Meh, can be blocked from starting at all due to: 1. Pretty easy to detect for most cases, especially as blunt in your (exaggerated, I know) example. Agencies s

Meh, can be blocked from starting at all due to: 1. Pretty easy to detect for most cases, especially as blunt in your (exaggerated, I know) example. Agencies should have a rough idea about realistic time frames for mission times in near earth orbits depending on what the satellite does. 2. They still need to have the propulsion unit integrated in the satellite, as otherwise they cannot guarantee the 5 years after mission time in higher orbits. They'll also need to prove that the propulsion unit used is very likely to actually work after mission time, e.g., your 160 year in radiation ridden space, which may be much more expensive than constructing one for the shorter, actual mission time.