> On Wed, 28 Mar 2018 07:07:29 -0700, Joerg <news@analogconsultants.com>
> wrote:
>
>> On 2018-03-28 05:25, Spehro Pefhany wrote:
>>> On Sat, 24 Mar 2018 12:08:28 -0700, Joerg <news@analogconsultants.com>
>>> wrote:
>>>
>>>>
>>>>
>>>> I don't know yet. They will have to decide on the level of rad-hardness
>>>> and then I'll have to see if the circuitry is even economically feasible
>>>> with that, given component availability.
>>>
>>> You can consider testing key parts yourself. There can be large
>>> differences between complex parts for no reason that is obvious from
>>> the outside.
>>>
>>> Last year I tested a bunch of parts in one shot.
>>>
>>
>> That is certainly an option but I'll leave that to the client. A lot of
>> liability can ride on self-testing.
>
> You would need the client to sign off on the type of testing as being
> representative. In my case it was a few nA of particle beam at a huge
> facility on the West coast. Fun stuff. Met guys from Intel and IBM
> doing their testing.
>
That I will leave to the client. If anything needs to be tested they
have to find out what, to which specs and then arrange it themselves.
All I need to know is to which spec to design.
Do you or another engineer in this NG know a distributor for space-rated
passives such as diodes, zeners capacitors and resistors? I know the
"usual suspects" for transistors and ICs but didn't have to deal with
space-rated passives in a very long time. Best would be if there'd be a
"Lunar Digikey" but that's only a dream.
--
Regards, Joerg
http://www.analogconsultants.com/
Reply by Spehro Pefhany●April 4, 20182018-04-04
On Wed, 28 Mar 2018 07:07:29 -0700, Joerg <news@analogconsultants.com>
wrote:
>On 2018-03-28 05:25, Spehro Pefhany wrote:
>> On Sat, 24 Mar 2018 12:08:28 -0700, Joerg <news@analogconsultants.com>
>> wrote:
>>
>>>
>>>
>>> I don't know yet. They will have to decide on the level of rad-hardness
>>> and then I'll have to see if the circuitry is even economically feasible
>>> with that, given component availability.
>>
>> You can consider testing key parts yourself. There can be large
>> differences between complex parts for no reason that is obvious from
>> the outside.
>>
>> Last year I tested a bunch of parts in one shot.
>>
>
>That is certainly an option but I'll leave that to the client. A lot of
>liability can ride on self-testing.
You would need the client to sign off on the type of testing as being
representative. In my case it was a few nA of particle beam at a huge
facility on the West coast. Fun stuff. Met guys from Intel and IBM
doing their testing.
--sp
Reply by ●March 31, 20182018-03-31
On Sat, 31 Mar 2018 08:00:49 +0300, upsidedown@downunder.com wrote:
>On Fri, 30 Mar 2018 20:03:27 -0400, krw@notreal.com wrote:
>
>>On Fri, 30 Mar 2018 11:03:54 +0300, upsidedown@downunder.com wrote:
>>
>>>On Wed, 28 Mar 2018 20:30:12 -0400, krw@notreal.com wrote:
>>>
>>>>On Wed, 28 Mar 2018 23:13:28 +1100, Chris Jones
>>>><lugnut808@spam.yahoo.com> wrote:
>>>
>>><clip>
>>>
>>>>>Yes, though most of these are in low orbits such that they decay and
>>>>>burn up fairly soon whether they want to or not. AIUI there are rules
>>>>>that discourage that sort of thing in long-lived orbits.
>>>
>>>There are international _recommendations_ that the debris should decay
>>>within 25 years after the end of operation.
>>>
>>>The problem is that the usable altitude range is quite limited. On one
>>>hand, the orbit must be high enough so that the intended mission (1
>>>month to 5 years) can be performed before decaying, which translates
>>>to 400-500 km. On the other hand, above 700-800 km, the decay time is
>>>more than 25 years.
>>>
>>>>
>>>>LEO is controlled too.
>>>
>>>It is just a recommendation.
>
>The recommendation is for max 25 years, but it doesn't limit the size.
>
>>Not for US companies, it's certainly not.
>
>The company should move their business to a more technology friendly
>country.
You're wrong, of course.
>
>>>>You can't just throw junk up there. It has to
>>>>be trackable.
>>>
>>>Trackable by whom ?
>>
>>NORAD
>
>Outside US, who, cares a damn what NORAD thinks.
Good Lord, learn to read!
>After all, this dispute seems to be blatant "protectionism", i.e. some
>big boys do not want competition and puts FCC to do the dirty work.
So you can read. It just gets lost in the space between your ears. Of
course, you're wrong again.
>Compared to NORAD claimed capabilities, these small satellites
>shouldn't be a problem. After all a tumbling 1/4U satellite should
>give similar reflections as 1/2U satellites, which are OK.
...and again.
>
>>>Anyway, there are experimental system flying now for de orbiting, such
>>>as electrostatic plasma brake tethers, but within a year or two we
>>>will see if it is reliable.
>>
>>Right out of '70s television.
>
>https://en.wikipedia.org/wiki/Aalto-1
Lost in (inner) space, again.
Reply by ●March 31, 20182018-03-31
On Sat, 31 Mar 2018 08:00:49 +0300, upsidedown@downunder.com wrote:
>On Fri, 30 Mar 2018 20:03:27 -0400, krw@notreal.com wrote:
>
>>On Fri, 30 Mar 2018 11:03:54 +0300, upsidedown@downunder.com wrote:
>>
>>>On Wed, 28 Mar 2018 20:30:12 -0400, krw@notreal.com wrote:
>>>
>>>>On Wed, 28 Mar 2018 23:13:28 +1100, Chris Jones
>>>><lugnut808@spam.yahoo.com> wrote:
>>>
>>><clip>
>>>
>>>>>Yes, though most of these are in low orbits such that they decay and
>>>>>burn up fairly soon whether they want to or not. AIUI there are rules
>>>>>that discourage that sort of thing in long-lived orbits.
>>>
>>>There are international _recommendations_ that the debris should decay
>>>within 25 years after the end of operation.
>>>
>>>The problem is that the usable altitude range is quite limited. On one
>>>hand, the orbit must be high enough so that the intended mission (1
>>>month to 5 years) can be performed before decaying, which translates
>>>to 400-500 km. On the other hand, above 700-800 km, the decay time is
>>>more than 25 years.
>>>
>>>>
>>>>LEO is controlled too.
>>>
>>>It is just a recommendation.
>
>The recommendation is for max 25 years, but it doesn't limit the size.
>
>>Not for US companies, it's certainly not.
>
>The company should move their business to a more technology friendly
>country.
>
>>>>You can't just throw junk up there. It has to
>>>>be trackable.
>>>
>>>Trackable by whom ?
>>
>>NORAD
>
>Outside US, who, cares a damn what NORAD thinks.
>
>After all, this dispute seems to be blatant "protectionism", i.e. some
>big boys do not want competition and puts FCC to do the dirty work.
>
>Compared to NORAD claimed capabilities, these small satellites
>shouldn't be a problem. After all a tumbling 1/4U satellite should
>give similar reflections as 1/2U satellites, which are OK.
Some additional information.
All four SpaceBEEs have received NORAD IDs so NORAD has successfully
tracked them. They are on 500 km nearly circular 97 degree polar
orbits, so they should decay well before 25 years.
The Stanford SNAPS launched for more than two years ago with a US
launcher was also a 0.25U CubeSat and it did not seem to cause
tracking problems.
Reply by ●March 31, 20182018-03-31
On Fri, 30 Mar 2018 20:03:27 -0400, krw@notreal.com wrote:
>On Fri, 30 Mar 2018 11:03:54 +0300, upsidedown@downunder.com wrote:
>
>>On Wed, 28 Mar 2018 20:30:12 -0400, krw@notreal.com wrote:
>>
>>>On Wed, 28 Mar 2018 23:13:28 +1100, Chris Jones
>>><lugnut808@spam.yahoo.com> wrote:
>>
>><clip>
>>
>>>>Yes, though most of these are in low orbits such that they decay and
>>>>burn up fairly soon whether they want to or not. AIUI there are rules
>>>>that discourage that sort of thing in long-lived orbits.
>>
>>There are international _recommendations_ that the debris should decay
>>within 25 years after the end of operation.
>>
>>The problem is that the usable altitude range is quite limited. On one
>>hand, the orbit must be high enough so that the intended mission (1
>>month to 5 years) can be performed before decaying, which translates
>>to 400-500 km. On the other hand, above 700-800 km, the decay time is
>>more than 25 years.
>>
>>>
>>>LEO is controlled too.
>>
>>It is just a recommendation.
The recommendation is for max 25 years, but it doesn't limit the size.
>Not for US companies, it's certainly not.
The company should move their business to a more technology friendly
country.
>>>You can't just throw junk up there. It has to
>>>be trackable.
>>
>>Trackable by whom ?
>
>NORAD
Outside US, who, cares a damn what NORAD thinks.
After all, this dispute seems to be blatant "protectionism", i.e. some
big boys do not want competition and puts FCC to do the dirty work.
Compared to NORAD claimed capabilities, these small satellites
shouldn't be a problem. After all a tumbling 1/4U satellite should
give similar reflections as 1/2U satellites, which are OK.
>>Anyway, there are experimental system flying now for de orbiting, such
>>as electrostatic plasma brake tethers, but within a year or two we
>>will see if it is reliable.
>
>Right out of '70s television.
On Fri, 30 Mar 2018 11:03:54 +0300, upsidedown@downunder.com wrote:
>On Wed, 28 Mar 2018 20:30:12 -0400, krw@notreal.com wrote:
>
>>On Wed, 28 Mar 2018 23:13:28 +1100, Chris Jones
>><lugnut808@spam.yahoo.com> wrote:
>
><clip>
>
>>>Yes, though most of these are in low orbits such that they decay and
>>>burn up fairly soon whether they want to or not. AIUI there are rules
>>>that discourage that sort of thing in long-lived orbits.
>
>There are international _recommendations_ that the debris should decay
>within 25 years after the end of operation.
>
>The problem is that the usable altitude range is quite limited. On one
>hand, the orbit must be high enough so that the intended mission (1
>month to 5 years) can be performed before decaying, which translates
>to 400-500 km. On the other hand, above 700-800 km, the decay time is
>more than 25 years.
>
>>
>>LEO is controlled too.
>
>It is just a recommendation.
Not for US companies, it's certainly not.
>
>>You can't just throw junk up there. It has to
>>be trackable.
>
>Trackable by whom ?
NORAD
>
>>Can't remember the details but one of the launch
>>companies just got their ass in a crack because they launched small
>>satellites from India (IIRC).
>
>Which company and by whom ?
Do you know how to do a web search?
>
>India has launched several satellites to sun synchronous polar orbits.
>There are only a few such usable orbits, most of them are above 800
>km.
>
>The primary (paying) customer determines the orbit for the primary
>payload and the secondary payloads have to accept what they got. Due
>to the risk of explosions, secondary payloads are typically not
>allowed to carry fuel or rocket motors. Thus, these satellites will
>end up in the same orbit as the last stage of the booster rocket.
Depending on the payload, of course.
>For the sane reason, rocket motors are not available for de orbiting
>the satellite at end of mission. The other question is, how reliable
>would the deorbit system be after several years in space.
Depending on the payload, of course.
>Anyway, there are experimental system flying now for de orbiting, such
>as electrostatic plasma brake tethers, but within a year or two we
>will see if it is reliable.
On Friday, 30 March 2018 09:03:01 UTC+1, upsid...@downunder.com wrote:
>
> >Can't remember the details but one of the launch
> >companies just got their ass in a crack because they launched small
> >satellites from India (IIRC).
>
> Which company and by whom ?
>
On Wed, 28 Mar 2018 20:30:12 -0400, krw@notreal.com wrote:
>On Wed, 28 Mar 2018 23:13:28 +1100, Chris Jones
><lugnut808@spam.yahoo.com> wrote:
<clip>
>>Yes, though most of these are in low orbits such that they decay and
>>burn up fairly soon whether they want to or not. AIUI there are rules
>>that discourage that sort of thing in long-lived orbits.
There are international _recommendations_ that the debris should decay
within 25 years after the end of operation.
The problem is that the usable altitude range is quite limited. On one
hand, the orbit must be high enough so that the intended mission (1
month to 5 years) can be performed before decaying, which translates
to 400-500 km. On the other hand, above 700-800 km, the decay time is
more than 25 years.
>
>LEO is controlled too.
It is just a recommendation.
>You can't just throw junk up there. It has to
>be trackable.
Trackable by whom ?
>Can't remember the details but one of the launch
>companies just got their ass in a crack because they launched small
>satellites from India (IIRC).
Which company and by whom ?
India has launched several satellites to sun synchronous polar orbits.
There are only a few such usable orbits, most of them are above 800
km.
The primary (paying) customer determines the orbit for the primary
payload and the secondary payloads have to accept what they got. Due
to the risk of explosions, secondary payloads are typically not
allowed to carry fuel or rocket motors. Thus, these satellites will
end up in the same orbit as the last stage of the booster rocket.
For the sane reason, rocket motors are not available for de orbiting
the satellite at end of mission. The other question is, how reliable
would the deorbit system be after several years in space.
Anyway, there are experimental system flying now for de orbiting, such
as electrostatic plasma brake tethers, but within a year or two we
will see if it is reliable.
On Wed, 28 Mar 2018 23:13:28 +1100, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
>On 28/03/2018 08:25, krw@notreal.com wrote:
>> On Tue, 27 Mar 2018 23:30:33 +1100, Chris Jones
>> <lugnut808@spam.yahoo.com> wrote:
>>
>>> On 27/03/2018 01:08, Joerg wrote:
>>>> On 2018-03-26 05:17, Chris Jones wrote:
>>>>> On 26/03/2018 13:10, tabbypurr@gmail.com wrote:
>>>>>> On Monday, 26 March 2018 01:28:44 UTC+1, Neon John� wrote:
>>>>>>> On Sat, 24 Mar 2018 08:37:03 -0700, Joerg <news@analogconsultants.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>>> On 2018-03-24 07:52, Francesco wrote:
>>>>>>>>> On Thursday, 22 March 2018 23:20:42 UTC, Joerg� wrote:
>>>>>>>>>> Got to arrive at a (very) rough estimate of what a rad-hard
>>>>>>>>>> circuit would cost. These days such pricing seems to be handled in
>>>>>>>>>> a very secretive way and going through the sales spiel for a lot of
>>>>>>>>>> parts is just too time consuming.
>>>>>>>
>>>>>>> The Deep State at work.� Sounds like things haven't changed much since
>>>>>>> I was designing rad-hard equipment for terrestrial use.
>>>>
>>>>
>>>> Nope, they haven't.
>>>>
>>>>>>>>>>
>>>>>>>>>> Does anyone know a site that has at least some pricing info for
>>>>>>>>>> rad-hard stuff? It's mostly discretes and maybe a gate or BJT
>>>>>>>>>> driver here and there. Ballpark pricing is all I need at this time.
>>>>>>>>>> Lead times would be nice as well as most of this is zero stock.
>>>>>>>>>>
>>>>>>>>>> -- Regards, Joerg
>>>>>>>>>>
>>>>>>>>>> http://www.analogconsultants.com/
>>>>>>>>>
>>>>>>>>> Hi Joerg, Can you share more details on your application?
>>>>>>>>>
>>>>>>>>> What is the maximum TID? Do you have extreme temperature cycles?
>>>>>>>>>
>>>>>>>>
>>>>>>>> Then I would get shot :-)
>>>>>>>>
>>>>>>>> Essentially scientific expeditions into space.
>>>>>>>
>>>>>>> ah yes, purposes classification.� The reason they keep making the same
>>>>>>> errors over and over.
>>>>>>>
>>>>>>> Since there are many successful spacecraft out there, can't you use
>>>>>>> data from some of those or is that info needlessly classified?
>>>>>>>
>>>>
>>>> Eventually there may be some data.
>>>>
>>>>
>>>>>>> In our applications (instruments near a reactor core, for example),
>>>>>>> dose RATE mattered more than TID.
>>>>>>>
>>>>>>> Just for grinz, I googled and found this paper.
>>>>>>>
>>>>>>> https://www.ncbi.nlm.nih.gov/pubmed/12056428
>>>>>>>
>>>>>>> That should be quite helpful.� The dose rate in outer space or even
>>>>>>> the Van Allen belt is orders of magnitude below what we designed for.
>>>>>>>
>>>>>>>> The ionization dose is still under discussion. If you go from
>>>>>>>> 100krad to
>>>>>>>> 300krad the number of parts shrinks substantially, if 1Mrad you
>>>>>>>> might as
>>>>>>>> well do it all in discretes.
>>>>>>>
>>>>>>> Can't you pry loose the expected dose rates from some other space
>>>>>>> craft project that's already been there?
>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>> Please have a look here: http://www.neutronix.co.uk/space.html
>>>>>>>>>
>>>>>>>>
>>>>>>>> Thanks, that will probably come in handy.
>>>>>>>
>>>>>>> Interesting site.� Thanks.
>>>>>>>
>>>>>>>>> Just to give you an idea of the price... a 1kohm 0603 resistor for
>>>>>>>>> space application may cost 5 GBP.
>>>>>>>>>
>>>>>>>>
>>>>>>>> Ah, thanks, now we are getting somewhere. I wonder what a gate
>>>>>>>> driver or
>>>>>>>> a power transistor would cost. Last time I had to do this was decades
>>>>>>>> ago and I don't remember prices.
>>>>>>>
>>>>>>> That's my problem with specifics.� Too many decades have past.� 1000x
>>>>>>> the price of equivalent non-hard parts sounds about right, though.
>>>>>>>
>>>>
>>>> Problem is, the parts are sold via different distributors and for every
>>>> part there is no price, just an RFQ button. Clicking it results in a
>>>> lengthy registration process. Why can't they just say $876.25?
>>>>
>>>> Time to warm up some old contacts there though some folks will be
>>>> retired for a while now.
>>>>
>>>>
>>>>>>> John
>>>>>>>
>>>>>>> John DeArmond
>>>>>>> http://www.neon-john.com
>>>>>>> http://www.tnduction.com
>>>>>>> Tellico Plains, Occupied TN
>>>>>>> See website for email address
>>>>>>
>>>>>> As you may guess I've not designed rad-hard. At those prices why not
>>>>>> have redundant unhardened circuitry feeding a rad-hard majority vote
>>>>>> gate or error checker.
>>>>>
>>>>
>>>> Then the sense and majority votting circuitry needs to be rad-hard.
>>>> Essentially just kicking the can farther down the road.
>>>>
>>>>
>>>>> AIUI Planet Labs uses ordinary parts and just has a reduntent whole
>>>>> satellite, or actually dozens of them.
>>>>>
>>>>
>>>> That's like placing bets of five roulette numbers simultaneously instead
>>>> of one, quintupling the cost :-)
>>>>
>>>
>>> Heh, yes, but the parts cost a lot less, whether it is 100x or 1000x, so
>>> the total cost of the space vehicles might be less even if there are a
>>> lot more of them. Presumably the downside is launch cost, but then the
>>> satellites could be a lot smaller and lighter to launch if they can use
>>> a wide range of recent parts and not worry quite so much about proven
>>> reliability. Also the performance might be better if they can use recent
>>> parts. There are some interviews with a Planet Labs engineer on the
>>> embedded.fm podcast which you might find interesting. I found these two
>>> but there might be more of them:
>>> https://www.embedded.fm/episodes/153
>>> https://www.embedded.fm/episodes/195
>>
>> I throws a lot of useless junk into valuable spots in space, though.
>>
>
>Yes, though most of these are in low orbits such that they decay and
>burn up fairly soon whether they want to or not. AIUI there are rules
>that discourage that sort of thing in long-lived orbits.
> Got to arrive at a (very) rough estimate of what a rad-hard circuit
> would cost. These days such pricing seems to be handled in a very
> secretive way and going through the sales spiel for a lot of parts is
> just too time consuming.
>
> Does anyone know a site that has at least some pricing info for rad-hard
> stuff? It's mostly discretes and maybe a gate or BJT driver here and
> there. Ballpark pricing is all I need at this time. Lead times would be
> nice as well as most of this is zero stock.
>
A follow-up question: Does anyone know a distributor that carries a
great variety of rad-hard parts?
What I saw was just a tiny selection and they all make you fill out
lengthy registrations before an RFQ would even go through. Some lead
times I saw can raise neck hair. 30 weeks seems to be nothing. OTOH that
allows a lot of time off for bike rides and beer brewing.
--
Regards, Joerg
http://www.analogconsultants.com/