Sometimes, some advance parts are denied to some country or to dual use programs. In this case, you may purchase mil grade or industrial parts and conduct new screening to upgrade these parts to space level. These types of parts may work well, however, the controlled parts of raw material, test procedures, documentation is missing. And reliabiltiy is not assured or built in to part by design.
For detail of required tests and its test conditions, you can refer to MIL-STD-750, MIL-STD-810 etc. ESA (Europen Space Agency) also have documented test required for each specific device. Once devices is approved for use in space, they get QPL status (Qualified Parts List). When you begin new design for Space, you generally prefer to use devices from QPL list. If your design is novel, you may like to get new devices manufactured and qualifed as per you plan. However, this may cost you few 10s of thousands of dollars. In space parts, many times, cost is of not concern as you have very good or unlimited budget. However, delivery time is of prime importance. If you miss to procure on critical part (or you failed the part in handling), your mission may get delayed by another 42 weeks.
In general, space qualified parts employs enhanced MIL-STD tests and procedures for their qualification procedure. This enhanced tests and procedures are done as per the goal of that space mission.
Prime requirement for space mission is that, once launched into space, the sysetm can not be repaired. Hence, parts and device must work faithfully in harsh space environment for rerquired duration of mission, which can be as long as 15 years or more. How do you assure zero failure almost 100% reliability for all parts?
First thing you should do is that all raw materials used are controlled, audited and documented in that they meet all required specifications. This also includes man power employed and facility/equipments used to achieve this. Second aspect is that you conduct many testing after at each major defined procedures. If is does not meet any established criteria, you must reject the lot and restart from scratch. All the test result are to be stored and if required, provided to client. When you approach vendor for space qualified device, they provide (or you should ask) detail qualification/screening procedure they employed. This may be good for your mission. If your mission is differnt, you may ask vendor to add additional test. If they agree, they will provide you with new plan and ask for additinal cost. Sometimes, you may ask to avoid few tests to reduce the cost to suit your budget and mision goal. One more thing which is very essential is asking heritage of the device. Here, vendor provides you with partial list of previsious missions where the device used with success.
All this is required to give you required confidential level that your mission will achieve its goal.
1. Aircraft control functions classified as critical will require electronic parts compliant to military grade, if available. Otherwise, special customisation to be made. In some cases, semiconductor sells the die, the packaging company hermetically seals it and conduct 100% burn-in test and deliver the chips.
2. Non critical functions may use automotive grade or industrial grade. Where applicable, parts may be tested for MTTF subjected to radiation, shock, temperature and ESD to ensure high level of reliability.
3. For passenger infotainment, commercial grade is permitted as given in the Approved Vendor List (AVL), unless discontinued of use by trusted consultants/specialists.
Hope this explains what you need to know.
Commercial grade parts are increasingly being used in space. I think Iridium may have been the first, but even NASA has flown some commercial grade parts. In some cases you have no choice. S-level parts are probably even more rare than what you remember Mark. For certain systems, size, weight, power and functionality trump rad-hardness and meeting spec limits over extended temperatures.
I just found some articles on the net on the IECQ site. They talk about a standard IEC TS 62239 which is a quality management process for using the commercially available off the shelf parts (COTS) for Avionics purpose. All interested can go to the link http://www.iecq.org/avionics/need.htm
For oil exploration, the temperature and vibration effects on electronics go beyond those published and documented for safe operation and storage of electronics. Not withstanding, most tool developers are force to characterize each and every relevant component at progressive temperature ranges to fully understand the device and system behavior.
Since some of these testing is destructive, the need to fully understand derating factors and effects on electronics from conditioning burning is not a trivial matter.
I am not aware of literature exploring this area of work, my observation has been that there is lots of IP acquired and not shared. The FAEs and Mfg reps that I have query have mentioned the legal aspect of no manufacturer wiliness to stick their neck too far into this area due the understandable liabilities.
I need to edit myself. The paragraph above should read:
For reliability purpose there are 9 unique environments defined for electronics in RADC-TR-82-177 ...
The first comment is a consequence of fast typing without review/editing.
Must have been a tough challenge for you in those days. In today's scenario, after so many generations of successful space programs and companies like Boeing and Airbus churning out jumbo size air crafts like pop-corn there must some agency which must have taken the ownership of standards required for such applications. May be US department of defense & NASA must have put together some standards for this. or could it be some standards from NEMA or IEEE?
In my experience working with telemetry for the space program there was a very limited list of "proven" components that were approved for use in space. As a new engineer I was surprised at how small the list was, and how dated the components were compared with what was available for commercial use. I also remember spending many hours in the "shake and bake" lab proving that our systems could withstand the rigors of space.
For reliability purpose there aren't there 9 unique environments defined for electronics in RADC-TR082-177 that include vibration, temperature, and radiation factors: ground, airborne, & space environments factors.
A Book For All Reasons Bernard Cole1 Comment Robert Oshana's recent book "Software Engineering for Embedded Systems (Newnes/Elsevier)," written and edited with Mark Kraeling, is a 'book for all reasons.' At almost 1,200 pages, it ...