kd2bd@ka2qhd.UUCP (John Magliacane) (02/10/91)
SB SPACE @ ALLBBS < KD2BD $SPC0211
* SpaceNews 11-Feb-91 *
Bulletin ID: $SPC0211
=========
SpaceNews
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MONDAY FEBRUARY 11, 1991
SpaceNews originates at KD2BD in Wall Township, New Jersey, USA. It
is published every week and is made available for unlimited distribution.
* U2MIR-1 NEWS *
================
Here is an example of what the U2MIR mailbox help file looks like:
B(ye) B [CR] disconnects you from PMS.
H(elp) H [CR] or ? [CR] displays this help file.
J(log) J [CR] displays a list of callsigns heard (optional date/time)
K(ill) K n [CR] deletes message number n (only to/from your callsign).
KM(ine) KM[CR] deletes all READ messages addressed to your call sign.
L(ist) L [CR] lists the 10 latest messages.
M(ine) M [CR] lists the 10 latest messages to/from your callsign.
R(ead) R n [CR] reads message number n.
S(end) S (callsign) [CR] begins a message addressed to (callsign).
Subject: max 28 characters ending with [CR].
Text: End each line with [CR]. End message by
typing /ex [CR] or CTRL-Z [CR]
at the beginning of a new line.
SR(eply) SR n[CR] Sends a reply to message n prompting only for text.
V(ersion) V [CR] displays the software version of the PMS system.
CMD(B/H/J/K/KM/L/M/R/S/SR/V/?)>
U2MIR-5 was active last week when U2MIR-1 was issuing "busy" signals.
* MAGELLAN NEWS *
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The Magellan spacecraft has now completed over 944 mapping orbits covering
almost 50 percent of the surface of planet Venus. All systems on board
the spacecraft are performing well.
* SHUTTLE INFO *
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Shuttle Communications Frequencies (UHF-AM)
243.000 MHz Standard military aircraft emergecy frequency
259.700 MHz Air-to-ground or suit-to-orbiter
279.000 MHz Suit-to-orbiter or suit-to-suit
296.000 MHz Primary UHF downlink
296.800 MHz Air-to-ground or orbiter-to-suit
The UHF communications system is primarily designed to support duplex
voice communications between EVA crew members and the orbiter. Two
UHF antennas are used in this system. The primary UHF antenna is an
annular slot antenna. The second antenna is a microstrip antenna having
a gain of -10dBci, and is primarily used by astronauts in the airlock.
Simplex mode:
The on-board voice signal from the audio system is first clipped to an
RMS-to-peak ratio of 0.427 (9.0 dB clipping) and filtered (300-3000 Hz)
before amplitude modulating the carrier with a modulation index of 90%.
Transmitter power is 10 watts.
EVA Mode:
The UHF communications system can support two astronauts performing EVA
for two-way duplex voice transmissions and reception of EKG signals.
In the primary mode, the orbiter UHF communications system transmits a
298.600 MHz carrier which is amplitude modulated by the voice signal.
It simultaneously receives the 259.700 MHz and 279.000 MHz AM carriers
from two astronauts. Each received Am carrier includes a voice channel
and a frequency modulated EKG subcarrier channel. Transmitter power is
lowered to 250 mW in EVA mode by bypassing the final power amplifier.
S-Band Microwave Frequencies (Wideband FM)
Air-to-Ground : 2205.0, 2217.5, 2250.0, 2287.5 MHz
Ground-to-Air : 2041.9, 2201.4 MHz
2287.5 MHz Primary digital downlink
2250.0 MHz Main engine analog telemetry during launch
The voice downlinks employ digital slope delta modulation and are
multiplexed with orbiter telemetry. Downlink TV is wideband FM.
* TNX QSL! *
============
A special thanks to all those who sent QSLs and letters to SpaceNews:
DE8MFJ : Peter Pfliegensdorfer, Haar-Ottendichl, Germany
VK8GF : Jeff Farmer, Alice Springs, Northern Territory, Australia
...and e-mail messages:
VE2DBM, K3GLK, WB3JFS, N4IRR, G6FWT, KL7RH, WB9OEP
* FEEDBACK WELCOMED *
=====================
Feedback regarding SpaceNews can be directed to the editor (John) via any
of the following paths:
INTERNET : kd2bd@ka2qhd.de.com
PACKET : KD2BD @ NN2Z.NJ.USA.NA
UUCP : ...uunet!rutgers!ka2qhd!kd2bd
MAIL : John A. Magliacane, KD2BD
Department of Electronics Technology
Advanced Technology Center
Brookdale Community College
765 Newman Springs Road
Lincroft, New Jersey 07738
U.S.A.
/EX
--
John A. Magliacane FAX : (908) 747-7107
Electronics Technology Department AMPR : KD2BD @ NN2Z.NJ.USA.NA
Brookdale Community College UUCP : ...!rutgers!ka2qhd!kd2bd
Lincroft, NJ 07738 USA VOICE: (908) 842-1900 ext 607