Can cubesats be used to qualify parts for spaceflight more cheaply than ground testing?

Question

I've been researching what drives the cost of spacecraft, to see why many spacecraft still use very antiquated electronics and power systems developed in the 1980's instead of up to date electronics and power systems. It seems the cost (I.E. man-hours) needed to qualify the new components outweighs the cost savings from buying off the shelf. I researched more deeply into why qualification testing is expensive, and it seems the main reason for high costs is the parts are put through a variety of what-if scenarios on Earth through simulated environments instead of just putting the part into the actual environment they'll be operating in.

That got me to thinking if cubesats could be launched with up-to-date parts to qualify them for use on future spacecraft by having them launch through the high vibration environment of a rocket, bake and cool in orbit, and deal with hard vacuum and radiation, taking advantage of being there instead of meticulously simulating it on the ground. The parts would be launched into orbit without the extensive ground qualification testing, instead doing a simple check to see if they work or not in orbit.

Now I understand I may be overestimating the cost of qualification testing, if this is, please correct this misunderstanding. But if it is very expensive, have cubesats been used to build up a list of new electronics, power systems, valves, etc. that have been proven to work in space through flights? Or would this be more expensive than testing them on the ground?

Answer 1

You have clearly already come up against the dilemma of "its expensive because its expensive". Your question is reasonable, notwithstanding the first answer about learning from hands-on post-test inspection and measurement.

Don't lose hope, but here are some other points that confound things:

There is often a strong emphasis on qualification testing being "representative". Where this applies it means that equipment that has prior flight experience is of little value unless that flight experience is directly representative. e.g. take a solar cell and wire it into a different circuit on a different substrate in a different orbit and little relevance remains. Even the vacuum around it can change if adhesives and grouting are different.

This means that if a planned mission implies an environmental temperature range of, say, -10 degC to + 40 degC then a candidate item of equipment must be taken through its paces, usually having to demonstrate its entire range of functions, at both temperature extremes. Equipment subject to life testing for whatever reason, be it radiation dose or mechanical movement, would thus be expected to still show that it can meet its specification (or some agreed, degraded but still useful state) at the end of the mission.

One of the cost multipliers is the need to show that the design is understood and that there are no critical uncontrolled parameters. This means a lot of time is put into planning tests, measuring all the right parameters before and after an environmental exposure (temperature, vacuum, vibration, radiation) and documenting it all so that the customer is finally happy. Think then of the many levels of customer and supplier relationships and its a wonder that the industry works "so well".

Going back to the benefits of a flight test, you can see that it could be hard to commercially demonstrate that a cubesat flight will have measured everything (just what was the temperature of and electron fluence onto that wirebundle in eclipse?).

That all said, there may well be some good cubesat demonstration mission ideas that still tick all these boxes. Even if not, microsatellite missions have been used for decades to gain reputation as much as for technical qualification. We're all human and at all levels in the business the "proof of the pudding" concept holds a strong grip on people's imaginations from satellite operator's buying a complete satellite to several levels of equipment integration before that.

Answer 2

In qualification testing, you want to be able to examine the parts after the test. If you can learn why a part failed, you can improve the design.

It also becomes harder to identify the cause of failure since you're doing all your tests at once. Was it a supply voltage spike, temperature changes or a cosmic ray that made the part fail? Again, not being able to examine the part afterward makes this harder to determine.

You can't control all the environmental factors. A debris strike can disable the part you're testing and all you know is 'it stopped working'.