alegator
sage
Reged: 10/27/04
Posts: 272
|
|
Wow, I'm surprised to read that "the control systems in the US space shuttles use 8086 processors and NASA was forced to buy some from eBay in 2002 since Intel could no longer supply them." CLICK for the link.
--------------------
Celestron 8 (1978 model!)+tripod+eq.wedge
|
rutherfordt
super member
Reged: 05/07/06
Posts: 113
Loc: Blountville, Tennessee USA
|
|
I think that this is typical of the processors in many space vehicles-- most would be considered "out of date" by earthly computer standards.
The reason is that the electronics must be "hardened" to survive the extreme conditions of outer space-- high cosmic ray doses, magnetic fields, heavy vibration at launch, etc. The older stuff, being less complex, has far greater survivability than something more up to date would have.
--------------------
Tom Rutherford
10-inch f/6 Homemade Dobsonian (Cave mirror)
8-inch f/6 Homemade Dobsonian
6-inch f/5 Meade SN6
6-inch f/10 Celestron C6
5.5-inch f/3.6 Celestron Comet Catcher
66mm f/6 WO Petzval
2-inch f/15 Nippon Kogaku (my first telescope)
assorted unassembled pieces and parts
|
Pess
(Title)
Reged: 09/12/07
Posts: 1910
Loc: Toledo, Ohio
|
|
Quote:
I think that this is typical of the processors in many space vehicles-- most would be considered "out of date" by earthly computer standards.
The reason is that the electronics must be "hardened" to survive the extreme conditions of outer space-- high cosmic ray doses, magnetic fields, heavy vibration at launch, etc. The older stuff, being less complex, has far greater survivability than something more up to date would have.
Pesse (That and Space Invaders just doesn't play the same on newer machines..) Mist
|
Fish
super member
Reged: 10/13/07
Posts: 160
Loc: Norridgewock, ME
|
|
So, do you think they use an 8087 co-processor to speed up the calculations?
Marc
|
Charlie B
super member
Reged: 03/22/08
Posts: 164
Loc: Virginia
|
|
Quote:
So, do you think they use an 8087 co-processor to speed up the calculations?
Actually, I think they take a laptop with them.
Charlie B
--------------------
Meade SN-8, DS-90, AT-66
DSI Pro II (Schuler Filters), DSI-C, LPI, Canon XTi
AIP4WIN, Nebulosity, DSS, Registrax, GIMP
running on Dell 1420 with Vista
|
Kobayashi
sage
Reged: 07/10/08
Posts: 291
|
|
This article has more info on the incident. Note that the chips are not in the Shuttle, it's used in test equipment (i.e ground support equipment) for the Shuttle.
And there's nothing unusual about it. If you have a custom-designed equipment that's been working fine for 20 years, and it just needs an obsolete replacement chip to make it work again, of course it makes sense to find a replacement. It's much more cost-effective than paying engineers to design a replacement that uses currently available parts.
--------------------
-- Ken Kobayashi
|
llanitedave
Humble Megalomaniac
Reged: 09/26/05
Posts: 10463
Loc: Amargosa Valley, NV, USA
|
|
Just goes to show you how capable those "simpler" circuits really are. Remember how primitive the Apollo computing hardware was. But it got us pinpoint landings on the Moon, and some really nice and precise splashdowns.
--------------------
"S.O.E." (Sauron's Other Eye) 16" Royce conical mirror: A permanent work in progress.
10" Homebuilt dob, old Coulter mirror
Next Project: The "Eye of Sauron" Observatory!
|
Kobayashi
sage
Reged: 07/10/08
Posts: 291
|
|
By the way, just last week I was in a position to look for a vacuum tube for use in lab equipment. Specifically a mercury-vapor rectifier for a high voltage power supply, which we use for a gas discharge lamp, which in turn is used to test a multi-million dollar space science instrument. I got as far as finding the original data sheet for the rectifier, and it was copyrighted 1936. Never did find the tube (not even on eBay) but if I did, we'd have bought one.
--------------------
-- Ken Kobayashi
|
jfosc
scholastic sledgehammer
Reged: 05/29/07
Posts: 917
Loc: Quakertown, PA
|
|
Quote:
Just goes to show you how capable those "simpler" circuits really are. Remember how primitive the Apollo computing hardware was. But it got us pinpoint landings on the Moon, and some really nice and precise splashdowns.
Also, both Voyager crafts launched ~30 years ago in the late 1970's are still sending back signals as they leave the solar system. I am still in awe that these crafts are working after all this time in the hostile conditions of space considering the technology they had at the time.
--------------------
-Jim
"The Universe is expanding. That should help ease the traffic" - Stephen Wright
"Listen, kid...when I was your age Pluto was a planet!"
Zhumell f/4.9 10" Dob w/ Upgrades
Telrad
Howie Glatter 2"/1.25" Single Beam Laser
Catseye Triple Pack Pro XL
Scope Gripps
Olympus 10x50 DPS R binocs
|
alegator
sage
Reged: 10/27/04
Posts: 272
|
|
Quote:
Just goes to show you how capable those "simpler" circuits really are. Remember how primitive the Apollo computing hardware was. But it got us pinpoint landings on the Moon, and some really nice and precise splashdowns.
It also shows how capable many of us are nowadays, that we use computing hardware thousands times more powerful for tasks thousands times simpler like playing pinball...what a waste! 
--------------------
Celestron 8 (1978 model!)+tripod+eq.wedge
|
Fish
super member
Reged: 10/13/07
Posts: 160
Loc: Norridgewock, ME
|
|
Ken,
Just curious - what was the number of the tube? And the rated PIV? In broadcast transmitters of years ago - some still in use! - we used mercury vapor rectifiers. Some were replaced with solid-state equivalents, essentially diode stacks in a tube enclosure.
Regards, Marc
|
Qkslvr
Pooh-Bah
Reged: 06/23/06
Posts: 1052
Loc: NE Ohio, US
|
|
In the 80's I did post sales support of Electronic Design tools, and one of my customers was Nasa. It so happened we provided design tools to a group that was modernizing some of the electronics on the shuttle.
It was interesting that while they did replace boards of discrete logic with programmable logic, they'd put resistors on the board so that the new board would disparate the same power as the older board, so they didn't alter the thermal design.
Also, iirc the shuttle was designed in the 70's, 8086 didn't exist then.
--------------------
Mike
N8/CG-5/40D
Coming sometime/Maybe FrankenRebel
|
LesB
Carpal Tunnel
Reged: 12/20/04
Posts: 1687
Loc: Z-Hills, FL
|
|
Quote:
The shuttles, Mr. Renfroe of the United Space Alliance noted in an awed tone, ''could go for 40 or 50 years.''
There are only three orbiters left. If NASA is buying from ebay they would still have to buy Mil-Spec. Don't know if that's good enough for space.
My first encounter with the 8086 was in '82 while working for Sanders Associates. That chip was being replaced at the time with the 8088. Built a lot of mother boards. That knowledge now belongs to the victrola crowd.
But, I could still wirewrap if given the chance!
--------------------
"The genius of humanity is to establish an identity which lies at an ever-increasing distance from our organic nature." Ray Tallis
Edited by LesB (08/05/08 09:26 PM)
|
gordianknot
sage
Reged: 09/04/05
Posts: 446
|
|
It may seem counter-intuitive that running big complex machines can be run off ancient lightweight processors, but it is actually the norm. In embedded systems like microwaves, watches, cars, cell phones, telescope handcontrollers, etc, very simple processors with small power profiles are the norm. In terms of units sold the embedded systems world dwarfs the PC CPU market. TI graphing calculators, which are quite powerful machines, use the Zilog Z80 processor whose design predates even the 8086. True the chips themselves were not made in the 70s, but the design hasn't changed. It's quite common for systems in these categories to run at the low tens of megahertz and have a few KB of memory.
Obviously if NASA ever does need new space-grade processors, it can simply redesign the components or perhaps emulate the components on existing space hardened programmable hardware.
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
[Re: 