[Ground-station] Satellite program
Jan Schiefer
jan at akalaitis.net
Mon May 21 22:23:36 PDT 2018
IPS on a soft RISC-V processor running on a SmartFusion2 FPGA, maybe?
Count me in, I've always had a soft spot for Forth.
: DEUTSCH PROBLEM KEIN;
Cheers,
Jan, ac7td, dl5ue
On 05/17/2018 12:02 AM, Douglas Quagliana via Ground-Station wrote:
> All,
>
> Here's more way more information than you wanted to know on a couple
> of the points that Bruce mentioned.
>
> Bruce writes:
> >They didn't always use rad-hard memory, just because they could not
> afford it,
> >but used error-correcting memory architectures and scrubbed the
> memory constantly
> >so that single-bit errors were corrected before they became large
> enough to be
> >uncorrectible.
>
> If I recall correctly, the memory scrubbing technique was used on the
> LEO Microsats and a three bank memory voting scheme was used on the
> IHU-2 on AO-40. See
>
> http://www.amsat.org/amsat/articles/g3ruh/124.html
>
> />EDAC memory:/ 20 percent. The EDAC (Error Detecting And Correcting)
> memory scheme used requires the actual memory to be three times as
> large as the processor sees. This is necessary to allow a two-of-three
> vote for each bit.
> >This scheme results in a much faster memory system than the Hamming
> 12 to 8 EDAC system used on previous designs, in order to support the
> much faster processor.
>
>
> Bruce writes:
> >They have their own FORTH-like language, first written in the '70's,
> which
> >does concurrent but not parallel threads. Most housekeeping is written
> >in this language.
>
> The language is IPS. First described in 1979! The original reference is
>
> Meinzer K.; IPS, An Unorthodox High Level Language, BYTE, January
> 1979, pps 146-159.
>
> which, before you groan about ancient references to out-of-print paper
> magazines, is actually available online at
>
> https://archive.org/stream/byte-magazine-1979-01/1979_01_BYTE_04-01_Life_Algorithms#page/n147/mode/2up
>
> But...if you want to learn IPS then you probably want the IPS book
> that James Miller, G3RUH, first published in 1997. Before you groan,
> again, about ancient references to out-of-print paper books, that book
> (actually the third edition of that book from 2016) is available
> online at
>
> http://www.jrmiller.demon.co.uk/IPS/IPS.pdf
>
> However, as you will quickly find out reading Miller's IPS book, the
> AO-13 IPS flight code is written in a German variant of IPS, so a lot
> of that IPS code looks like this:
>
> : TRQ-ST Z-MARKE @
> JA? E-FLAGS @ #14 UND >0 Z @
> MZEITGRENZE @ = ODER
> JA? 0 M-EIN !
> DANN Z @B 32 + #FF UND 64 < M-EIN @
> UND 1 UND MAGNET !B
> DANN ;
>
> which to some people looks a lot like line noise but here "JA" is
> "YES" and "DANN" is "THEN" and so on in German (hint: There is an
> "English/German cheat sheet" in the IPS book on page 82). If you wrote
> your own IPS code today you could use the English ones, but to read
> the old housekeeping code you need to be able to look up the
> equivalents in English AND understand the low level machine operations
> (such as byte addressing, a stack, bitwise operations... remember
> this language was designed and meant to be run (originally) on an 1802
> or an 8080 or a 6502 with maybe thirty-two KILObytes of memory. Yes,
> KILO-bytes of memory. Really. I'm not making this up. Go read the
> IPS book.)
>
> Emulators/simulators for running IPS code (German and English) are on
> the AMSAT website if you want to start coding. See
>
> http://www.amsat.org/amsat-new/tools/softwareArchive.php#pc-ips
>
> Lastly, if you feel you must have a real 1802 CPU, well, there
> actually are 1802 CPU chips still around (well, regular ones not the
> SoS rad-hard ones), and there is even an entire 1802 computer that you
> can buy as a kit complete with toggle switches, LEDs, and up to 64K of
> RAM. And it fits inside an Altoids tin! No, I'm not making this up
> either. See
>
> http://www.sunrise-ev.com/membershipcard.htm
>
> Note that the membership card 1802 CPUs are not rad-hard and they can
> run TinyBasic not IPS. But, I'm sure AMSAT still has at least one
> rad-hard 1802 CPU... somewhere. And, getting IPS to run on the 1802
> membership card is left as an exercise to the reader. If you're
> successful, I'd love to hear about it.
>
> 73,
> Douglas KA2UPW/5
>
>
> On Wed, May 16, 2018 at 9:08 PM, Bruce Perens via Ground-Station
> <ground-station at lists.openresearch.institute
> <mailto:ground-station at lists.openresearch.institute>> wrote:
>
> OK, I'm /sure /I'm going to get something wrong, so please, list
> folks, feel free to jump in and correct me when I do. I still
> don't know much about satellites.
>
> Keith,
>
> While silicon-on-insulator parts are a great way to go, there is
> at least a $1000 cost differential for CPUs and then you get to
> memory... So, cubesat folks have been creative in finding
> radiation-tolerant parts in consumer or industrial grades. The
> main problem we're trying to avoid is latch-up that actually
> damages the part. The second problem is bit errors. I have heard
> that some FLASH gate-array-based CPUs do not suffer /damage /from
> radiation induced latch-up and there are viable recovery
> mechanisms, and their FLASH-based gate-array does not require
> configuration memory and is resistant to single-element errors. I
> googled this:
> https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=3399&context=smallsat
> <https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=3399&context=smallsat>
> which discusses the Microsemi SmartFusion2 (which we used for our
> abortive Whitebox SDR, so Chris Testa knows it well). No doubt you
> can find more.
>
> Others in the group have experience with other radiation-tolerant
> consumer or industrial grade parts.
>
> The Cortex M0 is more than enough for housekeeping and might be
> enough for some signal and image processing tasks. But the
> housekeeping CPU need not be the signal-processing CPU as well.
>
> AMSAT has had some interesting strategies. First, they had a cache
> of SoS 1802s which they used for 30 years or so. They used a lot
> of components that were given to them from cancelled space
> projects. They didn't always use rad-hard memory, just because
> they could not afford it, but used error-correcting memory
> architectures and scrubbed the memory constantly so that
> single-bit errors were corrected before they became large enough
> to be uncorrectible. There was /no/ ROM onboard, a hardware modem
> loaded memory from the radio and then reset the CPU and set it
> running. Nobody's told me, but if there was any cryptography on
> that it wasn't much more than exclusive-OR of a secret word. They
> have their own FORTH-like language, first written in the '70's,
> which does concurrent but not parallel threads. Most housekeeping
> is written in this language.
>
> So, you can expect that some of an IHU project might be
> prospecting for radiation-tolerant parts that don't cost so much.
> Others have left breadcrumbs to follow.
>
> Even when you do have rad-hard parts, generally they have a
> consumer or industrial grade pin-equivalent so that non-flight and
> LEO units don't have to be made with the most expensive parts.
>
> Thanks
>
> Bruce
>
>
>
> On Wed, May 16, 2018 at 1:37 PM, Keith Wheeler
> <keith.m.wheeler at gmail.com <mailto:keith.m.wheeler at gmail.com>> wrote:
>
> Bruce,
>
> I'm not familiar with the requirements for an IHU, but I've
> done a lot of embedded firmware/hardware design. With the
> desire for DX (above LEO), I'm assuming rad-hard will be a
> requirement. I was looking at a rad-hard ARM Cortex M0. What
> kind of horsepower would the IHU require?
>
> -Keith Wheeler
>
> On Wed, May 16, 2018 at 11:54 AM, Bruce Perens via
> Ground-Station <ground-station at lists.openresearch.institute
> <mailto:ground-station at lists.openresearch.institute>> wrote:
>
>
> Legal stuff first: Image credit: XKCD #1992: "SafetySat"
> at http://xkcd.com/1992/ Creative Commons Attr-NC 2.5
> license.
>
> Yes, we should have a satellite program and do what AMSAT
> is not. Everyone I have heard from so far is asking for a
> "DX Satellite", "like AO-13" and not LEO.
>
> Mission should include digital communications using
> Michelle's design. I also have some blue-sky ideas that we
> can discuss at Hamvention, some of them might be good
> grant candidates. Think grant. Money is out there, we will
> start soliciting as soon as we have a mission plan.
>
> Build the satellite (and maybe P-pods) first, approach
> launch providers with flight hardware in hand and ready to
> go. Satellites are cheap, launches are not. Be prepared to
> take advantage of opportunities on very short schedules.
>
> I think we should fabricate extras of parts we design, and
> sell them as TAPR does to supplement their budget, but
> right off of Amazon Prime. Make them really easy and fast
> to buy, and someone else does the shipping. Aim at
> flight-quality but mostly going to classroom use rather
> than flight, to start. Nicer for the class than the PLA
> 3-D printer stuff that is so obviously non-flight that
> they are using now.
>
> Aim for 100% to 200% markup over cost, Amazon gets around
> 18% of the order and a warehouse fee and fulfills from
> their warehouse. Most of the commercial cubesat companies,
> like Pumpkin, are running 500% to 1000% markup in order to
> amortize R&D and operational costs and still make a
> profit, but most of them have flight heritage that we
> would not start out with. We use slave labor :-) and can
> mostly base our final cost on fabrication and sales costs.
>
> I have been looking at cubesat structures (because I feel
> competent enough to make one, at least with your help) and
> I really like Pumpkin's design. Almost all laser-cut
> 5000-class sheet aluminum, bent on a brake, anodized
> corners on the sheet, only the 8 corner pieces are
> machined, and that only simple shaping and drilling of bar
> stock into a simple rectilinear shape with
> specified-radius corners and edges and a place to put the
> springs and cutoff switch pins. Most other designers
> seemed to be more interested in showing their skill in CNC
> machining than making a practical structure. If you look
> at Pumpkin's stuff, it is clear that they put a lot of
> thought into mechanical engineering. And they actually
> engineered for cost and mass-production, while few others
> bothered. We will not ever directly copy anything (I am an
> intellectual property specialist, and will keep us legal),
> but we can and should learn from their work.
>
> Besides the structure, other non-mission-specific stuff we
> should be building would include an IHU (computer) and the
> other general bus components: lithium battery pack with
> heaters and per-cell management, magnetorquer, solar
> panels (what cells, from where?), maybe some heat
> distribution components like adiabatic heat pipes?
>
> Can we hear from volunteers for any of this?
>
> LIME mini might be a good flight candidate, besides Ettus
> and Rincon. Their CEO and Open Source guy are very
> friendly and their PCB design may already be licensed
> appropriately. No idea how the chip would take radiation.
>
> We should look into the Open Source finite element
> analysis and CFD programs. We should simulate as much as
> possible before going to thermal vacuum, vibration and
> shock, etc. And publish all input data so that it can be
> reused along with our part designs.
>
> I saw a really nice indium electronic thruster at Cal
> Poly. All proprietary, of course. Goes up with the fuel
> solid, gets heated in flight. No moving parts, works by
> wicking through a sintered tip. Probably very patented.
> But a source of ideas.
>
> Thanks
>
> Bruce
>
>
> On Wed, May 16, 2018, 09:23 Michelle Thompson
> <mountain.michelle at gmail.com
> <mailto:mountain.michelle at gmail.com>> wrote:
>
> Heh! The SDR really ties it all together in your
> sketch there.
>
> Yes, there's interest in building an open source
> satellite. The time is right and we have the best
> chance of making it happen that I've seen in a long
> time. There's a variety of forces at work in the
> industry, in academia, and in open source culture and
> achievement that help make a modern, innovative,
> amateur, open source payload possible.
>
> I don't know enough about MEO but I'm game for
> supporting any payload that enables an enduring
> amateur community through reliable communications in
> space. I'm very happy we get the chance to dig into
> this and I want to enable and support it as much as
> possible.
>
> The Careful COTS of an Ettus USRP effort is one way to
> get a capable SDR for space. This is a joint project
> between Phase 4 Space and GOLF to get the E310 in play
> soon/now for GOLF and the E320 later for Phase 4
> Space. Business unit at Ettus is reviewing it. Systems
> engineering lead for GOLF endorsed it as an open
> source effort. Meeting minutes were posted to the
> list. Next steps depend on what IP from Ettus. We'll
> proceed with the E320 as far as it takes us
> regardless. I expect to make a lot more progress here
> in late summer/early fall, especially at GNU Radio
> Conference 2018.
>
> The Rincon AstroSDR is another option, and Rincon has
> reached out with questions and clarifications in
> response to the Kittens Weekly Report. There will be
> more talks after Hamvention. Rincon will be a
> significant presence at GNU Radio Conference 2018.
>
> Propulsion, attitude control, solar power, and a
> variety of antennas all have open source flight-tested
> options at LEO. I don't know much about navigation.
>
> I do know that we have a lot of support out there from
> like-minded organizations and projects.
>
> I do know that a payload design is within the
> capabilities of people on this list and within our
> extended Slack/GitHub/phone/email/club/conference
> network. That does not mean it's easy by any stretch,
> and it means that our economic development team will
> be tested. I think we are up to the challenge.
>
> What's the first thing that you think we need to do?
>
> -Michelle W5NYV
>
>
>
> ---------- Forwarded message ----------
> From: Howie DeFelice <howied231 at hotmail.com
> <mailto:howied231 at hotmail.com>>
> To: "ground-station at lists.openresearch.institute"
> <ground-station at lists.openresearch.institute>
> Cc:
> Bcc:
> Date: Wed, 16 May 2018 04:16:15 +0000
> Subject: Satellite Building
> Just wondering if there is interest in putting
> together a project to build a satellite. There is
> no particular launch in mind and no particular
> mission at this pint other than the generic
> Amateur Radio goal of furthering the art of
> communication. I think most will agree that the
> LAST thing we need another LEO. To simply exploit
> the microwave bands I think we want to consider
> orbits that allow hours of coverage at a time. A
> GEO would be great, a HEO would be really good. An
> overlooked orbit, at least in ham radio, is MEO.
> An orbit between 8000 and 10,000 Km would provide
> about 2 hours of coverage and orbit the earth
> about twice a day. The problem is that not too
> many people fly there so we need another strategy.
> If we aren't in a big hurry, maybe we can get
> there from LEO. This means we need propulsion,
> attitude control, navigation, lots of solar power
> and a really cool radio. Does this sound
> reasonable? How long would this actually take with
> a milli-Newton thruster ? I have attached a sketch
> of my first ideas.
>
> - Howie AB2S
>
>
> ---------- Forwarded message ----------
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> Date: Wed, 16 May 2018 00:16:18 -0400
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> --
> Bruce Perens K6BP - CEO, Legal Engineering
> Standards committee chair, license review committee member,
> co-founder, Open Source Initiative
> President, Open Research Institute; Board Member, Fashion Freedom
> Initiative.
>
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