The point is that, while the first of them has 2 MPx cameras with crappy optics, the fifth one has 50 MPx cameras with automagic everything, and the tenths one has damn light stacking array of top tier cameras and on board AI to colour correct on the fly or some other magic stuff. And at the same time battery increases x10 times while losing half of the wight and thermal deficiencies, CPUs get better and more redundant, better memory, wheels are getting fixed in 1 year instead of 10 and the list goes on.
Or you don't need to craft a JWST with nail files anymore, but instead just lauch a swarm of mirrors to free float and emulate the whole thing. And if one mirror goes bad - just launch a new one for pennies (NASA pennies). Or if the whole project is nonviable somehow - no big deal, just launch next year a different architecture. Ok, not next year, but in like a few years. And not in three decades (LUVOIR anyone? hello? Is there anyone at NASA?), if on schedule, and forty years if not.
The list goes on. I get hedging risks and preserving institutional knowledge, sure. But not even discussing a different approach, which could be conducted in parallel, is very very bad.
Or you don't need to craft a JWST with nail files anymore, but instead just lauch a swarm of mirrors to free float and emulate the whole thing. And if one mirror goes bad - just launch a new one for pennies (NASA pennies). Or if the whole project is nonviable somehow - no big deal, just launch next year a different architecture. Ok, not next year, but in like a few years. And not in three decades (LUVOIR anyone? hello? Is there anyone at NASA?), if on schedule, and forty years if not.
The list goes on. I get hedging risks and preserving institutional knowledge, sure. But not even discussing a different approach, which could be conducted in parallel, is very very bad.