Browse
news items and significant events from the Winter quarter of 2001
highlighted on the NAS home page.
Summer
2001
9/21/01
-- Chimera Grid Tools Version 1.6 Released
A new version of the Chimera Grid Tools (CGT), a set of programs and scripts
for generating overset grids, was released today. Developed at Ames Research
Center, CGT is widely used for solving complex computational fluid dynamics
(CFD) problems in a variety of real-world applications, including aerospace,
marine, automotive, environmental, and sports.
Among
the many new features for CGT version 1.6 are:
- capability
to read and animate body dynamics by reading from a
dynamics table file, or from an arbitrary user routine
- capability
to read CART3D triangles and q file (.triq) containing
grid and scalar functions
- capability
to display scalar functions on triangles in DIAGNOS
- capability
to run OVERFLOW-D to create off-body Cartesian grids
and perform domain connectivity
- compatibility
with Tcl/Tk version 8.3.3
To
get more details, and find out how to get CGT, contact co-developer Stuart
Rogers in the NAS Division at rogers@nas.nasa.gov,
650-604-4481.
9/18/01
-- Ames Team Joins New York Rescue Efforts
As the NAS Division joins the nation in prayers and hopes for victims,
their families, and rescue workers, a six-person team from Ames Research
Center flew to New York on Wednesday, September 19, to help relieve other
volunteers in the enormous search and rescue effort. Among the team is
Mark Tangney, NAS Division facilities manager and overall coordinator
of the Ames Disaster Assistance and Rescue Team (DART).
.
Tangney and DART team members Paul Brown, Kelly Kasser, Roger Miller,
John Preston, and Phil Snyder, left via military transport from Travis
Air Force Base to the World Trade Center site. The Ames crew joins dozens
of other trained search and rescue workers, medical personnel, and logistics
and safety managers who have been on alert since the September 11 tragedies
in Manhattan, Washington D.C., and Pennsylvania.
“We are all proud that Mark and the other Ames team members are able
to offer much-needed assistance during this devastating time,” said
John Ziebarth, NAS deputy director. “We extend our thoughts and prayers
for their safety and that of all those working tirelessly in the rescue
effort.”
The
62-person squad is part of California Task Force 3 (CTF3), a coalition
of 13 agencies from the San Francisco Bay Area, based out of Menlo Park,
CA. The CTF3 participated in rescue work during the 1995 bombing of the
Murrah Federal Building in Oklahoma City and the Bay Area’s Loma
Prieta earthquake in 1989.
Get more information on the NASA
Ames Disaster Assistance and Rescue Team.
8/23/01
--
NAS Division Overcomes 802.11b
Wireless Security Flaws
The network security group in the NASA Advanced Supercomputing (NAS) Division
at Ames Research Center, in California’s Silicon Valley has successfully
installed a secure interoperable wireless network that addresses the well-known
problems of the 802.11b standard wireless systems -- with a minimum of
time and investment.
“Wired equivalent privacy isn't the equivalent of wired privacy,”
said Dave Tweten, computer security official at NAS. Tweten’s group
started with the premise that the network itself provides no reliable
authentication and no security from eavesdropping, and decided not to
depend on any security provisions bundled with 802.11b products.
Why? Recent conference results have established that 802.11b wireless
systems provide no substantial security protection in any of three important
respects: 1) The signal coverage perimeter cannot be easily limited to
conform to an organization's physical control perimeter; 2) Wireless card
hardware addresses cannot be trusted as tools to identify a user; and
3) Wired Equivalent Privacy (WEP) encryption of data sent between a laptop
and an access point can be cracked, regardless of key length.
In
addition, said Tweten, the means to derive a WEP encryption key from eavesdropped
ciphertext and a method for decrypting WEP traffic without ever needing
to derive the key are well documented.
The
NAS Division chose to secure its wireless network while assuming that
it would be accessible from areas outside the division's control. The
team also assumed that all information on the network would be subject
to eavesdropping, and that no identification information built into 802.11b
could be trusted. “All 802.11b security features were disabled on
the grounds that they only consume resources without delivering any real
security,” Tweten said.
For
minimum administrative overhead, basic use of the wireless network is
possible without authentication. This is possible because the services
that can be reached require authentication and perform encryption themselves.
At the same time, users are protected from an attack launched on the Internet
at large.
In the NAS Division, all this is accomplished by an off-the-shelf PC running
the OpenBSD operating system, an Apache web server, the Internet Software
Consortium DHCP server, the IPF firewall software -- all freeware. Network
and security team members Nicole Boscia and Derek Shaw developed the “glue”
software to make the rest of the components work together -- in about
40 hours.
For
more information, contact Dave Tweten at tweten@nas.nasa.gov, (650) 604-4416.
Get NAS's
wireless network security implementation details.
8/07/01
--
IPG
Team Given Prestigious NASA Award
NASA's Information Power Grid (IPG) team recently received the NASA Group
Achievement Award, presented to selected groups who make outstanding contributions
to the agency's mission. The NASA Advanced Supercomputing (NAS) Division
at Ames Research Center is leading the effort to build and test the IPG,
a network of high performance computers, data storage devices, and scientific
instruments. Ames is collaborating with colleagues at NASA's Glenn and
Langley Research Centers on the IPG project.
Presented
at the annual NASA Honor Awards Ceremony on Thursday, July 26 at Ames,
the award cites the "successful implementation of Information Power
Grid and completion of the first two level-one milestones" and recognizes
that the IPG will become the service delivery model for high performance
computing for NASA. In fiscal year 2000, the IPG team demonstrated a complete
version of a grid system and successfully performed high-speed data access
on the grid's infrastructure.
"I'm
particularly happy with the (NAS) organization's tremendous progress over
the three years that IPG has been underway," says NAS Division Chief
William J. Feiereisen. "Our work is now being recognized in the world
outside of NASA — people are looking to us to find out what to do
in high performance distributed computing."
"The
IPG is becoming the model by which NASA accesses its high performance
computing resources," says IPG Project Manager William E. Johnston.
"Three years ago we felt we had an opportunity to fundamentally change
the way computing is done — and we have accomplished that."
In late July, Johnston met in London with center directors for IBM's recently
announced grid initiative to present grid implementation methods developed
for the IPG.
The
IPG has been a major project under NASA's Information Technology and High
Performance Computing and Communications programs. For more information
on NASA's Information Power Grid,
contact William Johnston at wej@nas.nasa.gov
or Arsi Vaziri, IPG deputy project manager, at vaziri@nas.nasa.gov.
8/02/01
-- New Boron-Nitrogen Nanotube Research
Published
A new development in the field of nanotechnology by NAS researcher Deepak
Srivastava is described in Physical Review B, (Vol. 63, pg. 195413,
2001). In "Anisotropic
Nanomechanics of Boron-Nitride Nanotubes: Nanostructured Skin Effect,"
Srivastava and colleagues Madhu Menon (University of Kentucky) and KyeongJae
Cho (Stanford University) studied the way in which boron-nitride (BN)
nanotubes respond to compressive strains, and their mode of plastic deformation.
Their findings show that BN nanotubes may be useful as reinforcing fibers
in ultra-light and strong, functional composite materials. Additionally,
such a material will exhibit an anisotropy against external axial strains
-- when the nanotube structure is compressed from both sides, damage occurs
to one side only.
"We
have discovered an "anisotropic" mode of axial load transfer
in strained BN nanotubes," says Srivastava. Based on this finding,
the team has proposed a "skin-effect" model of nanocomposite
materials with parallel-aligned zigzag BN nanotubes. "Such material,
if fabricated, would limit structural damage to the "skin" side
of the material and not the inner core side," Srivastava explains.
"One application, for example, might be to someday use this material
in auto manufacturing, where damage in a collision could potentially be
limited the the outside of the vehicle."
Srivastava and collaborators are now investigating the characteristics
of nanotube-reinforced polymeric materials. BN nanotubes could be tested
as reinforcing fiber simulations in functionally smart polymer composite
materials of the future. If such a hypothetical material were fabricated,
it would have numerous useful applications in transportation, aerospace
and defense.
For
more information, contact Deepak Srivastava at deepak@nas.nasa.gov,
650-604-3486.
7/24/01
-- New NAS Technical Reports Online
Several new NAS Technical Reports are now available on the web. One report,
A
Framework for Control and Observation in Distributed Environments,
by Warren Smith, describes a software framework for control and observation
of resources, services, and applications that supports a dynamic grid
environment, and provides examples of how the framework can be used.
Other
new technical reports include:
Get a complete listing of NAS
Technical Reports.
7/18/01
-- New NASA Supercomputer Models Earth
Climate at Warp Speed
Using what may be the most powerful parallel supercomputer of its kind,
NASA scientists recently used a highly advanced prototype processor to
significantly advance the ability to evaluate the global impact of natural
and human-induced activities on our climate.
Developers
say the new 512 supercomputer is 10 times more powerful than today's supercomputers.
"This substantial increase in performance allows us to complete Earth
climate simulations in days, rather than months," said Dr. Ghassem
Asrar, Associate Administrator for Earth Science, NASA Headquarters, Washington,
DC. "This tool will help us to objectively evaluate the effects of
natural and human activities on global climate."
"When
we run the climate model after including Earth climate data from satellites,
ground and air observations, we can simulate hundreds of days of global
climate per day of computer processing time," Asrar added. "This
is a major milestone in our nation's computing capability, and sets the
stage for our next steps in advanced computing for climate models."
Scientists
at NASA Ames Research Center, Moffett Field, CA, continue to advance state-of
the-art supercomputing with corporate partner SGI, Mountain View, CA.
Ames and SGI have been cooperating under a memorandum of agreement since
1998.
The
512 supercomputer will lead to faster and better development of climate
models for the Earth Science community, government and industry. What
used to take a year to calculate on a single processor might be done in
less than a day on a 512-processor machine. "With large NASA computer
codes, we now have a technique that speeds up the processing time tenfold,"
Asrar said.
Ames
computer scientists plan to combine two 512-processor supercomputers to
make an even more powerful machine. "The full 1024-processor system
will be capable of doubling the speed of the climate models. The assembly
of the 1024 supercomputer is to be completed in August 2001," Asrar
added.
"By means of this work, NASA is establishing its world leadership
position in supercomputing," said Steven Zornetzer, Director of Information
Sciences and Technology at Ames. "This new ability to simulate future
climate dynamics followed efforts by NASA scientists and one of their
industrial partners to improve supercomputing."
For
more information on the NAS programming techniques used to model global
climate changes, contact Jim Taft at jtaft@nas.nasa.gov,
650-604-0704. Full
NASA Ames press release.
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