NASA Shuttle Flown PCB - Page 1
Forum section: electronics / general

author: mikey12608
author_rank: Newbie
timestamp: December 12, 2014, 03:40:01 pm
content: I got another NASA PCB to add to my collection. This one flew on STS-3 then was recovered and tested for reuse. This was then bench tested again and put into storage. I believe this is a converter variable resistance to dc voltage (CVRD) in a avionics computer aboard one of the solid rocket boosters. It has a date code dating before the first shuttle launch. I don't this this is a block test item because normally NASA puts the block version right on the hardware. I am currently reaching out to a few contacts to determine its full history. Regardless of the history of the specific serial number its a great piece!Link to fill res images:https://www.flickr.com/photos/mikesupczenskiphoto/sets/72157649662758876/

author: SeanB
author_rank: Super Contributor
timestamp: December 12, 2014, 04:01:48 pm
content: Nice looking board! Now to get a good frame for it.

author: mikey12608
author_rank: Newbie
timestamp: December 12, 2014, 04:06:31 pm
content: Quote from: SeanB on December 12, 2014, 04:01:48 pmThanks! That is actually on my to-do list today

author: SeanB
author_rank: Super Contributor
timestamp: December 12, 2014, 05:14:23 pm
content: I just did that this week for a board.............. Lying on the couch at the moment as I am busy painting the walls and that area needs a second coat on it this weekend.

author: TerraHertz
author_rank: Super Contributor
timestamp: December 14, 2014, 09:51:43 am
content: Quote from: mikey12608 on December 12, 2014, 03:40:01 pmWhat?! SRBs have avionics computers?That's a comical concept. What does it do? Decide when to unhitch?Err... I always assumed SRBs didn't have steerable anything. Wrong?

author: SeanB
author_rank: Super Contributor
timestamp: December 14, 2014, 10:57:32 am
content: The minimum a SRB needs is monitoring of chamber pressure, to tell when it has burnt out so it can be decoupled from the stack. When you have a monitor then you can add things like redundant detonators, self destruct charges ( basically vent the inner chamber to cut thrust) and then you can have guidance as well, using the common steerable pyrolitic carbon vanes in the exhaust, or a steerable nozzle. Then you can have the nice to haves like parachutes for soft landing, and then finally the beauty shots from video and still cameras on board for streaming.

author: max_torque
author_rank: Super Contributor
timestamp: December 14, 2014, 03:18:59 pm
content: Quote from: SeanB on December 14, 2014, 10:57:32 amOn a "reusable" system like the STS, a soft landing is a bit more than a "nice to have"........ ;-);-)

author: SeanB
author_rank: Super Contributor
timestamp: December 14, 2014, 04:45:00 pm
content: Thanks, but I doubt the reliant would have made a usable vehicle in any case. If you land in soft concrete like water then a little extra compliance works.

author: Towger
author_rank: Super Contributor
timestamp: December 14, 2014, 05:32:58 pm
content: Did the boosters not use 8088s?. And, at one point NASA had problems sourcing replacements.

author: SeanB
author_rank: Super Contributor
timestamp: December 14, 2014, 05:38:15 pm
content: 8080, 80186, 80286 and they still have stock of space rated i386 processors. the support chips though are getting rare, especially the 8080 clock generator which has some stringent requirements for reliable operation of the processor.

author: atferrari
author_rank: Frequent Contributor
timestamp: December 14, 2014, 08:53:16 pm
content: When I see those huge connectors I immediately think of vibration.How good they were/are?Just having spent long time in vessels, I know what vibration could do to equipment.

author: mikey12608
author_rank: Newbie
timestamp: December 15, 2014, 04:48:24 am
content: Quote from: TerraHertz on December 14, 2014, 09:51:43 amCorrect SRBs did not gimble but there is a lot of avionics for monitoring and transmitting telemetry.

author: mikey12608
author_rank: Newbie
timestamp: December 15, 2014, 04:56:20 am
content: Quote from: atferrari on December 14, 2014, 08:53:16 pmI'm sure NASA had put a lot of testing to vibrations on SRB hardware. I am not sure how the female end of the connector looked but I asume it has more then one point of contact and this part probably had a redundant partner. At the time of ignition of the SRBs NASA had to use water to damper the vibrations from reflecting off the pad.Here is a great video of ignition in slow motion.http://youtu.be/r7Km5fbtnIc

author: Paul Moir
author_rank: Frequent Contributor
timestamp: December 15, 2014, 06:35:14 am
content: Quote from: mikey12608 on December 15, 2014, 04:48:24 amThey don't but the nozzles do:(scroll down to "Thrust Vector Control")http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/srb.htmlEach has an hydrazine burning APU to power the hydraulics. Lots going on in those things.Nice board! Personally I like more curvy traces to keep the electrons from streaming off in the hard corners, but I promise I won't hold it against it.

author: SeanB
author_rank: Super Contributor
timestamp: December 15, 2014, 06:47:03 pm
content: Vibration is when you use circular locking military spec connectors. Yes they come as a whole lot of part numbers, including one for the pins, one for the shell, one for the back and one for the cable clamp, and a whole variety of each part. Then the socket has the same variety, including at least 4 different methods for sealing it off when not used. They will typically withstand thousands of insert cycles, and very high vibration levels.Failures are pins wearing from vibration against the socket, but that requires the connector to be part of an engine combustion chamber wall, and to have a couple of hundred hours of full power operation at heat to get it to fail. Vibration there is around 5mm PP and the wiring often will fail first.In most cases they fail from either corroding apart or just from poor insertion. If you have one that has had a good few hundred thousand cycles on it you just replace the pins, and after a few dozen pin cycles the shell.I still have some of the crimp tooling for them.

author: mikey12608
author_rank: Newbie
timestamp: December 16, 2014, 03:42:28 pm
content: Quote from: Paul Moir on December 15, 2014, 06:35:14 am