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I'm the Assembly, Integration and Verification Engineer of a cubesat project developed by students. Currently I'm trying to create the specifications for our payloads upcoming (mon)atomic oxygen (ATOX) and ultraviolet radiation test.

For the rest of the test campaign the standards published by the European space agency and other literature gave me a good idea where to start in developing the requirements, but it seems I am a bit out of my depth with ATOX and UV tests and finding information on how to carry them out. If somebody could point me in the right direction it would be greatly appreciated!

uhoh
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SmallSatEnthusiast1005
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    Defining your acronyms would really help readers understand your question. – Organic Marble Sep 09 '23 at 13:53
  • Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. – Community Sep 09 '23 at 17:17
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    Is it reasonable to start with the intended mission lifetime and your target LEO altitude? With these knowns, you could run a SPENVIS ATOX simulation and calculate the fluences at different energy levels over the period of your mission, as detected inside the spacecraft. Then, you may need to find information about the degradation of your materials and the change in their mechanical and electrical properties. Ideally, the requirement would be such that the said degradation is just tolerable to your mission lifetime, with a hefty margin to account for unknown unknowns. Just a thought... – Manny Sep 22 '23 at 22:46
  • @Manny the bounty expires in 23 hours, plus another 24 hour grace period where it becomes no longer visible but I can still award it. Can you consider expanding on that a bit and posting it as an answer? Folks sometimes write "partial answer" in their first sentence to acknowledge they have a contribution but it doesn't necessarily cover all aspects. To work an example you could just choose a typical altitude (for fluence) like 400 km (e.g. release from ISS) and use density for a quiet Sun and an active Sun for comparison. Mostly just reiterate the steps you already mention in your comment. – uhoh Sep 24 '23 at 22:44
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    @Manny thanks for your response! I did not check this post for a while and continued my research. I basically arrived at a similar conclusion to your answer. Once one has the expected fluence you can calculate the total fluence the satellite will "see" during the mission. Ground based testing for qualifying the new Material is a bit more complicated and still actively researched. (1/2) – SmallSatEnthusiast1005 Sep 26 '23 at 14:38
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    Basically what we will do is either use a plasma asher, running with oxygen or air, or find a facility where we can test with an ATOX beam (more realistic but expensive). In those tests we will also place a witness sample of Kapton. Since the erosion rate of Kapton is well documented one can calculate the fluence that was present during the test and with that information and measurements of the Item under test (weight/volume) one can approximate the degradation behaviour of the novel material. If someone has further questions the research by B.A. Banks and A. De Rooij helped me out quite a bit – SmallSatEnthusiast1005 Sep 26 '23 at 14:44
  • Ha! I used to use plasma ashers in a former life a million years ago! I wonder if there is a way to put your sample where there is minimal oxygen ions O+, O- or ozone and just expose your samples to atomic oxygen? I like the idea using Kapton as a calibration standard but that only works if you know if you have O+, O, O- or O3- – uhoh Sep 26 '23 at 16:53
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    Yeah the environment in an asher is pretty complex and actually more harmful to most materials than the LEO environment. Since we want to qualify a material thats no problem for us. But I totally agree with you that unless you also characterize the asher environment (and do a whole lot of reaction kinetics) you will get an indication of the degradation behaviour rather than a measurement – SmallSatEnthusiast1005 Sep 29 '23 at 11:28

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