I just said you painted with too broad a brush. There is a range of mission profiles, and (by design) some are more risk tolerant than others. A starting poin

I just said you painted with too broad a brush. There is a range of mission profiles, and (by design) some are more risk tolerant than others. A starting point is http://nmp.nasa.gov/ http://nmp.nasa.gov/ which is a series of missions that specifically accept risk to develop selected new technologies. There are also opportunities for higher-risk science-investigations (http://science.nasa.gov/about-us/smd-programs/earth-system-science-pathfinder/ http://science.nasa.gov/about-us/smd-programs/earth-system-s...). There is also a pathway through airborne systems, to develop new mission concepts (e.g., http://lidar.jpl.nasa.gov/co2las.html http://lidar.jpl.nasa.gov/co2las.html) It's a long road to space-qualify a new technology, and because system failure is a logical OR of subsystem failures, you can't put too much new tech or new science into a mission. You'll try a bunch of stuff and one thing will fail, and you won't learn much. Multiple launches of unreliable systems are not a particularly good way to reduce risk. That's not doing engineering, that's throwing darts.