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Another fireball was observed over Vancouver Island, Washington State
and mainland British Columbia at 21:22 PDT on April 22. We would be
interested in receiving any reports on this fireball. Information
required is as follows:
Your Longitude and Latitude from a topo survey map or GPS reading.
Compass Direction of first sighting, corrected to true north Elevation
above the horizon measured with a clinometer or similar device Compass
Direction of last sighting, corrected to true north Elevation above
horizon, as noted above.
Any photographs or video tapes would be most helpful. We will not pay
for these however as is requested by one individual who claims he has a
tape. Anyone who cooperates will be given credit in a scientific
report.
Forward reports to : epmajden@mars.ark.com
Thanks for your help: Ed
------------------------------------------------------------------------------
Edward Majden epmajden@mars.ark.com
1491 Burgess Road Meteor Spectroscopy
Courtenay, B.C. AMS Affiliate
CANADA V9N-5R8 MIAC Associate
======================================
(3) SPECIAL PUBLICATION ON THE 1999 NEAR SPACECRAFT ON ITS RENDEZVOUS
WITH ASTEROID 433 EROS
A.F. Cheng, R.W. Farquhar & A.G. Santo: NEAR overview. JOHNS HOPKINS
APL TECHNICAL DIGEST, 1998, Vol.19, No.2, pp. 95-106
APL, PLANETARY SCIENCE SECTION, LAUREL, MD, 20723
The Near Earth Asteroid Rendezvous (NEAR) mission inaugurates NASA's
Discovery Program. It will be the first to orbit an asteroid and will
make the first comprehensive scientific measurements of an asteroid's
surface composition, geology, physical properties, and internal
structure. NEAR was launched successfully on 17 February 1996 aboard a
Delta II-7925. It made the first reconnaissance of a C-type asteroid
during its flyby of the main-belt asteroid 253 Mathilde in June 1997
and will orbit the unusually large near-Earth asteroid 433 Eros for
about a year at a minimum orbit radius of about 35 km from the center
of the asteroid. NEAR will obtain new information on the nature and
evolution of asteroids, improve our understanding of planetary
formation processes in the early solar system, and clarify the
relationship between asteroids and meteorites. The NEAR Mission
Operations Center and Science Data Center are both located at APL. The
latter will maintain the entire NEAR data set on-line and will make
data from all instruments accessible over the Internet to every member
of the NEAR science team. Copyright 1998, Institute for Scientific
Information Inc.
===========================
(4) THE NEAR MULTISPECTRAL IMAGER
S.E. Hawkins: The NEAR Multispectral Imager. JOHNS HOPKINS APL
TECHNICAL DIGEST, 1998, Vol.19, No.2, pp.107-114
The Multispectral Imager, one of the primary instruments on the Near
Earth Asteroid Rendezvous (NEAR) spacecraft, uses a five-element
refractive optics telescope, an eight-position filter wheel, and a
charge-coupled device detector to acquire images over its sensitive
wavelength range of approximate to 400-1100 nm. The camera operates at
a frame rate of 1 Hz, and the detector is passively cooled. The primary
science objectives of the Multispectral Imager are to determine the
morphology and composition of the surface of asteroid 433 Eros. The
camera will have a critical role in navigating to the asteroid. Seven
narrowband spectral filters have been selected to provide multicolor
imaging for comparative studies with previous observations of asteroids
in the same class as Eros. The eighth filter is broadband and will be
used for optical navigation. The Multispectral Imager has a focal
length of 168 mm and a 2.93 x 2.25 degrees field of view. The spatial
resolution of the instrument is 16.1 x 9.5 m at a range of 100 km. An
overview of the instrument is presented, and design parameters and
tradeoffs are discussed in the context of the fast-paced, low-cost
Discovery Program. Copyright 1998, Institute for Scientific Information
Inc.
==============================
(5) THE DESIGN AND TESTING OF THE NEAR SPACECRAFT
T.J. Hartka & D.F. Persons: The design and testing of the NEAR
spacecraft structure and mechanisms. JOHNS HOPKINS APL TECHNICAL
DIGEST, 1998, Vol.19, No.2, pp.163-173
This article describes the primary structure and mechanisms of the Near
Earth Asteroid Rendezvous (NEAR) spacecraft. Presented are design
requirements as well as a description of the primary structure and
mechanisms to meet those requirements. The test philosophy for this
cost-and schedule-driven program is outlined along with a summary of
the test flow and results. The structure and mechanisms were designed,
assembled, and tested at APL, with most of the structure manufacturing
subcontracted. Testing continued at Goddard Space Flight Center, and
the final spin balance test was performed at Kennedy Space Center.
Copyright 1998, Institute for Scientific Information Inc.
===========================
(6) THE NEAR SOLID-STATE DATA RECORDERS
R.K. Burek: The NEAR solid-state data recorders. JOHNS HOPKINS APL
TECHNICAL DIGEST, 1998, Vol.19, No.2, pp.235-240
APL, DEPARTMENT OF SPACE, SIGNAL PROC SECTION, LAUREL, MD, 20723
Data recorders make it possible for the Near Earth Asteroid Rendezvous
(NEAR) spacecraft to delay and slow the transmission of information to
Earth, thereby accommodating the temporal and bandwidth limitations of
the communications link. NEAR is the first spacecraft developed by the
Applied Physics Laboratory to employ solid-state recorders, supplanting
magnetic tape recorders used previously. Also, the 132 dynamic
random-access memory devices, which are at the heart of the NEAR
recorders, constitute the first large-scale use of plastic encapsulated
microcircuits on a Laboratory spacecraft. Earlier spacecraft relied
almost exclusively on hermetically packaged microcircuits. Several
measures, including two layers of error detection and correction, were
taken to mitigate the effects of single-event upsets that may be
induced by charged particles in space. Copyright 1998, Institute for
Scientific Information Inc.
======================
(7) COOPERATIVE FABRICATION OF THE NEAR SPACECRAFT
J.R. Dettmer: Cooperative fabrication of the NEAR spacecraft. JOHNS
HOPKINS APL TECHNICAL DIGEST, 1998, Vol.19, No.2, pp.241-246
APL, ELECTRONIC SERVICE GROUP, LAUREL, MD, 20723
Cooperative fabrication was a key factor in building the Near Earth
Asteroid Rendezvous (NEAR) spacecraft within the cost and schedule
constraints dictated by the NASA Discovery Program. Because many of the
traditional barriers between the engineering and the fabrication teams
were avoided on NEAR, APL reaped the benefits of cooperative planning,
design for ease of fabrication and assembly, and team problem solving.
The result was a unified and high-spirited team focused on
accomplishing the task. That teamwork, in combination with many of the
enabling technologies within the fabrication organization, allowed APL
to meet NEAR's cost, schedule, reliability, and performance goals.
Copyright 1998, Institute for Scientific Information Inc.
========================
(8) THE NEAR SCIENCE DATA CENTER
K.J. Heeres, D.B. Holland & A.F. Cheng: The NEAR Science Data Center.
JOHNS HOPKINS APL TECHNICAL DIGEST, 1998, Vol.19, No.2, pp.257-266
APL, DEPARTMENT OF SPACE, TIMED MISSION DATA CTR, LAUREL, MD, 20723
The Near Earth Asteroid Rendezvous (NEAR) Science Data Center serves as
the central site for common data processing activities needed by the
NEAR science teams and the scientific community. The Center provides
instrument and spacecraft data to the science teams from around. the
world and redistributes science products produced by those teams,
allowing the teams to focus on analysis. These data and the
accompanying documentation are available at
http://sd-www.jhuapl.edu/NEAR/. In addition, the Science Data Center is
responsible for archiving spacecraft, instrument, and science data to
the Planetary Data System. Copyright 1998, Institute for Scientific
Information Inc.
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