NASA's Europa Clipper Launch

Cost of the Europa Clipper program is around $4-5 billion. Can anyone in the industry shed some light on why these programs are so expensive?

I worked on one component of the spacecraft which was a derivative of something we've built may times before. However, the test program was entirely unique to Europa Clipper, and most of the cost was in this bespoke testing. The use of a "heritage" component served mostly to lower risk; it did not save much cost overall.

And can introduce unusual failure cases for these bespoke missions. Mars Observer was lost in flight to Mars three decades ago, probably because of the inappropriate reuse of a satellite rocket engine. (1) The space environment out around Jupiter is really quite different from the environment that the JWST is facing around E-S L2 or what the Parker Solar Probe is facing right near the Sun. Even if the component is spec'd to handle the environment, you need to have actual educated humans (read: expensive labor) determine what those conditions will be, and then verify that the part will meet it, and that's where the money goes- to pay all of those humans.

If you built even 15 Europa Clippers the cost per-item would come down enormously (because all of those people's work could be re-used), but since the 1970's NASA has not had the budget for multiple probes per missions. So every mission is bespoke, and has to be done again completely from scratch.

1: The engine was normally used for circularizing the orbit of a geosynch comm satellite, so within a few hours of flight. For doing a Mars Insertion burn it needed to sit fueled for months in outer space, which was not appropriately tested, and probably the fuel tank exploded in flight because of that.

Yeah. I'm surprised that we don't have a standard deep space probe bus by now in at least serial production, at least for orbiters if not landers, rovers, and such.

Each mission has unique requirements, but since payload mass costs are coming down, ISTM it should be possible to create a standard buss that meets most requirements most of the rime, even if it's heavier than a bespoke effort for any one mission.