Re:Proven delivery system (Score 1)

When you take six months to plan each space walk, you're not quite ready to venture out of the Van Allen belts.

Spacewalks can be planned a lot faster than that if needed. During the STS-120 shuttle flight in 1997, a solar array on the Station accidentally tore while they were deploying it. So to fix it, they planned and executed a complete spacewalk from scratch, during the flight, in a total of only four days. The astronauts spent the third of those days building the various improvised tools and equipment they'd use to make the repair. It worked perfectly and the repair is holding up to this day.

http://en.wikipedia.org/wiki/STS-120 -- see flight days 8 through 12.

Space activities are extremely scheduled and meticulous because they can be, not because they necessarily have to be.