************************************************************************** * * * THIS IS THE WD0GML-AMSAT-ST.LOUIS BBS 24HR 7DAY AT (314)447-3003 * * 300/1200/2400 BAUD * * Mike Parisey WD0GML SYSOP * * Norm Newman NZ0Z Co-SYSOP * * * ************************************************************************** SB ALL @ AMSAT $ANS-063.01 AO-13 OPERATING SCHEDULE CHANGE HR AMSAT NEWS SERVICE BULLETIN 063.01 FROM AMSAT HQ SILVER SPRING, MD MARCH 04, 1989 TO ALL RADIO AMATEURS BT OSCAR-13 Spacecraft Attitude Adjustment & Transponder Schedule Change There will be a AO-13 spacecraft attitude reorientation maneuver taking place on March 15 inorder to make adjustments for seasonal changes in sun angles. As with all attitude readjustments, there will also be a transponder operating schedule change which will accompany this event. Effective March 15, 1989 the Operating Schedule for AO-13 will be as follows: Mode B From MA 100 to MA 160 Mode JL From MA 160 to MA 200 OFF From MA 200 to MA 255 Mode B From MA 0 to MA 100 The final Bahn Coordinates for AO-13 after the attitude change will be as follows: Bahn Longitude=210 degrees, Bahn Latitude=+5 degrees. At the present time there is no scheduled Mode S operating time but it is expected that this will change after RUDAK testing is finished. Listen to the Beacons on AO-13 and AMSAT Nets for the latest information on any operating schedule changes. The predicted Bahn Coordinates for March 6th are: Bahn Longitude=178.5 degrees, Bahn Latitude=-5.1 degrees. The above operating schedule will remain in effect until May 3, 1989. /EX SB ALL @ AMSAT $ANS-063.02 UO-9 ORBITAL DECAY COMPETITION HR AMSAT NEWS SERVICE BULLETIN 063.02 FROM AMSAT HQ SILVER SPRING, MD MARCH 04, 1989 TO ALL RADIO AMATEURS BT AMSAT-UK Sponsoring A "Chicken Little" Contest For UO-9 UoSAT-1, Britain's first low-cost satellite focusing on cost-effective spacecraft engineering and space education, was launched by NASA Delta rocket on the 6th October 1981 at 11:27 GMT into a 554 km 95 minute circular, near-polar, Sun-synchronous, low-Earth orbit. Because of the relatively low altitude, the residual Earth's atmosphere is gradually causing the orbit to decay, and as the orbit lowers, so the atmospheric rag increases, causing the satellite's orbit to decay faster. The effect is exacerbated by the increasing solar activity due to the Sun reaching a peak in its 11-year cycle, as this causes the Earth's atmosphere to rise, increasing the drag. The current altitude of the satellite is 434 km and it is decaying at a rate of approximately 400 m per day. It is possible to follow the decay of the satellite by monitoring how the orbital period (and hence the altitude) changes with time. This can be done by monitoring the Doppler shift of the satellite's signals over the course of two orbits to note the time between two consecutive "Time-of-Closest-Approach" (TCA)s. If you have a receiver with a Doppler shift output, plot the Doppler "S-shaped-curves" for two consecutive passes -- keeping a careful note of the time. (To see an example of what such a curve looks like, see "The Satellite Experi- menter's Handbook by K2UBC, page 10-4). The TCA can be found by reading off the time for which the curve's slope is steepest. The time between the two TCAs is the orbital period, from which the altitude can be derived using classical Newtonian mechanics. If you have a 2m amateur-radio with a center-frequency indicator, you can identify the TCA by noting the time at which the received frequency is exactly the frequency transmitted by the satellite (i.e. 145.825 MHz). If your receiver has none of these facilities, then the you may assume that the TCA is approximately half-way between the "Acquisition-of-Signal" (AOS) time, and the "Loss-of-Signal" (LOS) time, providing that your radio-horizon is fairly uniform. If you keep a record of your results over a period of time, you will be able to plot the decay curve of the satellite. This will also enable you to modify the Mean Motion (1440/Period) of the satellite in the Keplerian Element set, so that your orbital prediction programs can keep up with the rapid decay. The competition is as follows: Using any method you choose, predict the precise day (UTC) on which UoSAT-1 will decay completely (i.e. burn up in the atmosphere). Your entry must arrive at least four weeks before the date of your prediction. Please include the following information: Name: Occupation: Address: Receiving Equipment: Predicted Decay Date: Brief Note on Method Used: Sweatshirt Size (Large/Medium/Small): Sweatshirt Color (Grey/White/Light Blue): Several prizes will be offered such as a UoSAT sweatshirt and AMSAT-UK software. In the event of a tie, the winner(s) will be selected at random from the correct entries. In the event of there being no correct entries, then the nearest date will be declared the winner. Send in your answers to: "UoSAT-1 Orbital Decay Competition" AMSAT-UK 94 Herongate Road, Wanstead Park, LONDON E12 5EQ. /EX SB ALL @ AMSAT $ANS-063.03 LUNAR POLAR PROBE CONFERENCE HR AMSAT NEWS SERVICE BULLETIN 063.03 FROM AMSAT HQ SILVER SPRING, MD MARCH 04, 1989 TO ALL RADIO AMATEURS BT AMSAT To Co-Sponsor Lunar Polar Probe (LPP) Conference AMSAT-NA will co-sponsor the First Lunar Polar Probe conference being held in Houston, Texas on March 11-12. The Lunar Polar Probe conference is being organized by the Houston Space Society. Additional co-sponsors include the National Space Society, Space Studies Institute and others. The purpose of the Conference is to bring together individuals and organizations who will work together to design, build, launch, and track the Lunar Probe. The Lunar Probe series will collect information about the moon and promote the exploration, development, commercialization, and settlement of space. An AMSAT-NA Representive ill give a talk about "Other Small Satellites: The Amateur Radio Satellite Corporation." AMSAT members and space enthusiasts are encouraged to attend this interesting conference. For more information contact Jim Davidson at (713) 643-6373. /EX SB ALL @ AMSAT $ANS-063.04 Short Bursts HR AMSAT NEWS SERVICE BULLETIN 063.04 FROM AMSAT HQ SILVER SPRING, MD MARCH 04, 1989 TO ALL RADIO AMATEURS BT Short Bursts AMSAT-UK announced recently that they have a new offering in their soft- ware catalogue known as SATSCAN-II. This program is written for IBM PC compatabiles and will accommodate EGA/VGA modes in full color. This program will display satellite positions in a map or in a tabular format. SATSCAN-II also provides numerous other useful data to OSCAR satellite users. If you would like more information about this software package, please send a s.a.s.e to: AMSAT-UK, 94 Herongate Road, Wanstead Park, London E12 5EQ England. There will be a AO-13 Operations Net on March 11, 1989 at 13:00 UTC. Courtney Duncan, N5BF, will be the NCS. The downlink frequency for this Net will be 145.950 MHz. This Net is designed to give AO-13 users the latest operational news about OSCAR satellites. All are invited to check-in. If you would like a quicker update to the Keplerian elements of UO-9 than are provided from NASA, you are invited to call the NY0T BBS. Keith Goobie, NY0T/VE3PDD, is a Captain in the Royal Canadian Air Force who is presently stationed at the North American Air Defense Command (NORAD) in Colorado Springs, CO. Keith will be putting the "latest and greatest" elements for UO-9 on his BBS as he receives them from NORAD each day. So for daily updates for UO-9, call the NY0T BBS at (719) 637-1375. /EX FLASH! FLASH! FLASH! FLASH! FLASH! FLASH! FLASH! FLASH! FLASH! FLASH! THE FOLLOWING ADDED BY WD0GML-AMSAT-ST.LOUIS (314) 447-3003 24hr 7day 300/1200/2400 baud. This section may have additions through the week! AMSAT AO-13 OPERATIONS NET: An Operations Net session was held on AO-13 mode B (145.950) from 1546 to 1640 UTC, Saturday 25 February 89. Led by N5BF, WA5ZIB and W8GQW checked in and the session quickly evolved into a friendly round table. The just completed ZRO test, net scheduling (satellite and HF) need for more NCSs, and the need for ZRO results publicity were among topics discussed. Conditions were fair to good, and would have been better except for transponder pumping due to a number of high powered stations elsewhere in the passband. The AMSAT Operations Net schedule for the next several weeks is under preparation and will be released to telemail and print media shortly. The purposes for the net are: 1) To use something besides the telephone and telemail to conduct some AMSAT communications, 2) To provide incentive for operators to maintain and use their stations for something besides DXing and random contacts, and 3) To provide satellite operators regular access to AMSAT management. 73 all, Courtney, N5BF BILL EITEL-SILENT KEY: The March 6, 1989 edition of Defense News carried an obituary notice of the death at 81 of William Eitel, described as a radio amateur enthusiast and co-founder of one of Silicon Valley's earliest technology companies. Bill Eitel, WA7LRU/W6UF/W6AY, who with a partner, founded the Eitel-McCullough (EIMAC) company, will be remembered by many as a long-term, active and enthusiastic member of the amateur radio amateur community. An early participant in the amateur radio satellite program, Bill was active with the Project Oscar group in the 1060's and, as Life Member No. 9, provided strong personal and financial support for the AMSAT programs in the early 1970's. From 1972 to 1975, he served as chairman of the Amateur Satellite Service Committee (ASSC), a coordinating body with representation from Project OSCAR, AMSAT, and the ARRL. In this position, he undertook a number of initiatives aimed at garnering support for the amateur satellite program from the highest levels in Government. Bill was not as active in the past several years due to failing health, but continued to take a strong interest in the program. He will be missed.