[Ground-station] Satellite program

Tue May 29 10:27:28 PDT 2018

Good and you care a lot about the total dose, which inevitably leads to the
kind of permanent latch up you mentioned.  The 300K rad hardness of this
chip is outstanding.  But for us, this will mean we will have to pay
attention to the rest of the components and make no assumptions that
commercial off the shelf is good enough unless it has space heritage or has
been tested to death in some place like Brookhaven National Labs.  The
problem with these radiation tests is companys treat this as proprietary
information and use this data for marketing or contractual advantage
depending on the context.

Bob

On Tue, May 29, 2018 at 1:22 PM, Bruce Perens <bruce at perens.com> wrote:

> OK, I still don't know anything about satellites, so correct me if I get
> something wrong:
>
> The reason we *need *rad-hard for higher orbits is that conventional
> processors may get a radiation-induced latch-up between some part of the
> chip and the base silicon, and this latch-up can be soft, in that
> everything's OK if we just reset the chip, or hard, in that an over-current
> damages the chip through a gate rupture or other burnout, and no amount of
> redundancy or watchdogs will help us after that. Silicon-on-insulator
> fabrication prevents that sort of latch-up, but we still have to deal with
> events that cause upsets (logic state changes) or transients.
>
>     Thanks
>
>     Bruce
>
> On Tue, May 29, 2018 at 10:06 AM, Robert McGwier <rwmcgwier at gmail.com>
> wrote:
>
>> Looks like a good find.  Worse case ~0.4 watts at 135 ma on 3.3V supply
>> (and this is the nonexistent worst case).  It is very hard.  Inside an
>> aluminum box with tantalum slides it could be used for MEO!  For most
>> applications it will idle most of the time, so power consumption would be
>> very low.  I hate putting communications on IHU processors,  so that
>> doesn't break my heart.
>>
>> The development board and software look more than usable.
>>
>> Bob
>> N4HY
>>
>>
>> On Mon, May 28, 2018 at 2:23 PM, Bruce Perens <bruce at perens.com> wrote:
>>
>>> Please take a look at the Vorago VA10820. We can afford it. A board
>>> design we can copy exists in their tech notes and Open Source software
>>> supports it. Rather than redundant CPUs,  it triples all registers. It runs
>>> at only 50 MHz so maybe is not your communications processor.
>>>
>>> Thanks
>>>
>>> Bruce
>>>
>>>
>>> On Mon, May 28, 2018, 09:03 Robert McGwier via Ground-Station
>>> <ground-station at lists.openresearch.institute> wrote:
>>>
>>>> I'm always worried about seamless handover when one detects the lack of
>>>> agreement and you swap to the other.
>>>>
>>>> So I want to say I strongly recommend that state be maintained in ECC
>>>> memory and when fault is found the "other" processor pair is selected,
>>>> "boots", and takes over after initializing and restoring saved state.
>>>>
>>>> This is allows handoff to be asynchronous rather than trying to
>>>> maintain perfect synchrony.
>>>>
>>>> If there are unsafe activities possible then the highest priority is
>>>> shutting those down in some priority order: propulsion,  attitude change,
>>>> .......
>>>>
>>>> I can relate the tale that the strongest delivered proclamation I ever
>>>> received from Karl Meinzer was to never attempt this at all.  He was
>>>> adamantly opposed to multiple processors and handoffs in spacecraft.
>>>>
>>>> 73s
>>>> Bob
>>>> N4HY
>>>>
>>>> On Mon, May 28, 2018, 10:15 AM Jonathan Brandenburg via Ground-Station
>>>> <ground-station at lists.openresearch.institute> wrote:
>>>>
>>>>> [I'm speaking a bit for Zach Metzinger, so I've copied him on this
>>>>> email. I'm not sure if he's on this mailing list or not and want him to be
>>>>> in a position to expand or correct my statements, or even disavow anything
>>>>> I'm saying, if he desires.]
>>>>>
>>>>> A small team, primarily Zach Metzinger with the assistance of others
>>>>> (Bill Reed, Jordan Trewitt, me), is designing an IHU based on the TI
>>>>> Hercules safety-critical processor. While the Hercules is not necessarily
>>>>> radiation-hardened, the processor is designed for operation in very noisy
>>>>> environments. It's also designed to detect faults, by executing
>>>>> instructions on two cores in lockstep, detect when the result differs, and
>>>>> signal a failure. (I imagine there are other features, but this is a high
>>>>> point.)
>>>>>
>>>>> So, we've been designing an IHU with two Hercules processors and two
>>>>> digital transceivers configured in a fail-over configuration along with
>>>>> redundant power circuits. There's still work to be done, but Zach has begun
>>>>> laying out this board in a 1U footprint.
>>>>>
>>>>> [This is the part where I'm speaking for Zach...] I believe Zach is
>>>>> committed to ensuring this design is open and available. As a result, I
>>>>> expect we'll be quickly publishing this work (by ITAR/EAR definitions) as
>>>>> we achieve milestones. This IHU work was begun before the AMSAT Golf
>>>>> program was kicked off and is now being integrated into Golf. I don't know
>>>>> of any reason this work couldn't be leveraged and used in other satellites.
>>>>>
>>>>> Thus, I submit this IHU-in-progress for our consideration...
>>>>>
>>>>> Jonathan Brandenburg
>>>>>
>>>>> On 5/16/2018 1:54 PM, Bruce Perens via Ground-Station 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> 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>
>>>>>>> To: "ground-station at lists.openresearch.institute"
>>>>>>> <ground-station at lists.openresearch.institute>
>>>>>>> <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 ----------
>>>>>>> From: ground-station-request at lists.openresearch.institute
>>>>>>> To:
>>>>>>> Cc:
>>>>>>> Bcc:
>>>>>>> Date: Wed, 16 May 2018 00:16:18 -0400
>>>>>>> Subject: confirm db1d86455ef4eb7857a41676b75024137549ff1d
>>>>>>> If you reply to this message, keeping the Subject: header intact,
>>>>>>> Mailman will discard the held message.  Do this if the message is
>>>>>>> spam.  If you reply to this message and include an Approved: header
>>>>>>> with the list password in it, the message will be approved for
>>>>>>> posting
>>>>>>> to the list.  The Approved: header can also appear in the first line
>>>>>>> of the body of the reply.
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Ground-Station mailing listGround-Station at lists.openresearch.institutehttp://lists.openresearch.institute/mailman/listinfo/ground-station
>>>>>
>>>>>
>>>>> --
>>>>> Jonathan Brandenburg
>>>>> 1-214-213-1066jonathan at jonathanbrandenburg.com
>>>>> -----------------------
>>>>> When possible, please sign and encrypt your communication. See https://ssd.eff.org
>>>>>
>>>>> I updated my PGP certificate on December 8, 2015. Please update your keychain:
>>>>> PGP certificate fingerprint: 824E 8871 5474 61F7 09D4  9B67 8AFC 1E70 924D B20
>>>>>
>>>>> _______________________________________________
>>>>> Ground-Station mailing list
>>>>> Ground-Station at lists.openresearch.institute
>>>>> http://lists.openresearch.institute/mailman/listinfo/ground-station
>>>>>
>>>> _______________________________________________
>>>> Ground-Station mailing list
>>>> Ground-Station at lists.openresearch.institute
>>>> http://lists.openresearch.institute/mailman/listinfo/ground-station
>>>>
>>>
>>
>>
>> --
>> Bob McGwier
>> Founder, Federated Wireless, Inc
>> Founder and Technical Advisor, HawkEye 360, Inc
>> Research Professor Virginia Tech
>> Chief Scientist:  The Ted and Karyn Hume Center for National Security and
>> Technology
>> Senior Member IEEE, Facebook: N4HYBob, ARS: N4HY
>> Faculty Advisor Virginia Tech Amateur Radio Assn, Trustee K4KDJ
>> Member of PVRC (Roanoke-Blacksburg), TAPR,  life member of ARRL and
>> AMSAT, NRVR.ORG (Rocketry)
>>
>
>
>
> --
> 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.
>

-- 
Bob McGwier
Founder, Federated Wireless, Inc
Founder and Technical Advisor, HawkEye 360, Inc
Research Professor Virginia Tech
Chief Scientist:  The Ted and Karyn Hume Center for National Security and
Technology
Senior Member IEEE, Facebook: N4HYBob, ARS: N4HY
Faculty Advisor Virginia Tech Amateur Radio Assn, Trustee K4KDJ
Member of PVRC (Roanoke-Blacksburg), TAPR,  life member of ARRL and AMSAT,
NRVR.ORG (Rocketry)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openresearch.institute/pipermail/ground-station-openresearch.institute/attachments/20180529/706e6bfa/attachment.html>