Hmmm... my players always seem to do what I planned. :?
As my plan is that they will do the unexpected!
Actually, when it comes to a plan, my approach is to let the players write the story to the milestone I have created - this is just like managing a meeting and keeping everyone on track. Some of that must include reverse-psychology and knowledge of what is motivating your players (perhaps vs. what they see as their PCs motivations). The Ref has all the power to 'make' things happen to his/her players - the real trick is to 'make' things happen
with the players. That means the plan must take this into account - so my plans always involve conditionals... i.e. should the players choose X, Y, Z (...) or None of the Above. The last is one often missed by planners. Hence, my second statement in this post.
As to
emergency vacc suits and grav belts - I'd treat those as 2 different beasts. The emergency suit has fewer options and should be easy enough to 'don' without a skill check, regardless of skill - at the expense of lacking the protection of a true vacc suit and thus possibly having skill checks in operation to avoid damage, etc. - where skill or lacking thereof should be taken into account).
The grav belt, as an emergency item? IMO, such would respond to a local gravity well - therefore, orientation of application would be irrelevant. Of course, depending on TL, control would be limited - i.e. the device would endeavor to maintain a 'safe' rate of descent, and allow for minimal navigation (vector, but perhaps not rate). Notable, like a life vest that keeps one's head above water regardless of forthcoming impact with a small boat or overwater projection, the 'emergency' grav belt's simplicity can result in potential mishaps...
As to the notion of - no skill, no can do approach mentioned earlier - that is not in the rules, quite the contrary. That is what the -3 DM is for. As a PC I expect to be able to
attempt anything. Whether one succeeds is upto the Ref, one's own creativity of optimizing DMs and luck.
Exactly
how a PC
fails (and succeeds, of course), is up to the Ref.