[ibrault]

Depends on what you're working on and on if you're defining "getting stuff done" on a macro or micro scale. For large flagship missions, 2 years is nothing. The scale of work and level of verification required by these projects is massive and takes time. You've only got one shot to get things right with billions of dollars on the line, don't rush it.

[marmetio]

High-assurance isn't really the culprit. It's more of a funding issue. If long NASA programs could save part of the first year's budget to use the second year, things would go a lot faster.

You might get hired into an overstaffed team and not do that much for a year until it's crunch time and then you're underfunded so it takes an extra year. Arguably you spent three years to achieve one year's worth of accomplishments.