That is purely the cost of money, but what about extended payrolls and tracking, delay in actually getting the science (which hopefully we count as a value), perceived value by the public who are paying for it, etc. There are many intangibles gained with doing missions in 4 1/2 years like this could probably be done vs. 8 years like it is being scheduled.

I think anyone that has worked in the business world recognizes that maintaining urgency in getting things done is crucial to remain competitive. The problem is there is no competition from which to measure return on investment (other than a very loose comparison with NASA who has their own problems).

My opinion is that the extra time used results in relatively minor savings. Those minor savings are swallowed by bureacrats drawing a little extra pay for a few more years to drive scientists crazy with requests for proposals. A major downside is that any missions that would be affected by the probe findings will have to wait the extra 3 years it will take to get results. This is time that could be used to plan another mission.

In practical terms I understand why the ESA missions take so long, just by listening to the press conferences with the Cassini mission. Politicians and scientific committees rule ESA and corporations from every country must be given something to do. All the wrangling leaves little room for the actual mission work. It is the reverse pyramid management scheme, with 10 people doing the actual work and a 1000 bureaucrats overseeing it.

It just seems like launch and navigation should be starting to get standardized and more routine, yet it is hard to see it reflected in these very unambitious schedules. In any event, I applaud and welcome any contribution ESA makes to solar system exploration. I just want more sooner!