MARSBUGS:  
The Electronic Exobiology Newsletter
Volume 5, Number 12, 5 May 1998.

Editors:

David Thomas, Department of Biological Sciences, University of 
Idaho, Moscow, ID, 83844-3051, USA, thoma457@uidaho.edu or 
Marsbugs@aol.com.

Julian Hiscox, Division of Molecular Biology, IAH Compton 
Laboratory, Berkshire, RG20 7NN, UK.  Julian.Hiscox@bbsrc.ac.uk or 
Marsbug@msn.com

MARSBUGS is published on a weekly to quarterly basis as warranted 
by the number of articles and announcements.  Copyright of this 
compilation exists with the editors, except for specific articles, 
in which instance copyright exists with the author/authors.  E-
mail subscriptions are free, and may be obtained by contacting 
either of the editors.  Article contributions are welcome, and 
should be submitted to either of the two editors.  Contributions 
should include a short biographical statement about the author(s) 
along with the author(s)' correspondence address.  Subscribers are 
advised to make appropriate inquiries before joining societies, 
ordering goods etc.  Back issues and Word97 files suitable for 
printing may be obtained via anonymous FTP at:  
ftp.uidaho.edu/pub/mmbb/marsbugs.  Also, an official web page is 
under construction.  Currently it is part of 
http://members.aol.com/marsbugs/dave.html (right now, the page 
simply points to the FTP site).

The purpose of this newsletter is to provide a channel of 
information for scientists, educators and other persons interested 
in exobiology and related fields.  This newsletter is not intended 
to replace peer-reviewed journals, but to supplement them.  We, 
the editors, envision MARSBUGS as a medium in which people can 
informally present ideas for investigation, questions about 
exobiology, and announcements of upcoming events.

Exobiology is still a relatively young field, and new ideas may 
come out of the most unexpected places.  Subjects may include, but 
are not limited to:  exobiology proper (life on other planets), 
the search for extraterrestrial intelligence (SETI), ecopoeisis/ 
terraformation, Earth from space, planetary biology, primordial 
evolution, space physiology, biological life support systems, and 
human habitation of space and other planets.
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INDEX

1)	A DIPOLAR MAGNETIC FIELD AND THE IMPLICATIONS FOR A POSSIBLE 
ANCIENT MARTIAN LIFE.
By Richard Taylor

2)	HYDROTHERMAL ECOSYSTEMS ON PRESENT DAY MARS
By Christopher P. McKay

3)	PATHFINDER LANDING SITE OBSERVED BY MARS ORBITER CAMERA
From the Mars Global Surveyor Home Page

4)	CITIES TEAM WITH NASA AND EPA FOR "URBAN FORESTS" STUDY
NASA release 98-73

5)	EDUCATORS, COMMUNITY MEMBERS ONBOARD FOR JUPITER AND COMET 
MISSIONS
JPL release

6)	FUTURE MARS PROBE, OZONE RESEARCH, AND STUDENT EXPERIMENTS 
JOIN ALL-CANADIAN ROCKET MISSION
CSA release

7)	THIS WEEK ON GALILEO
JPL release

8)	STARDUST STATUS REPORTS
By Ken Atkins

9)	MARS GLOBAL SURVEYOR MISSION STATUS REPORTS
JPL releases

10)	1998 MARS SURVEYOR PROJECT STATUS REPORTS
By John McNamee

11)	JPL's OPEN HOUSE FEATURES PAST, PRESENT AND FUTURE IN SPACE
JPL release
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A DIPOLAR MAGNETIC FIELD AND THE IMPLICATIONS FOR A POSSIBLE 
ANCIENT MARTIAN LIFE.
By Richard Taylor
Probably Research Group, London, UK

Paradoxically, it is quite often by unexpected routes and through 
the law of unforeseen consequences that new, and often at first 
circumstantial, evidence favoring life on Mars appears.  This 
happened with the SNC meteorites, and most recently the Mars 
Global Surveyor (MGS) spacecraft may have performed a similar 
function.  At the low-point of a number of the early aerobraking 
passes the MGS magnetometer detected unmistakable signs of a 
dipolar magnetic field of about one-eight-hundredth of the 
terrestrial value.  Successive close passages revealed that Mars 
to posses at least eight or nine magnetic anomalies each a few 
hundred kilometers in extent.  These differ significantly in 
strength and their direction of magnetic polarity - the field 
appears to have inverted from time to time like that of the Earth.  
The greatest field strength measured so far by the MGS 
magnetometer at about 110 km above the Martian surface is 400 nT 
(nanoteslas) about 1/75 of the Earth's global field at similar 
altitude.  This remnant field strength suggests that the original 
dynamo field must have been considerably stronger - may be 10% or 
more of the current terrestrial value.

One of the interesting discoveries reported by McKay et al., 
regarding ALH84001 was the presence of magnetite particles closely 
similar to magnetosomes found in bacteria on Earth.  In 
terrestrial cells these particles act as a kind of compass and 
allow the microorganism to orient itself in Earth's magnetic 
field.  Prior to the MGS magnetometer data Mars was believed to 
have a magnetic field no greater than one ten-thousanth of the 
strength of the terrestrial value.  To produce the type of 
magnetite particles found in ALH84001 the processes involved are 
far from equilibrium and hence can be performed more easily by 
biology than by chemical and physical means.  However, at the time 
of the investigation there seemed no grounds for concluding that 
the Martian 'magentosomes' would be of any value in helping a 
Martian microorganism orient itself in the absence of a 
significant dipolar magnetic field.  The significance of the MGS 
discovery as a factor effecting the origin and early evolution of 
life on Mars should not be underestimated as it suggests that the 
simpler biological explanation, satisfying Occam's razor, rather 
than the far more complicated and improbable succession of 
unrelated physical-chemical equilibrium processes, can be used to 
account for the presence of magnetofossils in ALH84001.  Thus the 
ALH84001 magnetosomes may really have acted as compasses within 
living Martian microbial cells when the meteorite was still part 
of Mars.  Even if the claimed fossil life forms within the Martian 
meteorite turn out merely to be mineral artifacts, and the work 
reported by Bada, confirms some degree of biochemical 
contamination, the case for life on early Mars still cannot be 
ruled out.

The real problems lie in interpreting the observational, 
experimental and circumstantial evidence we have gained to date 
and are accumulating at an ever-growing rate.  There may be no way 
of reaching a conclusion, that is obtaining a firm answer to the 
question as to whether there life on Mars or not, without the 
human exploration of the planet.  To answer this age-old question 
a manned mission to Mars may be essential.
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HYDROTHERMAL ECOSYSTEMS ON PRESENT DAY MARS
By Christopher P. McKay
NASA Ames Research Center

The Viking results indicate that the surface of Mars is too dry to 
support life.  However, there has been renewed in the possibility 
of subsurface life on Mars (Boston et al., 1992).  The heat of 
geothermal or volcanic activity melting permafrost or other 
subsurface water sources could provide liquid water.

For subsurface life the problem is energy.  On Earth, the 
predominant energy source for life (by at least six orders of 
magnitude) is sunlight.  Even the deep-sea hydrothermal vent 
communities rely on the O2 produced by phototrophs at the surface.  
The reaction that powers these vents is 2H2S + 3O2 => 2H2O + 2SO2.  
Recently deep subsurface ecosystems have been discovered that are 
independent of sunlight (Stevens and McKinley 1995).  These 
systems derive their energy from the reaction 4H2 + CO2 => 2H2O + 
CH4.  The H2 is produced by the oxidation of the basalt rocks by 
water.  This system represents an independent, albeit tiny, 
ecosystem based purely on chemical energy, not sunlight.  On Mars, 
gases from volcanic activity deep in the planet could provide 
reducing power (as CH4, H2, or H2S) percolating up from below and 
enabling the development of a microbial community based upon 
chemolithoautotrophy, especially methanogens that use H2 and CO2 in 
the production of CH4.  With a source of hot water, all the 
ingredients for this subsurface habitat are present on Mars; CO2 
comprises the bulk of the martian atmosphere and basaltic rocks 
are abundant.

The possibility of subsurface life on Mars today depends on the 
existence of hydrothermal systems. However, it certainly seems 
clear that volcanic activity on Mars has diminished over 
geological time.  Nonetheless, as discussed previously, there is 
intriguing evidence for recent (on the geological time scale) 
volcanic activity in the SNC meteorites.  Volcanic activity by 
itself does not provide a suitable habitat for life--liquid water 
presumably derived from the melting of ground ice is also 
required.  It is likely that, any volcanic source in the 
equatorial region would have depleted any initial reservoir of 
ground ice and there would be no mechanism for renewal.  Closer to 
the poles ground ice is stable.  It is conceivable that a 
geothermal heat source could result in cycling of water through 
the cryosphere.  The heat source would be melting and drawing in 
water from any underlying reservoir of groundwater or ice that 
might exist.

The D/H measurements of water in the SNC meteorites shows that it 
has an enrichment of D about equal to that in the present martian 
atmosphere.  Assuming that this enhancement is due atmospheric 
escape then this similarity suggests that there was an exchange 
between that atmosphere and the rocks from which the SNC 
meteorites derived.  Probably this exchange involved hydrothermal 
groundwater systems driven by volcanism or impact events.

Such hypothetical ecosystems are neither supported, nor excluded, 
by current observations of Mars.  Tests for such a subsurface 
system involve locating active geothermal areas associated with 
ground ice or detecting trace quantities of reduced atmospheric 
gases that would leak from such a system.

Boston, P.J., M.V. Ivanov, and C.P. McKay 1992.  On the 
possibility of chemosynthetic ecosystems in subsurface habitats on 
Mars.  Icarus, 95, 300-308.

Stevens, T.O. and J.P. McKinley 1995.  Lithoautotrophic microbial 
ecosystems in deep basalt aquifers.  Science 270, 450-454.
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PATHFINDER LANDING SITE OBSERVED BY MARS ORBITER CAMERA
From the Mars Global Surveyor Home Page:
http://mars.jpl.nasa.gov/mgs/msss/camera/images/4_25_98_pathfinder
_release/index.html

25 April 1998

[Editor's note:  these images may be viewed at the web address 
shown above.  They are also included in the Word version of 
Marsbugs found at the Marsbugs FTP site.  DJT]

(A)[Image] (B)[Image] (C)[Image]

To view images, click on image size links, below

(A)	Viking Orbiter image of location of Pathfinder landing site 
landmarks (mercator projection, scale 30 m (100 feet) per pixel) 
(GIF = 475 KB)

(B)	MOC 25603, showing Pathfinder site at roughly 6.6 m (21.5 
feet) per pixel (GIF = 724 KB)

(C)	MOC 23703 and 25603, showing "Big Crater" in stereoscopic 
viewing at roughly 5m (16.4 feet) per pixel (JPG = 238 KB).  Note:  
stereo effect is seen when right eye views through red filter.

Caption

On its 256th orbit of Mars, the camera on-board the Mars Global 
Surveyor spacecraft successfully observed the vicinity of the 
Pathfinder landing site.  The images shown above include a Viking 
image at roughly 30 m (100 feet) scale, and a portion of the MOC 
image reproduced at a scale of 6.6 m (21.5 feet) per pixel.  Also 
included is a stereoscopic image pair in anaglyph format, made 
from the overlapping area of MOC 25603 and 23703.  This image is 
reproduced at a scale of 5 m (16.4 feet) per pixel.  Image 23703 
was acquired on 13 April at 7:50 AM PDT; Image 25603 was acquired 
on 22 April at 1:11 PM PDT.  The P237 observation was made from a 
distance of 675 km while the P256 measurement was made from 800 
km.  The viewing angle for 23703 was 21.2, for 25603, 30.67, 
giving an angular difference of about 9.5.  Owing to the relief 
on "Big Crater," this relatively small angular difference was in 
this case sufficient to show good stereo parallax.

The resolution of the MOC image that covered the Pathfinder 
landing site (MOC 25603) was about 3.3 m or 11 feet per pixel.  
The Pathfinder lander and airbags form a roughly equilateral 
triangle 5 m on a side.  Noting that the camera has not yet been 
focussed (it needs to be in the stable temperature conditions of 
the low altitude, circular mapping orbit in order to achieve best 
focus) and the hazy atmospheric conditions, the effective scale of 
the image is probably closer to 5 m (16.4 feet).  Thus, the scale 
of the image was insufficient to resolve the lander (more than one 
pixel is needed to resolve a feature).  In addition, the 
relatively high sun angle of the image (the sun was 40 above the 
horizon) reduced the length of shadows (for example, only a few 
boulders are seen), also decreasing the ability to discriminate 
small features.  Work continues to locate intermediate-scale 
features in the lander and orbiter images in the hope of 
identifying the precise landing site based on these comparisons.

Malin Space Science Systems and the California Institute of 
Technology built the MOC using spare hardware from the Mars 
Observer mission.  MSSS operates the camera from its facilities in 
San Diego, CA.  The Jet Propulsion Laboratory's Mars Surveyor 
Operations Project operates the Mars Global Surveyor spacecraft 
with its industrial partner, Lockheed Martin Astronautics, from 
facilities in Pasadena, CA and Denver, CO.
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CITIES TEAM WITH NASA AND EPA FOR "URBAN FORESTS" STUDY
NASA release 98-73

1 May 1998

Three U.S. cities will partner with NASA and the Environmental 
Protection Agency (EPA) to study how strategically placed "urban 
forests" and the use of reflective surfaces may help cool cities, 
reduce pollution, lower energy bills, modify growth plans and help 
mitigate further deterioration of air quality.  Slated to 
participate in the study, scheduled for May and June, are Baton 
Rouge, LA; Sacramento, CA; and Salt Lake City, UT.

Researchers from NASA's Marshall Space Flight Center, Huntsville, 
AL, will study bubble-like accumulations of hot air, called urban 
heat islands, and how these change between day and night.  Heat 
islands develop over cities as naturally vegetated surfaces are 
replaced with asphalt, concrete, rooftops and other man-made 
materials.

"The artificial materials store much of the Sun's energy and 
remain hot long after sunset," said the experiment's lead 
investigator, Dr. Jeff Luvall of the Global Hydrology and Climate 
Center at Marshall.  "This produces a dome of elevated 
temperatures over a city, 5-10 degrees higher than air 
temperatures over adjacent rural areas," he explained.

"The more a city grows--replacing trees and grass with buildings 
and roads--the warmer it becomes, increasing peak electricity 
demands.  To meet these demands, power plants must utilize fossil 
fuels to a greater extent, which ultimately has a negative impact 
on air quality," said Luvall.

To better understand which surfaces contribute or drive the 
development of heat islands, an aircraft equipped with thermal 
imaging equipment will fly over the three cities taking high 
resolution thermal measurements.  Researchers also will use 
thermal satellite imagery to map and measure "hot spots" and 
visible energy rising up into the lower atmosphere of the target 
cities.

Science team members will use the thermal imagery in 
meteorological and air quality models, allowing researchers to 
better understand how cities in different locations and with 
different land use characteristics impact local and regional 
climate.

Additionally, the EPA will use the satellite imagery to determine 
how urban heat islands contribute to the ground-level generation 
of ozone.  Not to be confused with the ozone layer protecting 
Earth from ultraviolet rays, ground-level ozone is a powerful and 
dangerous respiratory irritant found in cities during the summer's 
hottest months.

In findings from similar studies in Huntsville and Atlanta, GA, 
researchers have learned that parks and other urban areas with 
trees and grass are cooler than parking lots and areas with a high 
concentration of buildings.

"These 'green areas' are cooler because they dissipate solar 
energy by using it to evaporate water from leaves, thereby cooling 
the air," said the experiment's co-investigator, Dr. Dale 
Quattrochi of the Global Hydrology and Climate Center.

Researchers believe that cities could be "cooled" by reintroducing 
vegetated areas, such as "urban forests," into the cities.  
Certain varieties of trees shade buildings, preventing solar 
heating, and are able to naturally cool a city as they release 
moisture into the air and provide shade over urban surfaces.  
Another way to cool cities, the science team believes, is by using 
reflective surfaces, such as light-colored roofs, roads, and 
parking lots.  Light-colored surfaces reflect rather than absorb 
heat.

The researchers want to demonstrate that by "cooling" a city, it 
is possible to directly reduce energy use by buildings, which in 
turn reduces greenhouse gas emissions and ultimately improves the 
air quality.  Additionally, individuals, businesses and 
governments can save money by reducing the amount of energy 
consumed.  Based on the results of the project, the science team 
plans to disseminate its findings nationally so other cities also 
can incorporate what the team has learned into their long-range 
growth plans.

The study contributes to NASA's Earth Science enterprise.  The 
enterprise is responsible for a long-term, coordinated research 
effort to study the total Earth system and the effects of natural 
and human-induced changes on the global environment.  This project 
also is aimed at the enterprise's efforts to make the more near-
term economic and societal benefits of Earth science research and 
data products available to the broader community of public and 
private users.
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EDUCATORS, COMMUNITY MEMBERS ONBOARD FOR JUPITER AND COMET 
MISSIONS
JPL release

30 April 1998

Educators and community members from across the country have been 
selected from a field of hundreds of candidates to participate in 
educational training and grassroots programs sponsored by NASA's 
Galileo project and the Stardust comet sample return mission.

Both missions are managed for NASA by the Jet Propulsion 
Laboratory (JPL), Pasadena, CA.  These programs are part of 
ongoing JPL and NASA efforts to enhance science and math teacher 
training in U.S. schools, and to bring the excitement of space 
travel to the community level.

The Galileo project has named 55 new ambassadors and co-
ambassadors to educate the public in communities across America 
about the Galileo Europa mission's current journey around Jupiter 
and its moons.  The mission's main focus is on the moon Europa, 
which may have a liquid water ocean beneath its icy crust.  The 
addition of the new graduates, who span the country from northeast 
Maine to Hawaii, brings the total number of Galileo ambassadors to 
84.  Each ambassador has proposed at least five community events, 
such as planetarium shows, museum displays and programs for Boy 
Scouts and Girl Scouts.  The ambassadors, primarily K-12 
educators, join the recently appointed Galileo Fellows, who 
instruct other teachers in spreading the word about the Galileo 
mission.  A state-by-state listing of ambassadors, hometowns, 
contact information and a calendar of ambassador- hosted events 
can be found on the Internet at
http://www.jpl.nasa.gov/galileo/ambassadors.

The Stardust project, which will launch a spacecraft to a comet 
next February, has chosen the initial 10 educators from 10 states 
as Stardust Fellowship winners.  An additional 15 will be chosen 
in the fall.  The educators will receive intensive training on the 
mission and its science.  The training is designed to facilitate 
development of a nationwide teacher training initiative with 
supporting educational materials.  The effort is targeted at 
grades 4-8 and focuses on teaching students about small solar 
system bodies such as comets and asteroids.  Stardust's Fellows 
Program is part of an educational outreach partnership between the 
project, the Virginia-based Challenger Center for Space Science 
Education and Lockheed Martin Astronautics, Denver, CO, which is 
assembling the Stardust spacecraft.

Information on Stardust and its Educator Fellows can be found at 
http://stardust.jpl.nasa.gov.
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FUTURE MARS PROBE, OZONE RESEARCH, AND STUDENT EXPERIMENTS JOIN 
ALL-CANADIAN ROCKET MISSION
CSA release

The Canadian Space Agency's ACTIVE rocket mission will launch into 
space on Tuesday, April 28 at 8:00am EDT carrying a payload 
supporting two of Canada's most ambitious space science projects--
the future Mars Probe, Canada's first mission to Mars scheduled 
for launch in the summer of 1998; and OSIRIS, widely considered to 
be the world's most advanced ozone measuring instrument.

The ACTIVE payload will be launched from the SpacePort Canada 
commercial rocket range, located just outside Churchill, Manitoba.  
As part of the mission, CSA has arranged for local students from 
Churchill to also fly their own ozone-research experiments onboard 
the rocket.

Bristol Aerospace Limited of Winnipeg will supply a Black Brant 9 
rocket to take the CSA payload into space at a speed of 
approximately 3,500 km/hr to an altitude of 360km.  Bristol was 
also responsibe for the design and development of the payload 
support systems for the integration and test off the CSA science 
experiments and for range integration/test and launch support 
activities.

A Test Run for Canada's First Mission to Mars

The Auroral Composition and Toroidal Ion Velocity Experiment 
(ACTIVE) is an opportunity to test Canadas first scientific 
instrument to Mars, scheduled for launch from Japan in July 1998.  
Onboard the Japanese spacecraft Planet-B, the CSA's Thermal Plasma 
Analyser (TPA) will sample the Martian atmosphere upon its arrival 
in late 1999, measuring energetic particles similar to those that 
cause the Northern Lights above Canada.  These data will help 
scientists better understand Earth's own atmospheric systems and 
help prepare for future human trips and possible colonization of 
the Red Planet.  A prototype of the TPA instrument was refurbished 
for the ACTIVE mission, which will test the Mars probe and at the 
same time make important contributions to science closer to home.  
The ACTIVE principal investigator is Dr. Greg Garbe, University of 
Calgary and the TPA principal investigator is Dr. Andrew Yau, 
University of Calgary.

A Piece of the World's Most Ambitious Ozone Research Project

The POSSEX/MOZE suite of CSA instruments is designed to work in 
conjunction with Canada's most ambitious ozone-research project -- 
OSIRIS (Optical Spectrograph and Infra-Red Imaging System), 
scheduled to launch on a Swedish scientific satellite in March 
1999.  POSSEX will measure the polarization of the scattered 
sunlight in the atmosphere using four photometers.  Results from 
this experiment will be used to provide more thorough analysis of 
the OSIRIS data.  The MOZE experiment is a student project to 
measure ozone concentration as a function of altitude.The 
principal investigator for the OSIRIS experiment is Dr. Ted 
Llewellyn, University of Saskatchewan and the principal 
investigator for POSSEX is Dr. Wayne Evans, Trent University.

A GPS Test Flight by Calgary Company

In addition, the ACTIVE mission will test a prototype global 
positioning system from Novatel of Calgary that will provide 
accurate positional information of the rocket throughout its 
flight.

Student Activities

As part of its Space Education and Awareness outreach program, the 
Canadian Space Agency has arranged for the participation of 
students from Churchill's Duke of Marlborough High School.

The student portion of the rocket payload, named MOZE (Measurement 
of Ozone Experiment), will measure ozone concentration in the 
atmosphere as a function of altitude.  It will use two photometers 
of the same type as the CSA's POSSEX experiment, but with 
different filters.

Under the direction of science teacher Doug Isaak, the Churchill 
science students have been working on a number of mission-related 
projects about the atmosphere, space and the environment.  The 
students, from grades seven to 10, have been "consulting" with 
mentors Dr. Wayne Evans of Trent University and Dr. Ted Llewellyn 
of the University of Saskatchewan, who together are among Canada's 
leading ozone researchers.  The students received a pre-flight 
visit and "briefing" from Dr. Llewellyn in late March.

As part of their research, the Churchill students visited Ottawa 
in February to meet with representatives from the Canadian Space 
Agency and Routes Inc., the Kanata-based space-engineering firm 
that developed the ozone instruments for this mission.  In March, 
the students visited Bristol Aerospace in Winnipeg for a tour of 
their facilities and to "inspect" their payload during its 
integration into the Bristol Black Brant 9 rocket being used for 
the ACTIVE mission.

The students will see the cumulative sum of their efforts take off 
at the April 27 launch at SpacePort Canada, near Churchill.  
During a post-launch reception, students will make a public 
presentation based on the real-time data collected from the ACTIVE 
launch.

For more information:
Isabelle Hudon
Manager, Media Relations
Canadian Space Agency
(514) 926-4350
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THIS WEEK ON GALILEO
JPL release

20-26 April 1998

Galileo continues on the outbound leg of its orbit around Jupiter 
as it processes and transmits to Earth science information safely 
stored on the spacecraft's on-board tape recorder.  The 
spacecraft's 11 instruments gathered the information as they flew 
past Jupiter and its moons late last month.  On Thursday, the 
spacecraft performs a small turn to keep its antenna pointed 
toward Earth.  These turns are required to maintain the right 
telecommunications conditions and science data flowing to the 
ground.

The batch of information processed and transmitted this week is 
dedicated primarily to observations of Jupiter's icy moon Europa.  
The spacecraft camera, or solid-state imaging subsystem, returns 
two pictures of Europa this week.  The first is a high-resolution 
picture of a circular feature known as Tyre Macula.  This feature 
is believed to have been created by the impact of a mountain-sized 
asteroid or comet.  This region was imaged at lower resolutions 
during Galileo's primary mission in April 1997 and is scheduled 
for imaging again at the end of May.  The other picture that is 
returned this week includes a region of bright plains that 
transitions to a series of wedge shaped features.  The 
spacecraft's Near Infrared Mapping Spectrometer also returns two 
observations of the same region of Europa.  The region is 
characterized by pull-apart wedges, but also contains dark spots.

Finally, continuing from previous weeks, is the return of science 
information from the fields and particles instruments describing 
the interaction of Jupiter's magnetosphere with Europa.

For more information on the Galileo spacecraft and its mission to 
Jupiter, please visit the Galileo home page:

http://www.jpl.nasa.gov/galileo/
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STARDUST STATUS REPORTS
By Ken Atkins, Stardust project manager

17 April 1998

Assembly, Test, and Launch Operations (ATLO) activities:  The pre-
ATLO testing of the Cometary & Interstellar Dust Analyzer (CIDA) 
was completed and the flight electronics box has been installed on 
the spacecraft.  The navigation camera was delivered, bench-tested 
including full camera functional and end-to-end data flow testing 
and installation is planned for today.  The ATLO Test Unit (ATU) 
aerogel collector, partially loaded with examples of flight 
quality aerogel, was delivered to Lockheed Martin.  The ATU is a 
pathfinder for handling and contamination control procedures to be 
used on the flight unit later this year.  These deliveries signal 
that all flight instrument electronics are delivered to ATLO with 
significant interface testing behind them.  Good progress was also 
achieved this week on spacecraft avionics, holding schedules for 
deliveries next week.

Outreach:  Live video hook up between JPL and the National Science 
Teachers Conference in Las Vegas, Nevada allowed a full schedule 
of Question & Answer interactions with Teachers visiting the 
Challenger Center's booth in the exhibit hall on Friday.  Project 
personnel at JPL took half-hour segments in the Stardust JPL 
Mission Support Area (MSA).

24 April 1998

The spacecraft assembly effort this week was focused on completing 
most of the remaining power harness wrapping for protection in 
space, completing the Whipple cometary dust shields for the solar 
arrays, continuing preparations to install the flight solar arrays 
on the spacecraft, and interface testing of the power electronics 
and navigation camera.  Work also moved ahead on completing the 
installation of the Cometary and Interstellar Dust Analyzer (CIDA) 
electronics and installation and checkout of the spacecraft's 
central computer.

We also completed some final testing on the Sample Return Capsule 
(SRC) indicating it is essentially complete and ready for mating 
with the carrier spacecraft.  With the camera installation, all 
flight instrument electronics and the flight Dust Flux Monitor 
(DFM) are now on the flight spacecraft.

We also received the star cameras this week.  These are used to 
determine the spacecraft's attitude in deep space.  The team also 
performed some practice comet encounter simulations involving the 
CIDA and the navigation camera, with software simulations for the 
Inertial Measurement Units (IMUs) and the Dust Flux Monitor (DFM).  
Things are beginning to come together as a system.

The project delivered aerogel samples to the California Science 
Center in Los Angles on Thursday for an extended display in the 
museum's "Future Applications" area.

For more information on the STARDUST mission--the first ever comet 
sample return mission--please visit the STARDUST home page:
http://stardust.jpl.nasa.gov
------------------------------------------------------------------

MARS GLOBAL SURVEYOR MISSION STATUS REPORTS
JPL releases

24 April 1998

The Mars Global Surveyor spacecraft has completed the last of 
three attempts to image the Cydonia region of Mars, the two Viking 
lander sites and the Mars Pathfinder landing site.  Global 
Surveyor captured the final image of Cydonia as the spacecraft 
passed over the area at a distance of about 392 kilometers (244 
miles).  The images contain additional portions of "The City," a 
locale sporting a variety of geological features sometimes 
identified as "mounds," the "city square," the "pyramid" and the 
"fortress."  This area, photographed more than 20 years ago by the 
Viking orbiters, has been of public interest because it is 
adjacent to the so-called "Face on Mars."

The images are posted on JPL's Mars news site at 
http://www.jpl.nasa.gov/marsnews, on the Mars Global Surveyor 
project home page at http://mars.jpl.nasa.gov, and on NASA's 
Planetary Photojournal site at http://photojournal.jpl.nasa.gov.

The spacecraft also captured the Mars Pathfinder landing site in 
Ares Vallis after missing it during the first two imaging 
opportunities.  The data strips are being processed and the exact 
location of the lander is being determined.  A low-resolution 
image of the site will be available by the end of the day.  Raw 
data indicated that the lander was not visible due to a thick 
haze, although familiar landmarks close to the landing site, such 
as Twin Peaks, were visible.

The Viking 1 lander in Chryse Planitia was not identified in 
images of that site, possibly due to imprecise coordinates used to 
locate the landing site.  Winter weather in the northern 
hemisphere and heavy cloud cover prevented a view of the Viking 2 
lander in Utopia Planitia, as had been the case in the first two 
sets of images.

Mars Global Surveyor is currently in a fixed 11.5-hour orbit 
around Mars, coming as close as 170 kilometers (106 miles) during 
each looping orbit.  The spacecraft will be gathering science data 
during most of its five-month pause in aerobraking.  Further 
imaging of the Cydonia region and Viking/Pathfinder landing sites 
will not be feasible during the remainder of the aerobraking 
hiatus, however.  Mars will shortly pass behind the Sun from 
Earth's point of view, degrading communications with the orbiter.  
After that, lighting conditions will not be favorable for imaging 
Cydonia or the Viking/Pathfinder landing sites.  In September, the 
spacecraft will resume aerobraking to lower and circularize its 
orbit for the start of the mapping mission in March 1999.

1 May 1998

This week, the Mars Global Surveyor flight team closed out a 
successful month of dedicated science operations.  For over sixty 
consecutive orbits starting in early April and ending on Tuesday, 
the spacecraft's scientific instruments collected data near the 
low point of its 11.6-hour orbit.  Every day of that month, 
Surveyor transmitted nearly 25 megabytes of data back to Earth.

Much of the publicity generated by April's science collection 
activities focused on targeted observations of several selected 
sites on the Martian surface.  Because explicit targeting is not 
part of the Surveyor spacecraft's inherent abilities, these 
operations involved a substantial collaborative effort between Dr. 
Michael Malin's camera team, Dr. David Smith's laser altimeter 
team that assisted with Mars map corrections, and project 
engineering elements such as mission planning, spacecraft systems, 
and navigation.

Major imaging highlights included three photographs of the Cydonia 
region in the northern hemisphere.  This area is home to a one-
mile (1.5- km) wide object known popularly as the "face on Mars."  
One of the three Cydonia images shows the so-called face at 14.1 
feet (4.3 meters) per pixel, a resolution about 10 times better 
than the best Viking Orbiter image from 1976.

In addition to the Cydonia images, Surveyor's camera also obtained 
two photographs of the Viking 1 landing site in Chryse Planitia, 
and one image of the Mars Pathfinder landing site in the Ares 
Valles region.  Some of the objects visible in the Pathfinder 
image include major landmarks photographed on July 4th, 1997, 
including the famous "twin peaks" and "big crater."  However, the 
lander and rover are not discernible in part because at the 
imaging range of about 497 miles (800 km), their size in the 
photograph is less than one pixel.

Despite this fact, the resolution of the current image still 
exceeds the best photograph of Ares Valles taken during the Viking 
Orbiter mission over twenty years ago.  During mapping operations 
next year, the camera may have an opportunity to image the 
Pathfinder landing site again at ranges as low as 235 miles (378 
km).  In those images, small objects such as the lander and 
parachute may be visible.

The Viking 2 lander site at Utopia Planitia was also targeted by 
the camera for observation.  Unfortunately, clouds obscured the 
site during each one of the three attempts.  Similar to the 
situation with the Pathfinder site, further attempts at imaging 
the Viking 2 site may occur next year during mapping operations.

Other experiments on the spacecraft have also been busy acquiring 
data.  Besides the camera, the laser altimeter, magnetometer, 
thermal emission spectrometer, and radio science investigation 
teams have also collected data since the beginning of April.  
These measurements include northern hemisphere topography by the 
laser, local and global magnetic properties by the magnetometer, 
atmosphere and mineralogy studies by the spectrometer, and 
atmosphere and gravity field experiments by the radio science 
team.

Of particular interest, Dr. David Smith's laser altimeter team has 
been gathering data about the Martian north polar ice caps.  On 
every orbit, the laser measures the cap's topography in order to 
calculate its thickness.  In June, the ice cap's thickness will 
reach a maximum during the height of the northern winter season.  
Thickness measurements from April compared to those that will be 
taken in June will contribute toward a greater understanding of 
the Martian cap formation.

Although extremely successful, the flight team temporarily 
suspended science operations on Tuesday in preparation for a 
month-long event called solar conjunction.  Starting this weekend, 
communications with the spacecraft will degrade as Mars begins to 
pass behind the Sun's corona as viewed from the Earth.  As a 
consequence, the radio signals sent to and from Surveyor will 
experience a noise effect from solar electromagnetic interference.  
During the middle of the month, the Sun will directly eclipse the 
red planet and physically block radio communications with the 
spacecraft.

Solar conjunction will end in late May as Mars moves out from 
behind the Sun.  At that time, the flight team will re-establish 
commanding capability and resume science operations.  Data 
collection will then continue until the restart of aerobraking on 
September 11th.  The goal of this next phase of aerobraking will 
be to lower the current, highly elliptical, 11.6-hour orbit to a 
low, circular, two-hour mapping orbit by April 1999.

After a mission elapsed time of 540 days from launch, Surveyor is 
229.36 million miles (369.12 million kilometers) from the Earth 
and in an orbit around Mars with a high point of 11,108 miles 
(17,877km), a low point of 108.3 miles (174.3 km), and a period of 
11.6 hours.  A special, multi-week solar conjunction command 
sequence is currently executing on the spacecraft, and all systems 
continue to perform as expected.  The next status report will be 
released sometime late May.

Status report prepared by:
Office of the Flight Operations Manager
Mars Surveyor Operations Project
NASA Jet Propulsion Laboratory
California Institute of Technology
Pasadena, CA 91109
------------------------------------------------------------------

1998 MARS SURVEYOR PROJECT STATUS REPORTS
By John McNamee, Mars Surveyor 98 project manager

The Pressure Modulator Infrared Radiometer (PMIRR) instrument 
failed to operate properly during orbiter solar thermal vacuum 
(STV) testing.  A part failure in the 15V PMIRR power supply is 
the suspected cause.  All other objectives of the orbiter thermal 
vacuum test were accomplished successfully.  The plan is to break 
vacuum on Friday, April 24, troubleshoot the cause of the failure 
over the weekend, and reestablish vacuum conditions on Monday, 
April 27, if the team is confident the root cause of the failure 
has been diagnosed and fixed.

Lander integration and test activities are proceeding on schedule 
with no significant probleMs. ElectroMagnetic 
Interference/Compatibility (EMI/EMC) testing of the lander 
spacecraft was completed successfully.

1 May 1998

Orbiter solar thermal vacuum (STV) testing was resumed April 27 in 
order to calibrate the Pressure Modulator Infrared Radiometer 
(PMIRR) instrument.  All spacecraft and instrument STV test 
objectives were completed successfully (including the calibration 
of PMIRR) on April 28.  A system aliveness test was conducted 
following STV with no anomalies and the go ahead was given to 
remove the spacecraft from the thermal vacuum chamber.

The earlier PMIRR failure in STV was determined definitively to be 
a mechanical failure of the optical chopper assembly, however the 
exact failure mechanism (debris, power transients, etc.) has not 
been determined.  The damaged chopper assembly will be removed 
from the PMIRR instrument and replaced with the flight spare.  
This swap can be accomplished without removing PMIRR from the 
spacecraft.  The damaged chopper will be examined for the exact 
cause of the failure.

Lander integration and test activities are proceeding on schedule 
with no significant probleMs. Lander solar thermal vacuum testing 
in the cruise configuration is scheduled to begin on May 14.

The pyroshock and vibration re-test of the engineering 
qualification model Thermal Evolved Gas Analyzer (TEGA) Tunable 
Diode Laser (TDL) design fix was performed successfully.  
Subsequently, the flight TDL passed vibration re-testing with no 
probleMs. (Note:  Pyroshock re-testing was performed only on the 
engineering qualification model due to potential cumulative 
effects of this testing on the flight instrument).  The flight 
TEGA is on schedule for integration with the lander spacecraft in 
June.

For more information on the Mars Surveyor 98 mission, please visit 
this website:
http://mars.jpl.nasa.gov/msp98/
--------------------------------------------------------------------------------

JPL's OPEN HOUSE FEATURES PAST, PRESENT AND FUTURE IN SPACE
JPL release

28 April 1998

NASA's Jet Propulsion Laboratory will open its doors to the public 
during its annual Open House on Saturday, May 30 and Sunday, May 
31, from 9 a.m. to 5 p.m. both days.  This popular, free event 
celebrates JPL's "Past, Present and Future" with exhibits and 
demonstrations about the Laboratory's ongoing research and space 
exploration missions.

Many of the Lab's scientists and engineers will be on hand to 
answer questions about how spacecraft are sent to other planets, 
how scientists utilize space technologies to explore Earth and how 
researchers have begun searching for planets beyond the solar 
system.  Visitors will see exhibits, displays, demonstrations and 
presentations covering such topics as planetary imaging, space 
robotics, spacecraft communications and tracking.

Visitors will be able to see two Earth-observing instruments 
currently in development in JPL's Spacecraft Assembly Facility, 
looking in on the progress of the Quick Scatterometer (QuikScat), 
set for launch in November, which will study winds over the 
oceans, and the Shuttle Radar Topography Mapper (SRTM) that will 
ride on the Space Shuttle and collect three-dimensional images of 
the Earth in 1999.

Close-up images of El Nino will be on display at the Earth 
Sciences booth, as scientists and engineers display the different 
ways JPL has tracked this weather-altering phenomenon with 
satellites.

The Mars Yard--a replica of the Martian landscape, will feature 
two full-scale models of Sojourner, the little rover that landed 
on Mars on July 4, 1996 aboard the Mars Pathfinder spacecraft.

Also on display will be a full-scale model of Galileo, currently 
in orbit around Jupiter, along with a colorful exhibit of stunning 
images of Jupiter's moon, Europa, which is thought to have a water 
ocean beneath its icy surface.  A full-scale model of the three-
story-tall Cassini spacecraft, launched to Saturn in October 1997, 
can be viewed in JPL's spacecraft assembly facility.

Engineers who use NASA'S Deep Space Network to communicate with 
spacecraft will be on hand to explain spacecraft 
telecommunications.  The Space Flight Operations Facility viewing 
gallery, where spacecraft communications take place, will also be 
open to visitors.

Other featured projects will include JPL's Origins program, which 
is aimed at developing new technologies to detect other solar 
systems; JPL's Center for Space Microelectronics Technology, which 
develops miniaturized instruments and sensors for future space 
flight; and the New Millennium program, which is developing 
revolutionary high-tech instruments for space flight in the 21st 
century.

Food and beverages will be available, along with space souvenirs 
and NASA and JPL merchandise.

JPL is located at 4800 Oak Grove Drive in Pasadena, off the 210 
(Foothill) Freeway at the Berkshire Avenue/Oak Grove Drive exit.  
For further information, visit the JPL Open House web site at 
http://www.jpl.nasa.gov/openhouse or call (818) 354-0112.
------------------------------------------------------------------

End Marsbugs Vol. 5, No. 12.










