- pacsat - mailman.amsat.org

FalconSat-3 Description
by James McCullers 23 Sep '22

23 Sep '22

https://www.amsat.org/getting-started-with-amateur-satellites-falconsat-3/ 58 degrees north/south

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Thoughts about the FoxPac
by Burns Fisher (AMSAT) 22 Sep '22

22 Sep '22

I've been reading some of the documents and since there are a lot of references to Pacsat generically, I'm using "FoxPac" here to mean specifically the design that we are talking about on this mailing list. As I was reading the documentation, one thing stood out to me: There are lots of assumptions, and appropriately so, that the data rate and format is 9600 bps GMSK. One problem with this speed/format is that it is not supported by the most popular satellite radio these days, the ICOM 9700. Heaven knows why ICOM did not choose to support it, but they seem not to be doing anything about it. My thoughts below may be partly selfish since the 9700 is MY radio, but on the other hand, it IS very popular. One workaround: According to Mark Hammond, N8MH, the 9700 CAN be used for 9600 baud reception (by collecting the IQ (essentially IF) output) and decoding it in software. Thus the big problem is the uplink. Bill's initial design calls for 4 uplink receivers and one downlink transmitter. Suppose that the uplink receivers were designed to switch baud rates on command. We could set it by default to have (say) two receiving at 1200 bps and two at 9600 (or some other number). Alternatively, choose certain days when there were 1200 baud receivers operating. Another alternative: This is not a workaround so much as an offshoot project: Design a simple 9600 baud uplink transmitter. There already exists software and hardware for a AX5043 Raspberry Pi shield. We would "only" need to produce more shields (I believe Jonathan has that design), design a power amp for the output of the 5043, and design and write the software on the Pi. TBD whether the Pi software would do the doppler calculations, or whether it would accept commands from a traditional satellite tracking program (the latter certainly seems easier). I just wanted to send these ideas out for people to think about. It's up to Bill whether this is anything to talk about tonight or not. Maybe it is too soon anyway. 73, Burns Fisher, WB1FJ *AMSAT(R) Engineering -- Flight Software*

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Pacsat dev meeting #1
by Bill Reed 21 Sep '22

21 Sep '22

Pacsat Development team: I am planning the first Pacsat development meeting for Thursday, 9/22/2022 at 8PM CDT. I will send out invitations to all members of the pacsat(a)amsat.org mailing list as of 9/21. Think about the task lists and where you would like to get involved. ( and, of course, additional tasks ) Please send comments and ideas to me at nx5r(a)amsat.org Could this extract from the ground station manual be considered our first draft of a CONOPS document? THE AMSAT PACSAT GROUND STATION MANUAL: https://www.g0kla.com/pacsat/pacsat_ground_manual.pdf EXTRACTED FROM THE AMSAT PACSAT GROUND STATION MANUAL: The Pacsat satellite will run software that follows the PacSat protocols. This is a clever set of software routines that provide a delay tolerant network connection to the spacecraft. The protocols are split into two halves. The broadcast protocol and connected mode. The broadcast protocol is used to receive data from the spacecraft. The files and data available on the spacecraft are broadcast as a directory listing. This means that all ground stations can listen and record the data. Specific files are requested by transmitting a broadcast request to the spacecraft. The file is then broadcast in chunks of data and again all ground stations can receive it. Each ground station can then request the parts of the file that they missed. This makes it a very efficient way to communicate data to many stations and makes it possible to download the directory and files across fades and different passes of the spacecraft. To upload files a ground station makes a dedicated connection to the spacecraft by logging in. The spacecraft then confirms space is available and provides the file number to use. The data is then uploaded. Again, this is very delay tolerant and picks up seamlessly across fades or passes. You may think this is all very old and out of date, and perhaps using low speeds at 9600bps is, but the protocols form the basis of modern high speed, delay tolerant communications through spacecraft. It is a very robust solution for transmitting data around the world with no dependence on the telecoms infrastructure. I imagine a similar protocol will server us well when we exchange data with the moon or Mars. If you want to learn more about the Pacsat Protocols then have a look at the reference documents at the bottom of the page at: https://www.g0kla.com/pacsat OTHER INTERESTING LINKS: https://ke0pbr.wordpress.com/2020/11/06/tips-and-tricks-to-work-the-falcons… https://www.youtube.com/watch?v=Hd_8A0Lymzc https://www.youtube.com/watch?v=k6_aD0wQWxM https://www.amsat.org/falconsat-3/ https://www.g0kla.com/pacsat/ THINK ABOUT THESE TASK LISTS Hardware task list: TMS570 development kit AX5043 daughter boards attached to the dev kit Plug on modules for filters, amps and preamps file system memory power Software task list: TMS570 freeRTOS operating system AX5043 configuration and SPI interface multiple uplinks and single downlink file system w/EDAC IHU interface Pacsat protocol VERSION 2 ENHANCEMENTS: 4fsk 100 baud and other formats ???? Bill, NX5R

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I'd like to join the pacsat meeitng
by Burns Fisher (AMSAT) 08 Sep '22

08 Sep '22

73, Burns Fisher, WB1FJ *AMSAT(R) Engineering -- Flight Software*

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I'd like to be on the mailing list
by Rich Gopstein 08 Sep '22

08 Sep '22

Thanks.

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I'd like to monitor the development
by Zach Metzinger 08 Sep '22

08 Sep '22

Thanks! --- Zach N0ZGO

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Test
by BILL 03 Aug '22

03 Aug '22

Test ⁣Get BlueMail for Android

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