You don't give the heroes something as cool as an invisibility suit without at some point breaking it. Invincible technology makes for boring stories.
It's rather sad that we've gotten nearly to page 200 before an infiltration suit effect appeared that I am actually happy with.
Link o' the day: Spacelog. A niftily readable way to view the logs from early NASA missions. They have Apollo 13 and Mercury 6 up now and hopefully more coming soon.