SB SAT @ AMSAT $ANS-251.01 UNAMSAT-B IN ORBIT AND BEING HEARD HR AMSAT NEWS SERVICE BULLETIN 251.01 FROM AMSAT HQ SILVER SPRING, MD, SEPTEMBER 7, 1996 TO ALL RADIO AMATEURS BT BID: $ANS-251.01 Although nothing has yet been heard from the launch team, word has reached ANS from several other sources of the successful launch and subsequent reception of signals from the MICROSAT recently completed at the Autonomous University of Mexico under the tutelage of David Liberman XE1TU. According to reports, the UNAMSAT launch took place along with Cosmos-2334 from Plesetsk in Russia on 5 September at 1347_UT. This information was obtained from Phil Chien KC4YER who quoted Russian newsman Vladimir Agapov. One of those providing reception reports of the new satellite is Jeff Garrett, ZL1BIV. He says that he checked the UNAMSAT downlink on 437.206 +/- at 12:45 UT on 7 Sept, and a observed a good strong signal. He also notes that the Keps posted on AMSAT- BB by Phil Chien, KC4YER seem to be quite good. In two line format these are as follows: 1 24305U 96052B 96250.53952707 -.00001056 00000-0 -11565-2 0 148 2 24305 82.9412 204.1792 0028395 277.6649 82.5506 13.73077277 139 [ANS thanks Phil Chien, KC4YER and Jeff Garrett, ZL1BIV for this information.] Stay tuned for more. /EX SB SAT @ AMSAT $ANS-251.02 UNAMSAT TELEMETRY NEEDED HR AMSAT NEWS SERVICE BULLETIN 251.02 FROM AMSAT HQ SILVER SPRING, MD, SEPTEMBER 7, 1996 TO ALL RADIO AMATEURS BT BID: $ANS-251.02 A first look at telemetry from UNAMSAT indicates all is working ok aboard the satellite. It is tumbling as expected, so signal strength and polarization sense are changing randomly. It should lock in to the earth's magnetic field in a few days and that will stabilize the down link signals. The transmitter is running at a 'safe' power level of about .2 to .3 Watts throughout the orbit. Examination of the down link eye pattern indicates the transmitter in use is in good shape. Temperatures are a bit chilly but within nominal range. They may warm up as the stabilization system locks in. The solar arrays are generating power at the high end of the expected range and the batteries look to be in great shape. Expect the satellite to remain it its current mode for several days as the UNAM team returns to Mexico City and works through the checkout and test procedures. Please continue to collect telemetry in KISS mode and send files attached to email to wd0e@amsat.org for the next 48 hours. These data will be reviewed then archived for future comparison as changes are made and t he hardware ages. [ANS thanks Jim White WD0E Microsat Command Station for this information.] /EX SB SAT @ AMSAT $ANS-251.03 SA AMSAT ELECTS NEW PRESIDENT HR AMSAT NEWS SERVICE BULLETIN 251.03 FROM AMSAT HQ SILVER SPRING, MD, SEPTEMBER 7, 1996 TO ALL RADIO AMATEURS BT BID: $ANS-251.03 Hans van de Groenendaal ZS5AKV has been elected as President of SA AMSAT. He takes over from Gerald Klatzko ZS6BTD, who has headed up the South African group for the past two years. Tony Reumerman ZS6AOG was elected as Vice President, Hennie Rheeder ZS6ALN as Satellite Development Manager and Laurie Deveraux ZS5DL as Secretary/Treasurer. During his tenure, ZS6BTD has been directing most of his activities toward the completion of the Phase 3D 10 meter bulletin transmitter. The project is nearing completion and the finished hardware is expected to be delivered to the integration team in the next few weeks. He will continue to serve on SA AMSAT's committee for another year and remain responsible for the Phase 3D project. ZS5AKV said that during the next year SA AMSAT will concentrate on the following areas of interest: - Expansion of the Amateur Radio Satellite Service user base - Bulletin and educational projects on the Phase 3D broadcast transponder and - Ground station support for SUNSAT due for launch in early August 1997 [ANS thanks Hans van de Groenendaal ZS5AKV for this information.] /EX SB SAT @ AMSAT $ANS-251.04 SUNSAT TO BE LAUNCHED IN EARLY AUGUST 1997 PT.1 HR AMSAT NEWS SERVICE BULLETIN 251.04 FROM AMSAT HQ SILVER SPRING, MD, SEPTEMBER 7, 1996 TO ALL RADIO AMATEURS BT BID: $ANS-251.04 The launch of SUNSAT, South Africa's first satellite carrying an Amateur Radio and Experimental commercial payload has been delayed till early August 1997. The delay is due to rescheduling by USAF of launch of the primary payload on a McDonald Douglas Delta II from Vandenberg Airforce Base. SUNSAT is a 60kg, 45 by 45 by 62 cm micro satellite which is being designed, built and tested by 24 students at the Electronic Systems Laboratory (ESL) in the Department of and Electronic Engineering at Stellenbosch University. The students have done all the detailed design and the software. System level design was done by lecturers, some of whom studied at the Universities of Surrey, Stanford and MIT. It is therefore not strange that the satellite is very similar to the UoSATs built at Surrey. SUNSAT carries a camera system that will produce stereo or side images in three colors with 15 meter ground resolution from 800 km orbital height. The resolution is in the order of the same magnitude as the SPOT 2 and Landsat satellites. The communications payloads comprise high speed data-links as well as VHF and UHF transmitters and receivers operating in the 435 and 145 MHz bands. A 5w EIRP S-band downlink will transmit image data at 40 Mbit/s requiring only a 4,5 meter dish at the ground station. A L-band receiver permits uplinking data at 2Mbit/s and can be coupled to the Sband system for gateway operation. SUNSAT supports two modulation methods: a) 1200 baud AFSK which was the first choice of SA-AMSAT as it will afford many newcomers to the Amateur satellite scene to get a first shot at satellite operation without the need for an elaborate ground station. b) 9600 baud G3RUH compatible with the microsats, for those who have already invested in 9600 equipment, or who want better performance. In this group we consider the many international AMSAT members. Both these modulation methods use NBFM modulation, the G3RUH requiring 20kHz of IF bandwidth. Note that +3kHz and -3kHz Doppler shift occurs on 145 MHz, which is accommodated in the above bandwidth of any receiver not tracking the Doppler shift. Consequently, the hard-wired systems are restricted to FM modulation. (There are some DSP options that the University will try and upload in 1997/8). The consequence is that the IF bandwidths are 20kHz nominal, which makes 25kHz channel separations reasonable. G3RUH in the documentation for his 9600 baud modem recommends 20kHz IF bandwidth for receivers used with this modem. [ANS thanks Hans van de Groenendaal ZS5AKV for this update.] /EX SB SAT @ AMSAT $ANS-251.05 SUNSAT TO BE LAUNCHED IN EARLY AUGUST 1997 PT.2 HR AMSAT NEWS SERVICE BULLETIN 251.05 FROM AMSAT HQ SILVER SPRING, MD, SEPTEMBER 7, 1996 TO ALL RADIO AMATEURS BT BID: $ANS-251.05 Sunsat has two VHF transmitters, two UHF transmitters and two VHF receivers and two UHF receivers. Each of these has a single crystal in the amateur band, and an input from a synthesizer with 12.5kHz channel spacing. The Design Engineers preferred to have the default operating frequencies on the crystals (switch synth off), but can run the synths to unplanned frequencies. There also is plenty of memory on board to synthesize speech messages informing users of mode switches - e.g. "Parrot" operation enabled with 145.825 MHz uplink for the next 120 seconds." The L-band uplink and S-Band downlink gateway capability is in response to Jan King, W3GEY's articles in QST of some years ago talking about `gateways' capable of high rate uploads and downloads to satellites. Sunsat is Stellenbosch's first satellite, and for a long time the university was unsure whether they would ever get Sunsat into orbit. The strategy has thus been to include the gateway' capability in a simple way and test to see if and how well it works. If results are positive, the ground station will then see if there is support to establish such `gateways' at major locations. The S-band downlink is also used for the image data, which the Stellenbosch hopes to license in the 2200 - 2290 MHz earth exploration downlink band. The final Memorandum Of Understanding was signed between NASA and the South African Foundation for Research and Development (FRD). This secured the NASA launch in return for a inclusion of a NASA GPS receiver in the payload. Currently the launch is scheduled for early August 1997. In June Garth Milne ZS1AFH attended a ground operations meeting at Vandenberg to finalize the integration details with the launch vehicle. The substrates for the four solar panels were manufactured by Somchem, a company near Stellenbosch, South Africa. The substrate have been manufactured from carbon fiber. The students have completed the magnetorquer coils which were wound around the honeycomb structure of the substrate. Currently the GaAs solar cells are being fitted by EEV in England and the solar panels will be shipped back to South Africa within the next few weeks for integration. The flight model assembly is progressing well. All mechanical items on the top of the satellite have been assembled. This includes 4 monopole antennas for VHF, a modified turnstile antenna with elements bent at 30 degrees, a UHF monopole, the GPS Antenna, two horizon sensors, the star camera, magnetometer and tipmass and folded boom. The tipmass contains a star camera, a magnetometer and 8 laser reflectors. The boom was designed and constructed at the University and will undergo a final set of extensive deployment tests later this month. The PACSAT BSS is currently being tested and operating well with WISP. The operational frequencies are currently being finalized and will be announced soon. SUNSAT information is also available on the SUNSAT home page http://sunsat.ee.sun.ac.za Or, information can be obtained from: SA AMSAT P.O.Box 1842, Hillcrest 3650 South Africa Fax: +27 31 765-6456 [ANS thanks Hans van de Groenendaal ZS5AKV for this update.] /EX SB SAT @ AMSAT $ANS-251.06 AO-13 REENTRY KEPS HR AMSAT NEWS SERVICE BULLETIN 251.06 FROM AMSAT HQ SILVER SPRING, MD, SEPTEMBER 7, 1996 TO ALL RADIO AMATEURS BT BID: $ANS-251.06 James Miller, G3RUH says, that as most amateur satellite operators are aware, AO-13 will re-enter during December 1996. This gives us 2-3 months more operation, less than 200 more useable orbits. He notes that perigee height has been reducing at a rate of 1 km/day due to lunar-solar forces which increased the orbit's eccentricity. Now perigee height is so low (170 km) that when the satellite encounters the atmosphere it loses energy, and the orbit is tending to circularize, eccentricity decreasing. Mean motion is now increasing noticeably from its old value of 2.1 rev/day to 16 rev/day at re-entry. While this is happening, particularly in November/December, the published NORAD elements are always going to be stale and virtually unusable. In addition, since Mean Motion has a direct effect on rise and set times, and if history repeats itself, we can expect the usual plethora of conflicting "almost" Keplerian element sets lovingly massaged to perfection, that work for no-one else but their creators! To try and bring some order out of this chaos, James has placed on the Internet, a file of some 200 2-line Keplerian element sets that represent Oscar-13 every orbit until re-entry. The file, which is about 12K bytes long, is available via anonymous FTP as: ftp://ftp.amsat.org/amsat/satinfo/ao13/decaykep.zip This data has been derived by integrating the equations of motion, as described in reference [1]. Forces modeled are: - Earth's gravity up to degree 8 zonal, tesseral and sectoral terms from the GEM10B model - Sun and Moon differential gravitational pull - Atmospheric drag using US Standard Atmosphere 1976 - Solar radiation pressure. The integrator was seeded with position and velocity at apogee calculated using the NORAD propagation model SDP4 with the Norad mean keplerian elements: AO-13 1 19216U 88051B 96241.93209375 .00035764 10394-5 23983-20 2617 2 19216 57.1459 95.2606 7438684 49.0700 354.8698 2.115167526 2865 [ANS thanks James Miller, G3RUH for this interesting information.] /EX SB SAT @ AMSAT $ANS-251.07 AO-13 RE-ENTRY KEPS PT.2 HR AMSAT NEWS SERVICE BULLETIN 251.07 FROM AMSAT HQ SILVER SPRING, MD, SEPTEMBER 7, 1996 TO ALL RADIO AMATEURS BT BID: $ANS-251.07 Fine Tuning ----------- The uncertainty in re-entry analysis is caused by our not knowing the precise magnitude of atmospheric drag. This is because the upper atmosphere density depends on so many variable factors, including day/night, time of year, solar activity, Sun's rotation, position in 11 year sun-spot cycle, as well as the aerodynamic profile of the satellite. Over the 12 months 1995 Aug - 1996 Aug drag has gradually become discernible, enabling an estimate of the profile of the satellite to be made. At orientation Alon/Alat 230/0 it is Area/Mass = 0.0065 m^2/kg and Cd=1.4 >From 1996 Sep 01 the orientation is Alon/Alat 170/0 and Cd will be slightly different. Before re-entry a final re-orientation to Alon/Alat 90/0 will be made [2]. These changes will result in revision of the keplerian elements, which will be updated when known. James notes that typical satellite 2-line Keplerian element sets look like this: AO13-6422 1 30922U 88051B 96305.12146489 .00000000 00000-0 10000-4 0 08057 2 30922 57.1156 81.6242 7372121 54.7302 193.7462 2.232990956 4227 AO13-6423 1 30923U 88051B 96305.57123433 .00000000 00000-0 10000-4 0 08051 2 30923 57.1160 81.5232 7368989 54.7750 195.6866 2.237418466 4231 : 1. These sets are syntactically correct as per the NORAD specification: ftp://archive.afit.af.mil/pub/space/tle.doc 2. The Satellite Identifier, that usually appears as a title or menu entry in tracking programs, is AO13-xxxx where xxxx is the orbit number. 3. The Object Number for the real AO-13 is 19216. The object number for these fictitious satellites is 24500+OrbitNumber, e.g. 30922, 30923 above. This number is much higher than any real satellite's, and enables you to construct a database (for example in InstantTrack) with each "Oscar-13" unique. 4. The Element Set is mmdd where mm is the month and dd the day the element set was created. It's 0805 (August 05) in the example. 5. Decay is deliberately set to zero. This means that ideally you should use a Keplerian element set fairly close to the orbit it represents. When the true value of Decay is small you can be up to a month or so off, but at end-of-life when the true Decay is rising substantially every orbit, one MUST use the correct element set for the orbit or you'll suffer enormous tracking errors. Successive sets coincide at perigee. 6. Each set represents the osculating ellipse computed from the satellite's position and velocity near apogee (MA=180 deg) in the orbit. AMSAT tracking programs are designed to use osculating keplerian elements. Suggested References are: ---------- 1. J.R. Miller, "The Re-Entry of Oscar-13" Proceedings of the 12th annual Amsat Space Symposium, Orlando, Florida, USA, 1994. 4 pages. Also appearing in: Oscar News (UK) 1994 Oct No. 109 p 16-20 Jamsat Newsletter (JA) No. 166, 1995 March 25. p1-4 Amsat-DL Journal (D), Jg. 22, No. 1, Mar/May 1995. Amsat OZ Journal (OZ) No. 37, 1995 May The Amsat Journal (USA) Vol. 18 No.3, May/June 1995. James reminds us that the updated article and program listing is available via the Internet at: ftp://ftp.amsat.org/amsat/articles/g3ruh/a114.zip 2. J.R. Miller, "From Hardware to Vaporware; AO-13 Re-entry Plans" Oscar News (UK) 1996 Jun No. 119 p 36-41 Also appearing in The Amsat Journal (USA) Vol. 19 No.4, Jul/Aug 1996. Amsat-VK Newsletter No. 135/136, 1996 Jul/Aug Amsat-DL Journal (D), Jg. 23, No. 3, Sep 1996 (in preparation). ftp://ftp.amsat.org/amsat/articles/g3ruh/a121.zip [ANS thanks James Miller, G3RUH for this interesting information.] /EX SB SAT @ AMSAT $ANS-251.08 WEEKLY SATELLITE REPORT PT 1. HR AMSAT NEWS SERVICE BULLETIN 251.08 FROM AMSAT HQ SILVER SPRING, MD, SEPTEMBER 7, 1996 TO ALL RADIO AMATEURS BT BID: $ANS-251.08 FO-29 (Fuji OSCAR 29) FORMERLY JAS-2 FO-29 I heard a number of QSO's on 9/6/96 04:15 UTC. Signal strength was S7 to S9. This is a fine new addition to the OSCAR's. The AMSAT keplerian elements were incorrect on that date. I downloaded correct keps from KO-23. [ANS thanks Jim Weisenberger, AA7KC, for this report.] The FO-29 reports that the bird is now in good condition of hardware, and last week we tried digitalker a little bit, and it went well. The problem is to keep a charming voice for announcement. Now 9600 bps is going on, and sometimes we try some experiment of commanding and sending programs. MIR: The SAFEX II equipment onboard MIR's PRIRODA module has been powered on. 145.55 simplex has been active from the space station. RS-12: Operating normally. RS-10: Operating normally. RS-15 Operating normally. Down link signals are never very strong and there is much deep QSB. DO-17 (DOVE): The S band beacon is operational. KO-23: Operating normally KO-25: Operating normally. [ANS thanks Jim Weisenberger, AA7KC, for the reports on KO-23 and 25.} AO-27: Operating normally. AO-10: KF2SO reports hearing strong signals from OSCAR-10 Aug. 30 at 10:00 UTC. He says that it was at a range of 30,000+ kms. He notes that it was FMing, and wonders if anyone has monitored OSCAR-10 with clean, non-FMing signals lately. If so, he further wonders if the solar panels were lit by the Sun. [ANS thanks KF2SO for this AO-10 information.] /EX SB SAT @ AMSAT $ANS-251.09 WEEKLY SATELLITE REPORT PT 2 HR AMSAT NEWS SERVICE BULLETIN 251.09 FROM AMSAT HQ SILVER SPRING, MD, SEPTEMBER 7, 1996 TO ALL RADIO AMATEURS BT BID: $ANS-251.09 FO-20 FO-20 is also working, and it came just after FO-29s pass on the night of FO-29's launch day, as though it watched the new born brother OSCAR-11: During the last month OSCAR-11 has continued to provide good signals on 145.826 MHz. There have been a few shut downs, due to the watchdog timer, which has then been reset by ground control. OSCAR-11 can be heard on 145.825 MHz. Modulation is 1200 baud AFSK, with tones of 1200/2400 Hz. There have been many designs for suitable decoders, but perhaps the simplest way is to use an old telephone modem, using Bell 202, or V23 tones. It is essential to invert the modem's output signal, before feeding it into the computer. The current operating schedule is - 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) There are also additional status blocks after each bulletin is transmitted. It is possible that the long period of ASCII status blocks may be replaced by binary TLM and WOD. [ANS thanks Clive Wallis, G3CWV, for this update on OSCAR-11.] IO-26 ( ITAMSAT): ITAMSAT, now, is in good shape. Telemetry is every 60 seconds and the digipeater is OFF. The actual beacon is: ** 15th August 1996 ** Digipeater is OFF. Command station IK2XRO-IW2EGC in Buenos Aires. Thanks to LU8DYF-LUSAT Command team. 73 de ITAMSAT Command team. AO-13: Ed Krome KA9LNV reports listening to mode B QSO's being downlinked on AO-13 Mode S a few nights ago around MA50. "Such is the nature of mode BS", he comments. Ed noted that signals were excellent. He reminds us that Mode B signals come down on LSB since the S transponder is non-inverting and that regular Mode S is up and down on USB. [ANS thanks Ed Krome KA9LNV (ka9lnv@amsat.org) for this observation.] WO-18 (WEBERSAT-OSCAR-18): Has experienced many software crashes recently. Efforts are underway by the command team to identify the cause, and make the appropriate corrections. Controllers all hope that WO-18 will be operational again very soon sending telemetry, photos, weekly whole orbit data (WOD), and light spectra of the Sun or Earth. [Please send your Satellite reports to bjarts@uslink.net or to wt0n@amsat.org] /EX