yes, we roused the chinese about this last year, and for good reason, as was mentioned in the article. it just doesn’t seem to me like the risk is great enough to put that many more thoughts of little golf-ball sized pieces in space. yes, we can argue that most of those pieces will burn up in a small amount of time, but inevitably a high-energy collision is going to propel pieces further out into the atmosphere (especially if i am to believe this simulation). littering space just doesn’t seem like something we should be doing. and no one is going to die from hydrazine … not a chance. the only way someone one be injured is if this thing landed right on top of them, which is just so ridiculously unlikely it’s barely worth considering.

all that being said … if people who know this area far better than i do have decided that this is completely safe and will not eject long-term particles into space … and in reality this is an ability for us to test an unproven technology … then fine. sign me up. it seems to me as if this is probably what’s going on.

i would love to look at the theory behind these simulations. they are definitely done (i actually do know this) with a direct-simulation monte carlo (DSMC) technique, whereby the boltzmann collision integral is solved in small isolated regions (mesh elements), rather than considering large-area multibody interactions. i’m sure their code is nice. there is, as yet, no major open source DSMC code available, which is pretty unfortunate. it’s a great technique for transition regime flows (which is what this satellite is experiencing right now).