| From: US4RMC::"[email protected]" "MAIL-11 Daemon" 31-MAY-1994
To: Multiple recipients of list NEW-LIST <[email protected]>
CC:
Subj: CHANGE: Satnews on New Server
This change notice is to announce a change in the list server used.
SATNEWS on [email protected]
SATNEWS is a bi-weekly news digest of international satellite,
television, radio, and media news produced by M2 COMMUNICATIONS
LIMITED, a global publishing company responsible for
subscription-only titles such as Telecomworldwire, Data Broadcasting
News, Service Communications and Card Systems. M2 also provides
PitchLink, a cuttings and research service.
The Satnews list offers a time-delayed copy of the commercial product
as a courtesy to Internet users and a special offer is made for
subscriptions to the time-critical version. Many thousands of users
are already signed up to the server. This is a CHANGE OF LISTSERVER.
To sign up send e-mail to [email protected] with
subscribe satnews firstname lastname
in the message body
To unsubscribe send e-mail to the listserv, with
unsubscribe satnews
in the body/
Queries to [email protected] **ONLY** No list requests.
% ====== Internet headers and postmarks (see DECWRL::GATEWAY.DOC) ======
% Date: Tue, 31 May 1994 15:41:51 CDT
% Reply-To: [email protected]
% Sender: NEW-LIST - New List Announcements <[email protected]>
% From: Darren Ingram <[email protected]>
% Subject: CHANGE: Satnews on New Server
% To: Multiple recipients of list NEW-LIST <[email protected]>
|
| Article: 1196
From: [email protected] (Kenneth C. Jenks)
Newsgroups: sci.space.science
Subject: WWW pages on Space Environment
Date: 26 Aug 1994 15:45:07 GMT
Organization: NASA/JSC/SD5, Space Biomedical Research Institute
I just found a good description of the space environment, concentrating
on Low Earth Orbit (LEO), on the World Wide Web, and I thought I'd
pass on the reference to those of you with WWW capability. (For
those without WWW, get it -- it's worth it!)
http://http://satori2.lerc.nasa.gov/DOC/seeov.html
This isn't easy reading, but it is a good description.
-- Ken Jenks, NASA/JSC/SD5, Space Biomedical Research Institute
[email protected] (713) 483-4368
"The only way to make a difference in the world is to put ten
times as much effort into everything as anyone else thinks
is reasonable. It doesn't leave any time for golf or cocktails,
but it gets things done." -- Admiral Hyman G. Rickover
|
| From: US1RMC::"[email protected]" "MAIL-11 Daemon" 2-SEP-1994
To: [email protected]
CC:
Subj: JPL/Satellite terminal demo
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
Contact: Diane Ainsworth
FOR IMMEDIATE RELEASE September 1, 1994
The cost of tracking NASA satellites in low-Earth orbit
may be significantly reduced using a fully automated and
commercially available satellite tracking terminal recently
demonstrated at the Jet Propulsion Laboratory.
The automated terminal was able to acquire and process
telemetry completely on its own from the SAMPEX spacecraft,
a NASA Small Explorer Program mission in orbit around Earth.
The mission is operated by NASA's Goddard Space Flight
Center in Greenbelt, Md.
"The importance of this technology demonstration is
that it provides a new tool for ground-tracking, which can
significantly reduce mission operations costs for near-Earth
satellites and, generally, enable lower cost access to space
in the future," said Dr. Chad Edwards, manager of the
Systems Development Program in JPL's Telecommunications and
Mission Operations Directorate, which sponsored the work.
Development of the tracking terminal was carried out by
a JPL team of telecommunications experts led by Drs. William
Rafferty and Nasser Golshan.
"JPL defined the upgrade requirements to a commercially
available weather satellite tracking terminal and worked
with SeaSpace Inc., a terminal manufacturer in San Diego,
Calif., to implement the hardware specifications," Rafferty
explained.
The low-Earth-orbiting terminal was constructed using a
SPARC 10 workstation with weather satellite tracking
software and a special interface for monitoring and control
of the terminal subsystems, he said. A 3-meter (10-foot)
aluminum mesh antenna was enclosed in a fiberglass shell --
called a radome -- to protect it from rain, winds and other
environmental conditions and set up to track the satellite.
The new tracking system can be easily adapted to a
variety of antenna apertures, however, and receiver data
rates can be upgraded to speed telemetry readouts.
Recurring costs for the system would fall in the range of
$250,000 to $300,000, depending on antenna and receiver
options. That cost does not include site preparation,
installation or any additional software required for a
specific mission, Edwards said, but it is still significantly
lower than the tracking systems currently used.
The tracking system is suitable for a large percentage
of NASA's near-Earth missions and compatible with the S-band
radio frequency used to monitor many low-Earth-orbiting
satellites, such as NASA's Extreme Ultraviolet Explorer and
the TOPEX/Poseidon satellite. JPL plans to demonstrate the
system's capabilities again this fall using telemetry from
the Extreme Ultraviolet Explorer spacecraft.
In addition to its greatly reduced cost, the terminal
also features a high level of automation, Edwards said.
After initial setup, the terminal requires no user
intervention. Once per day, the terminal automatically
dials up an electronic bulletin board and retrieves orbital
elements supplied by the North American Air Defense in
Colorado Springs, Colo., for the spacecraft it will track.
Based on these orbital elements, satellite view
periods, antenna-pointing predicts and receiver frequency
predicts are automatically generated. If multiple spacecraft
are being supported, priorities can be assigned to allow the
terminal to automatically resolve scheduling conflicts.
"About a minute before a target spacecraft rises above
the horizon, the terminal automatically configures itself
for that spacecraft's telemetry mode and slews the antenna
into position," Edwards said. "Data acquisition takes place
completely unattended by human operators, although the
system can be monitored locally or remotely using a personal
computer running windows software."
Another innovative feature of the terminal system is
its use of data lines that are available from commercial
telephone companies. These lines provide a high-quality,
low-cost alternative bandwidth link for ground
communications support of many NASA missions.
"This approach allows the use of high quality,
commercially available services and hardware to interconnect
the remote, unattended terminal, the terminal administrator
and the science investigator sites together at low
installation and usage costs," Rafferty said. "Authorized
remote users of the terminal have easy access to the system."
In addition to the JPL development team, participants
in the demonstration included Dr. Robert Bernstein of
SeaSpace Inc., in San Diego, Calif., which upgraded the
weather satellite tracking terminal; Dr. Glenn Mason, SAMPEX
principal investigator at the University of Maryland; and
Jim Williamson, SAMPEX project operations director at NASA's
Goddard Space Flight Center.
The demonstration was conducted by JPL's Deep Space
Network Technology and Science Office for NASA's Office of
Space Communications.
#####
8/29/94 DEA
#9450
|