the Asia/Pacific
 region.

     By 2011, the McDonnell Douglas outlook says, a fleet of
 approximately 17,500 aircraft will be required for
 commercial service. To meet this requirement, future
 aircraft deliveries will be almost evenly split between
 narrowbody and widebody models, it said. "On the basis of
 value, however, the dominance of widebodies becomes very
 apparent, with over 76 percent of the total." The company
 estimated that the world's active passenger jetliner fleet
 totaled just over 8,000 last year.

     The company forecasts that international air traffic
 growth from now to 2011 will be 8 percent a year. Domestic
 growth - travel within each nation - will average 5.5
 percent per year, excluding the former USSR.

     Airlines domiciled in North America will continue to
 lead in the number of new aircraft deliveries required
 through 2011 with nearly 5,200 units, or 37 percent of the
 world total. Because of an extensive domestic travel market
 served by hub-and-spoke operations, North America will lead
 in required deliveries of narrowbodies at nearly 3,200, or
 about 46 percent of the world total.

     Asia/Pacific-based carriers will require the largest
 number of widebody aircraft, with 2,900, to serve the fast
 growing international routes between Asia and North America
 and Asia and Europe. With nearly 1,100 narrowbodies also
 required between 1992 and 2011, Asia/Pacific will rank
 second behind North America for total deliveries at almost
 4,000 aircraft.

     European airlines are expected to take 23 percent of
 all jetliner deliveries over the next two decades. The value
 of these  aircraft, expected to be a balance between
 widebodies and narrowbodies, will be about $214 billion.

     McDonnell Douglas says that new deliveries to airlines
 in the Middle East and Africa will be required primarily to
 satisfy capacity needs for medium and long range routes. New
 deliveries will be valued at more than $60 billion.

     Latin America will be the second fastest growing region
 in passenger traffic, and the fleet of aircraft is expected
 to expand by 134 percent. Most of the growth in new aircraft
 will be in short and medium range planes. The value of new
 aircraft will be about $50 billion.

     The aircraft outlook also forecasts jet fuel prices to
 remain relatively flat and stable, accounting for normal
 inflation. Demand for jet fuel will rise, but so will the
 supply, the McDonnell Douglas Outlook says. Shube warns,
 however, that short-term price fluctuations will remain a
 part of the world's oil environment.

 -END OF FILE-
----------
Contact: Sheila Carter-Hart
         Mcdonnell Douglas Aerospace
         [phone]
 93-76

PETE CONRAD TO BE INDUCTED INTO ASTRONAUT HALL OF FAME
 -------------------------------------------------------

     HUNTINGTON BEACH, Calif., March 18, 1993 -- Charles
 "Pete" Conrad Jr. and 12 fellow astronauts who orbited the
 earth during the Gemini program in the mid-1960s, will be
 inducted in the U.S. Astronaut Hall of Fame in Titusville,
 Fla., on March 20.

     The three-year old Hall of Fame originated with the
 induction of the Mercury Seven astronauts. This week, Conrad
 and his 12 Gemini colleagues will be honored and an
 individual exhibit will be dedicated to each inductee.

     The Gemini missions served as a bridge between the
 Mercury and Apollo flights. The program perfected all of the
 flight techniques necessary to go to the moon, including
 rendezvous, docking, space walking and long-duration flight.
 The 10 launchings of the two-man spacecraft took place in
 1965 and 1966. It was a time far removed from today's
 sophisticated computer-controlled flights.

     "In those days we did a lot of the work ourselves. We
 had to fly the vehicle by hand and manually make the burns
 for corrections. We actually carried charts on board because
 ground control couldn't quite keep up with the vehicle,"
 Conrad said.

     Selected as an astronaut by NASA in 1962, Conrad's 11-
 year astronaut career included four missions.

     His first flight on board Gemini 6 helped establish a
 space endurance record and placed the United States in the
 lead for man hours in space. Serving as commander of Gemini
 11, Conrad helped set a world altitude record. As commander
 of  Apollo 12 which make the second lunar landing, he became
 the third man to walk on the moon.

     On his final mission in 1973 he served as commander of
 Skylab 1, the first U.S. space station.

     Today as a vice president of new business for McDonnell
 Douglas Aerospace, Conrad is involved in the Single Stage
 Rocket Technology program in which he serves as flight
 manager for the DC-X vehicle test flights.

 -END OF FILE-
----------
Charles Redmond
Headquarters, Washington, D.C.                               March 22, 1993
(Phone:  [phone])

Linda Ellis
Lewis Research Center, Cleveland
(Phone:  [phone])


RELEASE:  93-50

NASA/OHIO AEROSPACE INSTITUTE TO HOST CYBERSPACE CONFERENCE

NASA's Lewis Research Center, Cleveland, and the Ohio Aerospace
Institute will host a conference in Cleveland, March 30 and 31, focusing on and
providing insights into the fascinating new world of Cyberspace.

Cyberspace is a metaphor coined and popularized by science fiction
author William Gibson to represent the "universe" that humans beings enter when
they use computers.

The Vision 21 Symposium on Interdisciplinary Science and Engineering
in the Era of Cyberspace conference will focus on this new metaphor and also
will feature a series of speakers.

"In keeping with the conference mission to foster speculative concepts
and advanced thinking in science and technology, this event will provide a
panoramic view of the research and technology that will assist humans in
exploration activities," said Dr. Sheila Bailey, conference Chairperson.

Bailey, who is a Lewis research physicist in the center's Power
Technology Division, also said that this new vision includes "not only the
Earth's environment and the Martian terrain, but the artificial reality of
cyberspace."

Each of the five speakers for the conference is an interdisciplinary
scientist with a unique view of the future.  Together, the speakers share a
common vision of cyberspace as a world where computers, robots and the
human mind will be more closely linked.

The speakers include Hans Moravec from Carnegie Mellon University's
Institute for Robotics, who believes that "robots with human intelligence will
be common in the next 50 years."

San Diego State University mathematician and science fiction writer
Vernor Vinge will talk about linking the mind and the computer.  His novels
explore the ethical questions associated with society's use of computers and
the potential for good and evil use of these computers.

Carol Stoker, NASA Ames Research Center scientist, who uses remote
sensing and telepresence in exploration activities being conducted in the
Antarctic, will talk about the science and engineering challenges of using
robots in the Antarctic and what might be faced in similar expeditions to the
moon or Mars.

John Dalton, NASA Goddard Space Flight Center manager for NASA's
Earth Observing System ground system, will discuss the use of information
systems to support climate research and how global environmental models are
evolving.  More and more scientific analysis of Earth environment information
is using scientific visualization methods which are themselves on the cutting
edge of computer science.  Many of the new data sets lend themselves to
presentation in a "cyberspace" environment.

Dr. Myron Krueger, Director of the Artificial Reality Corp., will
discuss how humans will experience and interact with or in cyberspace.  Krueger
termed the phrase "artificial reality" to describe human interaction with
computer-generated worlds.

Attendees at the 2-day conference also will have the opportunity to
tour the Ohio Aerospace Institute and the Lewis Research Center's Graphics
Visualization Laboratory.  That laboratory recently demonstrated distributed
processing and visualization by simulating the flow of air and gasses through a
turbo-jet engine - each component of which was running as a simulation on one
of over 2 dozen high-powered computer workstations.

 -END OF FILE-
----------
From: [e-mail] (Henry Spencer)
Subject: space news from Jan 25 AW&ST
Date: Thu, 25 Mar 1993 03:47:41 GMT

[What happened to Jan 18, you say?  I never got that one, and I've given
up on waiting for it.  Should it appear, I will summarize it.]

This is AW&ST's annual "laurels" issue.  Top slot for space goes to the
COBE folks at Goddard and elsewhere; runner-up is the Endeavour crew for
the Intelsat rescue.

Chinese authorities claim a "minor explosion" in the Optus B2 satellite
caused its loss in December, saying that the Long March's performance
was "positively spotless".  [The finger has recently pointed at a
shroud failure.]

Shuttle managers reject a proposal to add an experimental EVA to the
Atlantis mission in April, citing possible undesired effects on Spacehab
experiments from the usual lowering of cabin pressure.  The EVA people
are expected to respond with a plan that leaves the cabin pressure alone,
at the cost of more prebreathing time.

Goldin orders major studies on NASA's future launch needs.  The three
major options under study are:

1. Retain the shuttle until 2030, probably requiring major investments
   in new technology.  [I don't know as *I* would want to fly in
   a 50-year-old orbiter!]  Study led by Bryan O'Connor, DepAssocAdmin
   for spaceflight.

2. Replace the shuttle, circa 2005, with off-the-shelf technology [by
   which they mean 1950s technology, of course].  Study led by
   Wayne Littles, DepDirector of Marshall.

3. Retain the shuttle until an unspecified "early 2000s" date, replacing
   it by a major technological jump, possibly NASP- or SSTO-derived.
   Study led by Griffin.

NASA does not think any of these approaches will meet all of the NASA and
DoD needs in the next few decades, but which one is chosen will affect
how the gaps are filled.  The three groups will report in May.

Meanwhile, NASA is still developing ASRM, reportedly on schedule.  And
Draculauncher is rising from the dead yet again, as the USAF prepares
specs for son-of-son-of-ALS, this one dubbed Spacelifter.

January Endeavour mission successfully deploys another TDRS, has some
problems with the Diffuse X-Ray Spectrometer secondary payload, and
does the first overtly experimental EVA since Gemini.  Harbaugh and Runco
run a successful series of tests on moving large objects and moving into
and out of foot restraints, spending an hour afterward recording responses
to a detailed set of questions; the EVA was cut a bit short because it
started late and its secondary-objective status required that it stay out
of the way of later experiments.  A bad odor on the middeck, first
blamed on the new toilet, turned out to be a trash bin.  The experimental
shutdown and restart of a fuel cell was successful.

[That's it; a light news week.]
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

 -END OF FILE-
----------
Organization: National Institute of Standards and Technology formerly National
              Bureau of Standards
Disclaimer: Opinions expressed are those of the sender and do not reflect NIST
            policy or agreement.
Date: Thu, 25 Mar 1993 21:40:43 GMT

NIST Colloquium Series

The Solar System: A New View

Dr. Edward C. Stone
Director, Jet Propulsion Laboratory
Vice President, California Institute of Technology

10:30 AM
Friday, March 26, 1993
Green Auditorium
NIST (Gaithersburg, Maryland)

Since the beginning of the robotic exploration era just 30 years ago,
our knowledge of the planets has changed as dramatically as when Galileo
first turned his telescope towards the sky 4 centuries ago. Spacecraft
have visited every planet except Pluto and transformed our understanding
of the creation and evolution of the solar system. We can now identify
a number of processes that contribute to the surprising diversity among
the planets and moons, and we now realize more clearly how those processes
have shaped the Earth.

[ Readers please note: It is my opinion that the rest of this item somehow got
chopped in transmission, if the rest materializes it will be posted in full.
Hugh S. Gregory, Spaceflight Historian, Space Base ]

 -END OF FILE-
----------
3/26/93:  EXPLORATION EFFORT SHIFTED TO OFFICE OF SPACE SCIENCE

Paula Cleggett-Haleim
 Headquarters, Washington, D.C.                  March 25, 1993

RELEASE:  93-54

NASA Administrator Daniel S. Goldin today announced that the activities of the
Office of Exploration will be absorbed by the Office of Space Science,
effective immediately.

He said the change was being made in the interest of maintaining clear and
well-defined management responsibilities.  The exploration activitites will be
focused in a new organizational unit as a division of the Office of Space
Science.

"The Office of Exploration has provided a needed focus for the agency's vision
of the future," Goldin said. "But it is only practical that further studies on
human expeditions to the moon and Mars complement and build on the more near-
term robotic missions."

Associate Administrator for Exploration, Dr. Michael D. Griffin, has been
reassigned as the agency's Chief Engineer.

"Dr.  Griffin and his organization have served NASA well in charting a course
for the future," said Goldin. "The redesigned space station and our robotic
missions are the beginning and must be our priority tasks in the near term."

The Office of Space Science was created as part of a series of organizational
changes announced March 11, 1993.  At that time, it was identified as the
Office of Planetary Science and Astrophysics. The Office is headed by Dr.
Wesley J. Huntress, Jr., the Associate Administrator for Space Science.

 -END OF FILE-
----------
From the "JPL Universe"
 March 26, 1993

ACRIM, ATMOS set for shuttle flight
 By Karre Marino

     As part of NASA's Mission to Planet Earth series, JPL's
 Atmospheric Trace Molecule Spectroscopy (ATMOS) and the Active
 Cavity Radiometer Irradiance Monitor (ACRIM) will be on board the
 Space Shuttle Discovery, when it is launched sometime during the
 early part of April. The two instruments will study the chemical
 composition of the atmosphere and how it is changing, and will
 measure solar variations and their impact on the earth's climate,
 respectively.
     ATMOS, which is intended to fly aboard the shuttle about
 once every year, uses a technique called infrared solar
 occultation spectroscopy, which Mike Gunson, ATMOS' principal
 investigator, described as "taking sunlight -- and particularly
 sunlight at infrared wavelengths -- to create a spectrum.
     "As the sun's rays pass through the earth's atmosphere at
 sunset or sunrise, the sunlight is absorbed by gases in the
 atmosphere," Gunson said. "If you can produce a spectrum, you can
 see how much of that infrared sunlight is absorbed at different
 wavelengths and characterize which trace gases and how much of
 these gases is present in the atmosphere."
     Gunson, from the Atmospheric and Oceanographic Sciences
 Section 322, indicated that the window of opportunity is small.
 "During each orbital sunrise or sunset, ATMOS must take a very
 rapid series of observations. Since the sun's rays begin well
 above the Earth, and take just a few minutes to go behind the
 Earth," he explained, "we try to get about 100 measurements in
 two to three minutes." Even in such a constrained time period,
 Gunson said the team gathers "a huge volume of data."
     Each of these measurements is a high-resolution infrared
 spectrum containing some million points of data. And through each
 mission, Gunson said tens of gigabytes of data are accumulated.
     ATMOS will focus on the middle atmosphere ("from a few
 kilometers above us up to 150 kilometers") to discern how its
 composition is changing. "We want to measure as many different
 gases as we can," he said. "The trace gases -- those over and
 above nitrogen and oxygen -- include chlorofluorocarbons;
 measuring these will enable us to learn what processes in the
 stratosphere turn them into inorganic chlorine and how exactly
 this happens."
     While ATMOS does not measure chlorine monoxide, the gas
 directly involved in ozone destruction, it does measure the other
 forms of chlorine-containing gases.
     "So what we have from an experiment like ATMOS is a snapshot
 inventory of what's in the stratosphere. We can use these
 vertical-distribution profiles for each of these gases to help
 modelers to predict how the atmosphere will change."
     Gunson said that gathering the information creates a
 reference point for future comparisons, "which tells us how the
 atmosphere is changing."
     ATMOS first flew in 1985 aboard Spacelab 3 and flew in a
 second mission in March 1992 aboard Atlas I. Important data were
 gathered during both flights. "Looking at these measurements, we
 have seen distinct changes in the atmosphere's composition."
     Those changes are not always a result of man. Gunson
 described last year's eruption of Mt. Pinatubo in the Philippines
 as providing the perfect opportunity to study how such natural
 occurrences affect the atmosphere. "Nine months after the volcano
 blew -- the biggest eruption of the century -- it was still
 spewing bits of material into the environment," he said. "The
 volcanic residue created an aerosol layer of fine droplets of
 sulfuric acid and water in the lower atmosphere. Of course, it
 was purely serendipitous that the volcano erupted, and we're able
 to measure its effects."
     Gunson said history has shown that large volcanic eruptions
 have an effect on climate; why is only partially understood.
 "Pinatubo caused changes in the mean temperature worldwide," he
 explained, noting that a National Oceanographic and Atmosphere
 Administration analysis indicated a slight cooling trend. The
 aerosol layer will last a year to 18 months, then will
 precipitate out. However, he expects some longer-term effects.
     In the future, Gunson and his team would like to launch
 during the fall, which allows them to look at the Antarctic,
 "where we know we'll find some very interesting chemistry going
 on."
     He said the importance of ATMOS is seen in repeating these
 measurements over a decade or longer. "We provide measurements
 that the scientific community at large can pull together and make
 sense of. Our overall goal is to gather data with all these
 different settings -- solar output, the state of the atmosphere.
 This is part of NASA's large-scale program to which we all make
 our own small contribution."
     Making its own contribution is the ACRIM instrument, which
 will monitor and verify total solar irradiance (TSI) variability,
 providing reference comparisons with other solar monitors on
 satellites that are required to understand the sun's long-term
 behavior.
     According to Dr. Richard Willson, principal investigator of
 the ACRIM experiments, the earth's climatological mean is
 determined solely by how much of the sun's radiant energy -- our
 only source of heat and light -- falls on the planet's surface,
 oceans and atmosphere.
     The Atlas/ACRIM results, he said, will assist researchers in
 understanding the role of TSI variability in climate change.
 While JPL currently has the ACRIM II instrument on the Upper
 Atmosphere Research Satellite (UARS), "instruments on other
 satellites and/or the shuttle are required for comparisons with
 the results of ACRIM II to provide backup observations," Willson
 said.
     This comparative/backup role played by ACRIM's upcoming
 shuttle mission is helpful in several ways, Willson said. Most
 importantly, if the currently operating UARS/ACRIM II should
 cease functioning before ACRIM III is launched (projected for
 2002), the shuttle ACRIM results would be used to compare
 UARS/ACRIM II and ACRIM III.
     "The ACRIM instrumentation," Willson said, "although state
 of the art in the solar-measurement field, is not sufficiently
 accurate to sustain the required long-term precision in the TSI
 database should an interruption in the train of succeeding
 satellite monitors occur."
     Willson said sustained changes in TSI of "as small as 0.5
 percent per century" could cause all the climate variability
 known to have occurred in the past, and to detect solar
 variability at that small rate requires that the long-term TSI
 variability database be constructed with a precision equal to the
 in-orbit precision of the monitoring instrumentation. The only
 way to obtain this precision, he said, is to compare succeeding
 satellite solar monitors directly or compare both of them with an
 experiment like ACRIM.
     Willson, who works in the Atmospheric and Oceanographic
 Science Section 324, and his team are interested in the shuttle
 ACRIM observations, which he termed as "third-party experiments
 that can relate one satellite's of results to another's at the
 level of precision defined by all three instruments."
     Willson said the ATLAS/ ACRIM instrument's results, although
 just snapshots of TSI during week-long missions once per year,
 will thereby contribute to an understanding of the long-term
 database.
     "Solar monitoring by the first ACRIM experiment on the Solar
 Maximum Mission from 1980-89 showed that there is a solar cycle
 component of variability: TSI is directly proportional to solar
 magnetic activity, demonstrating an 0.1 percent peak-to-peak
 variation over solar cycles 21 and 22 (the last sun spot cycle).
 That in itself may be too small to have an observable effect on
 climate," he said, "but we're interested in whether this little
 0.1 percent `wiggle' over a solar cycle is superposed on
 longer-term, larger-amplitude variability. Periods of 80 to
 several hundred years are suspected to exist with amplitudes of 1
 percent or more. TSI variability is suspected to have caused
 known past climate changes on these time scales."
     Willson noted, however, that such subtle changes in TSI will
 be very difficult to detect since the results of many satellites'
 instruments must be used over many decades or even centuries to
 prove definitively that solar variability causes climate change.
     The only hope of providing a sufficiently precise TSI
 database over these time scales, he said, is to relate the
 results of solar-monitoring experiments at the level of
 instrument precision, which is orders of magnitude smaller than
 instrument accuracy. While this is ACRIM's third shuttle flight,
 Willson said that they have yet to determine whether the shuttle
 experimental environment will be adequate for the task of
 providing "third-party" observations.
     "We have had our share of problems trying to make good
 measurements aboard the shuttle," he said. "The first attempt was
 as part of the Spacelab 1 Mission in 1983, and the large array of
 experiments on board overwhelmed shuttle resources. Additionally,
 some of the untested, new shuttle instrumentation experienced
 mechanical and electrical problems.
     "Our ACRIM experiment functioned flawlessly, but it was
 attached to an ESA-provided command/data interface that ceased
 functioning when it was warmed by the sun. This resulted in our
 getting only an hour's worth of data when we'd been expecting
 about 25 hours," he added.
     Willson said that on ACRIM's second flight, aboard Atlas I,
 the shuttle systems functioned well, as did ACRIM, and a full set
 of results was acquired. "We made real-time comparisons with the
 UARS/ACRIM II experiment, providing a potentially useful
 reference point for the future."
     The upcoming Atlas II mission "should help us tie down the
 quality of observations we can expect from ACRIM in the shuttle
 environment." Willson said data will be received in real time, as
 they "pull it straight off the downlink, crunch the numbers and
 offer feedback to the Marshall Space Flight Center in Huntsville,
 Ala. We will have results within minutes of the actual
 measurement," he said.
     "Both climatologists and solar physicists are keenly
 interested in variations of TSI. Those monitoring the impact of
 increasing `greenhouse gases' on the earth are especially
 concerned."

 -END OF FILE-
----------
From the "JPL Universe"
 March 26, 1993

O'Toole discusses NASA's future
 By Karre Marino

     In an address on NASA's history and its future in a changing
 American economy March 16, Dr. Richard O'Toole, JPL's manager of
 legislative affairs, began with some humor, telling the audience
 that  "economists are people who are good with numbers, but don't
 have the personality to be accountants." The light mood, however,
 certainly belied the serious road ahead, as in the struggle for
 federal dollars, NASA will have to undertake a variety of steps
 to ensure it receives about $14 to $15 billion annually.
     O'Toole told a near-capacity crowd in von Karman Auditorium
 that the economically unrestrained days of the '60s are gone.
 "Those Apollo days are over. We have to get on with it." The late
 1980s -- the era of the Space Shuttle Challenger accident -- he
 said, signaled that NASA was in trouble. "NASA misperceived the
 funding increases it received after Challenger. It took them to
 be a long-term commitment that would continue indefinitely." The
 space agency was wrong. "Congress never bought into an
 Apollo-scale program," he explained. Indeed, he said, unless NASA
 can demonstrate that its projects have substantial societal
 value, they will be threatened in the future.
     Looking ahead, O'Toole indicated that the structural changes
 in the economy --fewer high-paying manufacturing jobs, less
 domestic gross product devoted to public investment, tax revenues
 of 19 percent that attempt to pay for expenditures of 25 percent,
 a lower-wage base, and a staggering federal deficit -- would call
 for a restructuring of NASA's own approach and the way it
 justifies its program. He explained that while the Clinton/Gore
 plan would call for sacrifice from all sectors of society, it
 encourages the very thing that NASA and labs like JPL do best --
 create technologies that can stimulate growth in the decades
 ahead.
     The trick, he said, is to redefine NASA's role, "to be
 consistent with the President's plan. It is about strengthening
 the link between NASA projects and competitiveness via
 technology, as well as fostering technological developments that
 lead to industrial competitiveness. The emphasis must be on a
 transfer of technology from the lab setting to private industry.
 NASA must push advances in space technology to help make U.S.
 technology more competitive."
     O'Toole also delineated the challenge that faces NASA
 Administrator Daniel Goldin. "He must redefine NASA's mission to
 meet this new environment. There is no entitlement for NASA; the
 space race is over. Projects now must stand on their own merit to
 meet society's needs." That includes shifting resources to
 support more important programs -- technology, human exploration,
 Mission to Planet Earth and space science.
     But the bottom line, O'Toole indicated, is that Goldin
 doesn't expect an influx of money for NASA, so he must ensure
 that the agency can do more by conducting more frequent, less
 costly missions. The NASA administrator is also attempting to
 encourage risk taking via smaller projects. "Cheaper projects are
 often more visible, the results more apparent," according to
 O'Toole. That means Congress and the public place more value on
 NASA's role.
     JPL is not lost in this new view. O'Toole said that "we must
 bring our strategy in line with the new external reality."
 Concepts like the Mars Rover/Sample Return that approached the
 $10 billion mark are no longer viable, he explained. Innovative
 ideas like the Mars Network -- with a $1 billion price tag -- are
 those that should be developed, he said.
     JPL Director Dr. Edward Stone's moves to cut the Lab's work
 force, for instance -- before it was mandated by others -- was an
 excellent idea, he added. "We get credit for such action. Our
 credibility goes up when people perceive that we're doing what is
 necessary -- and inevitable -- before we're forced to."
     In the end, O'Toole said, NASA will have to prove its value
 in contributing to solving real problems -- and its relation to
 all of America -- as it seeks funding. "The space program must
 show its relevance to all segments of society. We have to reach
 out to women and the minority community, more than we have in the
 past."
                           ###

 -END OF FILE-
----------
STS-55 Update:

The Check Valve which Leaked has been Isolated to the one in the Oxidizer
Preburner Augmented Spark Igniter (ASI) Line. This is part of the line which
takes a small amount of LOX and some H2 in a cavity at the top of the Oxidizer
Preburner where two Spark Igniters supply the Ignition source for the Oxidizer
Preburner. This Check Valve has been removed and flown back to the design
center in California for Failure Analysis.

The following is an UNOFFICIAL launch schedule (Pending outcome of the failure
analysis). Remember this is unofficial and subject to change but it is what we
are currently working to.

April 6  STS-56 OV-103 Discovery [Engines 2024/2033/2018]

April 23 STS-55 OV-102 Columbia  [Engines 2031/2109/2029]

May 18   STS-57 OV-105 Endeavour [Engines 2019/2034/2017]

---------------------------------------------------------------------
 Bob Waterman / NASA Space Shuttle Main Engine Avionics
 [e-mail]
 Disclaimer: This is NOT an Official NASA statement...I'm Just an Engineer
 ---------------------------------------------------------------------

 -END OF FILE-
----------
Press Release Nr.15-93
Paris, 23 March 1993

Spacelab D2 crew back in Houston

As announced by NASA, the Shuttle Columbia has had an
aborted launch on Monday 22 March and it is presently
expected that the countdown for the Spacelab D2 mission will
not be resumed before three weeks.

The following measures being carried out on the Shuttle
illustrate the complexity of the inspection procedures that have
begun :
The external tank has already been emptied, and the cooling
units for the biological samples in the orbiter have been set to
"zero".
On Tuesday 23 March, (local time at Cape Canaveral in
Florida), the servicing gantry has been brought back alongside
the Shuttle, and the biological experiments and experiment
racks have then been removed from the mid-deck.
The orbiter will then be reconnected to external supplies, and
on Tuesday 23 March in the evening NASA's servicing teams
will be draining the supercooled fuels from their various tanks.

On Wednesday 24 March, the suspect valves will be removed
from the propulsion system for inspection, and on Thursday
25 March the Shuttle's ignition mechanisms will be
dismantled. Maintenance work will also be done on the
Spacelab module.

On Monday 22 March in the evening, the entire crew was
flown back to Houston, where they will remain in readiness
for a continuation of the mission and the Space Shuttle system
is now fully secured.

This Spacelab flight- the 7th for the ESA developed manned
orbiting laboratory- is carrying 92 experiments, 32 of them
being developed with ESA funding. The responsibility for the
complete scientific programme is in the hands of DLR- the
German Aerospace Research Establishment.

The ESA facilities onboard Spacelab include mainly
Anthrorack and the Advanced Fluid Physics Module (AFPM),
(see ESA Release Nr 11-93).

 -END OF FILE-
----------
PHYSICS NEWS UPDATE A digest of physics news items prepared by Phillip F.
Schewe, AIP Public Information Number 120   March 26, 1993

LIGHT WAVES CAN BE USED AS A LENS to focus a beam of neutral atoms, creating
the possibility of a fundamentally new form of submicron lithography.  At the
APS meeting in Seattle this week, Gregory Timp of AT&T Bell Labs reported on
an experiment in which a stream of sodium atoms, cooled to mK temperatures in
an "optical molasses" setup and gently steered by the electric fields of an
optical standing wave, were deposited on a silicon substrate in a series of
closely spaced (less than 300 nm) lines.  A comparable grating pattern can be
created using transmission electron microscopy, but Timp believes that his
line spacings and line widths can be greatly reduced as his technique is
further refined.  Furthermore, he hopes that with additional focusing he will
be able to produce not just well collimated lines but also spots (quantum
dots).  Sodium atoms are easy to manipulate but are chemically reactive and
therefore not suitable for doing lithography, so Timp will try indium atoms
next.  At the same meeting, Robert Celotta of NIST reported on the laser
manipulation of neutral chromium atoms.

CARBON BUCKYTUBES are nanoscopic in width but potentially macroscopic in
length.  Richard Smalley of Rice University said at the APS meeting that he
had tapered to a thin point one of the two graphite electrodes used in making
fullerenes (in an electric arc) and that he hoped to use this configuration to
make nanotubes with lengths of centimeters or more.  Such tubes would be
stronger than any other known fiber, according to Smalley, and because of its
nm diameter would be invisible to the eye (besides which you would cut your
hand trying to hold one).  Actually the nanotubes produced so far (only
microns in length) usually appear not singly but in bundles and groups of
bundles in a tendon-like hierarchy.  The tubes can also be concentric and can
be used as containers for lead atoms (which, squeezed into a line only a few
atoms abreast, constitute the world's thinnest wire); these discoveries were
reported in January by scientists at NEC Corporation in Japan.  Thomas Ebbeson
of NEC said at the APS meeting that his colleagues were now also studying
other metals in addition to lead, and that carbon nanotubes may be useful for
studying one-dimensional chemistry.

POLYMERS CAN BE USED TO MAKE HOLOGRAMS.  At the APS meeting, W.E. Moerner of
IBM Almaden reported on the optical properties of a new polymer, a composite
chain molecule called PVK:F-DEANST:TNF.  In this material the photorefractive
effect---a nonlinear optical effect in which laser light causes the migration
and then selective storage of charges in various parts of the polymer---is
particularly strong, as strong as in some conventional inorganic
photorefractive crystals.  Moerner has already used the polymer to make a 125-
micron-thick hologram in which two laser beams are combined to write and read
information.  If the diffraction efficiency, one measure of the brightness of
the hologram image, could be improved from the current 1% to as high as 10%,
then potential applications could ensue.  These include erasable, high-
density, rapid-access storage of information (eventually the Encyclopedia
Britannica stored on a dime-sized hologram).  Polymer holograms will be
cheaper and more easily formable than inorganic crystalline holograms, said
Moerner.

 -END OF FILE-
----------
This is a digest of the April 1993 issue of Physics World magazine.  Contact
me if you'd like more details.

Many thanks,

Mark Ware [phone] (tel) [phone] (fax) =========================

PHYSICS WORLD DIGEST, APRIL ISSUE:

Threats to measurement

The UK's National Physical Laboratory is set to have its government funding
cut by 30%, with some programme budgets being more than halved. As explained
in a news item and the leading article, this threatens the UK's manufacturing
base to a much greater extent than many people might imagine, and runs
contrary to trends in other countries. (pp3,7)

Physicists transmuted into nuclear waste

Everybody knows that the UK's nuclear industry is in difficulties, but what is
happening to its employees, and physicists in particular? An anonymous article
by a reactor physicist gives a first-hand account of the effect on staff of
the closing down of fast-reactor research, and highlights the contrasting
public reactions to this development and to threatened closures of coal mines.
A news article provides a broader picture of loss of employment across the
UK's nuclear industry. (pp8,24)

School tests impossible

National curriculum tests of 16-year-olds' experimental abilities expect the
impossible, say science teachers. The highest levels of attainment-target AT1
require students not only to devise and carry out experiments but also to
hypothesise about the results. Teachers from state and independent schools are
reporting that they cannot devise adequate tests of such skills. The first
GCSE exams involving AT1 are due next year, with students already en route.
(p14)

The incredible shrinking space station

Just what is space station Freedom supposed to do? Microgravity experiments
look ever less relevant. "The only thing Freedom might discover is a bag of
you-know-what jettisoned from space station Mir", says physicist Robert Park.
And as the Clinton administration "descopes" the thing - the sixth
"downsizing" in nine years - it begins to look more and more like Mir anyway.
Says Park: Clinton should do the decent thing and kill it. (p21)


Adventures in wavepacket land

Ultrashort laser pulses are making it possible to study the quantum mechanics
of molecules on timescales less than one millionth of a millionth of a second.
Ultimately this could allow much greater control of industrially important
chemical reactions. This article looks at the theoretical and computational
techniques being used to model these interactions. (p46)

Contact: Stig Stenholm, University of Helsinki, Finland [phone]

Images of amorphous silicon

Fax machines, displays, photovoltaic solar cells, medical X-ray systems -
amorphous silicon plays a key role in all. Bob Street describes the technical
triumphs and the obstacles that remain in fulfilling this fascinating
semiconductor material's potential. (p54)

Contact: Bob Street, Xerox Palo Alto Research Center, US [phone]

Surface studies on the rebound

Helium atom scattering is a new technique for studying solid surfaces - its
high sensitivity and nondestructive nature provide information not accessible
by any other method. Its particular strengths are in looking at surface
"phonons" (vibrations in the atomic lattice), detecting surface defects, and
acting as a high-resolution probe of surface atomic structure. (p61)

Contact: Peter Toennies, Max Planck Institute for Fluid Dynamics Research,
G_ttingen, Germany  [phone]