Even if you halve the operational cost, it's stil not pennies.

And yes off cause they do. That's the whole point. It's easier to approve incremental than all at once

Yup a thing they would improve it would be to have very standard hardware interfaces. If a rack would always fit then you can easily start saving used but good racks when someone throws out a rack and it would be much to find the broken part.

Insight was:(approx)

• Spacecraft 600 million.
• Launch ticket 160 million.
• 2 years operation 60 million.

If we assume insight will last:

• 10 years, that's 300 million, 30% of total budget
• 15 years, that's 450 million, 37% of total budget
• 20 years, that's 600 million, 44% of total budget

A 820 million budget is much easier to approve than 1360 million budget

It's not pennies, you are simply wrong.

In this case nasa just screws the senators because the budget was for 2 years, not 5 years. So they need money for 3 more years.

NASA absolutely have shareholders, they are just government officials and they play politics with them to get their budget and project approvals

Sometimes the replacement cost as much as a new machine. Had to replace the rack in my dishwasher (it was rusten) ended up buying a new dishwasher as it was not that much more.