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cromwellian

I feel like this is an all-eggs-in-one-basket mission. If it fails to launch, we have nothing.

Why not build many JWSTs, surely the cost per unit would go down, and launch more than one?

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> surely the cost per unit would go down, and launch more than one?

Surely? They didn't build a JWST factory. It might go up, as people with specialized skills or knowledge have moved on.

Yes, surely. Most of the cost was in R&D and in the mirror manufacturing. They've been designing and manufacturing it for 20 years. Per-unit costs would go down. Take the mirror, it's made of segments, the facility used to produce those segments certainly would benefit from scaling up production. They'd get better at fabbing them over time, increasing yields, reducing costs.

What NASA is doing is building the equivalent of a $10 billion fab to produce one chip. Space telescopes could be continually produced on a schedule, and retired on a schedule, with constant improvement.

Look at RS-25 engines vs Raptor engines in terms of costs to produce one.

Increasing production from 1 unit to 2 doesn't necessarily reduce costs. Due to demand and limited supply, for example, some prices increase. We know almost nothing about this thing. It's very speculative to say the cost would decrease. Also, how many space telescopes of this variety do we need?

All that said, it would be interesting to see NASA research on mass producing the more common components of its 'product line'. It does it for rockets, of course, but computers? Solar panels? Mars rover components? I'm sure it's been considered and I expect it's done in ways I'm not aware of.

Certainly a lot of the cost of the project is R&D, but most people would be shocked by how much of aerospace project budgets are driven by quality. E.g., a bolt costs $200 not because it has to go through a new R&D cycle, but because it needs a chain-of-custody, inspections, metal coupons stored, etc.

There's also a huge amount of political risk for a government entity. Politicians will be reluctant to fund another JWST if the first one fails because many will fight it as a waste of money, and the previous failure just bolsters the JWST-opponent's position.

I think the verb tenses were not perfect... I think he just meant: why did they build only 1 in the first place? They could have built N instead, at a lower cost per unit.

Space/Science/Military spending do not seem to follow the normal rules of civilian production nor schedules. Alos, once the satellite is built and launched, there is the ongoing budgeting of the actual operations of the satellite. The budgets are limited in those capacities as well.

Because there's only one L2 point, and it'd be very risky to have two units orbiting. So your spare would just sit around costing money in the case the first one works. The folks that do this are pretty dang good at what they do, so they're willing to bet $10 billion on success the first time, vs $20 billion to hedge with a spare. Even with a spare it's not clear to me a malfunctioning first example would have enough Delta-V to get it safely out of the L2 point proximate.

If it fails, they'll learn all they can, then try again with another follow on project, that likely will take advantage of technological improvements since functional requirements on this one were set in stone. Pre-building a spare just doesn't make sense with this kind of project.

The cost per unit would probably remain around the same. You don’t really get price cuts for ordering 2 of a custom component instead of 1

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