A: You&#x27;ve got access to a lot of solar power, on a completely predictable schedule. Especially convenient since in this particular case you don&#x27;t need to convert it to electricity first. B: Anything you release as a gas flies harmlessly out into the universe, so your environmental restrictions are a great deal less. (Also, this is not &quot;cheating regulations&quot; or anything... this is <i>truly</i> an environment with fewer restrictions. If you can vaporize it, it can be made to truly go away forever.) C: You&#x27;ve got zero G, and this sort of &quot;massive mass spec&quot; plan, while I question the numbers in general, is probably a great deal more practical in zero G than not zero G.<p>And it would all tie together; if the exhaust is in excess of escape velocity, which it probably is by an order of magnitude or two, you can just let anything you don&#x27;t care to catch fly into space.<p>I&#x27;m not saying this is practical or necessarily a good idea, just pointing out that you <i>do</i> have some options in space that you don&#x27;t have on Earth.