To be completely honest, I probably wouldn't even try for sustainability, I'd just spam the technological specifications along with attention-catching astartes antics to keep the media from hiding it everywhere and watch the whole system crash and burn until the glowies zergrush through a fucking astartes squad. Best case scenario, the glowies stop hunting once their masters' paychecks no longer cash because the petrodollar makes tulip bulbs look like a good investment.
It's ironic, I'd have been perfectly content to simply become obscenely rich and ensure humanity colonizes the solar system, but if I know I'm gonna be killed for knowing too much anyway, might as well destroy everything out of spite.
The corporatocracy doesn't want escapees, especially escapees with access to the untapped natural resources of the asteroid belt and orbital high ground.
Monopolistic political systems have always avoided going beyond their borders because they fear losing control. Look at the fifteenth century Ming Dynasty ending the brief period of Chinese maritime exploration and attempting to shut the Middle Kingdom out from the rest of the world, a policy that continued with the Qing, and kept the empire largely isolated until the 19th century, because of foreign "initiative." Or the same thing with Shogunate Japan, isolated until Admiral Perry's "Black Ships".
In Europe, however, the drive for exploration was driven by intense competition: if your nation didn't establish colonies and trade routes then the other rival nation will. Portugal, Spain, then the Dutch, then the English, French, Germans, etc. all sent ships to dangerous unknown regions. Or the space race, when as soon as the soviet union fell, America basically gave up and cut NASA's budget to the point where basically all they can do is post concepts of spaceships they'll never have the money to build on the internet.
The reason why the
Beige Dictatorship will do anything in its power to try and stop space colonization is wanting to retain control.
Imagine you'd built a spacecraft capable of resource gathering and repairs via crew and automation. With careful planning and optimal personnel you could just... fuck off and not come back. You could just point yourself in whatever direction you wanted and escape. You'd probably die horribly but if enough groups tried, odds of averages would suggest that eventually a few of them would succeed.
At a minimum, this would mean the status quo would forever have some fraction of humanity outside of their control, at a maximum, that in a couple centuries, your descendants could return to earth and do the whole barbarian-invaders-vs-decadent-empire cliché vs the descendants of the status quo's leadership.
My proof that Outside Context technology will be suppressed since the fear of losing control of society will outweigh even the greed of the wealthy and powerful is the absence of asteroid mining.
Those startup costs are equal to
an oil-refining project three years ago and for much higher potential profits. The fact that it hasn't been done yet proves that
something is screwy.