[Ground-station] Satellite program

Wed May 16 11:54:14 PDT 2018

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>
>> 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.
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openresearch.institute/pipermail/ground-station-openresearch.institute/attachments/20180516/ae654db6/attachment.html>