Budget Satellite

codejunkie writes: "Check out this story from the Baltimore Sun. Apparently the middies were laughed at when they proposed a budget satellite for 50K. Boeing said it couldn't be done and gave them 250K. Well now they can build five more because the smart minds on the bay have built one."

Re:The quality?

[mikewas]

Space grade components are the same silicon die, off of the same production line, as any other grade IC.

The differences:

1. Package: Usually ceramic or welded metal cases that are hermetically sealed. The more common plastic components breath as they temperature cycle. When they "inhale" there's a posssibility that contaminants are drawn into the case.

2. Test: Almost all parameters are 100% tested whereas commercial quality components are minimally tested with thorough testing done on selected lots. Tests are also conducted over a wider temperature range, Often electrical performance is less than for commercial components (e.g. lower speed,less gain) but the parameters are guarenteed over a wider range of temperature

3. Burn-in: Parts are burned in, operated at elevated temperature & power, to weed out infant failures. This improves reliability at the cost of slightly decreased lifetime

4. Inspection: The manufacturing & test facilities are inspected & certified to assure consistentcy in the production of the components. You're assured that the parts were made & tested in exactly the same way that the parts characterized on the data sheet you used to design your circuit.

5. Documentation: The product's entire life cycle is documented. You know exactly who made it, when & where. If a problem does manage to slip through you can track it back to the root cause then forward to all individual parts affected.

6. Marking: The chips are distinctively marked. Not only the part number, for example, the tops of ICs are usualy painted silver.

Al of these are things you can work around. You can seal the box the parts are contained in instead of each individual component. You can buy large lots of commercial components to assure uniformity. You can build boards or larger subassemblies then test & burnin these assemblies trading of the cost of test vs. the cost of thrwing away failed assemblies.

This has all been done before for military & space qualified projects. My guess is that these guys have done a better job of managing the project & costs. Not a trivial task, since you be able to look into the future & understand how the entire development & production process works.

cheap satelites

[Anonymous Coward]

I hate to say this, but these midshipman have discovered nothing new. The Ham Radio operators have been doing this for years, with their Oscar satelites. They even used the tape measures for antennas. Tape measures also make it easy to set the antenna to the right length for the frequency they are using.