aug 28 2002
jul 29 2002
AMSAT-DL har nu krt igng tv nya satellitprojekt, P3-E och P5-A. Ls mer nedan:
AMSAT-DL announces formal go-ahead
for space missions
Phase 3-E and Phase 5-A
In July 2002 the AMSAT-DL (Germany) board of directors gave its official green light to develop and build the two spacecrafts AMSAT-Phase 3-E (P3E) and AMSAT-Phase 5-A (P5A). The high acceptance of the mission goals of these two projects expressed in the recent AMSAT-DL member s survey was the final element to arrive at this decision. Both satellites will be created in a common development process by an international team under the leadership of AMSAT-DL. The P3E satellite is to be launched as communication and scientific platform into a highly elliptical orbit around Earth. The second project with the working name AMSAT- Phase 5-A is destined to enter an orbit around the planet Mars. This spacecraft will then transmit scientific data to Earth – data from experiments on-board P5A as well as – via its repeater function – from experiments on the Martian surface or the planet s atmosphere.
So far three successful Phase 3 satellites were launched under the leadership of AMSAT-DL. The latest satellite of this series, P3D (now operational as AMSAT-OSCAR 40), was launched in 2000 and demonstrated sufficient bus and propulsion capabilities for a flight to Mars. So AMSAT-DL started a closer investigation into the possibility of such a mission. Based on the existing experience base and the overwhelming interest during the AMSAT-DL International Satellite-Workshop last year, the P5A spacecraft will not only carry scientific experiments, but also subpayloads to be released in direction to the Martian surface. Suitable launch windows to Mars exist in the years 2007 and 2009.
Two or three years earlier P3-E to be launched in an orbit around Earth is expected to continue the successful series of AMSAT- Phase 3 satellites. The main task of P3E is to serve as communication platform for the nearly 2 million radio amateurs worldwide. They constitute a network for further exploration of the so called uncoordinated multiple access , to provide simultaneous and freely available service to a large number of groundstations. Using existing technology and implementing the results of the member s survey, several transponders on frequencies between 145 MHz and 10 GHz are planned for P3E. Details will be fixed in a
design and payload meeting in the second half of 2002. Additionally the P3-E spacecraft will be an important test bed for some technology needed for the Mars mission. Work on the P3-bus has been started and a number of modules are already under construction.
So far all AMSAT-DL satellite missions in 1980, 83, 88 and 2000 were launched with ARIANE-launchers from French Guyana into geostationary transfer orbits. The excellent co-operation between Arianespace (with its current ARIANE-5-launch-system) and AMSAT-DL resulted in the development of various arrangements for the launch of secondary payloads on-board of ARIANE-launches. Thus Arianespace will be the first obvious choice for the launches of P3E and P5A.
Peter Glzow, DB2OS, President AMSAT-DL
Frank Sperber, DL6DBN, Vice President AMSAT-DL
Prof. Dr. Karl Meinzer, DJ4ZC, Projectleader
First background information about both missions can be found at:
jul 21 2002
Nytt schema frn den 16 juli.
Information frn AMSAT-UK enligt nedan:
Effective this 765, on all days except Wednesday, the S2/K-Tx beacon only and passband segments are active again for testing. Note that the beacon only session (no passband) for S2 and K Tx s is MA 116-120, and the beacon + passband session is MA 120-128. As before, on Wednesday, the V-Rx along with L-band Rx s are connected to the passband from MA 120-128.
There s been some RUDAK issues too. Assi (I didn t know he was working on it) said:
The AO40 RUDAK team uploaded test code to one of the DSPs. This code generates a carrier at around 2401.625MHz ( doppler). The intent of this code is to help users do a ZR0 type experiment and test just how good their S-Band receive station is. The program generates a clean carrier at full RUDAK power, and then starts decreasing power in 3dB steps, all the way down to -30dB. One full cycle is 30 seconds. The resulting pattern is a sawtooth, and it is active between MA128 and MA160.
The code is new, and needs to be debugged. We would appreciate if some of you could record a wav file of the signal in SSB. If you can do so, please set your receiver so a clean tone is heard, and then record for at least 2 full minutes. During the recording don t update the frequency or mode so receiver phase modulation is not introduced. Once we get this code working, we will extend the period. If you can do this, please send Assi a zipped file emailed to email@example.com
There were complaints about the amount of transmitter time RUDAK was taking; DB2OS commented:
The test code which Assi is working on is only a small part of things to come. This is to get a feeling about the I/Q modulator and performance of the DSP modems. And indeed it s a good test for you and other to test the system sensitivity, similar to the ZRO test in the good old days. The idea is to use the DSP modems for 1200 Bit/s BPSK PACSAT type operations, which would allow us to run RUDAK in parallel with the transponder passband.
Whatever will allow them to run the Passband and RUDAK downlink in parallel should be fine. 9600bps FM causes problems with distortion when the passband is on. 1200 Bit/s BPSK should be easy and if it works, they can look further ahead to other simultaneous digital modes.
Se ven ANS 202.
Klla: ANS 202, AMSAT-UK
jul 21 2002
Bob Bruninga, WB4APR, har lmnat en del info om vad som hnder med PcSat just nu. Har ett utdrag:
Bob Bruninga WB4APR announced that PCSat has turned DIGI OFF and all 1200 baud TLM off.
Although PCsat has been perfectly usable in the afternoons into early evenings, the satellite is still running the batteries down on every eclipse. So today I thought of one last low power mode I can try so we turned DIGI and TELEMETRY OFF to see if we can make it through just ONE eclipse. That s all we would need to recover PCsat back into a positive power budget.
I will try this for the daytime passes over the USA this week (which will affect the evening passes over Europe).
The lowest power mode of PCsat has been with all BULLETINS and all DIGIpeating turned off. Also we disable 9600 baud 1 minute telemetry as well. Thus the only thing remaining was the once per minute single 1200 baud telemetry packet which is required to keep the heart-beat fail-safe reset timer tickled. What s new, is that we realized that if we switched the 1/min TLM to 9600 baud instead of 1200, we would further reduce the minimum transmit duty cycle in our lowest power mode. Thus halving our transmit current drain.
Unfortunately, our TRANSMIT power is already less than 10% of the overall bus power, so this move will only gain us about 5%, but worth trying… Our minimum transmit average current drain (1 packet per minute) is only about 16 ma out of the nominal 160 ma low power mode. Dropping this in half saves us about 8 ma. Who knows, maybe it is the straw that can give new life to the camel?
Anyway, when PCsat is in this minimum mode, the ONLY thing you will hear will be a once a minute half second noise burst (9600 bd TLM) and nothing else.
Mera info p hemsidan:
Klla: ANS 202
jul 21 2002
Det pgr nu tester att frska kontrollera AO-7, ls mer nedan:
I guess it s time for me to step forward out of the shadows. The behavior you re observing is being caused by me, N1JEZ. I m the so called Covert AO-7 Command Operator .
Before everyone gets all crazy, please let me try and explain a few things.
First, I asked to remain covert for a period of time because I did not want to have to deal with the inevitable flood of email that will result from my identity being known. At the time, I was in a critical phase of trying to command the bird and needed to concentrate on that task. There were a number of technical hurdles to overcome, not the least of which is dealing with 30 year old stuff.
I know I m going to get a lot of email, so I ve put together the following FAQ. Please read through it. Hopefully it will answer some of your questions and avoid you sending them to me.
Q: Tell me how the commands work.
A: Sorry, I _will not_ discuss any of the command details. Don t even ask.
Q: Tell me how the hardware works.
A: Sorry, I _will not_ discuss any of the command details. Don t even ask.
Q: What are the plans for AO-7.
A: I haven t foggiest! My job is to investigate what commands work and what commands don t after 21 years. It s really exciting, but tedious work. Imagine the thrill of seeing this antique accept your first command after all these years! For me, this is similar to the experience I had not long ago hearing the AO-40 24 GHz K Band beacon the first time. I ve gone from techno to retro in a short period of time.
Q: I m doing a satellite demo next Monday night. Can you make sure AO-7 is in Mode B?
A: Sorry, as I stated above, my only job is to test various commands.
Q: When it comes to AO-7. I m mad as hell and I m not going to take it anymore! Just leave it alone!
A: OK, take one of your little yellow pills and then send off a note to your favorite AMSAT official. Honestly, if you have concerns, voice them to Robin, VE3FRH or one of the Board of Directors. Everyone here is trying to do the right thing.
Q: How can I help?
A: Of most interest to me is how AO-7 wakes up as it enters sunlight. Also, any observations of simultaneous multiple modes would be most valuable. Yoshi Imaishi, JF6BCC is compiling an excellent list of observations. Please send him whatever you have. firstname.lastname@example.org
You can view the list at:
Q: Can you tell us _anything_ about this satellite?
A: I can tell you that command attempts are successful. I ve only tested a very limited number of functions, but it s very encouraging. I hope to be able to do a write up on all the fun I ve been having. Maybe it will be in the AMSAT Journal or perhaps a presentation at the AMSAT Symposium later this year. (get your tickets now
I still have a ton of work to do. So please try and keep the email to a minimum. I ll try and answer what I can.
[ANS thanks Mike Seguin, N1JEZ, for the above information.]
Klla: ANS 202
jul 15 2002
Av en hndelse s snurrade jag frbi 145 830 och hrde packet trafik, snabbt p med modemet och det var PCSAT-11 som snde, jag noterade EB3GEK och W3ADO-1 i meddelandet.
Det gr ju rtt mkt packet trafik frn ISS ocks som man kan titta p, frekvens 145800. Jag satt ven och lyssnade efter AO10 i kvll nr jag tyckte det borde vara ett bra lge men det r fortfarande tyst. (jag saknar en mode B sat i DX bana!!!)
Fr vrigt s fr jag det till att man borde kunna se ISS i slutet p mnaden som afton stjrna, runt den 28/7 om mitt program stmmer.
Avslutningsvis s kan jag nmna att jag krde I2FAK via EME med 100 watt och 2 antenner i gr kvll p random, visserligen har han 24 antenner!! men i alla fall, det r ju en otroligt svag signal som kommer tillbaka till honom, testa grna ngon gng med era Oscar stationer det gr att hitta honom runt 144038 vid aktivitets helgerna.
73 Hkan SM7WSJ
Klla: Hkan SM7WSJ via mailinglistan