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Re: Introduction and Falconsat-3 question
by Burns Fisher (AMSAT) 30 Oct '22

30 Oct '22

That's pretty interesting that you feel we need 1 Watt or so for 9600 baud downlink, Mark. I'm not sure if anyone thought about that. We have also been talking about multiple speed uplinks. I.e. one receiver at 1200, 1 at 9600, or whatever. Personally I want a 1200 baud uplink for my *&)E^T# IC9700, which is otherwise a great radio :-) 73, Burns Fisher, WB1FJ *AMSAT(R) Engineering -- Flight Software* On Tue, Oct 25, 2022 at 12:04 PM Jonathan Brandenburg via pacsat < pacsat(a)amsat.org> wrote: > > > > ---------- Forwarded message ---------- > From: Jonathan Brandenburg <jbrandenburg(a)amsat.org> > To: pacsat(a)amsat.org > Cc: > Bcc: > Date: Tue, 25 Oct 2022 11:04:28 -0500 > Subject: [pacsat] Re: Introduction and Falconsat-3 question > On 10/25/2022 10:45 AM, Mark L. Hammond wrote: > > My question--is there one day each week where you'd like me to turn ON > > Falconsat-3 for about 24 hours of operations? > > Thank you for the offer, Mark! > > This might be the kick in the pants I need to finally assemble my > satellite packet station. I'll get to work on that right away. In the > meantime, I hope others on this list are more prepared than I am. > > Jonathan > > -- > Jonathan, KF5IDY > > > > > ---------- Forwarded message ---------- > From: Jonathan Brandenburg via pacsat <pacsat(a)amsat.org> > To: pacsat(a)amsat.org > Cc: > Bcc: > Date: Tue, 25 Oct 2022 11:04:28 -0500 > Subject: [pacsat] Re: Introduction and Falconsat-3 question > ----------------------------------------------- > pacsat mailing list -- pacsat(a)amsat.org > View archives of this mailing list at > https://mailman.amsat.org/hyperkitty/list/[email protected] > To unsubscribe send an email to pacsat-leave(a)amsat.org > Manage all of your AMSAT-NA mailing list preferences at > https://mailman.amsat.org >

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Re: Power Thoughts
by Eric Skoog 29 Oct '22

29 Oct '22

Bob - in addition to the Chapter 5 Pwr Generation material, this is an extremely good reference document for many CubeSat Development areas. Its open source, publicly published information provides excellent tutorial introductory material for many/most of our AMSAT CubeSat development areas. Consequently, I uploaded a copy to our GOLF SVN under "tech ref docs." I found the first few chapters very familiar given my 40 year System Engineering experience, and a great refresher for my aging brain! But I found the remaining chapters contain excellent tutorial information for the major engineering disciplines we must understand and apply to be successful in our ongoing/future CubeSat development efforts. ALL chapters include myriad hyperlinks to more material electronically published in the open literature. The material does "thin out" in the last few chapters as they appear to be 'works in progress.' What particularly caught my attention was mention of the University of Hawaii's *Artemis CubeSat Kit *they are offering new satellite developers. I had no luck finding any further information about that kit on their website, but there is an invite to contact the PoC, Dr. F. Zhu (shu@ hawaii.edu) for more information. Specifically mentioned is the availability of a 1U CubeSat structure, fully qualified to NASA and CalPoly requirements, whose mechanical pieces add up to $356.02 (not counting solar panels). That might be worth looking into as Tom Wu is researching commercially available 1U structures for FOX+(PacSat). Furthermore, it is stated that they also have a CAD package for that 1U structure, viz., a 3D model (in Autodesk Inventor) that is available. Perhaps that might be of interest to Tom K. and Marwan. Lastly, I would think Vincent might benefit from one of the references which documents the failures of many past deployable solar panel designs..................good stuff all. thanks, eric (K1TVV) On Fri, Oct 28, 2022 at 11:19 AM Bob Stricklin via pacsat <pacsat(a)amsat.org> wrote: > > > > ---------- Forwarded message ---------- > From: Bob Stricklin <bstrick(a)n5brg.com> > To: "pacsat(a)amsat.org" <pacsat(a)amsat.org> > Cc: > Bcc: > Date: Fri, 28 Oct 2022 15:19:09 +0000 > Subject: [pacsat] Power Thoughts > Group, > > Power requirments is something we need to be looking at carefully. > > I found this on the web: > > https://pressbooks-dev.oer.hawaii.edu/epet302/chapter/5-5-power-generation/ > > We can look at some data from other cubsats for power generation. > Reviewing Falconsat-3 telemetry would be a good idea. > > Power and thermal design will play off each other. > > With a 2.5 W power budget for a cubsat the pacsat payload could be a large > power consumer. May effect ability to get onboard. > > If Golf T had two of the TMS520 one must have been powered down until > needed? > > Designing for minimum power will yield more operating time and a longer > mission life. Falconsat-3 is demonstrating this point now. > > Bob N5BRG > > > ---------- Forwarded message ---------- > From: Bob Stricklin via pacsat <pacsat(a)amsat.org> > To: "pacsat(a)amsat.org" <pacsat(a)amsat.org> > Cc: > Bcc: > Date: Fri, 28 Oct 2022 15:19:09 +0000 > Subject: [pacsat] Power Thoughts > ----------------------------------------------- > pacsat mailing list -- pacsat(a)amsat.org > View archives of this mailing list at > https://mailman.amsat.org/hyperkitty/list/[email protected] > To unsubscribe send an email to pacsat-leave(a)amsat.org > Manage all of your AMSAT-NA mailing list preferences at > https://mailman.amsat.org >

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Re: Power Thoughts
by Burns Fisher (AMSAT) 28 Oct '22

28 Oct '22

Golf-Tee does not power down the standby processor. It is still handling its own telemetry and also keeping its on MRAM up to date with whole orbit data, not to mention running the command receiver. But remember Golt-TEE is a 3U with fold-out panels. 73, Burns Fisher, WB1FJ *AMSAT(R) Engineering -- Flight Software* On Fri, Oct 28, 2022 at 11:19 AM Bob Stricklin via pacsat <pacsat(a)amsat.org> wrote: > > > > ---------- Forwarded message ---------- > From: Bob Stricklin <bstrick(a)n5brg.com> > To: "pacsat(a)amsat.org" <pacsat(a)amsat.org> > Cc: > Bcc: > Date: Fri, 28 Oct 2022 15:19:09 +0000 > Subject: [pacsat] Power Thoughts > Group, > > Power requirments is something we need to be looking at carefully. > > I found this on the web: > > https://pressbooks-dev.oer.hawaii.edu/epet302/chapter/5-5-power-generation/ > > We can look at some data from other cubsats for power generation. > Reviewing Falconsat-3 telemetry would be a good idea. > > Power and thermal design will play off each other. > > With a 2.5 W power budget for a cubsat the pacsat payload could be a large > power consumer. May effect ability to get onboard. > > If Golf T had two of the TMS520 one must have been powered down until > needed? > > Designing for minimum power will yield more operating time and a longer > mission life. Falconsat-3 is demonstrating this point now. > > Bob N5BRG > > > ---------- Forwarded message ---------- > From: Bob Stricklin via pacsat <pacsat(a)amsat.org> > To: "pacsat(a)amsat.org" <pacsat(a)amsat.org> > Cc: > Bcc: > Date: Fri, 28 Oct 2022 15:19:09 +0000 > Subject: [pacsat] Power Thoughts > ----------------------------------------------- > pacsat mailing list -- pacsat(a)amsat.org > View archives of this mailing list at > https://mailman.amsat.org/hyperkitty/list/[email protected] > To unsubscribe send an email to pacsat-leave(a)amsat.org > Manage all of your AMSAT-NA mailing list preferences at > https://mailman.amsat.org >

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the list
by Bill 28 Oct '22

28 Oct '22

list attached

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Power Thoughts
by Bob Stricklin 28 Oct '22

28 Oct '22

Group, Power requirments is something we need to be looking at carefully. I found this on the web: https://pressbooks-dev.oer.hawaii.edu/epet302/chapter/5-5-power-generation/ We can look at some data from other cubsats for power generation. Reviewing Falconsat-3 telemetry would be a good idea. Power and thermal design will play off each other. With a 2.5 W power budget for a cubsat the pacsat payload could be a large power consumer. May effect ability to get onboard. If Golf T had two of the TMS520 one must have been powered down until needed? Designing for minimum power will yield more operating time and a longer mission life. Falconsat-3 is demonstrating this point now. Bob N5BRG

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Introduction and Falconsat-3 question
by Mark L. Hammond 27 Oct '22

27 Oct '22

Hello PACSAT Team---it was great to learn about this project from Jonathan at the recent AMSAT Symposium. I'm delighted to hear that you're working on a PACSAT version of something new... It was the original microsats/pacsats project and launch that got me interested in satellite communications, so I've been doing it for a while. Happy to give opinions or suggestions when needed--don't be afraid to ask. My question--is there one day each week where you'd like me to turn ON Falconsat-3 for about 24 hours of operations? I think it'll take this 'abuse' for a while; it's predicted to reenter around April next year, so we have a few months before it's gone.... Putting the satellite on an operation schedule will help people know when to expect it to be on. I though you all might enjoy listening/working it, making recordings, tests, whatever, while we still have it working. A challenge is that the orbit precesses like 30 mins per day, so eventually it shifts where all passes are during the sleeping hours...so there will some weeks where it might not be turned on... So, can you all pick the day when you'd like it on? I'll do my best to keep it going per schedule...Drew KO4MA is also on the list, and he'll help as needed I'm sure. Both of us are interested in an outline/overview of what you all imagine. I think I learned 1200 AFSK uplink (four frequencies/channels), 9600 baud FSK downlink. My preferred is 2M uplink, 70cm downlink (since it's so quiet). It'll take about 500mw to 1W on the downlink to be useable at 9600. Even more is desirable or necessary if you want to go higher than 9600... I think I'm one of the remaining dinosaurs that has experience and equipment to do 38k4 on the downlink...although wideband SDRs has changed that! 73! Mark L. Hammond [N8MH] (formerly KC4EBR) AMSAT Director and Command Station

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Pacsat ConOPS document
by Bill 26 Oct '22

26 Oct '22

Attached is version 1.0 of the AMSAT PACSAT Payload conops document. We will discuss this briefly at tomorrows dev meeting. Bill

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Pacsat Dev Meeting
by Bill 26 Oct '22

26 Oct '22

Pacsat Dev Meeting #2 Thu, Oct 27, 2022 8:00 PM - 10:00 PM (CDT) Please join my meeting from your computer, tablet or smartphone. https://meet.goto.com/909715813 You can also dial in using your phone. (For supported devices, tap a one-touch number below to join instantly.) United States: +1 (872) 240-3212 - One-touch: tel:+18722403212,,909715813# Access Code: 909-715-813 Get the app now and be ready when your first meeting starts: https://meet.goto.com/install Agenda: * Conops discussion * Engineering process * Task List

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Prototype Code
by Chris Thompson 26 Oct '22

26 Oct '22

I mentioned to Jim and some others that I was working on some Pacsat code for an ARISS project. This is just a prototype but it may be useful, especially for those seeking to understand the protocols. I cleaned up the code a bit and checked it all in to here: https://github.com/ac2cz/Pacsat/ I leveraged some of the old 1990s code from programs like PG and PB, but they are written in an old style of C that modern gcc does not like. They also rely on the bit size of char, int and long (and time_t it seems) in a way that does not work with modern computers. So I updated much of that to use uint32_t etc. Also PB/PG are for a ground station whereas this code is for the server. So there were just a few structures and routines to leverage, but most of this is new code. This runs on Linux and has been tested on Ubuntu and the Raspberry PI. I have assumed a little endian machine, there is no code to cope with big endianess It works with Direwolf's AGW engine as the TNC. I picked that over the KISS interface so I do not have to implement the connected mode state machine for AX25. Right now this just implements the broadcast protocol. Specifically it stores the PB status for up to 10 stations, it transmits the PB status periodically, handles directory broadcast requests and file broadcast requests. The functionality to handle holes in the directory and files is not fully tested, but the broadcast of a new directory or of a new file seem to work well. I have no idea how these things were done in previous spacecraft, so I chose a linked list for the directory, which is rebuilt at startup, and a fixed structure to hold 10 stations on the PB, with memory allocated and freed for the list of holes that they supply. If the directory grows to a large size then a hash table index by file id may be useful to save CPU at the expense of memory, but it is probably not needed given the frequency of requests is likely low (per second). The code it split into files to handle the creation or parsing of Pacsat Headers and Files, the creation and maintenance of a directory and the broadcast protocol. There are also test routines for each file, which you can see at the end. These demonstrate how most of the functions work. The Pacsat header/file routines may be the most useful to leverage as they are a pain to write and probably very portable. Though I have assumed a normal C file system to load/save the files. I'm happy to answer questions or discuss with anyone if that is helpful. I don't claim any great skill in the C language, so feel free to point out any issues or make suggestions if you want. Next I am going to finish up the handling of holes and then implement FTL0 for file uploads. I want to setup a test loop to measure the relative performance of AX25 vs FX25 under simulated LEO conditions. I also want to see if this prototype will work for the mission objectives of the ARISS Student Sensor project. 73 Chris -- Chris E. Thompson chrisethompson(a)gmail.com g0kla(a)arrl.net

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Re: PACSAT Components in My Possession
by Chris Thompson 25 Oct '22

25 Oct '22

Assuming you can ship some of the parts to me in Canada then I am willing to help in whatever way I can. Either testing with the ground station I developed, porting some of the Pacsat server code that I have written for ARISS or whatever else helps. Let me know. 73 Chris G0KLA / AC2CZ On Tue, Oct 25, 2022 at 11:30 AM Jonathan Brandenburg via pacsat < pacsat(a)amsat.org> wrote: > > > > ---------- Forwarded message ---------- > From: Jonathan Brandenburg <jbrandenburg(a)amsat.org> > To: pacsat(a)amsat.org > Cc: > Bcc: > Date: Tue, 25 Oct 2022 10:29:55 -0500 > Subject: [pacsat] Re: PACSAT Components in My Possession > On 10/24/2022 4:36 PM, JIm McCullers wrote: > > Is some of each acceptable? > Absolutely! > > I need a couple Launchpad boards to work out the dimensions and header > sizes needed for a daughter board. > > The documentation is sketchy to none. > That makes sense. I figure each active pacsat developer needs at least > one and perhaps two Launchpad boards. > > When do you believe the Raspberry Pi boards will be in? > > I want to do one while working on the Launchpad daughter board. > > If it's soon that would save one shipping. > OSHPark expects the panel on Thursday and will likely ship the boards to > me quickly after receiving the panel. I expect the Raspberry Pi boards > early next week. I'd expect each pacsat developer to need three boards > at peak development to implement a two-up-one-down system. If I'm right, > it might make sense to wait until the Raspberry Pi boards arrive. (For > those that might be confused, the Raspberry Pi boards are a convenient > way to develop using the AX5043 and can be jumpered to the LaunchPad... > I've done that before.) (Also, to be clear, the Raspberry Pi boards > require assembly with surface mount components. In particular the AX5043 > has a ground pad making the use of a reflow oven beneficial. Admittedly > it could be done with hot air and hand-soldering, too.) > > As to the board you sent me, do you have the schematic available? > > I'll assume it's Kicad. Package it together with any support libraries > and send it to me. > > I'll switch to my other computer and pull up what I have. I won't have > any software specifically written for that prototype board I > accidentally sent you as I hadn't assembled one. But I think you'll find > the AX5043 portion to be a lot like the V1.3 board with the addition of > the second antenna connection. Thus, the software written for the V1.3 > board should be functional on the prototype board. > > Jonathan > > -- > Jonathan Brandenburg, KF5IDY > > > > > ---------- Forwarded message ---------- > From: Jonathan Brandenburg via pacsat <pacsat(a)amsat.org> > To: pacsat(a)amsat.org > Cc: > Bcc: > Date: Tue, 25 Oct 2022 10:29:55 -0500 > Subject: [pacsat] Re: PACSAT Components in My Possession > ----------------------------------------------- > pacsat mailing list -- pacsat(a)amsat.org > View archives of this mailing list at > https://mailman.amsat.org/hyperkitty/list/[email protected] > To unsubscribe send an email to pacsat-leave(a)amsat.org > Manage all of your AMSAT-NA mailing list preferences at > https://mailman.amsat.org > -- Chris E. Thompson chrisethompson(a)gmail.com g0kla(a)arrl.net

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