It turns out NASA’s Mars helicopter was much more revolutionary than
we knew - Ingenuity packed more computing power than all other NASA
deep space missions combined. by Eric Berger - Jan 29, 2024 1:45 am
.<https://arstechnica.com/space/2024/01/now-that-weve-flown-on-mars-what-comes-next-in-aerial-planetary-exploration/>
Joe Gwinn
On Mon, 29 Jan 2024 11:43:10 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:
It turns out NASA’s Mars helicopter was much more revolutionary than
we knew - Ingenuity packed more computing power than all other NASA
deep space missions combined. by Eric Berger - Jan 29, 2024 1:45 am
.<https://arstechnica.com/space/2024/01/now-that-weve-flown-on-mars-what-comes-next-in-aerial-planetary-exploration/>
Joe Gwinn
It was an expensive PR stunt, mostly.
What value is all that compute power on Mars? We can do computing
here.
On Mon, 29 Jan 2024 09:58:20 -0800, john larkin <jl@650pot.com> wrote:
On Mon, 29 Jan 2024 11:43:10 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:
It turns out NASA’s Mars helicopter was much more revolutionary than
we knew - Ingenuity packed more computing power than all other NASA
deep space missions combined. by Eric Berger - Jan 29, 2024 1:45 am
.<https://arstechnica.com/space/2024/01/now-that-weve-flown-on-mars-what-comes-next-in-aerial-planetary-exploration/>
Joe Gwinn
It was an expensive PR stunt, mostly.
What value is all that compute power on Mars? We can do computing
here.
With a one-way propagation delay of from 8 minutes to 21 minutes,
depending on current orbital positions. This may make flight control
... interesting.
The big demonstration was that ordinary COTS stuff can work at all on
Mars, so maybe we don't need to full space-qualified everywhere.
Joe Gwinn
On 1/29/24 19:19, Joe Gwinn wrote:
On Mon, 29 Jan 2024 09:58:20 -0800, john larkin <jl@650pot.com> wrote:
On Mon, 29 Jan 2024 11:43:10 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:
It turns out NASA’s Mars helicopter was much more revolutionary than
we knew - Ingenuity packed more computing power than all other NASA
deep space missions combined. by Eric Berger - Jan 29, 2024 1:45 am
.<https://arstechnica.com/space/2024/01/now-that-weve-flown-on-mars-what-comes-next-in-aerial-planetary-exploration/>
Joe Gwinn
It was an expensive PR stunt, mostly.
What value is all that compute power on Mars? We can do computing
here.
With a one-way propagation delay of from 8 minutes to 21 minutes,
depending on current orbital positions. This may make flight control
... interesting.
The big demonstration was that ordinary COTS stuff can work at all on
Mars, so maybe we don't need to full space-qualified everywhere.
Joe Gwinn
Well, they did spend $80M on its development. Hardly COTS, I'd say.
OK, it has a few COTS components. Don't they all?
A parallel happened when the US DoD discovered that commercial epoxyGenerally true for high temperature 180'C designs too. The epoxy
IC packages yielded more reliable components the full hermetic ceramic packages.
On Mon, 29 Jan 2024 22:51:38 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:
On 1/29/24 19:19, Joe Gwinn wrote:
On Mon, 29 Jan 2024 09:58:20 -0800, john larkin <jl@650pot.com> wrote:
On Mon, 29 Jan 2024 11:43:10 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:
It turns out NASA’s Mars helicopter was much more revolutionary than >>>>> we knew - Ingenuity packed more computing power than all other NASA
deep space missions combined. by Eric Berger - Jan 29, 2024 1:45 am >>>>>
.<https://arstechnica.com/space/2024/01/now-that-weve-flown-on-mars-what-comes-next-in-aerial-planetary-exploration/>
Joe Gwinn
It was an expensive PR stunt, mostly.
What value is all that compute power on Mars? We can do computing
here.
With a one-way propagation delay of from 8 minutes to 21 minutes,
depending on current orbital positions. This may make flight control
... interesting.
The big demonstration was that ordinary COTS stuff can work at all on
Mars, so maybe we don't need to full space-qualified everywhere.
Joe Gwinn
Well, they did spend $80M on its development. Hardly COTS, I'd say.
OK, it has a few COTS components. Don't they all?
Yes, but the chips are plain old COTS, just like in your cellphone.
This was not supposed to be workable in space, or on Mars. And yet
...
A parallel happened when the US DoD discovered that commercial epoxy
IC packages yielded more reliable components the full hermetic ceramic packages. DoD paid for lots of component development back in the day
when only DoD systems could afford ICs, but it was the automotive
environment that drove reliability under harsh conditions. For a
nickel, not a few hundred dollars.
Joe Gwinn
Joe Gwinn
On 29/01/2024 22:15, Joe Gwinn wrote:
<snip>
A parallel happened when the US DoD discovered that commercial epoxyGenerally true for high temperature 180'C designs too. The epoxy
IC packages yielded more reliable components the full hermetic ceramic
packages.
packages have a little 'give' when hot, the ceramics don't.
I'm surprised that radiation wasn't a problem though. I would have
thought that older, larger geometries would be better.
On 1/29/24 23:48, Clive Arthur wrote:
On 29/01/2024 22:15, Joe Gwinn wrote:
<snip>
A parallel happened when the US DoD discovered that commercial epoxyGenerally true for high temperature 180'C designs too. The epoxy
IC packages yielded more reliable components the full hermetic ceramic
packages.
packages have a little 'give' when hot, the ceramics don't.
I'm surprised that radiation wasn't a problem though. I would have
thought that older, larger geometries would be better.
I believe it's not the size that makes a device rad-hard.
Mostly, old designs would tolerate larger spreads in device
parameters. They would survive radiation-induced parameter
shifts as well.
Some old designs contained lateral PNPs that were only barely
good enough. Those would fail early under irradiation.
Low power chips do not survive for very long either. All-NPN
designs with mA standing currents survive kGy doses just fine.
YMMV.
On a sunny day (Tue, 30 Jan 2024 10:21:57 +0100) it happened Jeroen Belleman <jeroen@nospam.please> wrote in <upaf1v$u7f7$1@dont-email.me>:
On 1/29/24 23:48, Clive Arthur wrote:
On 29/01/2024 22:15, Joe Gwinn wrote:
<snip>
A parallel happened when the US DoD discovered that commercial epoxyGenerally true for high temperature 180'C designs too. The epoxy
IC packages yielded more reliable components the full hermetic ceramic >>>> packages.
packages have a little 'give' when hot, the ceramics don't.
I'm surprised that radiation wasn't a problem though. I would have
thought that older, larger geometries would be better.
I believe it's not the size that makes a device rad-hard.
Mostly, old designs would tolerate larger spreads in device
parameters. They would survive radiation-induced parameter
shifts as well.
Some old designs contained lateral PNPs that were only barely
good enough. Those would fail early under irradiation.
Low power chips do not survive for very long either. All-NPN
designs with mA standing currents survive kGy doses just fine.
YMMV.
Old memory chips used one level charge per bit
later it has become muliple level.
High energy particles can discharge memory,
so multilevel chips should be more vulnerable.
https://en.m.wikipedia.org/wiki/Multi-level_cell
On 1/30/24 11:33, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jan 2024 10:21:57 +0100) it happened Jeroen Belleman >> <jeroen@nospam.please> wrote in <upaf1v$u7f7$1@dont-email.me>:
On 1/29/24 23:48, Clive Arthur wrote:
On 29/01/2024 22:15, Joe Gwinn wrote:
<snip>
A parallel happened when the US DoD discovered that commercial epoxy >>>>> IC packages yielded more reliable components the full hermetic ceramic >>>>> packages.Generally true for high temperature 180'C designs too. The epoxy
packages have a little 'give' when hot, the ceramics don't.
I'm surprised that radiation wasn't a problem though. I would have
thought that older, larger geometries would be better.
I believe it's not the size that makes a device rad-hard.
Mostly, old designs would tolerate larger spreads in device
parameters. They would survive radiation-induced parameter
shifts as well.
Some old designs contained lateral PNPs that were only barely
good enough. Those would fail early under irradiation.
Low power chips do not survive for very long either. All-NPN
designs with mA standing currents survive kGy doses just fine.
YMMV.
Old memory chips used one level charge per bit
later it has become muliple level.
High energy particles can discharge memory,
so multilevel chips should be more vulnerable.
https://en.m.wikipedia.org/wiki/Multi-level_cell
That is indeed likely. As a rule, we tried not to rely on
digital memory staying put. There was just a minimum of
local storage, rewritten from a remote location every
second or so. We did not use local hardware redundancy.
On the other hand, we did use Altera 7xxx CPLDs, some of
which have by now accumulated about half a kGy without
malfunction.
Just to set the scene, FAST TTL and LM337 regulators would
stop working with more than 40 Gy or so. LSTTL and LM317s
just keep going. I've used ECL in places, not because it
was fast, but rather because it survived >10kGy. I used
some LF351 opamps that just keep working, even after having
taken well over 50 kGy! Probably they are no longer within
the dataseet specs, but they are still good enough for what
I'm doing with them. (DC working point feedback in a wideband
amplifier.)
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