[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[jamsat-news:1288] * SpaceNews 19-Jun-2000 *
SB NEWS @ AMSAT $SPC0619
* SpaceNews 19-Jun-00 *
BID: $SPC0619
=========
SpaceNews
=========
MONDAY JUNE 19, 2000
* AMSAT PRESIDENT ON SPECTRUM *
===============================
AMSAT-NA President Keith Baker reports that he has been asked to be a
featured guest on the shortwave radio program "Spectrum" hosted by Mark
Emanuel, N2CBO and Stan Olochwoszcz, N2AYJ. The program is scheduled
to air live on shortwave radio station WWCR in Nashville, Tennessee
on 5.070 MHz AM at 03:00 UTC on Sunday 18-Jun-2000. Keith indicated
that he and the show's hosts will be talking about AMSAT, its origins,
triumphs, and challenges.
[Info via the AMSAT-NA News Service]
* SUNSAT NEWS *
===============
Johann Lochner reports that the SUNSAT spacecraft has recently entered
a solar orbit (permanent sunlight with no eclipses). This will lead to
higher spacecraft temperatures and more demanding control requirements.
SUNSAT will remain sunlit until November 2000. Experiments to ensure
that it survives this testing period will continue for an undetermined time.
An announcement will be made when the amateur radio services are resumed.
See:
http://sunsat.ee.sun.ac.za/index.html
for the latest information.
[Info via Johann Lochner, ZR1CBC]
* FM SATELLITE STATUS *
=======================
Here is a one line summary of currently active FM birds that you can
receive on your Mobile FM rig and mobile vertical whip antenna.
New items:
1) SUNSAT has turned off APRS mode while they manage high sun temps
2) MIR again goes silent as crew heads home
SAT DOWNLNK UPLINK S MODE COMMENTS
---- ------- ------- - ------------------ ----------------------------
MIR 145.985 145.985 9 S FM crew voice Off
UO11 145.825 4 R FM Bell202 ASCII Telemetry only
UO14 435.070 145.975 5 J FM Voice rptr lots of fun every pass
AO27 436.795 145.850 3 J FM Voice rptr days only but fun
SO35 145.825 436.290 8 B FM Voice rptr Off while in hot sun
SO35 145.825 436.290 8 B 9600 bd FSK digi Off while in hot sun
UO22 435.120 145.900 3 J 9600 bd FSK BBS ON
KO23 435.170 145.900 4 J 9600 bd FSK BBS ON but with probs in eclipse
KO25 436.500 145.980 3 J 9600 bd FSK BBS ON
TO31 436.925 145.925 5 J 9600 bd FSK DATA ON downlinks images
* If you don't hear it, then DONT TRANSMIT! Either the bird is dead
or your station is deaf. Don't embarass yourself and QRM everyone!
Between the hours of about 6 AM to noon and 6 PM to midnight local SUN
time there is usually one of these birds in view for a few minutes to keep
you entertained while traveling. UHF requires +/- 5 or 10 KHz Doppler
tuning. The "S" column is a subjective signal strength assessment. A
20" vertical whip in the center of your car roof will give you success
as shown below. This acts as a 3/4 wave on UHF giving almost 8 dBi above
30 degrees over a good groundplane for the UHF downlink birds. For
SUNSAT which operates mode B with a stronger 2m downlink and your 50 watt
mobile uplink, your normal dual-band mobile antenna will do better closer
to the horizon.
SIG RECEIVE RANGE
USING THE 20" WHIP FOR MODE J PACSATS: --- ------------------
As a rough approximation consider this table 9 Horizon to Horizon
which has been subjectively determined after 8 5 deg and above
3 months of daily monitoring. Home stations 7 10 deg and above
with 50' of RG 8 should subtract about 3 from 6 15 deg and above
the signals and 5/8 or dual band, or "gain" 5 20 deg and above
antennas should also subtract about 2. 4 25 deg and above
3 30 deg and above
The PACSATs do not officially digipeat UI 2 3 ele beam required
packets, but you can still see status and 1 6 ele beam required
telemetry and the USER lists on your Kenwood
data radios or any radio with 9600 baud TNC. For more info on mobile
satellite operations see http://web.usna.navy.mil/~bruninga/astars.html
[Info via Bob Bruninga, WB4APR]
* OSCAR-11 NEWS *
=================
During the period 16-May to 16-June-2000, fairly good signals have
been received from OSCAR-11's 145.826 MHz VHF-FM beacon.
The battery voltage during daylight passes has continued to decrease.
The average value observed was 13.4, with a range of 13.2 to 13.5 volts.
The internal temperatures have again decreased, by about one degree C.
They are now -0.5C and -2.0C for battery and telemetry electronics
respectively. Further reductions in temperature are expected until
July.
Ground control reset the magnetorquer attitude control counters at
the start of June. During May the Z-axis counter remained at its
maximum value of 1024, which was reached towards the end of April.
This stopped further magnetorquer firings, the attitude being
controlled solely by the passive gravity gradient boom, without any
spin corrections. During May, the spin period increased steadily from
286 to 450 seconds. After the counters were reset the spin period
quickly settled to an nominal -350 seconds. It is interesting to
note that the negative spin correction counter is now incrementing at
about half the rate of the Z-axis counter. The was the nominal rate
before October 1998, when the rate suddenly dropped to almost zero.
The cause of this anomaly remains a mystery.
Ground control has also corrected the software generated dates, but
the date in the hardware generated ASCII telemetry frames is still
advanced by three days. Unfortunately, the date in the hardware was
set up at the start of the mission and cannot be reset.
The single WOD survey of channels 10, 20, 30, 40 (+Y, -X, +X solar
array currents, array voltage), dated January 06 has been transmitted.
Note the year of this WOD survey is incorrectly displayed as 99.
This survey clearly shows the solar eclipses, and a spin period
of 340 seconds.
The operating schedule remains unchanged:
ASCII status (210 seconds)
ASCII bulletin (60 seconds)
BINARY SEU (30 seconds)
ASCII TLM (90 seconds)
ASCII WOD (120 seconds)
ASCII bulletin (60 seconds)
BINARY ENG (30 seconds)
The ASCII bulletin is currently a static message, detailing modes and
frequencies of all the amateur radio satellites.
There are additional status blocks after each bulletin is transmitted,
and between ASCII telemetry and Whole Orbit Data (WOD).
The Mode-S beacon is ON, transmitting an unmodulated carrier, but
telemetry indicates that it has partially failed, and delivering half
power. This beacon is a useful test source for those testing Mode-S
converters, prior to the launch of P3-D. However, the signals are very
weak, and there is a lot of Doppler shift. Users should also note that
the polarization of OSCAR-11 is left-hand circular. Even if you can't
hear OSCAR-11, your equipment may still be okay for P3-D. Any reports
of reception on 2401 MHz would be most welcome. Please direct them to
Clive Wallis via e-mail at: g3cwv@amsat.org.
The 435.025 MHz UHF beacon is normally OFF. However, it can sometimes
be heard when the satellite is being commanded by ground control, ie.
within range of Guildford, UK. When the UHF beacon is transmitting,
the VHF beacon is normally OFF. The data transmitted is mainly binary.
Listeners to OSCAR-11 may be interested in visiting a web site dedicated
to the satellite. The web site contains details of hardware required
and some software for capturing data, and decoding ASCII telemetry and
WOD. There is an archive of raw data (mainly WOD) for analysis, which
is continually being expanded as new data is captured. Also included
are some audio files, examples of each type of data transmitted by
OSCAR-11. Each one plays for about ten seconds. There are also examples
of mode-S reception. All the audio files are zipped, so that they can
be played off-line. These should help listeners identify the various
types of data, and give an indication of the signal quality required
for successful decoding.
The URL is:
http://www.users.zetnet.co.uk/clivew/
[Info via Clive Wallis, G3CWV]
* NEW VERSIONS OF PREDICT RELEASED *
====================================
New versions of PREDICT, the free, open-source satellite tracking and
orbital prediction software for DOS and Linux systems, have been released.
This release cures some minor bugs in the way the program calculates NASA
Two-Line element set checksums. Some other small code updates were also
included in this release.
The latest versions of PREDICT may be downloaded from:
(Linux) ftp://ftp.amsat.org/amsat/software/Linux/predict-2.1.2.tar.gz
(DOS) ftp://ftp.amsat.org/amsat/software/PC/tracking/predict2.zip
General program information is available at:
http://www.linuxfan.com/~predict/
* THANKS! *
===========
Thanks to all who sent news items and/or messages of appreciation to
SpaceNews in recent weeks, especially:
K3GNZ
* FEEDBACK/INPUT WELCOMED *
===========================
Comments and input for SpaceNews should be directed to the editor
(John, KD2BD) via any of the paths listed below:
WWW: http://www.njin.net/~magliaco/
MAIL: John A. Magliacane, KD2BD
Department of Engineering and Technology
Brookdale Community College
765 Newman Springs Road
Lincroft, New Jersey 07738
U.S.A.
PACKET: KD2BD @ N2TDU.NJ.USA.NA
INTERNET: kd2bd@amsat.org, magliaco@email.njin.net
SATELLITE: AMSAT-OSCAR-16, KITSAT-OSCAR-25
<<=- SpaceNews: The first amateur newsletter read in space! -=>>
<<=- Serving the planet (and beyond) since 1987 -=>>
/EX
--
-=-=-=-=-=-=-=-=-=-=-=-=- John A. Magliacane, KD2BD -=-=-=-=-=-=-=-=-=-=-=-=-
Internet : kd2bd@amsat.org | Voice : +1.732.224.2948
Satellite : AO-16, KO-25 | Morse : -.- -.. ..--- -... -..
Packet : KD2BD @ N2TDU.NJ.USA.NA | WWW : http://www.njin.net/~magliaco/
Video : 426.250 MHz/439.250 MHz | FAX : +1.732.224.2772
-=-=-=-=-=-=-=-=-=-=-=- Linux Doesn't Cost. It Pays. -=-=-=-=-=-=-=-=-=-=-=-
----
Via the ans mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe ans" to Majordomo@amsat.org